Table of contents

At present, COVID-19 is still having an enormous impact in global areas. International or long-distance travels are still risky. In consideration of the safety of all speakers and participants, the 2nd International Conference on Advanced materials and Intelligent Manufacturing (ICAMIM 2021) had been held online via Zoom on August 20-22, 2021.

As the material precursor for the emerging strategic emerging industries, advanced materials have become the key focus and core technology of international competition. Meanwhile, the development of advanced materials and their corresponding technologies and industries has also being regarded as "national development strategy" for the world's leading countries and gradually developed into a new "trump card" in the game between countries. Intelligent manufacturing, with the most technological innovation value, is along with a high-level knowledge and technology in the equipment manufacturing industry, a high-degree of integration and application on core technologies, new materials and components. What' more, intelligent manufacturing embodies the comprehensive strength of scientific and technological innovation ability, manufacturing technology level and international competitiveness.

List of Committee member is available in this pdf.

All conference organisers/editors are required to declare details about their peer review. Therefore, please provide the following information:

• Type of peer review: Double-blind

• Conference submission management system: AI Scholar System

• Number of submissions received: 352

• Number of submissions sent for review: 321

• Number of submissions accepted: 207

• Acceptance Rate (Number of Submissions Accepted/Number of Submissions Received X 100): 58.8%

• Average number of reviews per paper: 2

• Total number of reviewers involved: 90

• Any additional info on review process:

• Step 1. Each of selected paper will be reviewed by two/three professional experts in the related subject area.

• Step 2. Review Reports received from the experts will be judged by one of the editors either Review Reports are logical or not?

• Step 3. If not logical, then editor can assign new reviewer or can also judge at his/her own.

• Step 4. If logical, then Review Reports will be sent to authors to modify the manuscript accordingly.

• Step 5. Authors will be required to revise their papers according to the points raised.

• Step 6. Revised version will then be evaluated by the editor for the incorporation of the points raised by the reviewers.

• Step 7. Then the editor will send the revised manuscript to the reviewers again for re-evaluation.

• Step 8. If the reviewers approve the revise version of the manuscript, then will be accepted for publication.

• Contact person for queries:

Xuexia Ye

publication@keoaeic.org

AEIC Academic Exchange Information Centre

In the bridge expansion joint repair project, in order to ensure the efficiency of the project, the repair material needs to have better flow properties and higher early strength. The introduction of sulphoaluminate cement will significantly change the properties of UHPC. Compared with ordinary Portland cement, the composition of its cement clinker mineral belongs to another physical and chemical system, which has excellent properties such as early strength, high strength, impermeability and corrosion resistance. Therefore, different groups of UHPC were prepared by changing the content of sulphoaluminate cement, and the fluidity test of each group of slurry and the compressive strength and flexural strength test of 1d, 3d, 7d, 28d were carried out to study the sulfur. The influence of aluminate cement content on slurry fluidity and early mechanical properties in order to obtain the optimal mix ratio of UHPC materials for new bridge expansion joints.

Porous FeCrN stainless steel has excellent corrosion resistance, biocompatibility and mechanical properties matching human bone because of non-nickel and manganese, which is a new direction of medical implants. In this paper, FeCrN stainless steel with porosity of 28.21%-60.16% was prepared by powder metallurgy method. The microstructure, pore morphology and mechanical properties of porous stainless steel were analyzed by means of XRD, SEM, EDS and compression test. The microstructure of porous stainless steel is mostly austenite + ferrite. With the increase of porosity, the compressive yield strength, compressive strength and elastic modulus of the material decrease.

A lightweight lattice structure is proposed, which can be applied to the thermal protection system of high speed aircraft. The structure uses carbon fiber reinforced silicon carbide ceramic matrix composite as the framework, and the inner cavity can be filled with heat insulation materials with small thermal conductivity. In order to study the heat insulation performance of the structure, the three-dimensional finite element heat transfer model of the lattice structure with and without heat insulation material was established. Abaqus software was used to calculate the temperature distribution and change of the lattice structure under different temperature boundary conditions. The equivalent thermal conductivity of the lattice structures under different temperature boundary conditions is defined and calculated. The results show that the heat insulation effect of the lattice structure is improved obviously with the addition of heat insulation materials, but the time required to reach the stable state is increased. Without heat insulation materials, the strength of cavity radiation is greatly affected by the temperature boundary conditions on the top surface and positively correlated. Increasing heat insulation materials can effectively block the generation of cavity radiation, thus enhancing the heat insulation effect. The conclusion provides a foundation for further application of the lattice structure in thermal protection system of high speed aircraft.

In order to solve the problem of the stainless steel pipe falling off during the debugging process of the cross arm rotating clamping mechanism, the TRIZ theory is applied to the innovative design of the mechanism. Firstly, the problem description, causal analysis and function analysis are carried out, then the invention principle and separation principle of conflict resolution theory and the standard solution of substance-field analysis model are used to solve the design problem. After feasibility evaluation, the optimization schemes such as changing the clamping direction and increasing the shape of the clamping rubber bulge are obtained. The optimized cross arm rotating clamping mechanism is applied to the stainless steel tube automatic packaging production line, which solves the problem of the stainless steel tube falling off, and provides a reference for the design of similar clamping mechanism.

Fe-based composite coating doped well-dispersed titanium boride (TiB₂) and carbon nanotubes (CNTs) was fabricated via combined ball milling, spray drying, plasma spheroidization and high velocity air fuel (HVAF) spraying. The microstructure evolution of composite powders and coating, the tribological and corrosion behavior of Fe-based metallic, Fe-TiB₂ cermet and (Fe-TiB₂)/CNT composite coatings were investigated. The results show that doping 50 vol. % TiB2, especially further doping 2.5 vol. % CNTs could remarkably render the coating favorable microstructure with low porosity, enhanced hardness and fracture toughness, and superior wear and corrosion resistance. Mild oxidative and slight abrasive wears were the dominant wear mechanism, and the preferential corrosion was occurred at the pores, inter-splats and then the TiB₂-Fe interfaces.

In this paper, the chemical composition and mechanical properties of L360M pipeline steel are analyzed, and the formulation method of JCOE prebending process for submarine pipeline steel pipe is introduced. Based on the Augmented Lagrange, Ansys software was used to simulate the prebending process numerically with the whole process from model establishment to boundary condition and parameter setting is introduced in detail. The process of bending, yielding and springback of steel plate was analyzed to obtain the general rule of elastic-plastic change of steel plate during JCOE prebending forming. Comparing the theoretical and simulated values of the springback, the ultimate stress and the residual stress after springback in the JCOE pre-bending process, the relative errors are 7.8%, 6.6% and 15.2%, which are within the allowable error range. The results show that the JCOE finite element analysis model is effective and feasible.

A new composition steel was designed by adding 1wt.% Cu and 2wt.% Ni elements on the basis of low-carbon Ti-bearing microalloyed steel. The continuous cooling transition curve (CCT) is obtained by the phase transition curves, microstructure and hardness in the Gleeble3800 thermal simulation test machine. In order to further study the law of transformation and meet the needs of industrialized production, different cooling tests were carried out through industrialized trial production, and the corresponding organization and mechanical properties were analyzed. The results show that when the cooling rate increases, the microstructure transformation appears as granular bainite (GB) → granular bainite + lath bainite (GB+LB) → lath bainite (LB) → lath martensite (M). The mechanical properties increase with the increase of cooling rate, and the yield strength increases in a positive correlation trend. The results show that the steel can obtain good and stable comprehensive mechanical properties in a large cooling rate range without heat treatment. The best mechanical properties with a good combination of yield strength and impact performance are obtained under ultra-fast cooling conditions.

To study the dynamic response of metal fiber laminates subjected to the same energy and different velocities, a finite element model of aluminum alloy-carbon/glass fiber laminates was constructed to analyze the impact dynamic response and discuss the characteristics of interlayer damage. The results show that under the same impact kinetic energy conditions, the higher the initial velocity of the bullet is, the faster the velocity decays during the impact, and the more kinetic energy is consumed overall. On the whole, the shape of the failure area of the metal layer is similar to the shape of the bullet plane, and the failure area of the fiber layer will extend along the direction of the fiber layer. Whether it is a carbon fiber layer or a glass fiber layer, the tensile failure area is larger than the compression failure area. The fiber tensile/compression failure area is the largest, followed by the tensile/compression delamination failure area, and the matrix tensile/compression failure area is the smallest. As the bullet velocity increases, the failure area of the glass fiber layer in different forms becomes smaller, while the failure area of the carbon fiber layer in different forms does not change significantly.

The general die casting and vacuum die casting of magnesium alloy radiator were simulated by FLOW-3D simulation software, and the defects and entrapment results in the filling process were compared, and the product was trial-produced.By analyzing the microstructure and mechanical properties of ordinary die casting and vacuum die casting, the test results show that vacuum die casting can obtain magnesium alloy die casting with complete filling and excellent appearance, and its mechanical properties and elongation are increased by 14.2% and 43.7% respectively compared with ordinary die casting.

The mechanical properties of the zeolite model with cellular structure as a unit cell were studied via simulation. Four zeolite models were selected, and the mechanical properties of zeolite and traditional cellular structure were compared by mechanical finite element analysis. The results demonstrate that the zeolite structures possess better mechanical behavior under loading, accompany with uniform distribution of structural stress and less stress concentration. In addition, the effect of porosity on mechanical properties of zeolite model was studied. The results demonstrate that both yield strength and elastic modulus for zeolite decrease with the increase of porosity.

Tailoring coating microstructure and the fraction of quasicrystalline phase for enhancing the wear and crack resistance by selecting the appropriate thermal spraying parameters was investigated. To simplify the optimization process, orthogonal test was introduced. According to the statistical analysis and validation experiments, the orders of spraying-parameters that affected the hardness and fraction of quasicrystalline phase were proposed, respectively. The wear resistance and fracture behaviors of coating sprayed with optimal processing parameters were analyzed by pin-on-disk and three-point bending (3PB) tests. The current results indicated that the coating sprayed with optimal parameters exhibit a better wear and crack resistance. The high fraction of quasicrystal phase and dense microstructure contribute to the good wear resistance, meanwhile, the favorable fracture toughness is attributed to the tough phase existing in quasicrystal matrix and a fine-lamellar microstructure which facilitates the stress release during the crack propagation. This study gives insight into the crack propagation behavior in Al-based quasicrystal coating from nano-scale to micro-scale and might provide a viable guideline for the improvement of wear and crack resistance for thermal spraying quasicrystal composite coatings.

The chemical structures of different types of polycarboxylate superplasticizers were characterized by gel chromatography. The results showed that except PCE-5 was short main chain and short branch chain, the other polycarboxylate superplasticizers were long side chain structures. The properties of the superplasticizer were evaluated by the pulp experiment, and the adsorption and action mechanism were analyzed by testing the adsorption capacity and rheological parameters. The results showed that the order of saturated adsorption capacity of polycarboxylate in cement was PCE-5 > PCE-4 > PCE-3 > PCE-1 > PCE-2. The fluidity of paste is proportional to the adsorption amount of water reducing agent in paste. The thixotropic retention capacity of paste increased with the increase of polycarboxylate adsorption capacity.

The color of cigarette paper and its ash after combustion is one of the most intuitive evaluations for consumers. In order to solve the problem that the judgment of machine vision is not unified and there is no standard reference, an objective and accurate method of cigarette combustion gray benchmark adjustment and visual measurement based on ceramic stick was are provided in this paper. Through multi-faceted simultaneous shooting of a single cigarette in the state of static combustion or smoking, real-time image tracking acquisition is carried out to complete multi-faceted full vision acquisition of cigarette sample combustion. The experimental results show that there are some standard deviations in the three angles, and the method of taking the mean value reflects the gray of cigarette combustion to the greatest extent. Using ceramic bar as reference to calibrate cigarette gray, real-time acquisition and data processing can accurately and objectively determine and compare the test samples, which could be applied for scientific statistics and research. The uniform lighting design of multiple LED light sources ensures the quality of the collected images.

The effects of cryogenic treatment on microstructure, hardness, red hardness and wear resistance of M35 high speed steel(HSS) were studied by means of scanning electron microscope, X-ray diffractograph, friction and wear tester and Rockwell hardness tester. The results show that with the increase of tempering temperature, the residual austenite in M35 HSS decreases and the grain size increases gradually. After deep cryogenic treatment (DCT), the grain size of M35 HSS is refined and the wear volume is reduced. DCT at 525°C has the best wear resistance. With the increase of tempering temperature, the hardness of M35 HSS decreases first and then increases, and finally decreases sharply. The Rockwell hardness of M35 HSS at 525 °C is the highest, which is 67.1 HRC. The peak hardness of Rockwell increased by 0.7 HRC and the tempering temperature decreased from 550 °C to 525 °C, which showed good stability of red hardness.

In order to realize the recycling of waste glass, the influence of waste glass on the rheological properties of cement paste and concrete was studied. The rheological parameters were obtained by linear fitting with Bingham model. The results showed that for cement slurry system, with the replacement amount of waste glass increasing from 0 wt% to 20 wt%, the plastic viscosity of slurry increased gradually, while the yield stress decreased. Fixing the replacement amount of fixed waste glass at 5 wt%, the plastic viscosity and yield stress of cement slurry decrease with the increasing dosage of polycarboxylate superplasticizer. The cement slurry conforms to the characteristics of pseudoplastic fluid. For initial concrete slurry system, with the increase of waste glass replacement amount from 0 wt% to 20 wt%, the plastic viscosity of slurry increased, while the yield stress gradually decreased. And then the rheological properties of concrete slurry were closed to Newtonian fluid. After 1 hour, the plastic viscosity of concrete increased first, then decreased, and finally increased again. The yield stress decreased gradually. And the rheological properties of slurry were also close to Newtonian fluid.

The performance of moving walk tread is very important for the overall quality and safety of moving walk. In this paper, static and dynamic load tests are carried out on integral and split moving walk treads. The analysis of the test results shows that the disturbance of the integral type is less than that of the split type. When the frequency is low, the curve of feedback force is basically consistent with that of applied force, indicating that the tread is doing normal reciprocating motion under the action of force wave.

The color of cigarette paper directly affect the ash color and ash condensation quality of cigarettes. The ash color and ash condensation quality of cigarettes with black cigarette paper are studied by using the self-developed cigarette paper gray and ash condensation quality measuring equipment and taking black as the background color in this paper. The effect of black cigarette paper on the ash gray is discussed in the combustion process of black cigarette paper for the first time. The results show that the average grey value of black cigarette paper is 116.59, and the uneven grey value is mainly due to the non-uniformity of cigarette paper among different batches and the cut tobacco structure of medium cigarettes, on which the shooting from 3 different angles has a great impact. It is appropriate to calculate the grey and ash quality by taking the average value of 3-side shooting. Black background board is ideal for testing cigarette paper gray. The gray value difference of randomly selected cigarettes is too large, so it is necessary to measure in batches, and the measurement accuracy of gray value can be guaranteed only if the sample quantity is sufficient. The maximum deviation of gray value photographed by different cameras of the same cigarette is 18.17, which is 15.6% of the average value, and the average value of ash coagulation index is 90.20. The cigarette paper ash detection equipment used in this paper is accurate, which can reflect the cigarette ash performance comprehensively and objectively, and such an equipment has rich detective means, and has high automation and reliability in the analysis of detection results. It is necessary to take photos from different angles in the measurement process to ensure the accuracy of gray measurement value of a cigarette to the largest extent, as the samples showed significant differences.

: In this paper, the microstructure evolution of 30MnSi steel bar after drawing, quenching and tempering was studied by optical microscope and scanning electron microscope, and the mechanical properties at different stages were analyzed. The results show that when the quenching temperature is 925°C and the tempering temperature is 465°C, the microstructure changes from the ferrite and pearlite before cold drawing to the martensite after quenching, and then to the tempered troostite after tempering. After quenching and tempering, the yield strength can reach more than 1250Mpa, the tensile strength can reach more than 1450Mpa, and the elongation after breaking is maintained at more than 7.5%.

With the increasing development of urban transportation, many roads and bridges will have some cracks and damage. If not handled in time, long-term development will have a great impact on the durability and safety of the bridge. How to quickly and effectively repair the cracks of the bridge has become a problem that we urgently need to solve. As a high-strength, high-toughness, low-porosity, ultra-high-strength cement-based material, ultra-high performance concrete not only has excellent mechanical properties such as compressive, flexural, and impact resistance, but also has good bonding strength and toughness. This material is very suitable for use in bridge expansion joints. This paper proposes a new bridge expansion joint UHPC material by consulting a large number of documents, and studies the effect of early strength agents on it, laying the foundation for the actual use of the new bridge expansion joint UHPC material.

The intake channel of circulating water pump house is an important part of water supply system in thermal power plant. The good hydraulic performance of intake channel is very important for operation efficiency of water pump and ensuring the safety of power plant. A hydraulic model of scale 1:12 is used to study the hydraulic characteristics of circulating pump house with an ultra-short forebay in this paper, the reasons for the formation of undesirable flow patterns, such as flow bias at the inlet, rotating filter outlet of the flow channel and backflow the circulation of the pipe at the bottom of the flapper, and the appearance of the suction vortex in the suction chamber, are analyzed, a rectifying facility consisting of "column + beam" is proposed to be installed in the forebay, a curved bias pier is added at the outlet of the traveling network, and a breast wall is suggested to be set in the suction chamber. With undesirable flow patterns in the original scheme are eliminated, the uniformity of the flow velocity distribution in the flow channel is improved, the flow pattern is relatively stable and smooth, and the ideal inflow condition of the suction mouth is guaranteed. The research results can provide a reference for the design and hydraulic performance optimization of the pump house of similar thermal power plant.

This paper analyzes the characteristics of the exhaust heat recovery devices and the air conditioning system of the pharmaceutical factory, and points out that the pharmaceutical factory is more suitable for the liquid circulation heat recovery system. The principle and composition of the liquid circulation heat recovery system are also introduced. The actual engineering case proves that the use of liquid circulation heat recovery system can effectively reduce the fresh air load. Compared with the traditional fresh air pretreatment method, liquid circulation heat recovery system has a short payback period.

In order to reduce the temperature of the asphalt pavement, determine the coating viscosity and curing time at different temperatures, in this paper, a set of road heat reflection coating schemes is designed. Through the self-developed indoor coating cooling test box, brinell viscometer and other test instruments, the coating amount, cooling effect, curing time and coating viscosity analysis test were carried out. The coating scheme with the best cooling effect is determined, and the problem of explosion reaction of coating in the process of high-temperature construction is solved. The anti-skid performance of the coating under the optimal ratio of coating additives was evaluated. The results show that the reflectivity of the coating can be improved by the addition of functional material titanium dioxide, and the best mixing value is about 30% of the quality of epoxy resin, and the maximum cooling range of the coating reaches 7.35°C. The cooling effect increases with the increase of the coating amount, but the cooling effect tends to be stable after reaching a certain degree and the recommended coating dosage is 0.8kg/m². The addition of 2-ethyl-4-methylimidazole can prolong the curing time and reduce the viscosity of the coating.

In wet papermaking process, the dispersant concentration has great influence on the structure and properties of paper. In this work, dilute H₂SO₄ with a mass fraction of 20% was used as the dispersant, and the glass fiber filter materials were made under the five dispersant concentrations of 0%, 0.06%, 0.11%, 0.17% and 0.22%, respectively, and then the related structures and properties of filter materials were measured and analysed. The results showed that the filtration loss rate and drainage speed during the preparation progress increased with the increase of dispersant concentration. When the pH value of the slurry decreased from 7.78 to 2.59, the uniformity of the filter material became better and the defects reduced. With the increase of acid addition, the pore size of filter material increased gradually, but the thickness, gram weight and porosity decreased. In addition, all the prepared filter materials were hydrophilic and oleophilic. In general, the glass fiber filter materials prepared with the acid amount of 0.17% had the highest mechanical strength, and the glass fiber filter materials had the best performance when the pH value of the slurry was maintained in the range of 2.95~3.20.

The steam trap plays the role in steam blocking and drainage.The appropriate trap can make the steam heating equipment to achieve the highest efficiency. To achieve the best results, it is necessary to have a comprehensive understanding of the performance and characteristics of various types of traps. This paper mainly introduces the types, principles, application occasions and characteristics of drain valves, and analyzes the types of drain valves that should be selected in the process of oil tank heating and the problems that should be paid attention to in use

In order to improve the flame retardant property of asphalt, ATH (aluminum hydroxide)/EG (expandable graphite) composite flame retardant was obtained by hydrothermal method. The flame retardancy of asphalt was analyzed by oxygen index test. The rheological properties of asphalt were analyzed by dynamic shear rheological test and bending beam rheological test. The research results show that the optimal mix ratio of the compound flame retardant with the best flame retardant synergistic effect is ATH:EG = 1:1. Considering the flame retardancy and rheological properties, the content of ATH/EG composite flame retardant is recommended to be 15%~20%.

Waterflooding is regarded as one of the most common methods for oil recovery yet a great portion of residual oil still remained in the reservoir after waterflooding. Therefore, investigation on the residual oil saturation and its characteristics is of great importance. Specifically, microscale residual oil pattern and saturation are crucial to the analysis of oil recovery efficiency and decision for future EOR methods. In this work, transparent microfluidic devices were adopted to simulate waterflooding process and observe the change in the oil saturation as well as the residual oil pattern. Meanwhile the impact of displacement fluid viscosity and displacement rate on the residual oil saturation and pattern was inspected. Results revealed that as the displacement fluid viscosity increased from 0.895 to 1.763mPa⋅s, residual oil saturation decreased from 31.2 to 20%. Three patterns of residual oil were observed which were bulk, columnar and dead-end respectively. Bulk pattern took up the largest portion of the total residual oil, and as the displacement fluid viscosity increasing, decrease in the bulk oil saturation was the greatest. Dead-end residual oil contributed the least to the oil recovery and it could be the potential target for the future EOR method.

At present, the environmental protection and sustainability of decoration materials need to be improved in the environment of energy shortage. In recent years, the industry of bamboo decorative materials has developed rapidly, but the use of bamboo is more focused on scattered bamboo species such as Phyllostachys heterocycle. With strong natural fiber, Bambusa emeiensis can be processed into different patterns, colors and shapes. It is an ideal material for architectural decoration. A large number of Bambusa emeiensis materials are used in interior design, which can not only alleviate the tension between supply and demand of decorative materials, but also play an important role in the national major strategies such as rural revitalization and green development. This paper takes Bambusa emeiensis and its derivative materials as the main research object, discusses the design principle of Bambusa emeiensis in interior design, and the application of Bambusa emeiensis and its derivative materials in interior design.

During the operation of a wind turbine in a wind power generation limited liability company, the bolt connecting the blade and the paddle bearing broke. In order to find out the cause of fracture, a comprehensive test analysis was carried out on the connection bolt between the blade and the variable blade bearing by means of macro morphology analysis, chemical composition analysis, mechanical property testing, microstructure testing and fracture micro-area analysis. Experiments show that: the blade and blade bearing joint bolt fracture: was the main cause of the bolt in the operation process of changing, repeated impact of wind load and the effects of the alternating load blade rotation, along the severe stress concentration of thread form ascend a crack source and extension in fatigue, until the whole fracture failure.

Under the background of carbon neutrality, the constructed wetland-microbial fuel cell coupled system (CW-MFC) has attracted more and more attention in wastewater treatment. This study, the CW-MFC was developed for promoting nutrients removal in wastewater and electricity generation. The results showed that the average removal efficiencies of COD, NH₄⁺-N and TP in CW-MFC were 85.20%, 75.99% and 59.20%, respectively. While the average removal efficiencies of COD, NH₄⁺-N and TP in CW were 78.05%, 70.88% and 50.80%, which were all lower than those in CW-MFC. In addition, the maximum output voltage of 331 mV was achieved in CW-MFC, which could be used for the running of wastewater treatment plant in turn and further reduce the consumption of fossil fuel. Accordingly, the maximum power density of the CW-MFC system reached to 107.54 mW m^-3.

In order to study the road performance of the graded-gravel material, the dynamic and static rebound modulus test of continuous-graded gravel was carried out, and through the tested road for field rebound modulus test and reverse, while the indoor and field CBR was tested. The results show that with the change of the load on the graded-gravel material, the modulus shows a good non-linear characteristic, and the modulus gradually increases with the load increasing. The indoor and field rebound modulus of the graded-gravel mixes are in accordance with the current specification requirements, and the CBR test value also meets the specification requirements. The research has reference significance for understanding the road performance characteristics of the graded-gravel and the future design and construction.

In this paper, the prefabricated rod of quartz fiber was prepared by MCVD method. A thickness of ultra-low expansion(ULE) quartz glass was deposited in the wall of quartz tube, and then quartz and its dopants were deposited. Finally, the prefabricated rod of quartz fiber preform containing doped TiO₂ layer was successfully prepared by high temperature dehydroxylation treatment. The strength of quartz fiber obtained by wire drawing for the prefab rod is significantly improved. The experimental results showed that the quartz glass layer with TiO₂ doped has a lower thermal expansion coefficient, the doped of TiO₂ is amount 5wt%, and the doped layer thickness is 4%, the optical fiber has the best enhancement. The maximum tensile strength of the organic coating is up to 75.5N, which is higher (6.34%) than that of the commercial optical fiber (71N).

In order to solve the obvious corrosion at the resistance spot welding connection position of galvanized sheet smoke hood of gas-fired heating and hot water combi-boiler, and eliminate the potential safety hazard of smoke hood seal performance degradation and smoke leakage, the design and This paper analyzes the advantages and disadvantages of exhaust hood from the aspects of This paper analyzes the advantages and disadvantages of exhaust hood from the aspects of structure design, material selection and process optimization, and draws up the optimization scheme. Acid salt spray test was used to study the corrosion resistance of aluminum alloy core pulling rivet, TOX riveting and resistance spot welding. The test results show that the corrosion resistance of galvanized exhaust hood with aluminum alloy core pulling rivet and TOX riveting process is better than that with resistance spot welding. In view of the influence of manufacturing accuracy and production efficiency, TOX riveting process can be used for assembly and connection of galvanized sheet exhaust hood of gas-fired heating and hot water combi-boiler.

With the gradual transformation of oil and gas exploration and development objects to low-permeability and low-grade resources, horizontal well staged fracturing technology has become an important means for reservoir reconstruction and effective improvement of single well production. As an important downhole layered plugging tool for staged fracturing of horizontal wells, bridge plugs are increasingly widely used. In this paper, firstly, the structure of the degradable bridge plug is designed according to the design principles and working conditions, and the technical parameters of the main body of the bridge plug are determined. Secondly, the performance of the sealing and anchoring structure is analysed, as well as the hydrodynamic performance analysis of the influence of the water flow on the bridge plug. Thirdly, a test prototype of the degradable bridge plug is manufactured according to the engineering drawings and material selection requirements. Finally, the pressure-bearing performance of the designed degradable bridge plug is tested by the prototype test, which provides a theoretical basis for future field applications.

The low ductility of the titanium matrix composites (TMCs) at room temperature has become a significant obstacle for the engineering applications. Therefore, to achieve excellent mechanical properties in TiB_w/Ti composites, a processing route that hot extrusion on as-sintered TiB_w/Ti composites was proposed. Comparing with the microstructure of as-extruded TiB_w/Ti composite and as-sintered TiB_w/Ti composite, it revealed that the alignment of TiB whiskers in composite changed from randomness to along the extrusion direction with the hot extrusion completing. Moreover, according to the mechanical property test results, the mechanical property of as-extruded TiB_w/Ti composites enhanced at the same time (tensile strength of 789 MPa and plastic strain of 1.5% for as-sintered TiB_w/Ti composites; tensile strength of 940 MPa and plastic strain of 18.1% for as-extruded TiB_w/Ti composites). The obtained results provide a promising fabrication route for developing high-performance TiB_w/Ti composites suitable for industrial applications.

With the development of lightweight, aluminum alloy escalator steps are more and more widely used. This paper analyzes an escalator accident related to steps. At the same time, different types of aluminum alloy escalator steps are selected for fracture test, and the parameters such as fracture strength and maximum fracture deformation are analyzed. The fracture surface is analyzed by metallography and scanning electron microscope. The results show that most steps have metallurgical defects such as porosity and shrinkage. It is of great significance to scientifically design and manufacture aluminum alloy escalator steps and ensure their safe use.

In this paper, the durability of fire resistive performance of two types of water-borne intumescent coatings was studied using UV/water-spray and hydrothermal accelerated aging. Exposure conditions Type X intended for all environmental conditions with reference to ETAG-018-2 was used as the aging method. The aging effects and mechanism were preliminary analysed using fire test, adhesive test and X-ray Fluorescence spectrometer (XRF). The results show that after 2 stages of aging (for the intended use of 10 years), type-B coating shows better durability while type-A coating losses its basic performance of fire resistive and adhesion. Visually assessment and XRF results show that the aging is mainly caused by surface cracking and the precipitation of fire resistive components.

The microstructure and impact properties of TC10 titanium alloy bar after isothermal annealing are studied by metallographic microscope, SEM and impact properties test. The results show that there were two forms of a phases in the original microstructure of TC10 titanium alloy forging bar, one was primary equiathetic a phases, the other was secondary a phases. After the alloy was annealed with isothermal temperature, the content of the equiaxed a phases in the metallographic structure decreased with the increased of temperature, and disappeared after reaching the transformation point. While the number of platelet a in the structure increased with the increased of temperature, and the size increased. The impact toughness of the alloy shows a trend that first increases and then decreases with the increase of heating temperature. When the temperature exceeded the transformation point, the impact toughness decreases significantly. With the increase of heating temperature, the fracture morphology of the alloy mainly changes from a large number of relatively deep dimples to a few relatively shallow dimples, and dissociation steps appear. After the whole investigation, it can be concluded that the best heat treatment system in this experiment was 920°C×1.5h/FC→800°C×1.5h/AC+560°C×4h/AC, and the maximum impact toughness was 49.5 J/cm².

Based on the working conditions of transmissions and drive axles used in the construction machinery, and combined with the current testing requirements for the anti-rust performance of lubricants, this paper test the oils commonly applied in the drive train of the construction machinery through the copper corrosion, rust preventing test and damp-heat test. The results show that the damp-heat test acted as a dynamic corrosion test, its parameters are closer to the real working conditions and it can better investigate the corrosion performance of oils in different quality grades and provides a reference for the selection of drive train oils.

The relationship between mixing time, ladle kinetic energy and bottom blowing radial position, bottom blowing flow rate, slag layer thickness and a series of operating variables are studied. The mixing time has been measured in a 1:6 scale model, and the method of adding tracers has been improved to obtain more accurate results. In addition, the kinetic energy in the bath is calculated through the VOF+DPM coupling model. The experimental results show that the mixing time in the bath decreases with the increase of the bottom blowing rate or the decrease of the thickness of the oil layer. Compared with the bottom blowing radial position of 0.55R and 0.65R, 0.45R is more conducive to mixing in the bath. As the radial position of the bottom blowing approached the wall, the gas-liquid phase zone began to tilt toward the ladle wall. The kinetic energy in the bath is not necessarily related to the mixing time, but when the bottom blowing flow rate and position are the same, the kinetic energy decreases with the increase of the oil layer thickness. When the thickness of the oil layer is 1 cm, 2 cm and 3 cm, the kinetic energy compared with the thickness of the oil-free layer decreases by 24.07%, 30.56% and 36.30%, respectively.

Grinding is a process where the particle size of the material is reduced under the combined effects of the impact action and the abrasion action of steel balls (grinding medium). Even though there are studies related to the grinding process, only a few studies systematically reported the low-speed grinding process. In this paper, the two common minerals: pyrite and quartz are subjected to low-speed grinding using the ball mill technique where the mill rotation is optimized to facilitate the grinding medium to be in the state of cascading. In addition, the relative grindability and grinding kinetic analysis are used to elucidate the particle size distribution characteristics, and rules for achieving the ground product's particle size at low-speed grinding. Further, discussions are made on the grinding characteristics of the mill when the grinding medium is in the cascading motion. The results show that i) finer feed size induces a significant change in the particle size of the ground products; ii) the grinding fineness of pyrite is higher given the same grinding time, whereas the grinding fineness of quartz increases sharply when the grinding time is prolonged; and iii) the grinding processes of the two minerals follow first-order linear kinetic model at low-speed grinding. These findings provide a theoretical foundation to carry out further research on the motion law and grinding characteristics at low- speed grinding.

A novel method consists of nitriding and spark plasma sintering was used to fabricate high nitrogen austenitic stainless steel (HNASS). The influences of nitrogen contents in austenitic stainless steel on microstructure, mechanical properties and corrosion resistance were investigated. Results show that the ferrite-austenite phase transformed into single austenite phase after nitriding uptake. The nitrogen contents determined the type of precipitates chromium nitrides, and the contents higher than 2.77 wt. % promoted the formation of CrN, which corresponds well with thermodynamic results. The fine grain size (round 3μm) and precipitated chromium nitrides (200~600 nm) lead to a high yield strength of 817-1111MPa, which exceeds conventional stainless steel. The corrosion rate decreased with increasing content up to 1.29 wt. %, then the corrosion rate increased with increasing nitrogen contents, which results from the combined effect of solute nitrogen and nitrides.

Photovoltaic devices have attracted enormous attention in recent decades. Except for silicon, a traditional photovoltaic material, a lot of new technologies have emerged for a reduction in costs and application in flexible devices. To present a relatively comprehensive view of such devices, this paper summarized the newest researches and challenges faced by different materials respectively. To be more specific, the general working principles of photovoltaic devices are explained initially and then the development of several typical solar cells are introduced, including silicon, Copper indium gallium selenide (CIGS), organic, and perovskite cells, followed by a brief introduction of their fabrication processes. This paper aims to help with advances in manufacturing methods or device structures to improve solar cell efficiency through the analysis of the progress in the corresponding fields.

Aiming at the high and low temperature diseases of asphalt pavement, in order to improve the environmental adaptability of asphalt pavement, the road phase change temperature-regulating composite material (DTC) was selected to prepare phase change asphalt mixture, and the pavement performance of phase change asphalt mixture was studied by indoor temperature rise and drop test, rut test, immersion Marshall test, freeze-thaw splitting test and low temperature bending test. The results show that DTC reduces the rate of rise and drop during the indoor heating process. DTC can effectively absorb heat for 140min at 40°C and can effectively release heat for 80min at -18°C. With the increase of DTC content, the dynamic stability, residual stability and splitting strength ratio of phase change asphalt mixture show a trend of decrease, while the low temperature failure strain shows a trend of first increase and then decrease.

Eight common reinforced concrete columns were damaged by different sizes loads. The damaged reinforced concrete columns were strengthened by reinforcement mesh steel fiber. Three identical test pieces were made to explore the dispersion of the reinforcement method. The axial compression experiment was researched by factor of mortar types, damage degree, the lateral and longitudinal spacing. The formula of the axial bearing capacity of damaged square columns were strengthened by reinforcement mesh steel fiber was proposed. The calculated values agreed well with the experimental results. The test results showed that the damaged square columns were strengthened by reinforcement mesh steel fiber was an effective reinforcement method. This method was less discrete and can not only improve the ultimate bearing capacity, cracking load ductility and anti-cracking ability, but also the mechanical properties and failure mode can be effectively improved.

In order to improve the crack resistance of semi-rigid base materials, polyester fiber (PET), polypropylene fiber (PP), polyacrylonitrile fiber (PAN) and polyvinyl alcohol fiber (PVA) were selected to prepare cement-stabilized crushed stone mixture. The mechanical properties of fiber-cement stabilized crushed stone mixture were studied by unconfined compressive strength, splitting strength and compressive rebound modulus tests. The results show that the fiber can effectively improve the compressive strength and splitting strength of cement-stabilized crushed stone mixture when the fiber content is 0.05%-0.11%, and both the compressive strength and splitting strength of the mixture increase with the increase of fiber content. The compressive strength and splitting strength of the mixture with the same fiber and dosage showed a trend of slow growth first, then rapid growth, and then gentle growth during the curing period of 90d. Adding PET, PP and PAN reduced the compressive resilience modulus of cement-stabilized macadam mixture, while adding PVA increased the compressive resilience modulus of cement-stabilized macadam mixture.

Potassium-oxygen batteries as promising energy storage system have been widely concerned at present. In this paper, we obtain a zinc manganese oxide (ZnMn₂O₄) catalyst via a facile coprecipitation method. XRD and Raman tests show that ZnMn₂O₄ at the Zn and Mn molar ratio to 1:2 along with hot-heat treatment at 150 °C has a higher crystallinity and lower heterophase content. SEM observes that ZnMn₂O₄ material shows uniform spherical morphology with loose arrangement, which can be beneficial to mass transfer and discharge products storage. Electrochemical test results display that air electrode with ZnMn₂O₄ as catalyst has rapid electron and ion transfer speed and successfully carries out the charge and discharge process in the potassium-oxygen battery system.

It is necessary to strengthen energy management in chemical and petrochemical industries because of the shortage of energy supply. Aspen Plus was used to simulate and optimize vinyl acetate production process via ethylene gas-phase method. The appropriate thermodynamic equations and unit modules were selected. The simulation and optimization results of vinyl acetate production were in accordance with the industrial production data. Based on steady-state simulation and optimization results, heat exchanger network synthesis and heat pump assisted distillation technology were proposed for energy conservation. For heat exchanger network synthesis technology, energy conservation can be achieved through the energy matching of cold and hot streams based on pinch theory. As a result, cold utilities, hot utilities, heat transfer area and the number of heat exchanger decreased by 25.52%, 59.52%, 70.60% and 30.77%, respectively. For heat pump assisted distillation technology, compared with the conventional distillation technology in the purification of acetic acid from aqueous acetic acid solution, 48.05% of cold energy consumption and 82.40% of heat energy consumption could be saved. Based on the simulation and optimization results, it can be found that heat exchanger network synthesis and optimization as well as heat pump assisted distillation technology can provide good ideas for the rational use of energy.

Owing to the high theoretical capacity, low price, easy availability of aluminum, the rechargeable aluminum-ion battery (AIB) is very suitable as an electrochemical energy storage device for large-scale power storage. High preference of rechargeable AIBs is depended on the suitable electrolytes. In this paper, a kind of novel ionic liquid electrolyte is prepared by mixing aluminum chloride (AlCl₃) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TF₂N]). This electrolyte possesses high electrical conductivity and a satisfactory oxidation voltage (2.50 V vs. Al/Al³⁺), which are more excellent than conventional AlCl₃-based electrolytes. The Al|1.7AlCl₃-[EMIM][TF₂N]|carbon paper battery exhibits a stable discharge specific capacity of ~75 mAh⋅g^-1 at 100 mA⋅g^-1 with a near 100% coulombic efficiency, indicating that AlCl₃-[EMIM][TF₂N] ionic liquid is a promising electrolyte for high-voltage and high-performance aluminum-ion batteries.

Transition-metal selenides have recently attracted increasing interest in supercapacitors (SCs) owning to their fascinating electrochemical properties. Here, binary metal selenides (NiCoSe₂, NiCo₂Se₄, NiCo₂Se₄) are designed as novel electrode materials according to the reported NiSe and CoSe via a one-step electrodeposition process. The effects of different Ni/Co ratio on pseudo-capacitive properties of the binary metal selenides are investigated accordingly. Obviously, the designed binary metal selenides can combine the advantages of both metal selenides. As a result, the NiCoSe₂ sample exhibits an optimized performance with a high specific capacity (334.2 mAh g^-1, 1 A g^-1), good rate capability, and excellent durability (90.7%, 5000 cycles). Most notably, the NiCoSe₂//AC asymmetric SC (ASC) exhibits an excellent energy density of 41.7 Wh kg^-1 at 800 W kg^-1. Hence, a variety of ions with complementary advantages can be combined by electrodeposition, which provides an efficient way to synthesize excellent materials with various properties.

Classification treatment was applied for the fluorine-containing membrane material production wastewater, which was low biodegradability with high concentration of fluoride and salinity. Salinity wastewater was collected and pretreated by three-effect evaporation and ozone oxidation for desalting and improving the biodegradability, then mixed with other production wastewater with low concentration. Mixed wastewater was treated by hydrolysis acidification, AO biological treatment and modified Fenton treatment process. The operation results of stable operation showed that when the influent concentrations of COD, NH₃-N, fluoride, TN and TP were 5000mg/L, 50mg/L, 5000mg/L, 60mg/and 1mg/L, the effluent mean concentrations were 32mg/L, 1.2mg/L, 1.1mg/L, 13.5mg/L and 0.12mg/L, which could meet the discharge standards.

To study the tribological characteristics of the high-entropy alloy FeCoNiCrMn under MoS₂-oil lubrication conditions in detail, physical testing is combined with finite element method. At room temperature, a ball-on-disk contact pair is selected with reciprocating motion of 5 mm. The single-factor tests are carried out with variables of load (10~50 N) and speed (4.167~20.833 mm/s), and the related wear equation is obtained. Through the static friction contact finite element simulation, the stress and deformation of the friction pair are investigated (the error about 1%), which provides a basis for the partial displacement boundary conditions of the dynamic contact simulation; in the dynamic contact friction simulation, changes in contact pressure and friction stress are analyzed at different loads and velocities. Furthermore, the dynamic friction contact pressure is used to optimize the wear equation and increase the correlation coefficient from 0.89 to 0.96.

In this work, hollow Ni-Co-S nanocubes were designed and successfully prepared as a superior sulfur host for lithium-sulfur batteries (LSBs) by means of facile synthesis methods. The prepared hollow Ni-Co-S nanocubes possess multiple merits, including good electrical conductivity, sulfur encapsulated nanostructure and LiPS adsorbability. By employing Ni-Co-S nanocubes as the sulfur host, the electron transfer efficiency is incresed and the volume expansion during repeated cycling can be buffered. Besides, the shuttling effect is limited effectively due to the strong lithium polysulfides (LiPS) adsorbability. As a result, the sulfur utilization is significantly improved for better performance. Benefiting from these advantages, the LSBs exhibited a fairly high initial capacity of 1482 m Ah g^-1, a retained capacity of 669 m Ah g^-1 over 200 cycles and impressive discharge capacities of 710, 565, 370 and 186 m Ah g^-1 even at 1C, 2C, 3C and 4C, respectively.

The conventional lost circulation materials (LCMs) particles of seal in the formation are in linear contact. Therefore, there is no cohesive force interaction, which is susceptible to pressure fluctuations, resulting in lost circulation and control failure. In response to these problems, this paper tested the high-temperature adhesion properties of EVA in the viscous flow transition zone through high-temperature adhesion experiments; then a smart adhesive LCMs is prepared using thermoplastic EVA resin with conventional LCMs; finally, through the high-temperature and high-pressure plugging experiment, the system's performance for sealing fractures was tested. The experiment results show that the smart adhesive LCMs have good plugging performance and can bond LCMs in the fracture to form a high-strength sealing with a pressure-bearing capacity of up to 9.3MPa.

The Shamai tungsten deposit in Inner Mongolia is located in the Xing'an Mongolia Orogenic Belt, east part of the Central Asian Orogenic Belt. Orebodies exist in the fault zone of the biotite monzogranite (porphyry), in the pegmatite and greisen forms. This paper presents precise 40Ar/39Ar ages of muscovite related to the mineralization by laser incremental 40Ar/39Ar analysis. Muscovite yielded a well-defined ⁴⁰Ar/³⁹Ar plateau age of (138.4 ± 0.84) Ma, with normal and inverse isochron ages being (137.32 ± 0.73) Ma and (137.35 ± 0.73) Ma. These ages can represent the formation age of the deposit and suggest that the Shamai deposit is related to the magmatic activities of Yanshanian period, which is in conformity with things of the regional metallogenic events. Combined with the previous studies of the geodynamic settings of South China, the authors consider that Shamai tungsten deposit might be formed in an intracontinental extensional setting following the collision.

The mechanical and corona resistance of polyimide/alumina multilayer composite films were prepared by roller coating process. The mechanical properties and corona resistance of the films were tested, and compared with the single layer of polyimide/alumina composite films. The results show that the multilayer composite film can maintain the mechanical properties of the film and improve the corona resistance of the film when the same mass fraction of alumina is introduced. The results show that the alumina in the single layer is spherical agglomerated, while that in the multilayer composite film is strip. The surface layer of strip dense alumina in multilayer composite films plays a role in preventing corona discharge from penetrating into the internal organism and the discharge is concentrated on alumina. The aluminum oxide with inner strip distribution continues to resist corona discharge, and changes the path of corona discharge, which prevents the corona breakdown from happening in advance, so the corona resistance of composite film has been improved.

Different types of TKX-50/PBA-I composite materials were prepared by the solution-water suspension method, and the influence of the content of anionic groups on the coating effect was explored by SEM, FT-IR, XPS and TGA. The results showed that PBA-I were successfully coated on the crystal surface of TKX-50, and the content of anionic group -COOH increased, which was conducive to the coating effect of the bonding agent on TKX-50. Among the different anionic bonding agents, PBA-I-3 had the best coating effect.

The sodium chloride poisoning of proton exchange membrane fuel cell (PEMFC) has important influence on performance. The concentration diffusion of NaCl on a PEM fuel cell membrane electrode (MEA) was investigated. The MEA was soaked in five NaCl solutions with different concentrations (0mg/L, 50mg/L, 100 mg/L, 300 mg/L, 500 mg/L), and the surface morphology was observed by scanning electron microscope, and the element content was quantitatively analyzed by energy dispersive spectrometer. The results show that with the increase of pollution concentration, the number and size of sodium chloride square crystal on the gas diffusion layer also show a positive correlation.; At the same time, the analysis of the determination results of the energy dispersive spectrometer shows that the closer to the proton exchange membrane region of the membrane electrode, the percentage of sodium atom content also presents a positive correlation.

Five groups of transmission electron microscopy (TEM) specimens of Zr₆₅Al_7.5Co_22.5Ag₅ and Zr₆₅Al₇Co₇Ag₇Fe₇Ni₇ amorphous ribbons are prepared by ion milling. It focuses on effect of ion milling conditions on the structure changes of amorphous ribbons. The results show that Zr-based amorphous ribbons can be crystallized into nanoscale fcc-Ag or fcc-Zr₂M (M=Al, Co, Ag, Fe, Ni) under specific ion milling conditions. The crystallization reaction sequence of isothermal annealing Zr₆₅Al_7.5Co_22.5Ag₅ and Zr₆₅Al₇Co₇Ag₇Fe₇Ni₇ amorphous alloys is different. Besides of ion beams irradiation-induced stresses and surface effects, sputtering, argon ions implantation and irradiation damages, ion irritation effect and mixing heats among constituent elements are significant, resulting in fcc-Ag or fcc-Zr₂M precipitates from amorphous phase. The peak temperature locally reached of TEM foil during ion milling is estimated more than 750K.

It has innovatively teat-treated an ultra-high carbon steel via a novel technique with low energy consumption for automotive stamping die application in this study. Formation mechanism of isothermal transformation product at low temperatures in an ultra-high carbon steel has been investigated by the means of X-ray diffraction (XRD) analysis and metallographic examination on the resulting microstructure, which is optimally designed to achieve an excellent combination of high impact toughness and high hardness. It is indicated that microstructure morphology of resulting bainite isothermally formed at temperatures below 200°C is observably different from water-quenched shear-transformed martensite; in the case of isothermal transformation above 200°C for a long time, it obtains bainite sheaf which is composed of slender bainitic ferrite plates separated by parallel parent phase films; bainite sheaf is achieved by nucleation and growth of new parallel bainite plates in the vicinity of both body sides of the already formed bainite plate.

The thermodynamic properties of Mg, Zn, Al binary alloys and ternary alloys were calculated by Miedema model and Toop model, and magnesium was selected as the asymmetric component. The results show that the mixing enthalpy, excess entropy and excess Gibbs free energy of Al-Zn binary alloy are all greater than zero. The thermodynamic values of Mg-Al and Mg-Zn binary alloys are relatively similar, and both are less than zero. Within the range of composition variation, the excess Gibbs free energy of Mg-Zn-Al ternary alloy is basically negative. In the Mg-poor and Mg-rich regions, the thermodynamic value of the alloy changes greatly. Excess Gibbs free energy and mixing enthalpy of magnesium-zinc-aluminum alloy can be reduced by adding zinc and aluminum.

Reliable, nontoxic and eco-friendly solders are gaining attention in welding. Low-silver lead-free solder becomes a developing trend. Herein, the microstructures of Low-silver lead-free Sn1.0Ag0.5Cu micro-joints at different storage time in high-temperature environments are observed and analysed in this article. It is our primary focus here to analyse the thickness evolution of the interfacial intermetallic compound (IMC) layer. The numerical growth models of IMC bilayers are constructed, which provide an essential reference for lifetime analysis and reliability evaluation of Sn1.0Ag0.5Cu solders for long-term use in high temperature environment.

The effect of cooling method on microstructures and mechanical properties of the hot-extruded Cu-15Ni-8Sn bars were investigated by optical microscope(OM), scanning electronic microscope(SEM), differential scanning calorimetry(DSC) and tensile testing. The results indicated that the content of solid solution atom Sn in the water-cooled alloy after hot extrusion is greater than that in the air-cooled alloy. The precipitation onset temperature and dissolution termination temperature of γ phase in the water-cooled alloy are 24 °C and 32 °C lower than that in the air-cooled alloy, respectively. Both water-cooled and air-cooled alloys are composed of γ phase and supersaturated solid solution α(Cu), and show the similar grain size about 23 μm. In the air-cooled alloy, a large number of dispersed rod-like and granular γ-phases are precipitated in the grains, while only granular γ phase is observed in water-cooled alloy with. The tensile strength, elongation and microhardness of the water-cooled and air-cooled alloys are 588±12 MPa and 855±41 MPa, 41.6±2.0% and 15.2±1.0%, 166±7 HV and 292±5 HV, respectively, while the former shows a typical ductile fracture mechanism and the latter has somewhat brittle fracture characteristics.

CoNiCr and CoNiCu medium-entropy alloys (MEAs) were prepared by powder metallurgy with Co, Ni, Cr, Cu powders milled for 5h and 30h, and the effects of different milling time and different elements on the microstructures and properties of MEAs were studied. Through microstructures characterization (by scanning electron microscope and energy dispersive spectrum analysis, X-ray diffraction analysis) and mechanical properties (compressive performance, hardness, wear resistance) testing, the following conclusions are drawn: First, with the increase of the milling time, the density of the sintered samples is increased. Second, the microstructure of CoNiCr MEA is composed of Ni-rich FCC solid solution, Cr-rich BCC solid solution and CoNiCr intermetallic compound, while the microstructure of CoNiCu MEA is mainly composed of FCC solid solution with uniform Co, Ni, and Cu, and Co-rich FCC solid solution. Third, as the agglomeration of powder is weakened and the density of sintered sample is increased, the hardness of CoNiX (X=Cr/Cu)-30h is higher (about 20HV) than that of CoNiX (X=Cr/Cu)-5h, and long-term ball milling effectively improves the wear resistance, moldability and compressive strength of CoNiCr MEA, while the moldability and compressive strength of CoNiCu MEA are reduced, and the wear resistance of CoNiCu MEA is slightly improved. Finally, the hardness and wear resistance of CoNiCr MEA are better than that of CoNiCu MEA, the hardness is increased by about 70HV, and the wear resistance is increased by about 20-40 times, but the compressive performance of CoNiCu MEA is better than that of CoNiCr MEA.

Semi-process non-oriented electrical steel with poor corrosion resistance is easily get rusted during the process of production, transportation, and application by end customers. In response to this problem, the paper studies the effect of different tapping temperatures in the cold rolling annealing process and cleaning process after tapping on its corrosion resistance. The results show that the higher the tapping temperature is, the worse the corrosion resistance will be. Cleaning with formic acid can increase its corrosion resistance.

In this paper, the effect of Al and Ti on the high temperature plasticity of Q390 microalloyed steel was studied. The high temperature tensile tests of two Q390 steels with different contents of aluminum and titanium (0.02%Al-0.01%Ti and 0%Al-0.02%Ti) were carried out on Gleeble 3800 thermal simulation test machine. The high temperature plasticity of the two steels was compared and analyzed by calculation of shrinkage ratio, fracture morphology and energy spectrum of the precipitates. The study indicated: The toughness of 0%Al-0.02%Ti steel is 12%-35% higher than that of 0.02%al-0.01%Ti steel in the III brittleness temperature zone. Aluminum has a negative effect on the high temperature plasticity of microalloyed steel, while titanium has a positive effect on the high temperature plasticity of microalloyed steel. Therefore, the surface quality of Q390 microalloyed steel is improved when Q390 is adopted the composition of 0%Al-0.02%Ti steel.

Isothermal transformation is the key stage to carbide precipitation in microalloyed steel. Detailed phase transformation data are needed in order to control and study the precipitation process of carbides accurately. However, alloying elements will change the transformation process in this microalloyed low carbon steel. Therefore, the effects of titanium and molybdenum elements on isothermal transformation behaviour were studied by a Gleeble 3800 thermal-mechanical simulator. Microscopic test and dilatometry were applied to analyse the isothermal transformation of steels. The results show that the ferrite in steel changes from polygonal ferrite to quasi-polygonal ferrite to acicular ferrite with the decrease of temperature from 700°C to 550°C, and the addition of titanium and molybdenum elements retards the isothermal transformation and result in prolonged transformation time. Besides, alloying elements also tend to inhibit the phase transformation in specific temperatures and lead to more untransformed austenite.

Supersaturated Ribbons of the Al-12Mg alloy are prepared by melt spinning. The objective of this work is to explore the microstructure and microhardness of these ribbons. The results show that each Ribbon is a nearly single-phase solid solution containing a high density of dislocation, and there is few precipitation detected; Grains of the ribbon are equiaxed and the average size of them is 2.51 μm; During crystallization, {111} plane of the alloy grows preferentially parallel to the surface of the ribbon; The ribbons exhibit a relatively high microhardness of 113 HV. The feasibility of using these ribbons to prepare supersaturated Al-12Mg bulk alloy is discussed.

In this paper, aimed at the zinc ferrite products from the gossan bearing-zinc ore by direct roasting and their sulfuric acid leaching products, the differences of related products in element composition, mineral composition, specific surface properties and particle morphology were studied. The results show that the XRD diffraction peaks of low content zinc ferrite products are more complex and have more impurity peaks than those of high content zinc ferrite products and less impurity peaks. The XRD patterns of leaching residue have little difference after sulfuric acid leaching purification, but the high content zinc ferrite products have higher crystallinity, the diffraction peak of zinc ferrite from leaching residue is stronger. That is to say, the content of zinc ferrite in the roasted product will not affect the final purification effect by sulfuric acid leaching purification. The phase composition of the purified product is similar, which the main component is zinc ferrite, and contains impurities such as gangue minerals. The adsorption-desorption curves of two purified zinc ferrite products are of type III, but the curves of two products are different. The specific surface area of sample 1 is 9.66 times that of sample 2. The Pore volume and average pore diameter are 8.14 times and 1.97 times, respectively. Therefore, the purified zinc ferrite products with low content of zinc ferrite will have more application potential as adsorbents. There are relatively few soluble impurities in the high content zinc ferrite products, so the micro-morphology of the samples has little change after leaching. However, there are more soluble impurities in the low content of zinc ferrite. After leaching purification by sulfuric acid, the position of the soluble impurities becomes pore, the large particles are decomposed and the particles become finer.

The design based on high-entropy alloys (HEAs) is undergoing a conceptual expansion from equiatomic alloys to non-equiatomic alloys. To provide the experimental basis for non-equiatomic high-entropy alloys and their oxidation resistance at high temperatures, in this study, a Co50Ni2sAl8Ti8Nb3Ta3W3 high-entropy alloy was prepared by a vacuum arc melting method, and then it was subjected to different aging heat treatments. The phase composition, element composition distribution, and mechanical properties of the alloy were characterized by XRD SEM/EDS. In addition, we have systematically studied the high-temperature oxidation resistance of the alloy and analyzed the high-temperature oxidation mechanism of the alloy. The results showed that the phase composition of the Co₅₀Ni₂₅Al₈Ti₈Nb₃Ta₃W₃ high-entropy alloy is a single fcc solid solution phase, and the grains of the alloy become coarser after secondary aging. Many oxidation products were produced after high-temperature oxidation of the alloy. The oxidation products of the outermost layer of the alloy are mainly CoNiO₂, CoTiO₃, and M₂O₃, and the oxidation products of the intermediate layer are mainly Al₂O₃, TiO₂, and Nb₂O₃.

The effects of different contents of rare earth elements (erbium (Er) and yttrium(Y) ) on the microstructures and properties of 6016 aluminum alloy have been investigated. The results indicate that Er and Y can refine the grain size of 6016 aluminum alloy, and the precipitation of the second phase increases obviously and most of them are distributed in the grain boundary; the hardness values of the as-cast, rolled, T4 and T4P samples with Er and Y are obviously increased, which can be improved by 10~30HV, and the effect of Er on hardness improvement is better than that of Y When both the addition mass fraction of Er and Y are 0.5%, the tensile property, work hardening coefficient and plastic strain ratio of aluminum alloy in T4P state are better, and they are respectively: 172.663MPa, 345.218MPa, 34.2%, 0.37, 0.79.

In this paper, the effects of particle size and content of glass additive on the sintering densification, interfacial bonding and electrical properties of silver electrode of LTCC were investigated. The particle size of glass powder would mainly affect the densification rate of electrode film and the uniformity of glass phase distribution. The content of glass played a key role in the density of electrode film, the distribution of glass phase and the interface bonding. When the relative content of glass was low, the glass phase could not wet the silver powder effectively. Thus, the silver film was not dense and the interfacial adhesion was weak. When the relative content was too high, there would be too much glass phase at the surface and interior of the electrode film, which would increase the silver film resistance. By adjusting the particle size and relative content of glass, the co-firing compatibility of LTCC and thick film silver electrode could be better realized. When the content of glass additive was 1.0 wt%, the sintered film illustrated the optimum performance of densified microstructure and low sheet resistance of 1.32 mΩ/sq.

The metallization of plastic surface will improve the surface properties of plastic and make it have the unique functions of both plastic and metal. Vacuum coating process is one of the main technologies of modern plastic surface metallization.The principle of plastic vacuum coating technology and its common coating methods were introduced, the particularity of plastic as the substrate material of vacuum coating was analyzed, the application of vacuum coating process in the metallization of plastic surface was expounded, and the current research hotspots were put forward.

In this paper, zinc ferrite was prepared from zinc calcine by sulfuric acid leaching, and its properties were studied by the methods of XRD, XRF and SEM/EDS. The results show that sulfuric acid leaching of zinc ferrite from zinc calcine is mainly affected by the initial concentration of sulfuric acid and leaching temperature. If the initial concentration of sulfuric acid and leaching temperature are too low, the soluble oxides in zinc calcine can not be completely dissolved. The prepared zinc ferrite was not suitable for application for too many impurities. However, the higher initial concentration of sulfuric acid and leaching temperature are, the lower recovery of zinc ferrite is. The suitable conditions for preparation of zinc ferrite from zinc calcine by sulfuric acid leaching are liquid-solid ratio 7:1, stirring speed 400rpm, sulfuric acid concentration 160g/L, leaching temperature 85°C, leaching time 120min. The particle size of zinc ferrite is fine, most of them is between 2~5μm. The impurity content of zinc ferrite is less. Zinc ferrite particles are composed of spherical and irregular shape, and they are agglomerate and encase each other.

WC-Ni₃Al composite powders with different Ni₃Al contents were prepared by ball milling WC and Ni₃Al powder mixtures. Functionally graded WC-Ni₃Al cemented carbides (FGCCs) with Ni₃Al content gradient were prepared by lamination pressing different WC-xNi₃Al (x = 2, 10) powder mixtures and spark plasma sintering the layered compacts. The results show that there are some distinct gradient composition layers in the sintered bulk sample. With the increase of Ni₃Al content, the size of the WC grains decreases from 0.83 to 0.74 μm because Ni₃Al increases the free path of WC grains. And due to difference in Ni₃Al content and WC grain size, graded WC-Ni₃Al cemented carbides has a Vickers hardness of 1901.8 HV30 at the surface, which decreases to 1780.3 HV30 in the core. Nevertheless, the fracture toughness increases from 10.89 MPa⋅m^1/2 at the surface to 13.34 MPa⋅m^1/2 in the core. The present results show that FGCCs with high outer layer hardness and high inner layer toughness were successfully prepared.

Three kinds of high speed steels with similar composition were selected, which were produced by powder metallurgy (named PM20), spay forming (named SF20) and electroslag remelting (named ESR20) respectively. Their microstructure and mechanical properties were studied. The results indicated that the carbides in PM20 are fine and evenly distributed carbides, but there is carbide segregation in SF20, the carbides in ESR20 are banded distribution, carbide aggregation is much more serious than SF20. The segregation of carbides is beneficial to the wear property, but it will reduce the impact toughness. Consequently, PM20 has the worst wear properties but the best impact toughness, ESR20 is the opposite. The mechanical properties of SF20 are in between of them.

The phase transformation law and microstructure evolution of austenite in Ti microalloyed steel under different continuous cooling rates (0.1-30°C/s) after a two-stage deformation were studied based on the Gleeble-3800 Thermo-Mechanical Simulator. The continuous cooling transformation (CCT) curve was obtained by thermal expansion method combining with microstructures. The results showed that the Ac1 and Ac3 of the steel were 835°C and 902°C, respectively. With the increase of cooling rate, the austenite phase transition temperature decreased, from 778.5-712.2°C at 0.1°C/s to 633.7-488.7°C/s at 30°C/s. Accordingly, the austenite transformation structure changed from polygonal ferrite and pearlite to granular bainite. In addition, with the increase of cooling rate, the ferrite transformation was inhibited, and the transformation region of granular bainite was increased.

To prepare TiAlN coatings with excellent performance and obtain the influence law of doping amount on the performance of TiAlN coatings, Cr-doping and Cr-Ni co-doping were carried out under the optimal process parameters of TiAlN by multi-arc ion plating and magnetron sputtering. The paper changed the doping amount of Cr and Cr-Ni by changing doping time of magnetron sputtering, to study the influence of doping amount on phase structure, surface hardness and adhesion TiAlN coatings. The results show that, all the components in the coatings are evenly distributed and doping amount is directly proportional to the doping time, when doping time was 10min, the phase structure of the coating was consistent with of the undoped TiAlN coating. With the increase of doping time, Al-Ni alloy phase and CrN phase began to appear, and the peak strength also increased with the increase of doping amount. The surface hardness of the coating decrease with the increase of doping amount, and binding force of the coating reaches the maximum at the doping time of 30 min, which is about 40N. When doping time continues to increase, the binding force of coating decrease, which is related to the formation of composite coating.

In this work, dense NiTi shape memory alloy (SMA) was fabricated by selective laser melting (SLM) under different laser powers (150 W, 210 W and 270 W). The effect of altered laser power on the microstructure and mechanical properties of NiTi SMA was studied by X-ray diffraction, differential scan calorimetry, optical microscopy and compressive test. The results indicated that the grains of SLM NiTi SMA changed from the uniform and fine honeycomb crystals to large square crystals with the increase of laser power. Meanwhile, the phase transformation temperature of SLM NiTi SMA increased with the increase of laser power, which resulted in the volume fraction of B19' phase in the matrix increased at room temperature. More importantly, when the laser power was 150 W, the SLM NiTi SMA had best compressive strength of 3302.7 MPa and fracture strain of 34.5%, which were better than most of the reported compressive properties in SLM NiTi SMA. This is mainly attributed to the fine and uniform honeycomb crystals in SLM NiTi SMA by 150 W.

In this paper, the chemical formula of the main minerals in gossan were calculated, and the effects of the leaching agents such as NH₃-H₂O, NH₃-(NH₄)₂CO₃, NaOH, NH₃-NH₄Cl and NH₃-(NH₄)₂SO₄, mechanical activation leaching and leaching times were researched, respectively. It shown that the formula of siderite is (ZnCO₃)_0.1580⋅(ZnO)_0.2156⋅FeCO₃ and the formula of limonite bearing zinc is (ZnCO₃)_0.0623⋅(ZnO)_0.1122⋅(FeO(OH)⋅0.7011H₂O). In the conventional leaching, the zinc leaching rate is less than 50%. The best zinc leaching rate is about 53% in the multi-leaching, and the highest zinc leaching rate is about 63% when mechanical activation and leaching at the same time. It is indicated that zinc in smithsonite could be dissolved in leaching solution, zinc on limonite could be partly desorbed under the action of external forces and zinc in siderite could not be recovered due to its solubility in leaching agent. Therefore, it could be concluded that the alkaline leaching is difficult to recover zinc from the gossan ore for the reasons above mentioned. The leaching results agree with the calculation of the formula of the main minerals.

On the basis of orthogonal experiment in double glow plasma suface alloying permeability Mo process, using the genetic algorithm of back propagation neural network (BPNN) GA, pole spacing and heat preservation temperature, holding time was studied, the source voltage and working pressure of process parameters on the double glow ion permeability molybdenum permeability layer thickness, the influence of the optimization of the double glow ion permeability Mo process test parameters. The predicted results are in good agreement with the actual test results, and the absolute coefficient (R²) is 0.964. The recommended optimal prediction method can get representative results for both the optimal and various penetration thickness predictions. This paper provides a new method for the selection of the optimum process scheme of double brilliance ionic infiltration Mo process.

Because of its complex composition, low content of valuable metals and high development cost, the gossan ore has not been paid much attention by scholars at home and abroad. In this paper, the properties of gossan ore from zinc sulfide deposit were studied by the methods of mineralogical analysis, BET analysis and SEM/EDS analysis. The results show that the studied ore is typical zinc-bearing gossan type ore. The main elements in the gossan ore are zinc and iron, as well as a certain amount of silicon. The iron mineral of ore is limonite, most of which are monomers, a few connected with clay, dolomite and so on, and are closely adhered with some siderite, which generally contains zinc. Zinc minerals are mainly smithsonite and hemimorphite, a small amount of sphalerite, zinc mica, most of the siderite and limonite symbiosis. The nitrogen adsorption-desorption isotherm of the gossan ore is a typical type III isotherm, and the isotherm is concave and has no inflexion, which shows that the interaction of adsorbents is stronger than that of adsorbents and materials. The specific surface area of gossan ore is small, mainly composed of micro-pores, the smaller specific surface area and pore volume limit its adsorption capacity, which intimates that the untreated gossan ore is not a good adsorbent. The gossan ore particles are composed of many irregular crystal particles with uniform size and many large pore channels appear in the gossan ore particles. The particles are smaller and more dispersed, and that the interconnections between larger particles are mainly caused by the direct interaction of some smaller particles. This research will lay a theoretical basis for the follow-up development and utilization of the gossan ore.

In this study, Gleeble 3800 thermal simulator was used to simulate the continuous annealing process of industrial production of dual phase steel with the tensile strength over 980 MPa. In the experiment, four different annealing temperatures of 700 °C, 720 °C, 740 °C and 760 °C were set in the intercritical region while keeping other process parameters unchanged. The experimental results showed that the martensite content increases with the rise of intercritical annealing temperature. However, this growth is not persistent, the obvious change of martensite content can be seen only when the temperature exceeds 20 °C in current study. In addition, with the increase of temperature, the elongated ferrite grains tend to become more equiaxed.

Deep neural networks have powerful nonlinear performance, but until now there is no ideal method for hyperparameters tuning. In this paper, prediction correct rate of IF steel mechanical performance is used as evaluation criterion to establish a neural network regression model. The study shows that increasing the number of hidden layers and neurons could both improve the prediction accuracy. Under the same parameter magnitude, the effect of adding hidden layer numbers is better than neuron numbers. However, after the network depth reaches a certain threshold, the accuracy does not increase, or even drop. After a lot of attempts, we have obtained a model topology of 3 hidden layers and 100 neurons with 1 output feather. On the new test set of 1,000 samples, the yield strength(Rp_0.2,) tensile strength(Rm) and elongation(A80) prediction accuracy are 74.4%, 89.8% and 83.2%. Data expansion, test method stabilization and adding knowledge-driven sub-model could be used to optimize the model.

The semi-solid squeeze casting numerical simulation study of 7050 aluminum alloy was carried out using ProCAST software, and the forming properties of the alloy were investigated by adjusting the process parameters appropriately. The results show that the filling process of semi-solid aluminum alloy is relatively stable, and it is not easy to splash. The optimal process parameters after optimization are: pouring temperature 620°C, mold temperature 300°C, forming pressure 80MPa. Under this process parameter, the defect of the part is the least.

In the cutting process of high temperature alloys, the performance of the tool is closely related to the surface quality of the workpiece. In this paper, a turning test was conducted on nickel-based high-temperature alloy Inconel 718 using PVD-coated carbide tools, and the microscopic morphology of tool wear was observed by scanning electron microscopy (SEM), and the chemical elemental composition of the tool wear surface was analyzed by energy spectrum analyzer (EDS), and the wear mechanism of PVD-coated carbide tools in three stages of tool wear was analyzed in detail. On this basis, the characteristic quantities closely related to tool wear were extracted in the time and frequency domains by the collected cutting force signals, which provide effective characteristic inputs for the subsequent study of online tool wear monitoring.

Titanium alloy is a kind of typical medical implant material because of its excellent mechanical properties, corrosion resistance and good biocompatibility. The most important facts to the success of implanting operation are the combination reactions between the implant and living cells as well as tissues which include cell growth, adhesion, proliferation and differentiation. The combination ability of implant and living body depends on the surface microstructure and morphology of the implant to a certain extent. The bionics research results show that the surface microstructure of biological bone is of the micro-pit geometric characteristics with 10-100μm depth. The residual stress of plastic forming micro-pit were analyzed with finite element simulation software ABAQUS. The correctness of the simulation results has been verified by experiments.

Al2O3 ceramic and 1A95 aluminum alloy vacuum brazed joints were prepared with Al-Si-Mg-La solder. The effects of brazing time on the structure and shear properties of brazed joints were studied, and the interface of the joints was analyzed. Studies have shown that the shear strength of Al2O3/Ag-Si-Mg-La/Al joints all show a trend of increasing first and then decreasing with the increase of brazing temperature and holding time; when the best brazing process is 590°C×30 min, the boundary between AlSiMgLa solder and aluminum alloy disappears; the interface between Al2O3 ceramic and solder is well bonded, and the shear strength reaches 65.12 MPa. The fracture form of the joint is brittle fracture. Under different brazing process parameters, the fracture position of the joint is mainly divided into two types: when the joint strength is low, the fracture occurs near the interface between the aluminum alloy and the brazing filler metal layer; when the joint strength is higher, the fracture occurs at the interface between the Al2O3 ceramic and the solder.

The inner structure of cementitious materials is crucial for the intelligent design and construction in civil engineering. In this work, two kinds of samples made from Portland cement and metakaolin-based geopolymer respectively were prepared to be exposed in high-temperature environment. In the experiments, the samples were placed on a heater with a 400°C surface for 40 minutes. A high-energy X-ray computed tomography (CT) facility was used to detect the macroscopic inner structure of the samples. In addition, the infrared-ray morphology of samples was also tested and compared. Results show that metakaolin-based geopolymer was relatively more resistant to heat compared with Portland cement. However, the cracks development of metakaolin-based geopolymer was severer due to the shrinkage in the high-temperature environment. In addition, based on the X-ray CT images, a method to show the distribution of pores' sizes was proposed. It was found the distribution of pores' volumes and area surfaces can be fitted by power laws which are straight lines in the logarithmic coordinates, and the geopolymer samples have relatively higher goodness of fit. Moreover, a lower intercept of the fitting line indicates the frequency of larger pores in the sample is lower, and a lower slope indicates a tighter distribution range of the pores' sizes. These findings may provide insight for future intelligent design of digital cementitious materials used in hash environment.

CoNiCuCr_x (x=0,0.4,1) medium entropy alloys (MEAs) were prepared by powder metallurgy technology, and the effects of Cr content on the microstructures and properties of the alloys were studied. The results show that the CoNiCu MEA consists of FCC1 solid solution phase and FCC2 solid solution phase. With Cr addtion, some new phases appear in the CoNiCuCr_x MEAs, and they are FCC3 solid solution phase, BCC solid solution phase and a small number of NiCoCr intermetallic compound. The new structural phase improves the hardness, compressive yield strength, compressive strength and wear resistance of the MEAs, with the increase of Cr content. NiCoCuCr MEA shows good comprehensive mechanical properties, and the hardness, compressive yield strength, compressive strength and specific wear rate are 331 MPa, 511.87 MPa, 1142.71 MPa and 4.09×10^-4 mm³/N⋅m respectively.

6016 aluminum alloys with different niobium contents were prepared by smelting and casting. The alloys were rolled and heat treated, and the effect of niobium on microstructures and properties of the alloys were studied. The results show that the as-cast alloy consists of Mn-rich phases, Cu-rich phases, Mg-rich phases, Si-rich phases and small blocks of Zn-rich phases, and Nb element is solidly dissolved in these phases and matrix. After solution and pre-aging treatment, recrystallization occurs in the rolled alloy. The grain size of the rolled alloy is obviously smaller than that of the as-cast alloy, and the second phase precipitates dispersively. After solution treatment or solution treatment + pre-aging treatment, the tensile strength and plasticity of the alloy are significantly improved. With the increase of niobium content, the number and size of the second phase increase. The alloy with 1%Nb in T4P condition has the better comprehensive mechanical properties, and its elongation after fracture, tensile strength, yield strength, plastic strain ratio and strain hardening index are as following respectively: 34.20%, 372.77MPa, 208.54MPa, 0.82, 0.32.

Lithium metasilicate/disilicate glass-ceramics (LMGC/LDGC) are attractive composite materials for all-ceramic dental restorations due to their promising strength and biocompatibility. However, their strong mechanical properties make it hard to machine with current dental chairside CAD/CAM-milling. The root cause is the unclarity of their mechanical behaviour under dynamic abrasive machining. This paper conducted single-diamond scratching experiments on LMGC and LDGC to extract the actual diamond grain-material contact in grinding to understand their ductile-brittle transition behaviour. Scanning electronic microscopy (SEM) observation was performed to identify the fully-ductile, ductile-brittle and fully-brittle regimes of the two studied materials. 3D laser confocal microscopy (LCM) was used to measure the critical cutting depths for these regimes. The critical cutting depths for fully-ductile and fully-brittle regimes are 89 nm and 133 nm for LMGC, and 209 nm and 428 nm for LDGC, respectively. These results provide an in-depth understanding of ductile-brittle transition behaviour of LMGC/LDGC under abrasive machining and a guidance for dental technicians to choose proper machining conditions for high-quality LDGC restorations.

The whole production process of 50W800 grade non-oriented silicon steel hot rolling-cold rolling-annealing was observed,and the influence of its composition,structure,impurities and other factors on the iron core loss of silicon steel was analyzed.The results can be summarized as follows that:(1)The iron core loss can be reduced by increasing the silicon content within a certain range.(2) After annealing,the crystal grains become larger and the crystal defects are reduced,thereby reducing the iron loss.(3)The iron core loss is reduced by reducing the content of elements such as carbon,nitrogen,and sulfur.(4) The strength of strip steel can be enhanced by adding trace elements.

Mg-2.4Nd-0.2Zn-0.5Zr-xY (x=0, 0.6, 1.2, 1.8wt.%) alloys were fabricated by a casting method, the microstructure and mechanical properties of as-cast alloys were investigated. The results demonstrate that the A, B, C and D alloys are composed mainly of α-Mg and Mg₁₂Nd phases. Phases containing Y were not formed, because trace amounts of Y element was completely dissolved into Mg matrix. The addition of Y was found to improve the mechanical properties of the alloys. The Mg-2.4Nd-0.2Zn-0.4Zr-1.8Y alloy exhibits the optimal mechanical properties in the as-cast condition, the maximum value of ultimate tensile strength, yield strength and elongation to failure were 192MPa, 168MPa and6.5%, respectively.

Under the heating condition, the grain of ultrafine grain steel will change with the increase of temperature, so that the microstructure and hardness of ultrafine grain steel will change, and even lose the original strength and toughness. In this paper, the grain growth behavior, microstructure and hardness of ultrafine grain steel under different heat treatment conditions were studied experimentally. The results showed that under different cooling methods, the faster the cooling speed was, the more the amount of low-carbon martensite and pearlite was. The hardness obtained by water cooling was the largest. The hardness decreased with the changes of water cooling, oil cooling, air cooling and furnace cooling. The higher the maximum heating temperature was, the coarser the grain became. For ultrafine grain steel, the maximum heating temperature of 1000 °C should not be used.

Under the background that the high-grade industrial wire rod such as cold heading steel is mainly developed in the first line of Shaoguan Iron and Steel Co., Ltd., the controlled rolling and controlled cooling process of ultra-low carbon cold heading steel ch1t is studied in this paper. A large number of high-temperature tensile tests for CH1T are carried out on Gleeble 3800 thermal simulation testing machine, and the high-temperature plastic characteristics of CH1T and stress-strain curves at different temperatures are obtained, At the same time, the transformation points Ac1, Ac3, Ar1 and Ar3 of ch1t steel and the dynamic CCT curve were measured, and the process improvement measures were formulated on the basis of experimental research. The field practice shows that the proposed process improvement measures have greatly improved the problem of low yield of ch1t cold heading steel in the first high line of Shaoguan Iron and Steel Co., and achieved remarkable economic benefits.

Al2O3 ceramic and 1A95 aluminum alloy vacuum brazed joints were prepared with Al-Si-Mg-La solder. The effects of brazing temperature on the structure and shear properties of brazed joints were studied, and the interface of the joints was analyzed. Studies have shown that the shear strength of Al2O3/Ag-Si-Mg-La/Al joints all show a trend of increasing first and then decreasing with the increase of brazing temperature and holding time; when the best brazing process is 590°C×20 min, the boundary between Al-Si-Mg-La solder and aluminum alloy disappears; the interface between Al2O3 ceramic and solder is well bonded, and the shear strength is 56.74MPa. The fracture form of the joint is brittle fracture. Under different brazing process parameters, the fracture position of the joint is mainly divided into two types: when the joint strength is low, the fracture occurs near the interface between the aluminum alloy and the brazing filler metal layer; when the joint strength is higher, the fracture occurs at the interface between the Al2O3 ceramic and the solder.

In this paper, based on the analysis of oxidized ore from a mine in Guangxi, the composition and content of elements and minerals, and the chemical composition of main minerals were studied by mineral liberation analyser method. The results show that the ore is a zinc-rich limonite, the content of the main mineral limonite is 47%, the majority of limonite is monomer, a few limonite is associated with clay, dolomite and so on, and cemented by clay. Zinc occurs mainly in the form of minerals such as smithsonite and hemimorphite, while a large amount of zinc occurs in limonite in the form of dispersion. The content of smithsonite is 8.73%, most of them are crust-like, colloidal ring-like, and are associated with limonite. The content of hemimorphite is 3%, most of them are single particle. This study will lay a mineralogical foundation for the follow-up development and utilization of this type of ore.

The microstructure evolution and mechanical properties of 65Si2CrVspring steel at 420 °C with different tempering time were studied in this paper. The results show that the extension of tempering holding time will make the martensite recover more fully, so as to transform into massive ferrite, and the precipitated carbide increases at the same time. With the extension of tempering holding time, the strength of the sample decreases gradually. When the tempering time exceeds 300s, the ratio of length and width of carbide decreases gradually, spheroidization occurs and plasticity decreases sharply. Excellent comprehensive properties were obtained when holding for 300s. The tensile strength was 2083MPa, the elongation was 8.3%, and the product of strength and plasticity was 17.28 GPa %.

In order to refine the precipitate and grain, the combination of melt spinning and spark plasma sintering were used to prepare Al-11La-6Mg alloy. The results show that melt spun ribbon consists of some coarse precipitates. After spark plasma sintering, there are dual-scale precipitates in the matrix. As a result, the alloy exhibits a high compressive strength of 933 MPa and strain of 34% at room temperature. Unfortunately, the strength, at 300°C, is inferior to as-cast sample due to the fine grain.

Despite the great promise of lead-based perovskite solar cells, their inherent toxicity and stability issues have hindered their practical applications in solar cells. Titanium(Ti)-based vacancy-ordered double perovskite Cs₂TiBr₆ was proposed as a non-toxic and stable substitute for lead-based perovskites. However, the efficiencies of the Cs₂TiBr₆ double perovskite solar cells currently have a maximum value of only 3.28%, which is still far below typical perovskite solar cells. Since the bulk defects inside the Cs₂TiBr₆ absorber layer are the main reason for degrading the performance of the Cs₂TiBr₆ double perovskite solar cell, it is worthwhile to investigate the bulk defect density in the absorber layer to optimize the performance of the Cs₂TiBr₆ double perovskite solar cell. In this work, we simulate the Cs₂TiBr₆ double perovskite solar cell with the FTO/SnO₂/Cs₂TiBr₆/PEDOT:PSS/Au structure by using SCAPS-1D simulation software. We investigate the effect of the bulk defect density in the Cs₂TiBr₆ absorber layer for the performance of the Cs₂TiBr₆ double perovskite solar cell. The conclusion is that there is a threshold value for the bulk defect density in the Cs₂TiBr₆ double perovskite solar cell. Moreover, we obtain an optimal efficiency of 9.97% in the Cs₂TiBr₆ double perovskite solar cell by optimizing the bulk defect density. Our numerical simulation results show that the Cs₂TiBr₆ double perovskite solar cell has excellent potential and appropriate defect passivation is conducive for improving its performance.

According to the shape and structural characteristics of an automotive interior plastic part, this paper has designed a large hot runner injection mold in accordance with the customers' layout requirement, i.e., one mold and two cavities. It then analyzes the mold filling, cooling, and weld lines via the software, Moldflow, and hence determines a reasonable pouring system; a side core pulling mechanism, "lifter block + square push bar", has been adopted for the large inverted part on the inner side of the plastic part, while a "lifter + insert" is organized for the two bayonet catches or inverted buckles on the inner side of the plastic part; the combination form of "ejector pin + lifter" has also been employed for the mold release system, with complicated mold structure. Practices prove that the mold structure is reasonable and reliable, and the production of plastic parts meet the quality requirements.

This paper takes the medium and low grade non-oriented electrical steel as the research object. Through the data analysis in the production process, the corresponding relationship between the Cr content and the electromagnetic properties of the non-oriented electrical steel was studied. The results show that with the increase of Cr content, the core loss increases and the magnetic induction decreases, thus the magnetic properties are directly proportional to Cr content.

In the present study, the 6061 alloy was chosen as base alloy, and micro-alloying effect of different ratios of Er and Zr (2:1, 1:1) on microstructure evolution and mechanical properties was examined after T6 heat treatment. Hot rolling deformation was carried out at 450°C, then a solution aging heat treatment process was adopted at 570°C/0.5h+180°C/5h. The precipitation, recrystallization behaviors were characterized using transmission electron microscopy(TEM), scanning electron microscope(SEM) and electron backscattered diffraction(EBSD) techniques, the mechanical properties were tested using tensile tests. The results shown that recrystallization behavior was inhibited by co-additions of Er and Zr. With the increase of Er and Zr content, the recrystallized grain size and coarse Fe-rich phases at the grain boundaries decreased, the recrystallized grain distributed uniformly, the number of needle-like Mg₂Si and granular Al₃(Er, Zr) phases gradually increased. In 6061 alloy with Er/Zr ratio of 1, the distribution of precipitates were finer and more uniform, The uniformly distributed Al₃(Er, Zr) phases pinned the grain boundaries, which effectively hindered the movement of grain boundaries. The tensile tests exhibited that the properties of 6061 alloy with Er/Zr ratio of 1 reached the highest level, i.e., tensile strength of 344.0MPa, the yield strength of 296.0MPa, and elongation of 17%.

CoCrFeNiX (X=Mn, Cu) high entropy alloys (HEAs) were prepared by powder metallurgy. The effects of milling time and milling speed on the microstructures and properties of CoCrFeNiX (X=Mn, Cu) HEAs were studied. The results show that at high rotational speed, the particle size of the HEA powders is refined and is tended to be uniform, and obvious solid solution phenomenon occurs; the microstructure of CoCrFeNiMn HEA is mainly composed of BCC solid solution, FCC solid solution and CoNiCr intermetallic compound; with the increase of ball milling time, Cr-rich phase and CoNiCr compound decrease. The microstructure of CoCrFeNiCu HEA is mainly composed of BCC solid solution and FCC solid solution; with the increase of ball milling time, Ni-rich FCC solid solution is gradually replaced by Co-rich and Ni-rich FCC solid solution. CoCrFeNiMn and CoCrFeNiCu HEAs have higher compressive strength, compression ratio and hardness, and they are 1300 Mpa and 1100 Mpa, 34% and 33%, 400 HV and 350 HV, respectively; The friction coefficient curve of CoCrFeNiMn HEA is more stable than that of CoCrFeNiCu HEA.

The color-separation of ceramic-tiles is still dominated by human eye discrimination in actual production. According to the actual production, this paper proposes a ceramic-tile color-separation framework based on few labeled data training, which can realize the color-separation of ceramic-tiles with complex patterns. Firstly, the image with ceramic-tile only is obtained by image pre-processing, then the features are extracted by histogram statistics under HSV color space in sub-regions, and finally the support vector machine model is trained to obtain the classifier using the features extracted from a small number of training data and this classifier is applied to the automatic color-separation of ceramic-tiles. Experimental results of simulation and Practical application have proven the effectiveness of the proposed method.

Nanoindentation method is suitable for testing the mechanical properties of micron scale grains to ensure the effect of the second phase. In this experiment, the relationships between hardness, elastic modulus and the work of 7075 aluminum alloy grains with different single wall carbon nanotubes content were investigated. The results show that grain size decreases with the increase of single wall carbon nanotubes(SWCNTs) content, and MgZn₂ and Al₂Cu can be found. Hardness, young's modulus and the elastic reverse deformation of 7075 aluminum alloy increase firstly with increasing single wall carbon nanotubes, and then decrease obviously with the further increase of single wall carbon nanotubes, while the mechanical work and the plastic deformation work of the alloy have an opposite trend. It can be conclude that the single-walled carbon nanotubes at the grain boundary obviously changed the strain.

In this paper, RST rheometer is used to test the rheological characteristics of fresh cement paste under different water-cement ratio and different shear rate, and quantitatively calculate the area of hysteresis loop and the destruction energy of flocculation structure.The microstructure of cement paste with different water-cement ratio was observed by Ultra depth of field optical microscope, and the microstructure pictures were processed by Image-J software,then quantify the quantity and size of cement congeries.It is found that the destruction energy of flocculation structure can quantitatively characterize the destruction degree of flocculation structure.Under the condition of the same shear rate, the larger the water-cement ratio, the smaller the hysteresis loop area, the smaller the destruction energy of flocculation structure, the increase of the number of aggregates in cement paste, the enhancement of dispersion and the reduction of aggregate size.The attachment strength of aggregates in cement paste is weakened, and the flocculation structure is more easily damaged. Under the same water-cement ratio, the smaller the shear rate, the smaller the destruction energy and the lower the destruction degree of flocculation structure.With the increase of shear rate, the destruction energy of flocculation structure increases.

The main purpose of this study is to investigate the influence of soil heterogeneity on the mechanical responses of rectangular plates resting on elastic foundations and to determine reasonable physical model parameters. The bending problem of rectangular thin plates lying on Gibson elastic foundations is solved using an iterative procedure. First, plates and foundations are discussed as a whole system, based on the principle of minimum potential energy. Second, the governing equations and boundary conditions for plates are established. And the equation for the attenuation parameter in the mathematical model is also derived. Then an iterative procedure is used to iterate the two parameters simultaneously, which solves a key issue for the two-parameter foundation model. Third, a double Fourier series with supplementary functions is adopted, and the solution to the bending problem is obtained. The agreements between the numerical results and the literature results prove that the refined model is practical and achievable. The proposed method exhibits a certain universality in analyzing the interactions between rectangular thin plates and elastic foundations. Furthermore, Gibson soil has an influence on the structural responses of rectangular plates on elastic foundations.

The load transfer systems of racks and nut columns are important components of the rack and pinion vertical shiplifts which bear the ship chambers and transfer the ship chamber loads in special cases to the tower columns. Aiming at exploring a design based calculation method for the nut column, racks and the associated second stage embedded parts, this paper proposes the double elastic foundation beam model for both the rack load transfer systems and nut column load transfer systems by which the formulas for describing the axial distribution of internal forces and deflections of the rack, column nut and the associated second stage embedded parts are derived. The calculation method is demonstrated by the description of the application in the Three-Gorges shiplift.

The wheel load of the vehicle acting on the bridge expansion joint is a kind of dynamic load, and its impact coefficient needs to be determined, so as to provide basic design parameters for the bridge expansion joint. In this paper, the scale model of the bridge and the vehicle is designed and constructed, and the experimental study of vehicle model passing through bridge model is carried out. In the experiment, the wheel impact load of the vehicle on the bridge expansion joint is measured, and the impact coefficient of the wheel load is calculated. The measured results show that the greater the vehicle speed, the greater the impact load of the wheel on the expansion joint, that is, the greater the impact coefficient. The larger the width of the gap in the expansion joint, the greater the impact load and impact coefficient of the wheel on the expansion joint. The greater the mass of the vehicle, the longer the contact length between the wheel and the road surface, which reduces the impact effect and the impact coefficient of the wheel load on the expansion joint. The maximum impact coefficient of wheel load is greater than the design value in the Chinese bridge code, i.e. 0.45, even greater than that in the American bridge code, i.e. 0.75.

The pavement skid resistance condition of expressway has an important impact on driving safety. With the increase of service life, the pavement skid resistance condition decreases year by year, and an accurate prediction model is of great significance to improve the level of traffic safety. Firstly, the improved GM (1, 1) model and support vector machine regression model are established, and then the two are combined by entropy weight method to obtain the GM-SVR prediction model. In this paper, the skidding resistance index (SRI) of a certain section of Lezi expressway for limited years (2016, 2018 and 2020) is used as the basic data to predict the SRI values in 2021 and 2022. In order to verify the accuracy of the model, the pavement condition index (PCI) of the same road section in 2013, 2015 and 2017 are used as the basic data to predict the PCI values in 2018 and 2019; Taking MAE, MSE and MAPE as test indicators, the predicted values and measured values in 2018 and 2019 are compared and analyzed to test the prediction accuracy.

Standard or steam curing is generally used in the production of ultra-high performance concrete (UHPC), which puts forward higher hardware conditions for the production of this material. In order to promote the popularization and application of UHPC, it is necessary to explore its fabrication method under natural curing, that is, without accurate control of temperature and humidity. The research method used in this paper is experimental analysis. By adjusting the components of UHPC materials, adjusting the proportion of each component, humidifying with watering and other simple measures, the methods to improve the strength of UHPC under natural curing conditions are explored. The experimental results show that the addition of high-efficiency solid water reducer can make the UHPC blocks have higher compressive strength than liquid water reducer. When the ratio of silica fume to cement is 30%, the compressive strength of UHPC reaches the maximum. Reducing or increasing the silica fume will reduce the strength of UHPC. Humidification by simple watering can be used to improve the compressive strength of UHPC. UHPC with strength over 100MPa can still be obtained under natural curing condition.

In order to evaluate the influence of heavy vehicles vibration on precision instruments in a proposed experimental building, the three-dimensional environmental vibration induced by heavy vehicles was measured in a soft soil site. Combined with continuous wavelet transform and 1/3 octave frequency vibration level, the vibration transferring characteristics of the construction site were analyzed, and the Z vibration level of the site was tested. The results are as follows: (1) Vertical vibration is the main vibration; (2) The predominant frequency of soil layer is 4 Hz, and the excitation frequency of vehicles is 5 ~ 20 Hz; (3) With the increase of vibration source distance, the high frequency vibration is greatly attenuated, while the low frequency vibration is amplified; (4) The amplitude of heavy vehicles is about 3 ~ 5 times of the small cars; (5) The environmental vibration produced by the vehicles exceeds the vibration standard of the normal use of the instruments, necessary vibration reduction and isolation measures should be taken.

Due to the application of reinforced anchor technology in soil reinforcement, the anchor after long-term use will have serious corrosion, which greatly affects the safety of the engineering structure, leading to engineering accidents. In this paper, GFRP (Glass Fiber Reinforced Polymer) anchor is used instead of reinforced bolt for the pull-out experiment. In order to investigate the deformation of the soil around the GFRP anchor solid in the process of drawing, this paper improves the traditional indoor model pull-out experiment of GFRP anchor and introduces PIV (Particle Image Velocimetry) technology and its application to the analysis of soil deformation in the process of drawing.

L-type horizontal well has became a new well type for CBM development in Qinshui Basin, And the staged fracturing technique of horizontal well is the key technology to improve gas production of single well for coalbed gas. At present, the main fracturing technology of horizontal well is the fracturing technology of tubing carrying a packer at the bottom, and daily gas production of it exceed 10000 cubic meters in Zhengzhuang with ultra-low permeability. And the average daily gas production of a well is more than 6000 cubic meters. In recent years, we have gradually explored different fracturing technologies, containing plug-perforation joint fracturing, coiled tubing fracturing and staged fracturing of spray gun with expanding diameter. Taking the L-type horizontal wells of the casing fracturing in Qinnan as the research object, the adaptability analysis and the evaluation of development effect of four fracturing technologies, including the fracturing of common tubing carrying a packer at the bottom, the fracturing of spray gun with expanding diameter, plug-perforation joint fracturing and coiled tubing fracturing, are carried out. The analysis results show that the fracturing technology of tubing carrying a single packer at the bottom has the advantages of simplicity, low price and good effect on development, which can be used as the main technology of the L-type horizontal wells of the casing fracturing.

In order to obtain the natural frequencies and vibration modes of the rectangular storage tanks under liquid-filled state, open anchorage rectangular storage tank models of 1000 m³ are established and the dynamic characteristics analysis is carried out. Considering the influence of wall thickness(t), liquid storage level(h) and other factors on the natural frequencies and vibration modes of the models under static state, the finite element analysis models of rectangular tanks with different parameters are established, and different natural vibration frequencies are compared and analyzed. The results show that the natural vibration frequencies of the structure increase with the increasing of the thickness of the tank wall and the bottom plate. The liquid storage level is negatively correlated with the tank-liquid coupling vibration frequency. The natural vibration frequencies of the tank decrease with the increasing of the liquid storage level.

Two porous carbon materials were prepared from vacuum residue using the hard template method to construct high-performance dual-carbon lithium-ion capacitors. The results show that the mixture of vacuum residue for removing toluene insoluble matter and sodium citrate were subjected to aerobic rapid polycondensation, and the vacuum residue after polycondensation was heated at 700 °C to obtain ZYC-7 porous carbon with a specific surface area of about 181 m² g^-1. The ZYC-7 was further etched by KOH under 700 °C to obtain ZYCK-7 super porous carbon with a specific surface area than 997 m² g^-1. The ZYC-7 porous carbon exhibited a specific capacity of 600 and 300 mA h g^-1 at a current density of 0.1 and 2.0A g^-1, under 0-3 V vs. Li+/Li, while the ZYCK-7 super porous carbon revealed a specific capacity of more than 70 mA h g^-1 at a current density of 1.0 A g^-1 under 2.0-4.3 V vs. Li⁺/Li; The ZYC-7 and ZYCK-7 were assembled into a double-carbon lithium-ion capacitor with an energy density higher than 55 Wh kg^-1 at a power density of 10 kW Kg^-1, and its capacity retention rate was still greater than 85% after 3000 cycles of charge and discharge at a current density of 1.0 A g^-1.

This paper introduces the heating measures in the process of crude oil exploitation and transportation, meanwhile, it puts forward several process modes of solar heating technology, and illustrates the system principle and operation process of solar heating transportation of crude oil through actual cases, which opens up a new idea for the application of new energy technology in the petroleum industry and is conducive to the further promotion and application of new energy technology.

In order to analyze and evaluate the influence of ship vibration on the performance of proton exchange membrane fuel cell (PEMFC), firstly, the frequency domain and amplitude distribution characteristics of ship vibration are studied. Based on the general PEMFC simulation mathematical model, a boundary condition, loading method based on sliding grid technology (ZM-UDF) is proposed to establish the technical route of numerical simulation of PEMFC influence relationship on ship vibration performance. Secondly, in the full solution domain of ship vibration, a numerical simulation scheme is designed to study the influence of ship vibration direction, frequency and amplitude on the performance of proton exchange membrane fuel cell (PEMFC). Through simulation calculation, the performance database of ship vibration-proton exchange membrane fuel cell is constructed. Furthermore, the linear programming model of simulation data is established by using the difference- piecewise fitting method, and a prediction map construction method of ship vibration proton exchange membrane fuel cell performance characterization based on numerical simulation data is proposed. The performance prediction map of ship vibration proton exchange membrane fuel cell is drawn and verified by simulation.

When an air source heat pump is used in a low temperature and high humidity area, frost on the surface of an outdoor heat exchanger will lead to the decrease of the heating performance of a whole unit. So periodically defrosting is very necessary. However, when the commonly used reverse cycle defrosting method is applied, the unit stop heating indoor and the temperature will drop. In this paper, the method of spraying solution with low freezing point is used to defrost in order to ensure the normal operation of the unit and provide continuous heat supply. The results show that the continuous heat supply can be provided during the defrosting process and the working unit doesn't need to be stopped. Moreover, exhaust pressure of the prototype compressor is more than 3.0 MPa, while air outlet temperature of the indoor unit is more than 40°C. And the heat capacity of the unit is over 2000W, which enhances indoor thermal comfort. In addition, the influence of different outdoor ambient temperature on the performance of the air source heat pump is studied when the spray defrosting is in progress. It is found that the lower the outdoor ambient temperature is, the lower the heat capacity and COP of the unit will be.

The Supercritical carbon dioxide (S-CO₂) Brayton cycle can be used to recover the exhaust heat energy of marine diesel engines. The hybrid heat exchanger is one of the potential solutions for heat exchange between flue gas and S-CO₂, but there is no good design theory and design method at present. The traditional hybrid heat exchanger has an one-to-one correspondence between the fin and the etched plate. However, under special requirements, it is necessary to insert etched plates in the hybrid heat exchanger to improve the thermalhydraulic characteristics. In this study, four CFD models of the hybrid heat exchangers with interpolated etched plates were established. When the total mass flow rate and the total mass velocity are constant, the thermalhydraulic characteristics of the hybrid heat exchanger are analyzed by Fluent. The results show that regardless of the constant mass flow rate or the constant mass velocity, inserting etched channels into the hybrid heat exchanger will increase the total heat transfer coefficient. When the total mass flow rate of the cold and hot fluids is unchanged, the heat transfer coefficient and pressure drop of the etched channel decrease with the increase of the inserted etched channel. When the total mass velocity of the hybrid heat exchanger is unchanged, the insertion of the etched channel causes the pressure drop and the convective heat transfer coefficient of the fin channel to increase. Meanwhile, the pressure drop and convective heat transfer coefficient of the etched channels are reduced, but the total heat transfer coefficient is increased. The study can provide guidance for the design of the hybrid heat exchangers.

Titanium welded tubes are widely used in condensers and heat exchangers of coastal power plants because of their excellent manufacturing properties and seawater corrosion resistance. In this paper, the leakage analysis of titanium welded tubes of condensers in nuclear power plants that after 4 years of service is carried out, and experimental studies such as morphology analysis, chemical composition analysis, hardness test, metallographic examination, mechanical properties test, and scanning electron microscope analysis are conducted. The results show that the cracks initiated at the maximum vibration amplitude of the titanium welded tube and gradually expanded in a fatigue method. Large vibration of the titanium welded tube is the main cause of the leakage.

In order to explore the influence of ultrasonic surface rolling process (USRP) parameters on 45 steel surface integrity, the significance of static pressure, amplitude, feed rate and rolling times on rolling effect was analyzed. The grey relational degree of the comprehensive index of surface integrity after USRP was obtained by orthogonal test and grey relational analysis, and the optimal combination of process parameters was obtained. The feasibility of process parameter optimization was verified by experiments. The results show that the significant influence of USRP parameters on 45 steel workpiece surface integrity was as follows: rolling times> feed speed> static pressure> amplitude. The optimal process parameters are rotational rolling times 9 times, feed speed 3200 mm⋅min^-1, static pressure 300 N and amplitude 6 μm. Under the optimum combination of process parameters, the surface roughness decreases by 70.8 %. The surface hardness and the surface residual compressive stress increase by 16.5 % and 134 % respectively compared with the surface performance parameters of the material before rolling.

BIM technology is rapidly and profoundly affecting all fields of bridge construction. How to apply BIM technology to reinforcement calculation of arbitrary components is a problem worthy of study. Based on Dassault Systems 3DEXPERIENCE R2018X, this paper successfully solves the problem of strength calculation of arbitrary section of reinforced concrete members by means of analytic method, iterative method and graphical method, applying the principle of material mechanics, and compiles the program of strength calculation of arbitrary section of allowable stress method under Dassault 3DE platform.

Resonator is the core structure of hemispherical resonator gyro (HRG), and its vibration characteristics play an important role in the output accuracy of gyro. A method combining dynamics model and finite element method (FEM) is proposed to study vibration characteristics of resonator. Firstly, this paper established dynamics equations of ideal resonator and dynamics equations of resonator with density distributed nonuniformity, and gave the mathematical expression of frequency split. Then, accomplished modal analysis and obtained natural frequency, mode shapes of resonator based on ANSYS Workbench. Finally, established the resonator model in consideration of density distributed nonuniformity by FEM, and investigated the influnce of the 4^th harmonic of density nonuniformity on resonator's frequency split. The finite element analysis was in good agreement with the results calculated by dynamics equations, which verified the accuracy of dynamics model.

Electron beam selective melting is a metal additive manufacturing technology, through electron beam scanning, melting powder materials, layer-by-layer deposition to manufacture three-dimensional metal parts, suitable for the forming and manufacturing of refractory, high-performance metal materials such as titanium alloys and titanium-aluminum-based alloys. Because it can form high-performance metal parts with complex shapes, it has broad application prospects in aerospace, biomedical, automobile manufacturing and other fields. This article summarizes the principles, compares the advantages of selective melting with laser, shows the modern application of the technology, and points out the current technical difficulties and future development direction.

In this article, Ansys workbench is used to perform mechanical simulation on the undetermined layout of the zero point system, and the difference between the layout and quantity of the different points of the connecting pins is analyzed, and the best layout is selected as the outer ring square (side length is 760). The inner circle is distributed in an equilateral triangle (side length is 250).

With 5G, industrial connectivity and cloud computing going deep into the manufacturing development process, it is particularly important to improve the quality and efficiency of the manufacturing industry. This paper constructs the evaluation index system of manufacturing capacity from four aspects: efficiency creation capability, scientific and technological innovation capability, product distribution capability and information service capability, and constructs the manufacturing capability evaluation model based on AHP-Entropy-TOPSIS to analyze the development of manufacturing capacity in various provinces under digital and intelligent transformation. The results show that since the proposal of "Made in China 2025", the manufacturing capacity of each region has generally increased, and the innovation ability and information ability of the regions with higher grades are obviously ranked higher. We suggest that all provinces should correctly handle the relationship between government and market in the development of science and technology, establish intelligent manufacturing benchmark enterprises in various industries, pay attention to innovation subjects, and promote regional informatization development.

To study the segregation of burden distribution during the hopper discharging process of bell-less top system with two parallel hoppers, a 1:1 model of the bell less top system with two parallel hoppers of 5500 m³ blast furnace was established, and the influence of rotating chute structure, and central throat diameter on the falling point radius was also studied. From the experimental results, it can be concluded that the distribution of the inner and outer falling point radius of burden in the circumferential direction of throat is not uniform, and the segregation of the falling point radius of burden can effectively reduce by using the rectangular rotating chute. The outer falling point radius of burden is almost same when the central throat tube diameter is 650 mm and 730 mm, and the inner falling point radius of burden when the central throat tube diameter is 650 mm is smaller than that when the central throat tube diameter is 730 mm.

Taking the Euler Beam as the research object, the finite element models of beam structure under five support conditions, using solid elements, shell elements and beam elements respectively, are established for considering the influence of different boundary conditions. Based on the eigenvalue method, the first three natural frequencies of the beam structure under five kinds of support conditions are calculated. Through the contrast analysis of the theoretical value and simulation value, the most reasonable simulation constraints are given for different element types. Also, the selecting rules of the element numbers and element types for the Euler Beam are offered which provide the reference and basis for the beam structure modal calculation.

In this study, the effect of ultrasonic vibration on the surface quality of ZTM ceramic material grinding was carried out. The surface roughness characteristics of ZTM ceramics obtained by ultrasonic grinding and ordinary processing were compared, and the effects of abrasive grain size, table speed, grinding wheel speed, grinding depth and ultrasonic grinding processing methods on the surface quality of ceramic materials were studied. The linear speed of the grinding wheel and the grinding depth have close effects on the grinding surface roughness of ZTM ceramic materials. Ultrasonic grinding has a positive effect on the surface of ZTM ceramic processing, but it needs to be processed with a lower particle size grinding wheel to obtain a better improvement effect.

Cyber-Physical System (CPS) serves the key to realize smart manufacturing, while Digital Twin (DT) acts as the key to realize CPS. The evolving and maturing Digital Twin concept has several inherent shortfalls. In this paper, a new RSDM model enabled by Digital Twin is proposed to address these problems with iterative design optimization and efficient design knowledge management. The results show that RSDM model is helpful for enhancing radar structure design efficiency and design optimization, and is a promising framework for implementing smart design.

With the goal of increasing the coverage of wireless sensor network nodes and reducing node deployment time, a model of wireless sensor network node deployment based on fuzzy data fusion is designed. According to the wireless sensor network structure, the communication range and communication radius of the node are determined, so as to obtain the coverage of the node. Establishing a wireless sensor network coverage perception model to obtain the perception probability and joint perception probability of the target point. Finally, through fuzzy data fusion and fuzzy fusion rules, the fusion of the target node is realized, and the judgment criterion is obtained, and the deployment of the wireless sensor network node is finally completed under constraints. Experimental results show that this method effectively improves node coverage and reduces node deployment time, indicating that this method is beneficial to enhance the perception quality of wireless sensor networks.

Isothermal compression experiments of 2050 AL-Li alloy were carried out by Gleeble-3800 thermal-mechanical simulator. Hot compression deformation behavior of the alloy under the conditions of deformation temperature of 300~500 °C and strain rate of 0.01~10 s^-1 was studied. The constitutive model of thermal deformation was established. Results indicate that there is an obvious rheological steady state in the isothermal compression process of 2050 aluminum alloy. The microstructure shows that the alloy has recrystallization. 2050 aluminum alloy is a positive strain rate sensitive material. At constant temperature, the steady state flow stress increases with the increase of strain rate. Arrhenius constitutive model can accurately predict the rheological behavior of 2050 aluminum alloy. The average absolute relative error (AARE) of the relative error between the experimental value and the predicted value is 8.59%.

As an important part of the microfluidic system, the microfluidic channel is a key factor to improve the microfluidic performance. The glass microfluidic channel has huge application potential in the fields of medical diagnosis, biochemical analysis and microelectromechanical systems. The micro-channel was ground on the surface of quartz glass by micro-grinding machining. The micro-ground micro-channel with different depths ranged from 80 μm to 200 μm were obtained. The influences of the machining depth and liquid flow rate on flow characteristics of micro-channel were investigated. The experimental results show that when the flow velocity was less than 2.5 m/s, the flow characteristics of the micro-channel first decreased and then increased with the increasing machining depth. When the flow velocity was greater than 2.5 m/s, it decreased as the increased depth.

The many to one communication mode of clustered sensor network is prone to information transmission interference, which leads to network data transmission congestion, resulting in frequent network dynamic changes and resource constraints. In order to solve the above problems, this paper proposes a congestion control method based on T-S fuzzy model for Clustered Sensor Network, so as to achieve reasonable control and processing of massive data in the congested network environment.Based on the analysis of the characteristics of clustering sensor networks, this paper describes the strategies of congestion detection and congestion avoidance, and focuses on the introduction and analysis of typical congestion relief algorithms based on rate control, traffic scheduling and transmission scheduling. Finally, the development trend of congestion control technology is prospected. Experiments show that clustering based on T-S fuzzy model is feasible The congestion control method of sensor network has high control effect in the practical application process, and fully meets the research requirements.

In order to make up for the deficiency of liquid-liquid annular flow generator in microfluidic devices, IASE method is used to innovate the annular flow generator in microfluidic devices, and a feasible scheme is proposed, which meets the functional requirements of the annular flow generator in microfluidic devices and generates stable annular flow; Fluent software is used to analyze and compare the VOF model of the two schemes; Through their pressure, flow velocity and flow state screening, the device structure that meets the requirements is selected. This paper summarizes a flow channel structure of L-type flow channel and coaxial flow channel in series. This structure can generate stable annular flow pattern and is easy to manufacture, which is suitable for the requirements of microfluidic equipment manufacturing at present.

According to the characteristics of small thickness, low rigidity and easy deformation for the thin-walled structure of flexible joint, the geometric and material constitutive models of flexible joint Thin-walled structure based on the ABAQUS software were established. And the numerical simulation and data analysis were carried out through the orthogonal experiment method. The influence of different cutting parameters on the cutting characteristics of Thin-walled structures was discussed. The prediction model of deformation is consistent with the cutting parameters of the Thin-walled structure. Experiments results show that the most considerable deformation of the Thin-walled structure was not the thinnest point of the Thin-walled structure, but the place where close to the Thin-walled structure in the thin-wall processing direction. This model provides the foundation for cutting process simulation and process optimization.

The profile equation of disc cam with translation flat-face follower is derived, the motion fidelity analysis is carried out, and the minimum size range of flat-face is deduced based on the rotation transformation tensor and meshing principle. The coordinate data of cam profile point is calculated by VC++, and the cam modeling and mechanism assembly are carried out with Creo software. The kinematics simulation analysis is completed, and the displacement, velocity and displacement of follower are obtained. The simulation analysis verifies the correctness of the design method, and the research has practical significance for the design of the disc cam with translation flat-face follower.

At present, numerous studies on surface topography prediction models for plane workpieces have been performed at home and abroad. Given the complexity of curved surface models (especially free-form surfaces that cannot be expressed in analytic formulas), prediction models for the surface topography of free-form surfaces are rarely studied. This paper aims to establish and simulate a 3D surface topography model of ball-end milling for all types of curved surfaces, including simple surfaces and free-form surfaces. The dynamic factors influencing the surface topography, such as the spindle runout initial phase angle, runout amplitude, axial drift initial phase angle, and axial drift amplitude are considered in this model. Moreover, some processing parameters influencing the surface topography, such as cutter tooth number, machining inclination, radial cutting depth, feeding frequency and feed per tooth are also considered in this model. The simulation results can be used to optimize the milling process of the actual free-form surface to improve workpiece surface quality or to predict the surface topography of the given machining parameters.

Metal bellows have been widely used as expansion joints to absorb expansions and contractions in many engineering applications from the start of the century. In conventional metal bellows forming process, the main disadvantages are high cost of tooling required and lack of flexibility. To avoid the disadvantage, this study presents a new metal bellows forming process using water jet incremental forming technology. In this paper, the incremental forming method of high-pressure water jet is used to study the forming technology of bellows.

During the grinding process of the impact and abrasion actions synchronously coexist and continuously occur, the two actions may exert forces in different areas and transform to each other periodically. So it is difficult to characterize the respective crushing characteristics of the impact and abrasion actions. Based on the kinematics theory of grinding media, to ensure the grinding medium to be in cascading motion state in which minerals are crushed by only abrasion action of medium, to investigate the crushing characteristics of three kinds of minerals of quartz, pyrrhotite, and pyrite. Moreover, the difference in the ability to resist the crushing in the grinding process and the influence of feed sizes on the crushing were investigated by analyzing and comparing the breakage rate of the different minerals and the yield of specific product size - t₁₀ value under different test conditions. The research results indicated that the grinding resistance of quartz is the strongest, followed by pyrite and pyrrhotite. Besides, a smaller feed size resulted in a more grinding and crushing effect on the minerals. Therefore, during production, the grinding system should be adjusted according to the change in the material property to prevent over-grinding.

Hybrid excitation motor has two excitation sources: electric excitation and permanent magnet excitation. It has the advantages of convenient air gap magnetic field adjustment, high power density, wide voltage and speed adjustment range, etc. It has broad application prospects in industrial drive, new energy power generation and aerospace fields. Based on the magnetic adjustment principle of hybrid excitation motor, this paper summarizes the existing main classification methods and gives the equivalent magnetic circuit diagram. According to that coupling relationship between the permanent magnet magnetic circuit and the electric excitation magnetic circuit, the hybrid excitation motor is divided into series type, parallel type and parallel type, and further classified into stator main body type, rotor main body type and average type according to the placement position of the permanent magnet and the excitation winding. The typical motor structure and magnetic circuit characteristics are introduced.

According to the structural characteristics of the radiator, two different gate structures were designed. The filling process of metal liquid in different gate structures was simulated by using the simulation software FLOW-3D, the size and location of possible defects in die casting were predicted, and the best design scheme of gate and overflow trough was put forward. The results show that under the conditions of pouring temperature of 680°C, preheating temperature of mold of 220°C and pouring speed of 60m/s, the most reasonable design scheme is that the whole casting can be filled with molten metal evenly and the concentration of surface defects is low.

This paper proposes an identification method based on ensemble empirical mode decomposition (EEMD) and Hilbert transform. The main procedures are: First, the system responses of an n degrees of freedom (DOFs) system are decomposed into intrinsic mode functions (IMFs) and residues by EEMD. The obtained ensemble mean IMFs and residues are then analysed by the Hilbert Transform to form the corresponding analytical signals. Second, the analytical signals of the n IMFs and the residue of each system response of each DOF are added to form a new analytical response. Third, the system equation of motion is rewritten into complex matrix equations for parameter identification. Numerical simulations are carried out on multi-DOFs systems with varying system parameters to demonstrate good robustness, effectiveness and accuracy of the proposed method, which attempts to offer a new means to study identification for linear time variant systems.

Digital twin technology is widely used, and all industries can improve the level of science and technology through digital twin technology to a certain extent, especially production enterprises. Through the digital twin technology, the physical model is fully used to build the 3d digital model of real production line data, and the function of online management and control of physical entities through virtual entities is realized. Based on the concept of digital twin, this paper puts forward a digital twin system which can be applied in flexible packaging production workshop, which is of positive significance to improve the industrial production efficiency.

The macroscopic transport behavior inside the tundish simultaneously adopting electromagnetic weir and dam were investigated via a 3D computational fluid dynamics modeling. Results showed that the flow pattern of molten steel can be effectively controlled by local electromagnetic brake force to replace the conventional weir and dam made of refractory in the given tundish. The increases of magnetic intensities for both the electromagnetic weir and dam within the range of 0.05~0.35 T are conductive to the reduction of dead volume fraction and the increases of plug volume fraction and residence time of molten steel in the tundish. The recommended values of magnetic intensities in both the electromagnetic weir and dam zones are 0.3 T owing to that the changes for all RTD characteristics tend to moderate when further increasing the magnetic intensity. This work will provide a pertinent advice on designing electromagnetic weir and dam for the tundish to gain a desire flow pattern without physical flow control devices.

In order to analyse the influence of the soft reduction of secondary cooling zone on the flow field of molten steel in the mold and the secondary cooling zone, a three-dimensional model including the submerged entry nozzle, the mold and the secondary cooling zone was established. The influence of the soft reduction of secondary cooling zone on the flow characteristics and the fluctuation of free surface in the mold and the secondary cooling zone is analyzed. The results show that: (1) There are two vortex regions in the mold and the secondary cooling zone, which are above and below the nozzle jet. Compared with the slab thickness of 52 mm, the vortex area above and below the nozzle jet is larger when the slab thickness is 72 mm.

Based on the orthogonal experiment of laser cladding technology on the surface of aluminum alloy, the effect of powder type, laser power, spot diameter and scanning speed on the surface hardness of laser cladding process on aluminum alloy surface was studied using genetic algorithm back-propagation neural network (GA-BPNN), and the process parameters of the laser cladding process test on the aluminum alloy surface were optimized, and the surface hardness under various process parameters was predicted. The predicted results are in good agreement with the actual test results, and the errors are all less than 1%. The results show that the optimal combination of surface hardness influencing parameters is not unique, and this result is closer to the actual production requirements. In addition, no matter whether it is the optimal or various surface hardness predictions, the proposed optimal prediction method can obtain representative results. This paper provides a new method for the selection of the best process scheme for laser cladding of aluminum alloy surface.

Solar cell is a kind of energy conversion device that converts solar energy directly into electric energy and has received a lot of attention in the past decades. Here, we summarize the latest progress in the field of solar cells. Firstly, the working principle and device structure of solar cells are introduced. Then it introduces the four most representative solar cells, which are silicon-based solar cells, copper indium gallium selenium thin film solar cells, organic solar cells, perovskite solar cells, and summarizes the advantages and challenges of these four types of solar cells. Finally, we summarized the preparation method of solar cells. We hope that we can help people to understand this field and invest in the research and development of solar cell materials and devices.

Photoelectric devices based on various theories and effects of photoelectricity have become the basic devices of human's life, and are still a hot research field. Lateral photovoltaic effect (LPE), among significant photovoltaic mechanisms, exhibits a phenomenon in which the surface potential difference of a specific material system changes linearly with the incident laser position. Depending on this unique property, LPE has been extensively developed in position sensitive detectors (PSDs). The material and theoretical systems of LPE were constantly innovated with the emergence and continuous progress of nanotechnology and new materials. This article reviews the recent progress of LPE theory, e.g., P-N junction model and the theories based on Schottky barrier, Dambet effect, and diffusion. Meanwhile, material systems that contribute to LPE, including metal-semiconductors (MS), metal-oxide-Semiconductors (MOS), metal oxide, perovskites and organic semiconductors, are summarized as well. As an important tunning method, local surface plasmon resonance is also concerned together with some promising future of the material systems.

Based on the actual situation of a university dormitory building, this paper uses CIBSE GUIDE D to evaluate its elevator system, conducts a quantitative analysis of the elevator selection and configuration of the building, and optimizes the elevator selection and configuration plan of the building to improve the level of building automation and intelligence.

With the widespread application of BIM technology in highway engineering, the practice of coding asphalt pavement diseases and integrating it with BIM models in the highway management and maintenance stage can contribute to the clarity of data collection and source-tracing of the disease and strengthening the circulation of disease data in the whole life cycle of highway engineering. This paper compares the coding methods of construction and infrastructure coding at home and abroad, and identifies the disease of asphalt pavement according to existing norms and clarifies the rules for formulating disease coding in the aim of producing a unified coding method of asphalt pavement disease. At the same time, based on the establishment of the disease model, the coding information is integrated with the BIM model to fill in the gaps in the coding work in the management and maintenance of highway engineering to improve the circulation of code-integrated BIM disease model in the maintenance phase.

In view of the randomness and fluctuation characteristics of railway settlement deformation, an unbiased grey model based on Markov optimization was established to predict railway settlement deformation.On the basis of unbiased optimization of the grey model, Markov correction is carried out to improve the prediction accuracy.Through the measured data of the settlement deformation of a high-speed railway, the prediction results of the model presented in this paper are compared with those of the grey model and the regression model, and the model presented in this paper has higher prediction accuracy and stability.

Global demand for livelihood buildings is still strong, and construction in the traditional way will continue to increase CO2 emissions. The COVID-19 epidemic has led to a shortage of construction personnel sent overseas, and the transformation of the construction industry to a mechanized, prefabricated and digital construction model will alleviate these problems. The paper will develop a low-cost, industrialized, integrated precast and decoration concrete volumetric modular integrated net zero carbon emission building technology mode based on the whole building life cycle evaluation method. This building module product has various functions of zero carbon building at the beginning of the design, and it constitutes zero carbon building after on-site assembly. This technical system has higher production efficiency and better process quality than cast-in-place concrete buildings, and reduces construction time, cost, waste, on-site safety risks, noise and dust. It is the best choice of concrete building to pre-fabricated pre-finished volumetric construction technology transformation, is the construction industry to help "Two carbon" climate goal to achieve one of the green technology path.

In order to determine the reasonable mechanic parameters of the damper on the passive energy dissipation structure, which combined with the basic principle of Chinese seismic design code and capability spectrum. It is important for the self-centering hydraulic damper to fully consider their additional stiffness and the additional damping ratio. Then determining the parameters and quantities of the damper through the performance limit of the story drift. In this paper, taking a six-story steel frame structure as an example. The damper parameters of passive energy structure are designed and the nonlinear response history analysis is used in the OpenSees. The calculation and example analysis shows that the performance-based seismic method is feasible.

Due to the long-term action of load, the material properties and structural shape of bridge structure will gradually change during service, resulting in the change of bearing capacity. In this paper, a calculation method of maximum bearing capacity is proposed for old steel arch bridges. The calculation method considers the material nonlinearity and geometric nonlinearity, as well as the residual deformation of the structure of the old bridge caused by the overload vehicle, collision of the vehicle and ship, resulting in the difference between the actual structure and the design drawing. Taking an 85 year old steel arch bridge in Ningbo as an example, the current material properties and the current configuration of the structure are actually tested, and the bearing capacity is calculated. The results show that: (1) The steel used in the bridge is well protected, and the properties of steel still meet the requirements; (2) For steel arch bridges, the deformation of arch ribs, especially the deformation out of plane, may greatly weaken the bearing capacity of the bridge; (3) It is necessary to consider the material nonlinearity and geometric nonlinearity for the calculation of the maximum bearing capacity of the old bridge.

A nonlinear finite element model of the circular concrete-filled steel tubular (CFST) member under lateral impact is established based on the existing drop weight tests, and the accuracy of numerical simulation is validated by comparing with the test results. Then the segmented numerical model of the circular CFST member is divided evenly to obtain the distribution of energy consumption along its length. The results indicate that the prime areas of energy consumption for the circular CFST member are distributed at the impact position (within 1/6 of the effective length) and the support position (within 1/12 of the effective length). On this basis, the affect of impact position on energy absorption distribution is carried out to reveal the changes of the prime areas of energy consumption. The results of this investigation can provide a reference for the impact resistant design and damage reinforcement of circular CFST members under lateral impact.

This paper mainly studies the law of the change of the internal force of the conductor and the climbing line with the number of rotation angles and the change of the jacking height during the construction process of the electric in-situ jacking of the transmission tower. First, the initial line type of the wire is calculated by the nodal line method to obtain the control point coordinates, and then the initial coordinates are repeatedly iterated through the Midas Civil finite element to obtain the final line type and the theory of the internal force change of the wire and the climbing line during the jacking process is calculated. law. Finally, combining the actual engineering case, the theoretical value and the actual value are compared and analyzed, and several conclusions are drawn.

This study explores the dynamic characteristics and the nonlinear wind-induced buffeting response of the bridge based on a six-tower cable-stayed bridge, the Jiashao Bridge. The effect of structural system characteristics (number of anchor piers and different conditions of longitudinal constraints) on the dynamic characteristics and the wind-induced buffeting performance of multi-tower cable-stayed bridges has been studied in detail. The analysis indicates that the different amounts of anchor piers have a limited effect on changing the overall stiffness of the bridge, but have an obvious effect on the buffeting displacement response of the side spans to which they belong. As for the condition of longitudinal constraints between the girder and towers, it mainly changes the vertical and transverse bending stiffness of the girder which means with the enhancement of the longitudinal constraints, the bending stiffness of the girder increases, and meanwhile significantly influence the transverse buffeting response of the girder.

Owing to that the anchor rod is easy to be cut through and maintains good mechanical properties, it is widely used in reinforcement engineering. In this paper, the performance of grouted mortar GFRP anchor rod was studied through laboratory experiments in terms of the ultimate pull-out resistance, stress change, bolt deformation, and surrounding soil deformation. The results showed that the pull-out force suddenly decreased when it reached the ultimate pull-out load, the displacement of the anchor head increased sharply, and the axial force on the anchor rod body decreased exponentially with the distance from the pulling point. Through these regulars, it can provide a theoretical basis for the application of anchor rods in the actual foundation pit engineering.

Relying on Yunliang River Bridge of Beijing-Harbin expressway reconstruction and expansion project, the pile-soil interaction model is established by using ABAQUS. Based on the sensitivity analysis of the vertical deformation, cross-bridge deformation and additional bending moment of the old pile under different design parameters such as pile diameter and pile length, the influence of different design parameters of the new pile foundation on the additional internal force and deformation of the old pile is studied, which provides a theoretical basis for the construction of bridge pile foundation in cold areas.

The elastic modulus adjustment procedures (EMAPs) can achieve much higher efficiency than incremental nonlinear finite element method (INFEM), however it could not take into account the stability effect on structures. In this paper, the elastic modulus reduction method (EMRM) was presented to estimate the stable bearing capacity of dumbbell-shaped concrete filled steel tube (CFST) arch. Firstly, the homogeneous generalized yield function (HGYF) was developed for dumbbell-shaped CFST members under combined action of axial force and bending moment by means of the fiber model technique, which was employed to determine the stable bearing capacity of these members. Secondly, the HGYF was adopted to define the element bearing ratio so that the EMRM was proposed for evaluating the stable bearing capacity of the dumbbell-shaped CFST arch by strategically reducing the elastic modulus of the highly stressed elements. Finally, results from the INFEM and test data of 3 dumbbell-shaped CFST arches and 30 dumbbell-shaped CFST members were adopted as examples to validate the proposed EMRM and the HGYF, which shows that the stability has a significant influence on the CFST arches and the proposed EMRM achieves higher accuracy and efficiency than the INFEM.

Taking a single-tower cable-stayed bridge as the engineering background, this paper simulates the cable replacement process of the bridge by finite element analysis method, and improves the structural stress state by optimizing the cable force. Combined with the construction technology of demolishing old cables and installing new cables, the force of stay cables is controlled. The results of construction control and load test are compared and analyzed. It is found that bridge structure is safely stressed in the construction process, with no excessive displacement for main girder and bridge tower. Furthermore, after the cable is replaced, the overall stiffness of the bridge is significantly improved, and the load-bearing capacity and reinforcement effect are increased.

Dynamic fingerprints of structures such as dynamic displacements, vibration patterns and frequencies are important parameters for structural health monitoring. In this paper, a structural damage identification method based on spatio-temporal sequence images is proposed for the shortcomings of traditional structural health monitoring systems such as high cost, discontinuous measurement points and mismatch between sensor lifetime and the lifetime of the structure itself, which uses a camera to collect the vibration information of the structure and adopts the optical flow method for spatio-temporal sequence The method uses a camera to capture the structural vibration information, adopts the optical flow method to track the dynamic displacement of the structure in the images, obtains the full-domain displacement, vibration pattern and frequency of the structure, and uses Python to compile a flexibility difference calculation program to locate the structural damage according to the flexibility difference after the structural damage. The method was experimentally studied on a cantilever beam structure. The results show that the dynamic characteristics of the structure obtained by using the method in this paper match the results of the numerical simulation, and the maximum error of the structural frequency is 2. 9%. The damage location of the structure (unit 9) can be precisely located according to the flexibility difference after damage. The method has the advantages of being convenient efficient, full information, low cost and non-contact, while its accuracy is comparable to that of the theoretical method, providing a new means of obtaining holographic dynamic properties of structures and locating structural damage.

In this paper with a practical project as an example of super-long basement, using structural analysis software MIDAS/Gen (2014) Chinese version, through the analysis of the temperature effect of indirect effect, analyze the super-long basement roof temperature stress of concrete structure, calculation of super-long structure under temperature influence of temperature stress, and according to the temperature stress calculation reinforcement, and the structure of the combination of action effects, to solve the temperature stress generated in the basement of super long concrete structure.

Recent demand for a longer span has complicated the dynamic behaviours in the strong wind. The limited amplitude but frequent occurred buffeting response of bridge affect fatigue resistance of the bridge, which should be considered. The time-domain buffeting response and fatigue performance of Yue yang Dongting Lake Suspension Bridge are realized by mixed programming with MATLAB and ANSYS. The gusty wind was simulated by the WAWS method, while the self-excited force was modelled as the elemental aeroelastic stiffness and damp matrices by the element Matrix 27. The mode superposition method was then adapted to calculate the buffeting response of the bridge in ANSYS, and its accuracy is verified by the results of the RMS and PSD using the traditional frequency-domain method. It was found that the fatigue life reliability of the suspender neat tower of the leeward side is 97.54% during the structure's service in the design wind speed.

Taking the main span of 716 meters mixed girder cable-stayed bridge (side mid-span ratio 0.251) as an example, the key technologies such as fully floating and semi-floating structure system, the position of steel-concrete combined section, and the use of thick slab concrete and iron sand concrete for side span weight are studied. The results show that :(1) As for the main girder, the bending moment at the column of the full-wave scheme is only 36.4% of that of the semi-wave scheme, and the bending moment of the stiffened girder in other areas is the same as that of the semi-wave scheme. In terms of main beam stiffness, there is little difference between full - floating scheme and semi-floating scheme. (2) In the completed bridge state, the longitudinal bending moment of the joint section located at the middle span is far greater than that of the side-span scheme, and the dead load bending moment distribution of the main girder is not ideal. Under the operation condition, the longitudinal bending moment of the main girder of the two schemes is roughly the same under live load. In terms of supporting reaction force, the joint section is located at the middle span, and the supporting reaction force of the auxiliary pier near the bridge tower is far greater than that of the side-span scheme. (3) The thick slab concrete design can not only ensure that the bridge and the construction state of the side span of the fulcrum are not negative reaction and under pressure, but also has no pressure to fix measures, simplify the construction process, convenient later inspection and maintenance.

The impacts of metakaolin and silica fume on the mechanical properties of fly ash based geopolymer mortars were discussed in this study. Fluidity, 3-d and 28-d flexural strength and compressive strength were tested, microstructures were also observed by Scanning Electron Microscope (SEM). studies concluded that the metakaolin contained geopolymer mortars has better mechanical properties and denser microstructures, but silica fume contained geopolymer mortars have an adverse situation, the addition of silica fume should be under 5% and the best addition need to be further studied.

The new grouting material is a kind of material which can realize rapid condensation at high w/c and has a broad development prospect in many engineering fields. In order to simulate the hydration process and predict the compressive strength, we establish the hydration model by using CEMHYD 3D program to simulate the hydration process. Based on the hydration simulation results, the strength prediction model was established by using the strength formula of "cement-air ratio". The results show that CEMHYD 3D program can be used to simulate the hydration reaction process of new grouting materials. The strength prediction model based on the hydration simulation results has high reliability with prediction error of less than 10%.

Aiming at the problem that there is no uniform requirement for the section height of the prefabricated concrete anti-collision wall, the critical height of the prefabricated concrete anti-collision wall during design and installation cannot be confirmed. The co-simulation method of LS-DYNA and Hypermesh is used based on the common anti-collision on the market. Five finite element models of concrete anti-collision walls with different heights and widths were established for the wall, and common cars were used to simulate their collisions. The three indicators of vehicle turning, seat position acceleration, and vehicle exit angle are selected to evaluate the anti-collision performance of the anti-collision wall. The research results show that increasing the height of the anti-collision wall can significantly increase the anti-collision performance of the anti-collision wall when the width of the anti-collision wall is constant and the position is fixed.

Compared with the traditional retaining wall, the Gabion retaining wall has the advantages of good flexibility, strong durability and high strength. In order to better promote the application of Gabion retaining wall in highway engineering, this paper analyses the structure of Gabion retaining wall, put forward the main requirements of common materials of Gabion cage and Gabion fillings; According to the different heights of Gabion retaining walls, the requirements of foundation bearing capacity are put forward. Common foundation treatment methods are proposed for soil, stone and mixed soil and stone foundation. At the same time, the foundation drainage should also meet the corresponding requirements. The research results have been demonstrated on a highway in Guangdong province with good results.

For bridges crossing active fault, combined with relevant standards and recent research results, the seismic conceptual design such as bridge axis trend planning, bridge type selection, fault trace avoidance distance of substructure, fault span and lap length are systematically summarized; some suggestions on seismic analysis methods such as the value of horizontal and vertical acceleration response spectrum, the generation of ground motion acceleration and displacement time history, and the input mode of time history are put forward.

In recent years, rectangular pipe jacking technology has been gradually applied in urban underground engineering. Based on a parallel rectangular pipe jacking project, a three-dimensional finite element model is established for numerical analysis, and the surface settlement caused by rectangular pipe jacking construction is studied. The research shows that the pipe jacking construction has the most obvious impact on the soil above the pipe jacking axis, and when the clear distance between parallel rectangular pipe is 1D (D indicates the pipe inner width), the main influence range of pipe jacking construction on soil mass is about 1D along the longitudinal direction of pipe jacking. With the increase of parallel rectangular pipe distance, the surface settlement trough becomes wider and the maximum surface settlement decreases. The main influence range of parallel rectangular pipe jacking construction at the outside of the pipe jacking is about 1D~1.37D along the lateral direction. When the pipe distance is greater than 2D, the interaction between parallel pipe jacking is weak, and the influence range at the outside of pipe jacking is almost the same as that of single pipe jacking construction. The research results can provide a reference for the design and construction of similar pipe jacking projects.

Typical dual capacity tank level control systems suffer from long control regulation times, large nonlinear output deviations and hysteresis. Facing with this situation, an optimization of multi-parameter control of PID controller using particle swarm algorithm (PSO) is proposed to reduce the overshoot phenomenon. By analyzing the mathematical model of the dual capacity water tank, the PSO intelligent algorithm is combined with the PID controller to obtain the optimal control parameters and performance indicators in MATLAB, through the OPC communication protocol, the water level of the tank is transmitted to the Kingview monitoring system to display the change curve in real time. The results showed that the PSO algorithm and OPC protocol can combine the complex algorithm function of MATLAB with the excellent plotting of Kingview, play a key role in the dual capacity tank level systems.

In the soft soil stratum, problems such as non-uniform settlement, leakage, and loss of bearing capacity occur during a shield tunnel's construction and operation process. The wrong selection of the inner diameter of the shield tunnel segment will even increase the scale of the problem. It has not been clear how the inner diameter of the segment will influence a tunnel's bearing capacity. Thus, a 3D numerical model is built to determine the mechanism between the inner diameter and the bearing capacity. Two kinds of the diameter of shield tunnel, which refer to 5.5m and 5.9m, are analyzed in this model. The results indicate that the deformation mechanism of these two kinds of shield tunnel in both normal loading process and a loading process concerning the surrounding engineering activities; meanwhile, it is found that the shape of the deformed tunnel is like a horizontal ellipse; finally, the deformation mechanism of segment and bolt is further revealed.

In order to avoid the difficulties of unloading due to natural cooling and solidification of cargo oil in the process of shipping, the cargo oil is heated and insulated. In this paper, based on the heat transfer theory, and the fluid dynamics software FLUENT was used to establish a three-dimensional scale model to simulate the actual heating process of the cargo oil in the oil tank, and the change law of the temperature field of the cargo oil in the oil tank was calculated and analyzed.The results show that the temperature of cargo oil is approximately proportional to the heating time. During the heating process of the cargo oil, the rise of the temperature of the cargo oil leads to the increase of oil fluidity, and the oil above the heat source flows upward along the bulkhead, resulting in vortexes of different sizes. In the same heating time, the external temperature difference is 40 K, the oil temperature rise difference is 1.5 K. The variation of temperature field in the heating process of cargo oil is of engineering significance to improve heating efficiency, reduce operating cost and reduce environmental pollution.

Based on the structure and mechanism of flash riot bomb widely equipped by PAP, the paper discusses the disposal methods, procedures and preventive measures. The unexploded reasons for flash riot bomb can be divided into three typical situations, one is human error, the other is firing mechanism failure, and the third is ignition tube failure. Corresponding disposal methods are re-throwing, provoking and bundling detonation, and the procedures are also refined. On this basis, effective preventive measures such as strengthening training and education, intensifying prior inspection and establishing a risk assessment mechanism were proposed. Through above research, it can effectively guide PAP to improve the ability to dispose unexploded bombs on the spot, which has important practical significance for ensuring actual combat training.

The tidal bore is a kind of nonlinear strong discontinuous flow that has a great impact on the wading buildings. During the tidal wave propagation, the local water flow structure of the wading buildings changes significantly. In order to analyze the evolution characteristics of local hydrodynamics of wading buildings under tidal action, a small-scale mathematical model of tidal current is established, and the local hydrodynamic changes of different forms of spur dikes and piers are studied. The results show that the flow velocity fluctuations in front of the non-submerged shoal dam and the dam head are more fluctuating than the submerged spur dikes, and the influence of the tidal dam on the submerged shoal dam area is more severe; the square piers under the tidal wave The turbulent energy and backwater recirculation zones are larger than circular and streamlined piers.

This paper studies the 125mm tank high explosive projectile equipped with two-dimensional correction device. To investigate the aerodynamic characteristic of two-dimension trajectory correction device before starting the correction device for ballistic control, a mathematical model of the fixed-canard rotation was established and the simulation calculations were performed, which uses a ballistic correction procedure to calculate the possible ballistic deviation caused by the rotational speed. The results show that the trajectory distribution is less than 1m, in the speed interval, and determines the best time to reduce the correction device and control the trajectory according to the change of polar restraining moment.

If the elevator breaks down during operation, it may lead to emergency braking. Emergency braking of the elevator may cause impact injury to personnel in the elevator car. In this paper, the injury degree of personnel under different working conditions is quantitatively analyzed by dummy test. The results show that within the allowable capacity of brake, safety gear and buffer, the stress and compression deformation of personnel in the lift car are within the allowable value in case of emergency braking.

Objective This paper is based on the technical improvement of the infrared sensor devices and has combined with the moisture permeability experiments of various food packaging materials, aiming to explore the application performance and effect of infrared sensor method equipment in the moisture permeability test of food packaging materials. Methods The improvement of the temperature control capacity of the equipment together with the sample clamping device helped to ensure a stable temperature during the test. In addition to the test of film/sheet, vessel type samples, the equipment subject to the referee-cup method principle and the equipment of the infrared sensor principle in this study were utilized to test the leather, PET film, sheet, PP film, PET/AI/PA/CPP film and VMPET film with varying moisture permeability levels respectively for their water vapor permeability rates at two different test conditions: 23°C, 90%RH and 38°C, 90%RH. Results The improved infrared sensor method equipment and cup method equipment share a similar relative uncertainty in the test. The water vapor permeability deviations between materials with distinct levels of moisture permeability are within the allowed range after tests with two methods and at different test conditions. Moreover, the homogeneity of test results of each food packaging material is satisfactory. Also, compared with the previous infrared sensor method equipment, the improved equipment witnessed an increase in both uncertainty and precision. Conclusion Therefore, the improved infrared sensor method test equipment can test the water vapor permeability of food packaging materials with different performances in a more accurate and reliable way.

In the production process of traditional shuttle kilns, energy consumption is high with serious pollution. Moreover, during its periodic operation, the heat loss is huge, and its material and energy are wasted seriously. Therefore, based on the traditional shuttle kiln, the shuttle kiln in this project is dynamically controlled by improving the control level of the kiln and the arrangement of burners. Thereby, the temperature in the kiln can be more evenly distributed, which can reach the ideal level during the firing process at the kiln temperature of 0-1200°C. Meanwhile, energy consumption increased by more than 30% year-on-year, and the temperature control accuracy is improved by more than 40%.

The container manufacturing industry is a typical labor-intensive industry in China, its manufacturing technology urgently needs to be automated with the demographic dividend disappearing. According to the technical requirements and space limitation for automatic locking screws between the wood floors and container steel girders, and based on the application of dynamical simulation technology, EtherCAT bus servo control technology, multisensory information fusion technology and other technologies, our team has developed an intelligent robot, which meets the automatic drilling and screwing process for dry containers. The robot has up to 49 servo motors, and through the data fusion of torque, position and image etc., the robot can move and locate by itself, and automatic deal with the exceptional situations of tool wear, floating lock, not drilled through and etc., and realizes the flexible production of multi-axis drilling and screwing. The robot can generate processing data reports, making container digital manufacturing further.

In this paper, the extrusion casting molding process of A356 aluminum alloy communication baseplate was numerically simulated by Anycasting. Through the analysis of the filling and solidification process, the curve of heat conductivity changing with time and the curve of the relationship between filling rate and solidification rate were obtained, and the forming reason of the curve was analyzed. The results show that the solidification rate becomes slower with increasing time. The results show that with the increase of time, the solidification rate becomes slower and slower, while the solidification rate gradually increases with the increase of filling rate. Through the analysis of the combined probability defect parameter distribution diagram and the temperature field during the whole casting process, the possible location of shrinkage cavity and porosity was obtained. By comparing the cloud images of temperature distribution at different time, it was found that this was caused by non-sequential solidification, which was confirmed by pressure test.

The failure reasons of a carbon monoxide cryogenic storage tank were analyzed by the composition, hardness and metallography analysis. The results show that the martensite phase was found in the head skirt of the inner vessel, and the hardness of head was much higher than that of the cylinder. The comprehensive analysis indicated that the fatigue cracks on head skirt leading to the leakage failure were mainly due to the decrease in fatigue properties caused by the martensite transformation during the forming process of the head.

The cracking of cold heading steel during drawing was researched in this paper. The defects were detected by scanning electron microscope and EDS energy spectrum analysis, the direct causes of cracking were discussed and analysed, and the corresponding improvement measures were put forward. Results showed that the large size inclusions with high alumina content in steel were the main cause of cracks in cold heading steel due to their poor deformation ability. The plasticity of inclusions could be controlled through optimization of refining slag to reduce both the CaO and Al₂O₃ content.

The existing monitoring system has the problem of imperfect database, which leads to low data processing efficiency. Therefore, a comprehensive integrated operation and maintenance monitoring system for information and communication networks is designed. Hardware part: effectively optimize the main control board of the system, connect the power interface and other accessories; software part: extract information and communication network characteristics, measure the distance between nodes, build an integrated comprehensive database, calculate data sampling frequency, establish operation and maintenance monitoring mode, and divide administrators. The permission level, combined with the relevance of the warning information, set the system warning function. The simulation experiment results show that the designed information and communication network integrated integrated operation and maintenance monitoring system has higher data processing efficiency under different communication overhead data packet conditions, which proves that the actual application value of the designed operation and maintenance monitoring system is greater high.

High Pressure Water Jet Incremental Sheet Metal Forming (HPWJISMF) brings higher process flexibility and better tools to workpiece interface conditions. AWJISMF is quite suitable for the production of multi-varieties and small batch products and trial-manufacture of new products. But up to now, there is not suitable machine tool for HPWJISMF. The facility for HPWJISMF designed consists of three main components. A high-pressure pump capable of delivering a constant volume flow of 30 L/min at maximum pressure 120 MPa, a table with a working area of 600 × 600 mm and a controller. The workbench has three translational degrees of freedom and the nozzle has two rotational degrees of freedom. The machine tool operates flexibly. The conical parts are processed on the machine tool. The parts meet the machining accuracy after measurement.

The pun recognition task is divided into pun detection task and pun localization task. Puns are divided into homophonic puns and heterographic puns. Until now, researchers have proposed a variety of recognition systems that try to construct features of puns from different perspectives. In this paper, we survey and analyse most of the classical pun recognition systems experimented in SemEval 2017 shared task 7 datasets, and summarize the main challenges in pun recognition tasks so far.

Smooth surface grinding depends on material micro-removal by diamond grain, but thermal damage is unavoidable. Hence, the thermal distribution between diamond grain and workpiece is adjusted to improve the ground surface quality by changing grain top area. Firstly, the grain top area was determined through thermal transmission balance on workpiece surface. Secondly, the mechanical dressing was utilized to remove the diamond grain top. Finally, the dry grinding of D-star die steel was conducted to analyze the correlation between surface quality and grain top area. The results show that the mechanical dressing increases the grain top area by about 2 times to reduce the workpiece grinding temperature. At the thermal transmission balance on workpiece surface, the thermal deformation is suppressed to decrease the ground surface roughness by 72.4% for smooth grinding.

The route selection and collision avoidance performance of UUV was studied based on fuzzy control theory. Firstly, a six-degree-of-freedom motion experiment is simulated for the submarine, and a fuzzy controller is designed according to the motion parameters obtained from the experiment. The fuzzy control system includes the heading control and depth control, and uses the fuzzy BK triangle sub product algorithm to design the next instantaneous safety course, so as to achieve the anti-collision function. In the numerical simulation, the performance of the controller is evaluated by setting a single point obstacle and a multi-point obstacle, respectively, for both the heading control and the collision avoidance path planning. The results show that: The fuzzy control system has better function of route selection, can determine the best course in time, and can pass the obstacle on the course with enough safe distance, which verifies the feasibility of this method.

Based on the structure and working principle of permanent magnet synchronous motor, a mathematical model suitable for engineering practice is established. For the system chattering problem caused by sliding mode control, a variable gain sliding mode controller is proposed to suppress chattering. Based on the MTLAB simulation platform, the permanent magnet synchronous motor servo control system model is designed and verified by simulation to verify the static and dynamic performance of the system. An experimental platform with DSP and FPGA as the core is built, and a new sliding mode control algorithm with DSP and FPGA as the core is verified. To verify the feasibility of the control strategy described in this article, the load experiment was carried out on the platform. Simulation and experimental results shown that the permanent magnet synchronous motor servo system based on dual-core sliding mode control technology has high response speed, high steady-state accuracy and robustness, and has good static and dynamic performance.

This paper takes the steel mill heat treatment furnace with the supporting control system as the carrier. On the basis of utilizing the existing hardware, Using the latest control ideas and control concepts, further research and optimization and improvement of the control system software, improve automation control. Strive to maximize the capabilities of the existing hardware, improve the utilization rate of the effective heating space in the furnace and accelerate the production rhythm of the heat treatment furnace, to help enterprises to improve the product heat treatment quality, improve productivity, further save energy, reduce consumption, and increase efficiency.

The construction of Smart City is faced with technical issues and innovative concept challenges such as data island, information fragmentation, large amount of data "sleeping". In this paper, on the basis of macro-demand and industrial practice analysis, the framework of Smart City platform based on Big Data is proposed. The structural design of the platform includes Data Access Layer, Data Management Layer, Data Analysis Layer and Release Management Layer. The application architecture design includes People's Livelihood Service, Citizen Big Data, Urban Operation and Big Data Map. The platform can digitize and analyze a large number of government business activities and provide support for fine governance decisions.

As the proportion of building energy consumption in the total energy consumption continues to increase, more and more countries pay attention to the prediction analysis and operation control of building energy consumption. In this paper, an office building energy management and control system based on the building information modeling (BIM) and back-propagation neural network (BPNN) technology is proposed. Firstly, the BPNN algorithm is used to predict the energy consumption of the building, and then the model predictive control (MPC) method is employed to search the optimal control parameters to realize the energy saving of air-conditioning system and other equipment. In addition, the office building environment model is established through the BIM technology, which can real-time display the operating conditions of equipment and more visually control the equipment in the office building. The experimental results show that the system can satisfy the comfort level and significantly reduce the energy consumption.

The construction of sports venues has the characteristics of large-scale in construction, complex structure and long construction period, which has a high requirement for construction scheme, technology, process and coordination management. Taking an Olympic Sports center as an example, this paper introduces the application of BIM technology in stadium project in details. Planning the overall application and implementation, as well as the technical disclosure of complex nodes and construction process in visual have been conducted with BIM technology which improve the construction quality. Moreover, the project cloud computing platform is established, and the material tracking system, progress control system, safety monitoring system are completed by applying the BIM technology which improve the construction environment of safety and civilization in site and the information management. And simultaneously, by simulating technical scheme of key and complex parts, steel structure hoisting scheme has been adjusted to reduce the structure deformation and ensure the high safety and accuracy. Finally, aims of ensuring the quality of the project, reducing the cost, shortening the construction period and saving materials are achieved.

With the in-depth development of cloud computing technology and the continuous application of various new technologies in the process of modern building construction, the application of embedded technology, communication sensing technology, cloud computing technology and other technologies to create energy-saving building energy monitoring systems has become a research hotspot. This paper first compares and analyzes the network structure of the traditional building energy monitoring system and cloud-based building energy monitoring system, and then focuses on the overall architecture of the system and the design and implementation of the terminal intelligent monitoring unit. On the one hand, the development of building energy monitoring system based on cloud computing realizes cloud processing of building energy monitoring. On the other hand, the control strategy formulated by big data effectively improves the overall energy saving efficiency of the building.

Focusing on the problems of Safety and Quality Control of Engineering Project, research on technologies for safety and quality control of engineering projects based on blockchain and BIM technologies can be investigated. A software intelligent system based on BIM, blockchain, artificial intelligence and data mining technologies is established. The problem of trace and tracking in the safety and quality management process can be solved. The innovation of engineering project safety control models can be promoted.

The floor tiling is a hard work, and a high level of skill is also necessary for the operators. Therefore, the current global floor tiling construction costs continue to increase. The use of robots to replace manual operations is becoming more urgent. Robotic floor tiling can reduce the work intensity of workers while improving the efficiency and the quality. This paper proposes a control system scheme for a floor tiling robot. Based on the characteristics of the multi-motion unit structure of the robot and the design concept of hierarchical control, the control system was divided into the user layer, the system control layer, the intermediate drive layer and the hardware execution layer. The system had clear functions and strong reusability. The user layer played a role of human-computer interaction which received the user's instructions. The system control layer was the brain of the robot, which was mainly responsible for the coordinated control of all the motion units during the floor tiling process. The middle driver layer provided the device controllers for all dedicated hardware devices, realized recognition of system control layer instructions and took the hardware execution layer devices to work. The hardware execution layer mainly executed the actions in the process of the floor tiling. The test results show that the control system can realize stable control for the floor tiling operation, and the system is stable and reliable. The research results on this study would provide a reference for the control system design of other construction robots or special equipment robots.

Through the finite element software abaqus, the finite element model of prefabricated segmental box girder with one joint and three spans(42m+66m+ 42m)in the section from the airport expressway to XinZheng is established. It is demonstrated that the stress of the box girder and the stress between joints are in the safe range during the symmetrical splicing construction of middle piers. By changing the value of the pre-stress, the influence of pre-stress on the mechanical performance of the box girder in the construction stage is discussed.As a result, during the construction process, the roof pre-stress has a bigger impact on the construction stage than the web pre-stress, and it is proposed that the loss of pre-stress should be reduced during the construction stage.