bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Single-Buffer and Double-Buffer Design in a Systolic Array Generator
Authors: Su Dongchu , Li Yong
Published: May 2021

In application fields such as face recognition and image recognition using deep learning, more convolution operations are required for the increasing amount of data. Therefore, the use of systolic array acceleration is becoming a key technology trend to accelerate the development of deep learning applications. In previous designs, most of the systolic array used single-buffer or double-buffer structures, but most of them did not compare the difference between the two in detail. This work designs and implements a three-level systolic array generator, which can be configured in single-buffer or double-buffer modes. We also program the generated systolic array accelerator on Nexys-Vedio FPGA to explore the performance and overhead of single-buffer and double-buffer structure modes. The results show that the throughput of the double-buffer structure is increased by nearly 3 × compared to the single-buffer structure while only brings an additional 28% power consumption and 25% area overhead under the SIMC 130nm technology. And compared with the previous work, the proposed systolic array generator reduces power consumption by 75% and area overhead by 34% with almost no loss in performance.
Investigation of monolayer and submonolayer films using X-ray photoelectron spectroscopy
Authors: Afanas’ev V P , Selyakov D N , Ridzel O Yu , Semenov-Shefov M A , Strukov A N
Published: May 2021

A method of layer thickness determination by X-ray photoelectron spectroscopy (XPS) is analyzed. Angle-resolved XPS spectra measured for three samples (gold films of different thicknesses located on top of silicon substrates) have been interpreted by the straight line approximation (SLA) model. Two configurations of films were considered: (i) a flat surface of a semi-infinite layer (substrate) is covered with a flat homogeneous layer, (ii) coating constitutes an island (cluster) structure. It is shown that the simplest model of an island coating makes it possible to qualitatively explain the effect of decreasing of the effective average coating thickness observed in the angle-resolved XPS experiments.
Ion irradiation effect (Ar+, E = 20-40 keV) on the mechanical properties and microstructure of aluminum V95 alloy
Authors: Gushchina N V , Makhin’ko F F , Ovchinnikov V V , Kaigorodova L I , Rasposienko D Yu , Vichuzhanin D I
Published: May 2021

The effect of 20-40 keV Ar+ ion irradiation on the mechanical properties and structural and phase state of hot-pressed profiles 6 mm thick made of an V95 alloy (Al-Zn-Mg-Cu system) after artificial aging has been studied. Irradiation (without causing heating) at fluences of 2∙1015 cm−2 and 1 ∙ 1016 cm−2 has been revealed to increase the relative elongation by 5%, without changing the strength characteristics. Electron microscopy examination has showed that irradiation has an effect on the state of the subgrain structure of the alloy. Irradiation at these fluences results in partial enlargement of the subgrain structure, and at higher fluence of 9.4∙ 1016 cm−2 it completely transforms the structure into coarse-grained one. At a distance of 150 μm from the irradiated surface, there is a slight increase in the subgrain size. The irradiation changes the morphology of Al6(Fe, Mn) intermetallic compounds in both the surface layer and the sample volume; namely, it sharply decreases the bulk density of lath-shaped intermetallic compounds and increases the density of the equiaxed ones. The degree of influence depend on the irradiation mode.
Microstructure of 1469 aluminum alloy after severe plastic deformation and ion irradiation
Authors: Gushchina N V , Ovchinnikov V V , Makhin’ko F F , Kaigorodova L I , Rasposienko D Yu
Published: May 2021

The effect of accelerated Ar+ ion beams with an energy of 10 keV on the microstructure and phase composition in 1469 alloy (Al-Cu-Li-Ag-Mg-Zr-Sc) initially subjected to severe plastic deformation (SPD) has been investigated by transmission electron microscopy. Irradiation has been found to result in the formation of a predominantly recrystallized nanocrystalline or fully recrystallized submicrocrystalline structure in the alloy, depending on the ion fluence. The irradiation liquidates the banded structure found in the alloy after SPD. Therefore, the structural elements (nanofragments, nanograins, submicrocrystals) are distributed uniformly in the volume of the irradiated sample. In addition, irradiation increases the volume fraction and the size bimodality of heterogeneously-generated T2-phase particles. The mechanism of nucleation and growth of excess phases has been proposed. The structure changes at a higher rate than it does during a long low-temperature annealing process, and structural changes are observed at a distance of ∼200 μm from the surface, which considerably exceeds the projected ion range (∼ 10 nm).
Increasing wear resistance of austenitic stainless steel by anodic plasma electrolytic nitrocarburising
Authors: Mukhacheva T L , Belkin P N , Burov S V , Dyakov I G , Silkin S A , Kusmanov S A
Published: May 2021

The effect of plasma electrolytic nitrocarburising on the wear resistance of 12Cr18Ni10Ti steel was investigated. The phase composition of the modified layer and the surface morphology were studied using X-ray analysis and scanning electron microscope. The wear of the specimens was determined with dry friction of the lateral surface of a cylindrical specimen against a bearing steel disc (60 HRC). It is shown that anodic PEN/C of steel samples results in the formation of a hardened layer with a microhardness up to 370 HV due to its saturation with nitrogen and carbon followed by quenching. The wear resistance of steel enhances by 8.5 times after treatment in a solution of carbamide (12 wt. %) and ammonium chloride (10 wt. %) at 800 °C for 5 min with quenching in an electrolyte.
Specificity of carbon diffusion during plasma electrolytic treatment of steel
Authors: Shadrin S Yu , Kusmanov S A , Kovrizhnykh T A , Belkin P N
Published: May 2021

This work is devoted to evaluation of the diffusion coefficient of carbon using the thickness of the martensitic layer after plasma electrolytic carburising in various electrolytes followed by quenching. The effective diffusion coefficients of carbon in the structure of mild steel containing oxide and martensitic layers are determined. The maximum diffusion coefficient at a carburising temperature of 900 °C is 23.6. 10−8 cm2/s for treatment in an acetone-based electrolyte for 1 min. The obtained values were comparable with the calculation results for the thickness of the pearlite layer after anodic plasma electrolytic carburising as well as data of measurements of the distribution of carbon concentration in the carburised layer after cathodic saturation. The influence of the oxide layer inhibiting the diffusion of carbon and the possibility of controlling its thickness by varying the concentration of ammonium chloride, which provides anodic dissolution of steel, were confirmed.
Simulation of sputtering a sandwich target in a reactive gas medium
Authors: Smirnov V V
Published: May 2021

A model of reactive sputtering of a sandwich target in nitrogen is considered. The target temperature is determined as a function of the ion current density. For the mathematical description of the process, the basic postulate of chemical kinetics is used, taking into account the Langmuir isotherm equation and the Arrhenius equation under non-isothermal conditions. In addition, thermionic emission and evaporation of the target surface are taken into account in the model.
Research on Improving Strategy of Technology Innovation Capability of Equipment Manufacturing Industry in Liaoning Province
Authors: Fan Xiaonan , Liu Yang , Dai Minghua
Published: May 2021

With the development of the economy and the advancement of technology, major enterprises are also under heavy competitive pressure while welcoming huge opportunities for development. With the improvement of the global value chain system, all industries have realized the importance of improving technological innovation capabilities. As a traditional industrial province in our country, Liaoning Province has made some progress in technological innovation in the equipment manufacturing industry, but still has the problem of weak technological innovation capabilities. This paper takes the equipment manufacturing industry in Liaoning Province as the research object. This paper summarizes and analyzes the development status and technological innovation status of the equipment manufacturing industry in Liaoning Province. The author uses the entropy method to evaluate the technological innovation capability of the equipment manufacturing industry in Liaoning Province, and compares and analyzes it from the vertical and horizontal directions. At the same time, using the means of empirical analysis, with the help of Eviews software, a multiple linear regression model was constructed to study the factors affecting the technological innovation capability of Liaoning’s equipment manufacturing industry. Finally, combined with the empirical research results, the countermeasures and suggestions for improving the technological innovation capability of Liaoning’s equipment manufacturing industry are put forward.
Machining errors control method for near-net-shape jet engine blade CNC machining process
Authors: Wu Dongbo , Wang Hui , Yu Jie
Published: May 2021

This study proposes a method based on on-machine measurement to control the machining error in the blade CNC machining process. Firstly, the mechanism of machining error formation of the near-net-shaped jet engine blade are analyzed, and the composition of the machining error source and its impact are qualitatively analyzed. Secondly, the adaptive CNC machining process are introduced. Thirdly, the influence of adaptive CNC machining process on the final machining errors is analyzed. The results show that the adaptive CNC machining process is of the excellent ability of machining errors control, and this method is effective in machining error control.
An smart toilet integrated performance detection device combined with machine vision
Authors: Feng Panpan , Chen Zhuo Liang , Chen Tianyu , Xu Hua
Published: May 2021

The traditional smart toilet comprehensive detection device proves unsatisfying on integration, intelligence, time and effort cost, and precision. In order to improve the detection accuracy and efficiency of smart toilets test, and overcome the poor integration of equipment and low intelligence, image processing technology is applied to the comprehensive performance detection equipment for smart toilets in this paper. Lenovo all-in-one computer is used as the upper computer to realize the collection and analysis of key data. Siemens PLC, as a lower-level computer, controls multiple temperature water tanks, frequency converters and pipeline valves, and collects and transmits data on temperature and cleaning power. Meanwhile, CCD camera is innovatively introduced to locate the seat temperature test points on the smart toilet. The test results show that the detection accuracy, efficiency and integration of the device are improved obviously.
Study of the External Inverting Process of the Mild Steel Thin-walled Tube
Authors: Zheng Yuqing , Yang Minghao , An Yuanyuan , Hu Yan , Wang Fangni
Published: May 2021

The invertube is an ideal energy absorber to improve the crashworthiness of the vehicle skeleton body structure, but the low cost mild steel thin-walled tube often suffers some serious tearing phenomena in the external inverting process on the forming die. In order to investigate the interference factors of external inverting deformation, the optimum parameter of die structure design and the axial resistance force level of thin-walled tube in the external inverting process, a nonlinear finite element explicit dynamic codes were adapted to simulate the plastic inverting process of a mild steel thin-walled tube. The tube has the outer diameter of 60mm and the wall thickness of 2.0mm. The external inverting processes were conducted upon two kinds of round corner dies. Based on the results of previous theoretical analysis, the radius range of the corresponding die were obtained by theoretical calculation. The two die section forms and a series of dies with different round corner radii were also designed to build finite element simulation models. The inverting simulation results show that the optimal induced radii of the dies are within the range of 10.5-11.0mm. Meanwhile, it can be seen that the mild steel thin-walled tube has good formability in the early stage, which is convenient for the subsequent fine shaping of the invertube end. Moreover, the die bears less axial extrusion force, which is conducive to the improvement of the working life of the die. In the last, an ideal alloy steel die with the optimal rounded radius of 10.7mm was manufactured and used to verify the feasibility to finish the invertube manufacturing using mild steel thin-walled tubes. It provides a good simulation technology reference for the die structure design to realize the external inverting of the mild steel thin-walled tube.
Construction Practice of Centralized Maintenance Mode for Asphalt Pavement of Expressway
Authors: Wang Hongxiang
Published: May 2021

At present, one of the most prominent problems in Jiangsu Expressway Maintenance Project is the contradiction between maintenance operation and traffic. Based on the centralized maintenance project of Guangjing Xicheng Expressway in Jiangsu Province, this paper analyzes and summarizes the centralized maintenance mode from two aspects: the preparation points and the control in the construction process. The practice of this project shows that the centralized maintenance project needs to focus on the characteristics of multi-dimensional concentration of time, space and material, make targeted preparation from the aspects of organization, human, machine, material, technology and emergency plan, and ensure multi-directional control through summary and improvement, multi-party coordination, dynamic control, construction standardization and a series of measures in the implementation process. Compared with the traditional maintenance mode, the centralized maintenance mode makes the maintenance project better in quality, faster in progress, more controllable in safety and better in benefit. The research results provide important practical experience for similar projects.
Cause and analysis of hydraulic pump failure
Authors: Shang Li , Wang Na
Published: May 2021

After a period of use, the internal parts of the hydraulic pump will be worn one after another, resulting in the reduction of the movement efficiency of the hydraulic pump and various problems. Usually, this is a sign of damage to the hydraulic pump. If the hydraulic pump is seriously damaged and beyond the scope of repairable technology, it should be replaced in time and repaired effectively. If it is difficult to repair, replace the parts if necessary to improve the working efficiency of the hydraulic pump. Under certain circumstances, experienced maintenance personnel can fully improve the working efficiency of hydraulic pump through precise maintenance and effective matching.
Research on microstructure and hardness of AISI1050 disk based on FDM and FEM methods during quenching process
Authors: Zhang Yishuai , Fu Jia , Sun Hongxing , Liu Hua
Published: May 2021

Microstructures of AISI1050 disk during quenching were simulated by DEFORM-HT, and corresponding parameters of mechanical properties were investigated by applying the algorithm of finite difference method (FDM). Above all, thermo-physical parameters and diagrams of CCT curve were calculated by JMATPRO. Besides, the simulation of multi-phase microstructure considering initial thermo-physical parameters was realized by DEFORM-HT. The volume fraction of single phase were obtained by the FDM method, and then a weight function considering carbon equivalent of phases was introduced to predict the final hardness of multi-phase and according to the quenched microstructure and independent single phase hardness simulated. Temperature field, stress field and microstructure change of an AISI1050 disk under different quenching processes were studied by using the DEFORM-HT software numerical simulation calculation, combined with the continuous cooling transition curve ( CCT curve) of AISI1050 steel. The martensite transformation of the disk tread during the quenching process can increase the wear resistance. According to the actual working conditions combined with the CCT curve of AISI1050 steel, the hardness of the disk rim surface is 54.8 HRC, which can meet the requirements of 51-56 HRC. It is concluded that the maximum equivalent stress of the disk( the equivalent stress after unloading is the residual stress) is distributed near the disk inner layer in the inside of the plate to hand over the location. The microstructure of the specimen is observed and compared with the simulation results, which prove that the simulation results are reliable. The simulated hardness by using both JMATPRO and DEFORM-HT can provide some basis to predict the hardness on certain degree.
Mechanical behaviors and its main influence parameters of flexible assembly joint of timber column and reinforcement concrete beam
Authors: Wu Zhongtie , Fan Pingping
Published: May 2021

Flexible assembly joint is the key problem to coordinate the deformation of hybrid structure. This study aims to investigate the mechanical behaviors and its main influence parameters of flexible assembly joint of timber column and reinforced concrete beam. Finite element models were established and analyzed. The mechanical behaviors of the flexible assembly joint were discussed including the horizontal bearing capacity, horizontal stiffness and load-displacement hysteretic loops. The influence of the vertical load and rubber performance property on the mechanical behaviors of flexible assembly joint was analyzed. The results indicate that the relationship curve of horizontal load and displacement is the bilinear form before its failure. The vertical load and rubber performance property have great influence on its mechanical behaviors including the horizontal bearing capacity, horizontal stiffness and load-displacement hysteretic loops, which are regarded as important indexes to do the performance design.
Research on the Application of UAV Tilt Photography Technology in Engineering Project
Authors: Wu Bei , Li Bingnan , Li Shanshan , Li Hongjie , Zhou Rui
Published: May 2021

Based on the teaching building project, the three-dimensional model generated by the fusion of tilt photography data processing process and panoramic image is applied to compare the three-dimensional model in the construction network plan with the real three-dimensional model. By using the advantages of fast modeling of tilt photography, the 3D real scene under 360 degree panorama is combined with different construction stages, and the models of different stages are visualized to realize the real preview of the project, so as to improve the quality of project construction, solve the problems in the construction process, and ensure the smooth progress of construction.
Research on deep foundation pit excavation based on numerical simulation
Authors: Cao Shiyong , Song Shuai , Xili Qi
Published: May 2021

The safety of deep foundation pit excavation has always been an important topic of urban construction safety. The traditional method is to control the construction safety by monitoring and adjusting the construction process, but the timeliness of monitoring makes it limited in the control of construction safety. In this paper, MIDAS / GTS software is used to simulate the excavation process of a hospital foundation pit in Guiyang. The maximum horizontal displacement in X direction is 4.03mm, and the minimum is -4.78mm. The maximum horizontal displacement in Y direction is 4.41mm, and the minimum horizontal displacement is - 4.9mm. Through the study of the common horizontal X and Y displacement nephogram of crown beam, waist beam and anchor, the synergistic effect can be well expressed. The maximum horizontal displacement in X direction is 5.56mm. The minimum horizontal displacement is - 3.54mm. The maximum horizontal displacement in Y direction is 6.56mm. The minimum horizontal displacement is - 4.45mm. By comparing the numerical simulation results with the field measurement results, the reliability of the numerical simulation in the evaluation of the foundation pit is fully proved.
Study on the Effect of Silane-silica Sol Hybrid Material on the Properties of Cement-based Materials
Authors: Li Li
Published: May 2021

This article analyzes the preparation of cement-based materials and the preparation of silane-silica sol hybrid materials. The author studied the effects of materials on the water permeability, gas permeability, ion permeability, freeze-thaw resistance, material mechanism and other properties of cement-based materials. The purpose of this article is to improve the performance stability of cement-based materials and extend the service life of cement-based materials.
Welding procedure research of R04200 niobium plates
Authors: Jiang Chengjun , Meng Jin , Zhang xiaoli , Xue Xiaolong
Published: May 2021

The weldability of R04200 niobium plates is analyzed. The mechanical property, bending property and corrosion resistance are tested by the butt welding procedure of GTAW. Test results show that butt joints by the welding procedure perform good property, and the corrosion resistance microstructure of the welding joint is normal. The success of the procedure qualification test is of great help to the standard formulation of the niobium pressure vessels.
Basic Principles of Microwave Communication
Authors: Mao Ziyu
Published: May 2021

Microwave is a form of electromagnetic radiation with one meter to the one-millimeter range. It has the excellent capacity to carry a lot of information and is a good choice to deal with data crisis. It can be used in many fields, and the development of microwave technology is being studied extensively. Microwaves can be used in scientific research, and the structure of the internal substances can be analyzed according to the different degrees of microwave absorption by different substances. Also, the microwave physiotherapy instrument created by microwave technology can kill some diseased cells and play a therapeutic role. This thesis will discuss and introduce some basic knowledge and equipment of transmission line theory, waveguide theory and microwave chemistry, to have a basic understanding of microwave technology. The results show that microwaves should have optical characteristics, skin effects, and other properties. Antennas, radars, transmission lines, and remote sensing measurement applications are all related to these characteristics
Research on Torque Control Distribution between Motor and Engine in P2.5 Hybrid Vehicle
Authors: Jing Junchao , Liu Yiqiang , Wujie  , Wang Yongjian , Huang Weishan
Published: May 2021

The normal torque distribution of the P2.5 hybrid system is based on the strategy of open-loop engine control, dynamic engine torque estimation and the motor torque compensation. To meet the rapid acceleration and the deceleration, the motor torque is compensated according to the estimated engine torque to satisfy the driver torque request first, and then satisfy the battery charge torque. Other torque distribution strategies are defined according to the special working conditions below:1) To improve the efficiency of the engine and the response of the system and to avoid the drop of engine speed, the motor compensation enabled condition and torque distribution strategy is defined.2) To enhance the performance of fuel consumption and emission during the catalyst heat phase, the catalyst heat phase is divided into two phases and the torque distribution strategy is defined. 3) To decrease the battery heat time and extend the battery health life, the battery heat enabled condition and torque distribution are defined. The vehicle results are conducted and show that the normal torque distribution control can meet the acceleration and deceleration goal and drivability performance. The motor compensation can meet the driver torque by the motor and avoid the drop of the engine speed. The control of the catalyst heat phase can do good to the emission and fuel consumption.
Research on Phone Shell Detection Based on Machine Vision
Authors: Cai Li , Li Jingchuan
Published: May 2021

With the continuous development of computer technology, machine vision technology has the incomparable advantages of manual detection, such as non-contact, non-fatigue, so it is widely used in the field of industrial detection. The traditional method of mobile phone shell detection does not meet the increasingly intelligent demand. It is of practical significance to use machine vision technology to realize mobile phone shell detection. Combined the technology of image processing technology, this paper proposes a kind of mobile phone shell detection based on machine vision method. First of all, the original image is preprocessed, and then a method combining median filter and wavelet tool is used to eliminate image noise. On this basis, image segmentation and edge extraction are carried out. The improved Canny operator is used to detect the edge of the image, which has good effect in eliminating the false edge and ensuring the integrity and continuity of the edge. Meanwhile, mathematical morphology is used to extract the characteristic parameters of the target, and the effectiveness of the detection method is verified by simulation in Matlab.
Fast calibration method of alignment prism based on image transformation relation
Authors: Li Yihao , Zhang Weimin , Zhang Zhijing
Published: May 2021

The alignment assembly based on the principle of coaxial imaging has high accuracy, and the accuracy of coaxial imaging is the key to it. Manually calibrating the pose of the prism to ensure the accuracy of coaxial imaging, which has disadvantages such as difficult operation and long time consuming. This paper analyzes the image relation between the upper and lower parts of the prism based on the optical imaging theory, and solves the image transformation relation between the target part and the assembly part with an experimental method, and proposes a rapid calibration method for the alignment prism based on the image transformation relation. The tedious steps of manually adjusting the prism are eliminated. The experimental results show that this method realizes the high-precision assembly of parts by the micro-assembly system.
Experimental Study on Noise Reduction Characteristics of Slanting Serrated Trailing Edge Blades
Authors: Li Guoping , Ma Zhenlai , Chen Changsheng , Zhang Yi , Wang Qiang , Chen Eryun
Published: May 2021

In order to suppress the narrowband tone noise generated by the blunt part at the root of non-flat plate serrated trailing edge, a novel slanting root serrated trailing edge is adopted on NACA65019 blade. The experimental investigation on the aeroacoustic characteristics of the blade with slanting serrated trailing edge is carried out in the full anechoic wind tunnel laboratory. Reynolds number (Re) based on the chord is 2 × 105 and attack angle is 0° to 12° in the experiment. The result of experiment shows that the blade with traditional serrated trailing edge will reduce noise in high frequency range at small angle of attack, but it will produce narrow band peaks at specific frequencies, leading to an increase in overall noise level. The blade with slanting serrated trailing edge can maintain the noise reduction effect in broadband frequency range, while significantly weakening narrow band peaks. At the large attack angle, the narrow-band peaks of the traditional blunt trailing edge disappear and the noise reduction effect is obvious, while the novel slanting serrated trailing edge has more obvious noise reduction effect. The results of this paper can pro-vide a new idea for the bionic design configuration of blades.
Simulation Analysis of Cab Mounting System of Flat-head Truck
Authors: Li Panqi , Wang Yinwei , Cheng Weitao
Published: May 2021

Because the working environment of heavy truck with flat head is harsh, it is often in full load or vibration and impact load for a long time, and the cab suspension system receives these responses, and the driver’s intuitive feeling is the output response of the system. In this paper, the static and dynamic characteristics of air spring are tested, and the stiffness and motion characteristic curves are obtained. Then, according to the test data, the model of cab air mount system is established in ADAMS software, which simulates the response of cab mount under real vibration and evaluates its vibration reduction performance.
Research on the Application of Artificial Intelligence in the Field of Mechanical Automation
Authors: Li Wanling , Meng Fanzhao
Published: May 2021

As a branch of computer science, artificial intelligence involves disciplines such as computer science, psychology, philosophy, and linguistics. It can simulate certain human thinking processes and social behaviors. In the past 20 years, the application of artificial intelligence has penetrated into many areas of life and production, including economics, space technology, active control, computer planning, and mechanical manufacturing. It has produced huge economic benefits in production practices and pushed human society forward by a huge step. With the increasing research and development of artificial intelligence technology, its application in mechanical engineering has become more and more extensive. Through its high-end technology and intelligent algorithms, it can effectively and accurately solve various problems in the process of mechanical automation experimental research and production use. This article will analyze and research the application of artificial intelligence in the field of mechanical automation.
Design and Motion Analysis of Octopod Bionic Robots Based on a Multi-Link Walking Mechanism
Authors: Li Shuge , Zhao Pengju , Sun Wencheng
Published: May 2021

In this paper, a bionic robot walking mechanism based on a multi-link mechanism was proposed, which consisted of two crank-rocker mechanisms, one parallelogram mechanism and two tripods, all of which were connected by hinges. An octopod bionic robot was designed by using the multi-link walking mechanism. The kinematics analysis of the robot walking mechanism was carried out by using MATLAB software, and the linear walking gait of the virtual prototype of the robot was simulated by using ADAMS software. The simulation results showed that the octopod bionic robot had good motion stability, strong terrain adaptability, and good practical application and popularization value.
Study on dump truck dumping process and dust extraction device design
Authors: Geng Tianyin , Chen Kailang , Huang Xin
Published: May 2021

The particle diffusion and movement rules of the dump truck dumping material are simulated in Fluent based on the gas-solid two-phase flow theory. The simulation results show that the dust generation mainly occurs in two stages. One is that when the particle flow is falling, the particle diffusion mainly concentrates on the back of the particle flow. The other is that when particle flow collides with the contact surface, dust diffusion occurs in the area where the collision point is consistent with the outflow direction. According to the simulation results, a dust extraction device for dump truck is proposed to capture dust generated into the atmosphere. The influence of three representative factors: ambient temperature, shape of the dust collection port, fan speed on the performance of the dust extraction device is studied by means of orthogonal experimental design. The results show that the use of plain multiple slot suction port and higher fan speed can improve the dust removal effect and work efficiency of the dust collection device.
Application on large-span reconstructed structure with external prestressing technology
Authors: Zhao Guodong , Duan Shixin , Sun Bo , Yuan Xiaohua
Published: May 2021

The application of external prestressed reinforcement technology in large-span reconstruction projects is introduced through a project example of drawing columns to increase the use space of existing buildings. Simplified calculation method and midas gen finite element analysis software are used to analyze and calculate the bearing capacity limit state and normal service limit state of GHJL-1 and GHJL-2. In order to ensure the safety and applicability of the large-span reinforcement and reconstruction project, the static load method is used to inspect the serviceability limit state of the structure after the reconstruction. The results show that the deflection and crack width of GHJL-1 and GHJL-2 meet the requirements of the code limits.
A Discussion on the Type Selection of the 200 m Span Closed Coal Shed in the Thermal Power Plant
Authors: Si Xiaofei , Wu Baohui , Huang Gangying , Ma Bailing , Zhang Kai
Published: May 2021

This thesis discusses the type selection of the concrete implementation of the 200 m span closed coal shed in the thermal power plant. We analyze the characteristics and development situations of five schemes for selection, and focus on introducing and recommending the closed coal shed which uses the PVDF membrane material as its outer space cover. Then we choose the steel grid of three-centered circulars and the membrane framework as its structure selection, and strives to make it highly coordinated with the surrounding buildings and environment. Such renovation is to turn it into an industrial construction in the new era with both aesthetics and practicality, and to promote the rapid development of the membrane material structure as a new product of new technology. At the same time, the paper provides guidance and reference for the type selection of the supramaximal span structure of 200 m and above.
Research on electrode lifting system based on recursive least square method and fuzzy PID
Authors: Zhou De-Dong , Su Fang
Published: May 2021

The electrode of calcium carbide furnace bears the function of conduction, heat transfer and furnace condition regulation. How to keep the furnace condition in the best condition by lifting and lowering the electrode has always been a hot and difficult point in the research. In this paper, based on the analysis of the equivalent circuit of calcium carbide furnace, the system model of electrode position-current is identified by the recursive least square method, and a fuzzy PID controller based on the constant control strategy of electrode current is designed to keep the furnace condition in the best state. The simulation and application results show that the designed system has good dynamic response, anti-disturbance ability and robustness.
A Novel Method for Distribution Transformer Short-circuit Test
Authors: Luo Xiaoxiao , Xiao Qianbo , Wang Qian , Sheng Zhiping
Published: May 2021

Short-circuit test of distribution transformer is an important test to check out the short-circuit resistance of distribution transformer. This paper presents a novel short-circuit test method of distribution transformer based on energy storage short-circuit test device, which can complete the short-circuit field test of distribution transformer. The basic principle of the device is introduced, and the feasibility of the method is verified by simulation and experiment.
Application of Automation Technology in Automobile Machinery Manufacturing
Authors: Wang Xuhui , Wang Yinuo
Published: May 2021

China’s science and technology have become increasingly mature in today’s society, and various fields of society will actively apply relevant advanced technologies to reshape the original operating model during the development process. In particular, the application range of automation technology has become more extensive, because automation technology itself has more advantages and cannot be replaced by many other traditional technologies. It can fundamentally improve the work efficiency of some manufacturing industries. Thanks to the application of high-precision automation technology, all work can be carried out continuously in accordance with established computer programs. In this way, the number of errors caused by human work is actually reduced, and the pass rate of the product can also take this opportunity to be significantly improved. When performing various tasks, workers in the mechanical manufacturing field will actively apply the most suitable automation technology according to their actual conditions, and organically integrate their valuable work experience with brand-new automation technology. This allows all work to be of higher quality in the implementation process. In the automobile production industry, since many parts are manufactured on the assembly line, if the advanced automation technology is actively applied, the production time of parts can be saved, and the assembly and processing work of the staff will be carried out in an orderly manner. In this way, the profits of the automobile manufacturing industry can be effectively improved and unnecessary cost input can be reduced.
SIW-Based Leaky Wave Antenna with High Radiation Efficiency
Authors: Li Yihui , Wang Min , Wu Wen , Zhou Xin , Qiu Changjin
Published: May 2021

In this letter, a substrate integrated waveguide (SIW) based leaky-wave antenna with high radiation efficiency is presented. The radiating unit of the proposed LWA consists of a pair of meandering slots with different lengths. The combination of slots with different lengths effectively improves the leakage factor of leaky-wave antenna and thus improves the radiation efficiency of the antenna. The proposed antenna can scan from -46° to -9°, and the radiation efficiency of the antenna is 87.55%-97.6%. The leaky wave antenna is fabricated and measured. The measured results show good agreement with the simulation ones.
Research on an under- actuated bionic manipulator
Authors: Wu Binghui , Qiu Tong , Chen Yuhan
Published: May 2021

Through the analysis and statistics of the calcaneus angle of deer, horse and other cloven-toed animals, the appropriate manipulator configuration is selected. This paper proposes an under-actuated bionic manipulator to assist astronauts in space welding tasks. The motion simulation of the manipulator was carried out utilizing ADAMS, and the relationship curve of the angular velocity at each joint of the under-actuated bionic manipulator was obtained. Through curve analysis, it is not difficult to see that the design of the fingertip spring bar is the key to ensuring the reliable operation of the bionic manipulator.
Effect of Environmental Factors on Ultrasound Detection of Plastic Encapsulated Microcircuits
Authors: Zhao Hailong , Zhang Kui , Zhou Zhenhua , Xi Shanbin , Yin Lijing , Huang Jie , Peng Hao
Published: May 2021

Based on the problems encountered in ultrasonic detection of Plastic Encapsulated Microcircuits (PEMs), the relationship between storage environment, immersion time, baking treatment and temperature test and other environmental factors and the stability of PEM are studied for the characteristics of plastic encapsulated materials that are susceptible to temperature changes and moisture. And its effect on the results of ultrasonic testing, the reasons for the inconsistency of ultrasonic testing results are analysed, and storage, transportation, immersion time, baking treatment requirements before and after the test, and device use recommendations are put forward.
Research on technology of safety automatic particle forming equipment for pyrotechnic
Authors: Li Jing , Zhang Yuli , Yang Hao , zhang Hongguang , Liu Jingsong , Sun Yang , Mu Jiaqing , Li Jianbai , Zhu He , Gu Peng , Ou Xibin , He Fei , Yang Ming , Yin Xiangchun , Zhang Yiqun
Published: May 2021

Pyrotechnic agent was a sensitive energetic material that produces explosion and combustion effects of pyrotechnics. It plays a decisive role in the safety, reliability and effectiveness of the weapon system. Because the current pyrotechnic agent is sensitive to high temperature, mechanical impact, and friction, there are many unsafe factors in its manufacture and use. The demand of continuous, automatic and environmental protection production technology for pyrotechnics in China is increasing. The traditional sensitive explosive can not meet these requirements, so it is necessary to accelerate the development of sensitive explosive to safeandinsensitive explosive.Therefore, in order to solve the key issues such as the safety and high-efficiency preparation of multi-component pyrotechnic agents, realize the environmental protection, safety and low-cost production of pyrotechnic agents. Based on the project design of a mixed propellant production system in an initiating explosive device factory, this research carried out the research on the safety automatic particle forming equipment for initiating explosive. It provides technical support for the innovation of weapons and equipment, and the upgrading of weapons and equipment manufacturing and production technology.
Analysis and Experimental Study on Friction and Wear Characteristics of Super High-Speed Mechanical Seal
Authors: Guo Jungang , Hu Liguo , Li Zhenjiang , Jianag Jinbo , Huang Weifeng
Published: May 2021

Mechanical seal is the core component of the servo system. It’s sealing, reliability and wear resistance depend not only on the structural design of the seal, but also on the matching of friction pair materials on the end face of the seal. On the basis of the feasibility study of ion implantation on the surface of the seal ring, a comprehensive test scheme is proposed to verify the friction and wear characteristics of the seal pair. By selecting typical graphite and rotating metal ring pairs to test and test under dry grinding conditions, changing the linear velocity and the end face specific pressure, the friction and wear characteristics of paired friction pairs are compared and analyzed by using friction and wear testing machine, the influence of load and rotational speed on the pair friction coefficient of sealing pair is systematically studied, and the sealing tribological characteristics are revealed. This paper introduces mechanical-seal work reliability of temperature stress and system test performace based seal pair, the application of these plans will provide a reasonable and efficient technical way for the verification of life and reliability test of ultra-high speed mechanical seal.
Research on optimization model of Equipment network maintenance Equipment
Authors: Wei Xia , Quan SHI , Zhuang YIN SHI , Song AI YAN
Published: May 2021

Aiming at the problem that the demand quantity of networked maintenance equipment is not accurate in the demand analysis results of networked maintenance equipment, an optimization model of maintenance equipment is established by using the principle of queuing theory and simulation method to describe the optimization problem of maintenance equipment quantity. According to the improved genetic algorithm, the established optimization model is solved, so as to get the optimal quantity of maintenance equipment.
Design of Quadruped Inspection Robot for Substation
Authors: Dong Xu , Zhang Bin , Hu Xuran , Meng Jian , Dong Jiyuan
Published: May 2021

The intelligent inspection robots in substations mostly use wheeled chassis, which have good passability when running on flat roads, but it is difficult to effectively cross obstacles under terrain conditions such as steps and stairs. A quadruped inspection robot for substation is designed to improve the walking ability of the robot with a four-leg alternate walking mode to optimize the leg structure design for road conditions such as steps and stairs in the substation. The robot is equipped with pan-tilt detection components and inspection equipment such as multi-degree-of-freedom manipulators can complete intelligent inspection and lightweight maintenance tasks in open substations, and achieve full coverage of the inspection area.
Numerical study on the flow characteristics of slot cooling header after rolling
Authors: Shi Jianhui , qi Xingang , Liang Ruquan , Zhang Danhui
Published: May 2021

In order to study the flow distribution characteristics of the slot cooling header after hot rolling, and the influence of different structure and technological parameters on the flow uniformity of outlet velocity and length direction was obtained. The three-dimensional steady-state numerical simulation analysis of the flow inside the manifold was carried out by FLUENT analysis software. The influences of inlet pressure, shape and structure of intermediate transition cavity were studied respectively. The results show that within the range of 0.1~ 0.5MPa of the inlet pressure, the velocity fluctuation in the direction of the outlet length increases with the increase of the pressure, and the width decreases from the middle of the gap to both sides. The flow velocity at the jet outlet can be increased by changing the angle of outflow tilt of the water supply pipe.
The Study on AlxGa1-xN Film Deposition by Radio Frequency Magnetron Sputtering
Authors: Deng Danxia , Qin Zuoyan , Hu Hao , Jin Lei , Sun Zhenhua , Wu Honglei
Published: May 2021

A series of AlxGa1-xN films are deposited on Si (111) substrates by radio frequency magnetron sputter with different experimental Parameters. Crystallinities, elemental components and surface morphologies of films are investigated in terms of their deposition Parameters. The results reveal that the films grow along with the (004) crystal direction and have a more Al component than the target, which is attributed to the higher bond energy of Al-N. A higher pressure and nitrogen concentration lead to more surface structures such as bubbles on the AlxGa1-xN films. Using a pressure of 1.0 Pa and nitrogen concentration of 33%, AlxGa1-xN films with good quality are finalized achieved.
Liquid metal based flexible pressure sensor for tactile sensing of robots
Authors: Chen Ruiyang
Published: May 2021

In contrast to circuit made by rigid material, flexible electronic devices are fabricated by flexible conductive material and have potential future in field of wearable electronic devices, biomedicine and intelligent sensor. Liquid metal is a kind of metal or alloy material that can remain liquid at room temperature. In recent years, it has been widely used in the field of stretchable electronics. This research applied adhesion different of liquid metal on different materials’ surface to print liquid metal circuit of certain pattern on thermal transfer paper and trans-printed the circuit to flexible base to fabricate stretchable and flexible pressure sensor. In the research we tested the electrical property of pressure sensor and applied the results to tactile feedback research of intelligent robot. Not only does this liquid metal pressure sensor have simple structure and low in cost, but is suitable for large area and mass production. We believe this pressure sensor can be widely used in field of human-computer interaction and robot intelligent sensing.
Reliability modeling of gear system considering strength degradation
Authors: Bai Enjun , Yang Hui , Huang Shutao , Xie Liyang
Published: May 2021

The traditional reliability models of gear system were usually developed without considering strength degradation of gear tooth. Although some analysis methods considered strength degradation, but they ignored the uncertainty of strength degradation that is due to the random load. In order to consider the statistically dependent failure between the gears and the uncertainty of gear strength in the strength degradation process, the reliability models of gear system are developed based on the theory of stress - strength interference. The failure relationships between teeth are expressed by the minimum order statistics. The uncertainty of the strength degradation is expressed by the distribution of material parameter. Using the Monte Carlo simulation, the proposed model is validated. Taking a planetary gear system for a case study, the system reliabilities with strength degradation are analyzed. The results show that the strength degradation has a little influence on the gear system reliability at the early stage and it has a great influence on the gear system reliability at the middle and late stages.