bluuebunny/crossref_metadata_2025 huggingface dataset:
A Multi-Objective Reservoir Optimization Software (MORO) with Sediment Flushing Computation
Authors: Li Fangfang , Wang Hongru , Qiu Jun
Published: September 2022

Sedimentation not only diminishes the benefits of reservoirs, but also leads to the degradation of riverine ecosystems. Reservoir sedimentation appears particularly serious for China with the maximum annual storage loss of 2.3%, resulting from both the hyper-concentration sediment rivers and the rapid increase of large reservoirs. This study proposed multi-objective reservoir optimization software (MORO) with sediment flushing computation based on measured data of sediment concentration, which was applied to a large reservoir and can be generalized to other reservoirs. The results show that within the recommended discharge variation of 4%, the sediment release can be increased by 1.41×106 t as the reduction of per 1010 kWh in annual power generation. Compared with the original scheme, the sediment release can be increased most by 2.97% at the cost of 0.29% loss of power generation. Moreover, the dual objective in the flood season has been optimized by 6.40% and 3.39%, respectively.
Optimal Configuration Mode of Soil and Water Conservation Measures in Small Watersheds in Northern Grasslands
Authors: ABIyas  , Rong Hao , Ge Nan , Miao Henglu
Published: September 2022

Prairie soil and water loss and eco-construction have been studied for many years. On the basis of the status quo and causes of soil and water loss in the north typical prairie areas, we put forward the disposition model of comprehensive control measures of small watershed in the north typical prairie areas. Centering on combining engineering measures with biological measures to improve grasslands eco-environment, we take beach shallow groundwater exploration as a breakthrough, and take close improvement and artificially planting grasses as methods aiming at improving grasslands productivity and promoting the development of animal husbandry so as to provide successful experiences for the comprehensive control of resemble small watersheds.
Research on Blasting Technical Scheme of Hillside Open-Pit Mine with Heterogeneous and Complex Rock Mass
Authors: Chen Yajun , Dong Fa , Geng Xinyu , Bai Xiaojie , Wang Yanbin
Published: September 2022

In order to reduce the large rocks produced by blasting of hillside open-pit mine with heterogeneous and complex rock mass in arid area, based on the lithology characteristics of complex rock mass of the Dabancheng Limestone Hillside Open-pit Mine in Hongshun, Xinjiang, the key technology for blasting in homogeneous and complex rock mass hillside open-pit mine is proposed in this paper. We can conclude from the experiment that (1) it is preferable to have a detonation network that realizes multi-stage millisecond differential, multiple combinations of detonating unit forms, and variable blast hole connection lines; (2) the blasting parameters, charge structure and millisecond interval are optimized to make the blasting efficiency to be effective continually; (3) the radial tensile stress of reflected tensile wave is enhanced and the rock breaking mechanism of heterogeneous complicated rock mass is revealed.
Performance Comparison of Analytical and Numerical Methods of Elastic Properties of Composite Micromechanics
Authors: Erturk Alpay Tamer , Acikgoz Cagatay
Published: September 2022

Because of the anisotropic nature of composite materials, they can show different material properties in different directions. Therefore, it is decisive to determine the mechanical properties of composites. In this study, performance comparison of analytical methods and numerical methods are investigated. The most well-known analytical method, the strength of the material method, and the relatively more complex and widely used Chamis’ equations and Tsai-Halpin equations were selected. Numerically, the finite element-based representative volume element (RVE) homogenization method without periodic boundary conditions is chosen. As a result, the modulus of elasticity in the fiber direction and the major Poisson’s ratio values are similar for all methods. Tsai-Halpin method and RVE Homogenization method can predict the transverse elasticity value close to each other, Chamis’ equations also provide results relatively close to these results, but the results obtained from the strength of material approaches are not acceptable. From the study, it was revealed every method can be used to identify modulus of elasticity in fiber direction and major Poisson’s ratio but modulus of elasticity in the transverse direction and shear modulus can be calculated in other methods.
Determination of Boron in NdFeB Alloy by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
Authors: Ma Lan , Lian Weijie , Zhang Juncheng , Zhai Yuxin , Yu Qiong , Li Shuang
Published: September 2022

The alkali melting method was used to pretreat the specimens of Neodymium-iron-boron alloy, and the inductively coupled plasma atomic emission spectrometer was used to determine the main element boron in NdFeB alloy. The parameters of the instrument were optimized to select the best spectral line for the determination of boron, and the effect of matrix effect was overcome by adding Fe. The method has good precision and accuracy, the recoveries are in the range of 99%∼101%, and the RSD are less than 1%, which is suitable for the determination of boron in daily production analysis.
Microstructure Evolution and Element Redistribution in Carburizing Process of Ethylene Cracking Furnace Tube
Authors: Chen Jun , Zhang Zhenjie , Ding Xiaofei , Ma Haitao , Ma Haoran
Published: September 2022

Carburizing is the main damage form of ethylene cracking furnace tubes. In this process, the microstructure of the furnace tube would change and the element diffuses and redistributes. After serving for about 41000h, the radiation section of a plum blossom tube of SC-1 tubular cracking furnace from a petrochemical company was tested and analyzed in this article. Results show that the higher the service temperature, the more serious the carburizing of the furnace tube. In the inner-wall carburized zone of the middle temperature section of the furnace tube with an initial C content of 0.1wt%, the maximum C content reaches 1.83wt% and the number of carbides increases obviously as well as its organizational morphology changes from fine granular to coarse block or chain like and its organizational type changes from single M23C6 to the coexistence of M23C6, M7C3 and MC type carbides. The Cr and C elements in the carburized zone are mainly concentrated in the grain boundary area in the form of carbides. At the same time, the diffusion of alloy elements causes Cr deficiency in the matrix, and the carbide deficiency zone appears in the subsurface of the inner wall.
Detecting Lead Ion in Water with Boron-Doped Diamond Film Electrode
Authors: Zhang Xuanhao , Li Zhijun , Zhang Shengxiang , Li Jinyuan , Fu Chenxiu , Wu Liang , Liu Xinghong , Yu Xiang
Published: September 2022

Monitoring Pb2+ contentin drinking water is an important measure to safeguard water safety for residents. To overcome drawbacks available electrochemical sensors, this work attempts to fabricate a boron-doped diamond (BDD) electrode for detecting Pb2+ in water. A systematic investigation was conducted on microstructural and electrochemical performances of BDD electrode. The results show that, diamond grains arrange well on BDD electrode surface. The electrode exhibits a high electrochemical active surface area and low charge transfer resistance, favorable to accelerate the stripping reaction process of Pb2+. BDD electrode has a low detection limit in optimized parameter set. Also, the BDD electrode has a good anti-interference ability. The designed BDD electrode is expected to be applicable for monitoring Pb2+ content in waters.
A Photothermally Smart Hydrogel Material with Fast Response Properties
Authors: Wang Yixian , Mu Rong , Ren Haohao , Jia Bingsen , Gao Xiao , Sun Chufeng
Published: September 2022

Hydrogel is a kind of functional polymer material. Because of its excellent characteristics such as high-water absorption, biocompatibility and stimulus response, hydrogel is widely used in biological tissue engineering, drug-controlled release, wastewater treatment, chemical mechanical devices, household products and other fields. The traditional hydrogels often have some disadvantages, such as slow response rate and fragile, which limit the application range of hydrogels. In this paper, we prepared a photo curable hydrogel photothermal response driving material. Because PNIPAAm hydrogel has excellent thermal driving response effect, it will shrink when the temperature is higher than 32 °C, and gold nanoparticles are good photothermal response materials. Therefore, the hydrogel actuator can realize fast response driving, and has excellent photothermal response efficiency and good environmental adaptability. The research scheme is to first prepare gold nanoparticle sol with appropriate concentration, and then synthesize PNIPAAm /AuNPs nano hydrogel. Its performance was characterized by SEM, TEM and UV spectroscopy, and its driving performance was studied.
Research on Synthesis of Mesoporous Alumina Based on Utilization of Red Mud
Authors: Hao Bingyu , Zhong Li
Published: September 2022

A novel green controlled synthesis method is proposed in this paper. Mesoporous alumina was prepared by using sodium aluminate extracted from red mud as an aluminum source. The influence mechanism of temperature, template agent and sodium aluminate concentration on MA properties was studied systematically. The results show that the prepared mesoporous γ-alumina has a good catalytic activity of short-range arrangement, medium acidity, narrow pore size distribution, thermal stability and hydrothermal stability. This economical and green synthesis method can also be used to prepare other mesoporous or porous materials.
Fabrication and Microstructure Characterization of Cold Sprayed Al-SiCp Nanocomposite Coating
Authors: Zheng Xudong , Wang Hongtao , Wang Ruoyu , Zhang Wangnian , Bai Xiaobo , Ji Gangchang
Published: September 2022

A dense Al-SiCp nanocomposite coating with high volume fraction of nano SiCp reinforcement (60 vol.%) was fabricated through cold spraying deposition of milled Al-60SiCp nanocomposite powder in the present paper. Microstructure evolution of Al-SiCp nanocomposite powder during ball milling process, microstructure characteristics and hardness of sprayed Al-SiCp nanocomposite coating were studied. Al particles underwent fracture deformation and nano SiC particles were evenly distributed in the soft Al base material after ball milling. Dense Al-SiCp composite coating had been successfully prepared through cold spraying solidification of the milled nanocomposite powder. Nano SiC particles uniformly distributed in the as-sprayed Al-SiCp composites coating. Microhardness of Al-SiCp nanocomposite coating was highly reach up to 530±53 Hv0.3 compared to 34±3 Hv0.3 for the pure Al bulk.
Effect of B4C on the Microstructure and Mechanical Properties of SiC Refractory Ceramics
Authors: Chen Jiaxin , Chen Pingan , Li Xiangchen , Zhu Yingli , Wang Feng
Published: September 2022

In this paper, the effect of B4C content and heat treatment temperature on microstructure, mechanical properties and oxide resistance of SiC refractory ceramics were investigated. The results show that the inclusion of B4C could improve the crystallinity of gengerated SiC and graphitization. When the B4C content was 6%, the linear change of SiC-based refractory ceramics after heat treatment at 1450°C decreased from 1.39% to 0.58%. At the same time, the cold modulus of rupture and cold compressive strength increased by 1.8 times and 2 times, respectively. Meanwhile, with the increase of B4C content, the oxidation index of the SiC-based refractory ceramics decreased from 30.33% to 16.63% after oxidation at 1400°C.
Effect of Retrogressions on Precipitation Characteristics and Strength Property in an Al-Zn-Mg-Cu Alloy
Authors: Ren Weicai , Li Xiwu , Wen Kai , Zhang Yongan , Lv Xinyu , Xiong Baiqing
Published: September 2022

Retrogression treatment is a crucial process to obtain preferential microstructure and mechanical property for aviation Al-Zn-Mg-Cu alloys. In the current work, ramping time, preservation time and temperature were set as variations to investigate property evolution and precipitation characteristics for a commercial Al-Zn-Mg-Cu alloy. The results showed that the strength exhibited a continuously decrease trend with the enhancement of preservation temperature or the extension of preservation time. For a same strength level with different preservation temperature and time matches, GPII zone and η’ phase were detected as the main types of precipitates, which showed apparent coherency and semi-coherency with the matrix, respectively. Phases with relatively large size possessed larger proportions for higher preservation temperatures while the average grain size exhibited an increase trend. As for prolonging ramping time, similar strength degradation was observed under equivalent preservation regimes. For the same strength level with different ramping and preservation time matches, the precipitates were still GPII zone and η’ phase. With the prolonging of ramping time, the proportion of phases with relatively large size exhibited a decrease trend, so as to the average grain size (AGS). The subtle differences of precipitation characteristics and strength property matches were analyzed, which provided a promising way to improve overall performance of Al-Zn-Mg-Cu alloys.
Optimized Mechanical Properties and Oxidation Resistance of Al2O3-B4C-C Refractory Ceramics
Authors: Li Yaxiong , Wang Feng , Li Xiangcheng , Chen Pingan , Zhu Boquan
Published: September 2022

The effect of B4C addition (0, 3 wt%, 6 wt%, 9 wt%) on the mechanical properties and oxidation resistance of Al2O3-C refractory ceramics was studies in the paper. The results indicated that the addition of B4C could reduce the apparent porosity, increase the mechanical strengths and improve the oxidation resistance. After fired at 1100 °C, the specimen with 6 wt% B4C achieved lowest porosity and permanent linear change. The cold crushing strength was improved from 14.65 MPa to 47.18 MPa. The cold modulus of rupture was significantly improved from 12.1 MPa to 36.29 MPa. When the fired temperature rose to 1450 °C, the lowest porosity and permanent linear change were obtained when B4C additive was 3 wt%. CCS was significantly improved from 12.40 MPa to 57.32 MPa. CMOR was also increased from 7.16 MPa to 28.71 MPa correspondingly. Meanwhile, the oxidation index could be also reduced from 47.6% to 3.9% when B4C content was 6 wt%. These improved properties were due to the formation of liquid phase B2O3 by the reaction between B4C and O2/CO. The compact structure was constructed by volumetric expansion of B2O3.
LaB6 as a Functional Separator Modifier for Improved Lithium Sulfur Batteries
Authors: Zhang Tong , Jin Biao , Li Zhenzhen , Chen Chaoda
Published: September 2022

Metal borides have excellent chemical and electrochemical stability, high electrochemical sensitivity, and abundant active sites. According to experiments, metal borides can greatly reduce the shuttle effect in lithium-sulfur batteries and boost their electrochemical performance when used as sulfur host materials. In this thesis, we use polar lanthanum boride materials as materials for lithium-sulfur batteries that modify separators, and take advantage of its strong chemical bonding with polar polysulfides to reduce the shuttle effect. The experimental data demonstrate that the polar lanthanum boride can significantly improve the overall reaction kinetic performance as well as cyclic stability of the cell, resulting in excellent electrochemical performance.
Research on the Influence of Multiple Factors on the Deformation of the Detection Institutions
Authors: Liu Yanhua , He Gaoqing , Zhang Luping
Published: September 2022

The detection institution in this paper has higher requirements on precision and belongs to precision instrument. In order to improve the detection accuracy, the paper analyzes the deformation of the detection institution from many aspects, including the environmental temperature, the heat generated by the operation of the mechanism, and the structural stiffness. After determining the factors affecting the deformation of the institution, finite element analysis and experimental data analysis are carried out by software. According to the results of the analysis, the optimization scheme is designed, and the structure is optimized continuously to improve the accuracy of the detection mechanism.
Study on the Issue of Tooth Root Step After Gear Grinding
Authors: Zhao Liyuan , Xue Yu , Wang Xiaonan , Zhang Qingyu , Shen Xinjunan
Published: September 2022

Gear transmission is the most widely used transmission form in shearer. It has the characteristics of accurate transmission, high efficiency, compact structure, safe and reliable work, long service life and so on. The manufacturing level of gears also reflects the technical level of an enterprise producing shearers. With the development of shearers to high-power models, gear transmission is also developing in the direction of high precision, large load-bearing and long life. However, gears are subject to many factors such as load, working environment and so on. The tooth root of shearer is easy to be ground because the tooth root is not ground. The tooth root is discussed by analyzing the design of the Hob, the allowance of the retained grinding, the parameter setting of the gear grinder and the deformation of heat treatment. At the same time solving a major problem of how to avoid grinding the tooth root and grinding steps in the actual production of gears, and also lays a solid foundation for improving the service life of gears.
Application Research on Impact Tool Combining PDC Bit
Authors: Sun Mingguang , Zhang Haiping , Suo Zhongwei
Published: September 2022

With the development of oil drilling in depth, the strata are more ancient and abrasive. The Rate of Penetration (ROP) is low in conventional drilling methods, and Positive Displacement Motor (PDM) matching PDC bits is often used to improve it. However, the application of excessive Weight on Bit (WOB) would easily lead to PDM brake, over-standard well inclination, bit wearing aggravation and other bad phenomena. Moreover, the ROP improving effect is limited. As a result, a hydraulic jet impact tool was designed to use in conjunction with the PDC bit to integrate the advantages of vibration shock and rotary cutting in rock breaking process. The impact tool exerts dynamic load on the bit, which improves the rock breaking state at the well bottom and optimize the bit’s rock breaking efficiency as a result. Rock breaking mechanism of the PDC bit assisted by impact tool was analyzed, structure and working principle of the impact tool was introduced, and influence of tool structural parameters was analyzed based on indoor tests. Finally, field applications were carried out using the impact tool and PDC bits in the HY-4 wells of Saudi Aramco block and PX-3 wells in China. The ROP improving effects were 61.8% and 95% higher than that of the adjacent wells respectively. Application and analysis result proves the ROP improving effect of the impact tool combining the PDC bit in hard and abrasive strata.
Study on the Detection of Defects in Steel Plate Welds with θ Eddy Current Probe
Authors: Li Xuemin , Li Donglin , Guo Juncheng
Published: September 2022

The evaluation of weld defects plays an important role in ensuring the safety of equipment, but due to the unevenness of the weld itself, the use of conventional eddy current probes to detect weld defects can be affected by the lifting effect, so this paper introduces a new type of θ eddy current probe for the evaluation of steel plate weld defects. Firstly, using COMSOL simulation software, a model of the probe and the steel plate weld is constructed, and the effect of changes in excitation coil height and thickness as well as detection coil height and thickness on the detection sensitivity of the probe is fully investigated, and the optimum probe size is calculated by combining the results of simulation and optimisation analysis. Finally, the experimental platform is built and the test results show that the new θ eddy current probe has a good suppression effect on the lifting effect caused by the different width and depth of the weld seam and the lifting effect caused by the unevenness of the surface of the weld seam.
Modeling and Simulation of Tubular Form-Fit Joint Forming by Internal Rolling
Authors: Duan Xiaoyan , Yang Jingchao , Li Heng , Li Guangjun , Men Xiangnan , Xi Zhaohui
Published: September 2022

A method of tube joining by plastic deformation has efficient, reliable and environmentally friendly features, so that it is widely applied into the fabrication of aviation pipeline. Internal rolling has potential to join high strength titanium alloy tubes withstanding high pressure medium with better sealing performance. Taking TA18 titanium alloy tubes as the case material, this presentation combines numerical modelling with experiments to describe the deformation behavior of joining by rolling process. The distribution of the residual contact stress and plastic strain was analyzed by partitioning the deformation regions of the tube. Finally, it is concluded that a robust and accurate FE model of Internal rolling can be obtained.
Research on Dynamic Modeling and Cable Tension Optimization of Marine Cable-Driven Parallel Cleaning Robot
Authors: Li Jian , Chen Yizong , Wang Shenghai , Han Guangdong , Sun Yuqing , Luo Weirong
Published: September 2022

Ship cleaning is mainly done manually, which is high operation risk and low work efficiency. For that, it is proposed to apply the cable-driven parallel robot to the field of ship cleaning. The related research of the traditional cable-driven parallel robot is mainly focused on the fixed base, which largely ignores the influence of the base motion on its work performance. Considering the influence of ship motion caused by wave excitation on modeling accuracy, the dynamic model of the system is established by Newton-Euler method. And then, the least variance method of correlation force was used to optimize the cable tension. Finally, the correctness and rationality of the proposed theory are verified by Simulink-Adams co-simulation. The simulation results show that the trajectory comparison effect is good, which verifies the accuracy and validity of the proposed theory.
Accurate Simulation Technology of Cabin Connection Fracture Based on Damage Constitutive
Authors: Jiang W.X. , Wang C.H. , Jin J.F. , Qin Y.L. , Tong Y.N.
Published: September 2022

In this paper, based on the damage constitutive law of elastic-plastic materials, the virtual test platform plug-in was developed by using the built-in Python software of Abaqus to establish and form the virtual test capability of simulating the bearing failure process of the deck segment connection structure with high fidelity, and the precision confirmation technology of step by step model inspection was adopted. Virtual/real test comparison from test rod to end frame was carried out to verify the feasibility of virtual test of cabin connection structure. The results show that based on the model and algorithm, the relative error accuracy of the ultimate bearing capacity of the cabin connection structure can reach 12%.
Influence of Non-Metallic Inclusions on Fatigue Life of High-Speed Railway Bearings Steel
Authors: Sun Chengwu , Yi Ben , Zhang Gang , Guo Xiaohan , Jiang Danqing , Zhang Zhenqiang , Ren Zhongming
Published: September 2022

On the basis of simulation analysis, according to the process route from macro to micro, the effects of the contact stress on the raceway surface and the micro stress distribution of the inclusion on the raceway sub surface on the fatigue life of high-speed track bearings are simulated and analyzed. Firstly, by establishing the most common spherical inclusion as the simulated inclusion in this paper, the influence of subsurface stress in the case of inclusion is compared and analyzed, and the influence of the size, depth and type of inclusion on the stress is explored. Secondly, the influence of the change of fatigue life with size, depth and type is obtained from the fatigue life results calculated by the fatigue life calculation formula. The simulation results verify that the fatigue calculation model has a certain degree of accuracy, which provides a basis for the future research on the fatigue life of high-speed railway bearings.
Construction of MBD Model-Driven Quality Control Data Chain for Parts Machining Process
Authors: Zhai Cheng , Wang Meiqing , Cao Yansheng , Ye Chenhao , Zhong Wenhao
Published: September 2022

Aiming at the problems of inconsistent data sources and much manual intervention in the process of quality inspection planning, data acquisition and analysis of traditional parts machining, an MBD model-driven quality control data chain model for parts machining process is constructed. Firstly, through the analysis of the MBD model and the quality characteristics-oriented primary inspection planning, the automatic generation of the inspection task XML file for the inspection process is presented. Secondly, the automatic generation method of the MBD model-driven CNC program for the on-machine inspection of the CNC machine tool and the CMM inspection DMIS program is given. Then the automatic acquisition method of the on-machine measurement results of the CNC machine tool based on OPC UA and the CMM inspection results based on the secondary development of PC-DMIS are proposed, which realizes the automatic acquisition of quality data for process-oriented tasks, XML format packaging, and then realize the quality analysis and monitoring of the processing based on quality data. Finally, the MBD model-driven inspection planning and quality data acquisition system (MD-IPQDA) is developed, which significantly improves the accuracy and transmission efficiency of quality data verified by application.
Vibration Transfer Analysis of a Passive Hybrid Vibration Isolation System Based on Impedance Synthesis Method
Authors: Ma Junde , Wang Haiwei , Ren Yafeng
Published: September 2022

Precision instrument will be disturbed by the vibration of mechanical equipment in the working process, which will deteriorate its normal operation and delay the test progress. So, it needs to be protected by vibration isolation device. In this paper, a hybrid vibration isolation platform is proposed which contains a high static low dynamic quasi-zero stiffness isolation system and a passive bilayer isolation system. And a fully flexible impedance dynamic model is established for this system based on the impedance synthesis method. The vibration transfer characteristics of the hybrid platform under the real excitation of the engine testbed are analyzed and verified by relevant tests. Results show that the designed vibration isolation device has fine broadband vibration isolation effect and can meet the usage requirements.
Study on Thermal Stress and Fatigue Stress of Nuclear High Temperature and High Pressure Three-Way Valve
Authors: Chen Yiwe , Shi Hong , Wei Dong , Wang Yan
Published: September 2022

The seismic performance of nuclear power valve is one of the important indexes to measure its safety and reliability. The seismic performance analysis, thermal stress calculation, fatigue analysis and experimental verification of a nuclear class I three-way valve are carried out. Firstly, the natural frequency, stress and strain of a three-way high temperature and high pressure valve are analyzed. Secondly, the calculation methods of thermal stress and fatigue stress of the three-way valve are put forward. Finally, through the frequency sweep test and seismic test of the valve, the natural frequency and operability of the valve are verified, that is, the designed valve meets the design specifications and can meet the working conditions. The analysis results of this paper provide a theoretical basis for the seismic stress and operability analysis, thermal stress and fatigue analysis and further design optimization of this kind of high temperature and high pressure nuclear three-way valve.
Design of Common Rail Fuel Pipe for High Pressure Direct Injection Natural Gas Engine in Marine Cylinder
Authors: Ji Xiaojuan , Liu Kunran , Yu Maolin
Published: September 2022

The natural gas common rail Fuel pipe which is an important component of marine high pressure direct injection natural gas engine is need to optimize. A 1-D dimensional working process model including natural gas common rail pipe and high-pressure natural gas pipe was established in this paper and different common rail pipe schemes was compared and analyzed. The results show that transient pressure fluctuation before the first cylinder injector in the four schemes of short natural gas common rail pipe is little difference, and the cyclic variation coefficient decreases with the increase of the volume. Finally, the short common rail pipe scheme 1 is choose as the best design scheme.
Evolution of Microstructure and Mechanical Properties of the Gears on Coal-Cutting Machines in the Processes of Rapid Carburization and Heat Treatments: Numerical Modeling and Experiments
Authors: Yuan Yuedong , Zhang Qingyu , Xue Yu , Shen Xinjun , Jiang Yang , Liu Kun , Wang Xiaonan
Published: September 2022

To modify the rapid carburization and heat treatments of 18Cr2Ni4WA heavy-duty gears on coal-cutting machines, numerical modeling and experimental investigations are carried out for understanding the evolution of microstructure and properties. Through numerical modeling, the fractions of austenite, bainite, and martensite are evaluated. The Vickers hardness distribution across the hardening layer, calculated by the Maynier equation, compares well with the experimental measurement. The microstructure of the hardening layer is mainly composed of fine martensite and carbides, while that of the interior area is the martensite. The gradient of the microstructure from the hardening layer to the interior area leads to the variation of the hardness distribution. The experimental results show that the high-temperature tempering and quenching are beneficial for the refinements of the grains in the hardening layer and the interior area. The present study indicates that the combination of numerical modeling and experimental observation provides a powerful tool for the modification and improvement of the carburization and heat treatment processes.
A Research Method of IGBT Non-Stationary Mode for Power and Electrical Equipment Control
Authors: Lu Zhiyu , Popov Maksim G. , Zakharova Elena V. , Gushin Mikhail V. , Paschoareli Jr. Dionizio
Published: September 2022

The non-stationary mode characteristics of the generalized power equipment numerical experiments are analyzed, and the electrophysical dynamic characteristics and reliability of the IGBT in the power conversion process are studied. Based on the results of short-circuit numerical experiments and the steady-state mode of pulse width control, this paper introduces a method for analyzing the nonlinear dynamic process of IGBT drive modules during power conversion. The structure of a software algorithm for conducting numerical experiments to study the non-stationary operation mode of asynchronous electromechanical machines is proposed, and the numerical solution of transient nonlinear differential-algebraic equations of electrical equipment is described by gradient parameter method. The results of this study will help to study the dynamic nonlinear characteristics of the operation process of power and electrical equipment control and automation tools, and have practical significance for evaluating the computational efficiency and reliability of developing mathematical models in the next research work.
Research on Cold End Diagnosis and Optimization of Thermal Power Unit with Coal Consumption as Objective Function
Authors: Jia Changwu , Ma Kuiyuan , Li Wei , Liu Gang , Xue Qingyuan , Chen Zenghui
Published: September 2022

In this paper, the optimal operation system of circulating water of thermal power unit is perfected. Through field test and theoretical calculation in different thermal power plants, the optimal operation mode of circulating water of different modes is determined under different load, water temperature and exhaust steam pressure of low-pressure cylinder. Taking the coal consumption rate of power supply unit as the objective function of circulating water system optimization, the analysis and calculation model of circulating water system optimization was established. The influence coefficient of exhaust steam pressure on power and heat consumption rate between low load condition and rated condition was studied by field measurement and theoretical calculation method, so as to improve the accuracy of optimization conclusion in low load condition.
A Sensor Waveform Conversion Management System
Authors: Zhang Ying , Wang Tuo , Jiang Cunsheng , Wang Hongqian , Feng Li
Published: September 2022

The management system consists of a sensor waveform conversion system, a fault handling detection system, and a switching execution system. In this paper, the integration circuit is used for waveform transformation, the elimination of the offset voltage of the amplification circuit, and the integration compensation in feedback control. And we collect data from each state of the system under test, and use the redundant fault-tolerant system to manage and warn the system status to verify the effectiveness of the model. Combined with the waveform generation circuit and the waveform transformation circuit, the output of the signal generator is connected to the input of the integration circuit. The function of the waveform transformation system is to transform one waveform into another waveform, which can convert the square wave into a triangular wave. The redundant fault tolerance model proved to be effective on this management system, that is, the redundant fault-tolerant system has good generalization and can be implemented in the aerospace scene.
Design of γ-Suboptimal H∞ Speed Controller for Diesel Engine
Authors: Chang Guanghui , Su Pan , Zhang Yachao
Published: September 2022

Diesel engine is a complex nonlinear system. In view of the uncertainty of the model in the process of linearization of diesel engine model and the insufficient robustness of the existing PID controller, the robust control theory is applied to the speed control of diesel engine. Firstly, the quasi-steady state model of diesel engine is locally linearized to establish its state space model. Then, by analyzing the robust stability under friction torque uncertainty, the diesel engine speed H∞ controller is established, and the control law is finally obtained by solving the LMI method. Finally, a simulation experiment is designed in the MATLAB/Simulink environment. The simulation results show that the designed speed controller has strong model fault tolerance, good resistance to external disturbance, and the speed regulation is obviously better than the traditional PID speed controller.
Manipulator Trajectory Tracking and Force Compliance Control Based on Model Predictive Control
Authors: Yang Rui , Liu Zhaoming , Mu Li , Liu Nailong , Miao Lei , Wang Hongwei , Cui Long
Published: September 2022

The pillar shaping work of solid rocket motors involves complex trajectory tracking and force control problems, which are dangerous by manual operation. In this paper, a position control method based on MPC is proposed, and the admittance control is used to realize the local compliance of the manipulator contact force. In the numerical simulation, the control manipulator tracks a given trajectory and the manipulator shows suppleness in contact with the environment in the presence of external forces. Simulations were conducted to compare the MPC control method based on the improved computational torque control with the conventional PID method, with the fastest reduction of 0.34s in the regulation time and up to 0.165 rad in the overshoot.
Research on Low Overlap Point Cloud Registration Algorithms in Medical Surgery
Authors: Wang Yunmeng , Liu Zaoming
Published: September 2022

With the development of medical surgical navigation system, more and more orthopedic surgeries benefit from the accurate real-time positioning of the navigation system. Due to the extremely high time cost in surgery, how to achieve accurate and fast registration with a small number of manually extracted key points is a research problem in the field of medical point cloud registration. In this paper, the algorithm of point cloud rough registration stage is improved, and a new registration algorithm, SSAC+ICP, which is suitable for medical surgical navigation system with low overlap rate is proposed. Four groups of fusion experiments were performed to register the CT point cloud images of spinal contours and the manually collected key point cloud data. Experimental results show that the registration accuracy of SSAC algorithm is much higher than that of NDT, 4PCS and PCA.
Digital Twin of Non-Ferrous Metal Casting Robot
Authors: Wu Hang , Liu Zhaoming , Cui Long , Guan Lirong , Wang Hongwei
Published: September 2022

The robot system for non-ferrous metal casting process can replace a large number of manual operations while ensuring product quality, and complete the casting process independently. The automatic casting process requires a robot to pour molten metal quickly and accurately into a mold that moves in real time. To achieve this, traditional robots adjust the path through manual teaching. The steps of manual teaching take an immense amount of time and effort. In addition, temperature is the main factor affecting the service life of the robot. The service life of various precision parts of the robot will be significantly reduced under the high temperature environment of metal casting. This paper presents a digital twin system for optimizing traditional non-ferrous metal casting robots. By establishing a digital twin platform, twin robots, virtual scenes and the physical world mapping, the problem of long manual teaching time is solved, an algorithm for estimating the service life of the rolling functional parts of the joint bearing is proposed, and the casting robot is obtained. The end joint bearing functional parts work continuously for one day in the actual casting scene, and their service life is reduced by about 3.9%. Estimated service life of robot functional parts can prevent some potential failures of robot equipment and improve the overall service life of the robot.
The Influence of Electrode for the Electrochemical Dyeing of Cotton Fabric
Authors: Hou Yinyan , Jiang Yingze , Huang Guinian , Niu Yanping , Hu Yujiang , Wei Jiaqi , Xiong Wei
Published: September 2022

Using nickel electrode as dyeing electrode, sodium carbonate as fixing alkali and anodic region as dyeing region, cotton fabric was electrochemically dyed by reactive blue X-BR under external DC power supply. By comparing the dyeing rate, fixation rate, polarization curve and evenness of the two dyeing methods, it can be concluded that the electrochemical dyeing effect of nickel electrode on reactive dye cotton fabric is far better than that of traditional reactive dye dyeing method.
Multi-Layer Compound Passivation and Dual-P Diffusion Enhanced Si Power Diode Performance
Authors: Jiang Xianwei , Wang Haibo
Published: September 2022

Power diode with multi-layer compound passivation and dual-P typed diffusion are studied and manufactured. Combine multiple advantages, a power diode with reverse breakdown voltage higher than 2200V, static on-resistance 1.11Ω and leakage current of 8.3mA can be obtained on silicon with a drift layer thickness of 280um and a resistivity of 60Ωcm. Simulation shows multilayer passivation layer with polysilicon contact can effectively change the edge carrier distribution, thus reducing the transverse current generation and improving the voltage withstand. Inserting a light and deep aluminum doped layer into PIN diode can increase the reverse withstand voltage by more than 16% through expanding depletion layer. And the moat structure of the device can further reduce the edge peak electric field, thus reducing the risk of breakdown. This device can be used in switching power supply and inverter.
Evaluation Technology of Service Life of Electrical Cables Based on Arrhenius Model
Authors: Yuan Donghui , Di Jiancai , Lü Xiaopeng
Published: September 2022

The electric cable is one of the most important materials in the high speed train, accurate service life directly affects the safety of the operation of the motor car group and the operating cost of the vehicle. Due to the importance of cable life assessment, based on Arrhenius model, this paper evaluates the service life of the cable. First, the mathematical model of Arrehenius is deduced, at the same time in order to solve the problem to facilitate the corresponding simplification, the parameters of the model were obtained by the least square method. Finally, the feasibility of the method is verified by the accelerated thermal aging test of the cable.
Edge Computing Resource Optimal Allocation Method Based on Blockchain Technology
Authors: Jia Pingfan , Cao Junhai
Published: September 2022

An edge computing resource optimal allocation approach based on blockchain technology is suggested to achieve efficient and safe allocation of edge computing resources. The edge computing resource optimal allocation approach based on priority task is utilized in the method to reduce calculation time and energy consumption while achieving resource optimal allocation based on work priority. In the resource allocation, the resource privacy protection method based on private blockchain is adopted to ensure the resource security in the resource allocation for edge computing. The proposed strategy considerably improves the efficiency of edge computing in resource allocation, according to the experimental results. In comparison with the results before using the method, the energy consumption after using the method is reduced by at least 13 J. The safety coefficient of the optimal allocation of the edge computing resources is as high as 0.95. The time consumption of edge computing resource allocation of this method is shorter. Therefore, the method can quickly adapt to the increase of data volume in comparison with the similar methods, so as to adjust the allocation for edge computing resources at the fastest speed, and achieve the optimal allocation of edge computing resources.
A Distributed Secondary Frequency Control Method with Photovoltaic and Energy Storage
Authors: Wu Xinhua , Wu Xiaogang , Ji Qingfeng , Du Qianyun , Zhou Yifei
Published: September 2022

With more and more distributed microgrid such as the photovoltaic and energy storage connected to the isolated microgrid cluster, the power flow of the traditional microgrid are deeply integrated, which reduces the control ability of the isolated microgrid and makes the voltage and frequency fluctuation more and more frequent. The paper first puts forward the distributed cooperative control theory based on microgrid, then applies the distributed secondary frequency control method of the distributed microgrid cluster with the photovoltaic and energy storage. The simulation experiment of the distributed microgrids distributed control shows that the frequency secondary control method of distributed microgrid proposed in this paper is effective and practical.
Analysis of Temperature Drift in Precise Temperature Measuring Circuit of 12.5 μm Long Wave Infrared Detector
Authors: Dong Jie , Jin Zhanlei , Song Li , Xu Yunfei , Xu Lina , Yuan Na
Published: September 2022

The 12.5μm long wave MCT infrared detector requires mK temperature control precision, which makes the temperature drift suppression problem of precision temperature measuring circuit prominent. Firstly, the temperature drift model of the precise temperature measuring circuit is established in this paper, and the influence of ambient temperature change on the accuracy of temperature measurement circuit is deeply analyzed. Secondly, according to the classical design parameters, the temperature drift model of temperature measurement circuit is simplified, and the main influence parameters of temperature drift are determined by the first level operational amplifier and reference voltage reference, therefore, some suggestions are proposed to reduce the temperature drift of precision temperature measurement circuit. Finally, the test results show that the output of precision temperature measurement circuit drifts 16mK with every 1°C change of ambient temperature. The test data is consistent with the theoretical analysis results, which proves the correctness of the temperature drift model. The temperature drift model provides an important design method for the temperature drift suppression of precision temperature measurement circuit.
A System with Minimal Redundancy for Intelligent Prediction Management
Authors: Zhang Ying , Wang Tuo , Shi Dongqiang , Tao Yizhu , Feng Li
Published: September 2022

This paper proposes a predictive redundancy method for management, which is used for intelligent prediction management, which can effectively improve the real-time online reliability of agents. This method changes the multi-redundant post-processing scheme of traditional system and adopts single-redundant real-time pre-switching. Through a large number of experiments, the feasibility of the system is verified, and the system can be built as a redundant fault-tolerant system. The redundant fault-tolerant system has good generalization and can be implemented in the scene. A redundant module that is about to fail is used, including: the proposed redundant module that continues to decline in health, a redundant module that rapidly decreases in health at a certain time, and a redundant module that is always in a sub-healthy state. After the health assessment, you can enter the early warning model and observe whether the early warning model can issue a health warning, which can verify the effectiveness of the early warning model.
The Mutation Analysis of Ultrasonic Acoustic Emission in Cavitation
Authors: Sui Meili , Lin Chen , Wang Nan , Wang Jianxin
Published: September 2022

Cavitation and embolization of plants accompanied by conduit vibration due to intermolecular adhesion of water or the adhesion of the conduit wall are signs of water stress. Ultrasonic acoustic emission (UAEs) was used to detect plant air pockets and embolic events transmitted by vibration. The UAEs could be detected in ultrasonic frequency between 100K Hz and 1 MHz. In general, the spatial location of UAEs sources for the influence of signal spatial distribution are greater than the UAEs signal wave shapes to the time. Using the electro-acoustic similarity theory, UAEs can be seen as the step voltage sources, the medium as the load, the water column rupture model (UAEs mutation model) in the plant conduit can be established by the analog circuit method. Without considering the change of plant stems medium density and ultrasonic velocity, the ultrasonic energy is proportional to square of the ultrasonic pressure. According to plant water stress relationships between ultrasonic energy release and ultrasonic energy, the UAEs ring counts or signal strength can be used to indicate the range and extent of plant conduits embolism, which can establish the model of UAEs and physiology by statistical laws. Studies have shown that the UAEs waves transmit in the plant fiber, signal attenuation in the fiber is a function of cell tissue hardness, and the approximate attenuation values are 1 dB/cm, 10 dB/cm and 20 dB/cm in hardwood, softwood and herbaceous plants, respectively.