bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Intelligent Geomagnetic Search Navigation Method Based on Evolutionary Gradient Strategy
Authors: Ren Xintian , Zhang Qi , Pan Mengchun , Chen Dixiang , Liu Zhongyan , Hu Jiafei , Chen Zhuo , Wang Zhenxiong , Wang Ze 
Published: May 2021

Abstract
Currently, most of the geomagnetic navigation methods are matching navigation algorithms, which require the geomagnetic maps retrieved in advance, and saved in a database. However, there are a great number of unknown environments exist worldwide that limit the extensive application of the geomagnetic matching method in practice. In this paper, an intelligent geomagnetic search navigation method based on the evolutionary gradient search (EGS) algorithm is proposed. The performance of the search and navigation method is analysed with both simulated and real geomagnetic data. And the conclusion is that compared with other intelligent search strategies, the proposed algorithm has better navigation performance with less average navigation error, 161m, which is equivalent to the most traditional geomagnetic matching algorithms. Thus, the EGS algorithm proposed in this paper can effectively improve the performance of geomagnetic navigation without prior geomagnetic information.
Data-driven multi-objective optimization of laser welding parameters of 6061-T6 aluminum alloy
Authors: Wu Jianzhao , Zhang Shuaikun , Sun Jiahao , Zhang Chaoyong 
Published: May 2021

Abstract
In this paper, a data-driven multi-objective optimization approach using optimal Latin hypercube sampling (OLHS), Kriging (KRG) metamodel and the non-dominated sorting genetic algorithm II (NSGA-II) is presented for the laser welding process parameters on 6061-T6 aluminum alloy. The experiments are designed by OLHS and carried out to obtain the data results. The complex relationship between the process parameters and the bead profile geometry is established by KRG using the data results. The accuracy of the established KRG metamodel is validated using experiments. Then, NSGA-II is used to explore the design space and search the Pareto optimal solutions of process parameters. Besides, the validation experiments were carried out to obtain ideal LW bead profile, which shows that the approach can bring dependable guidance for LW experiments.
Modeling and Motion Simulation of a Stamping Manipulator
Authors: Zhang Weiwei 
Published: May 2021

Abstract
With the development of modern industry, manipulator gradually replaces manual operation. The manipulator needs high accuracy in the process of grasping the workpiece, moving and placing the workpiece. After designing the manipulator according to the working environment and related parameters, it is necessary to model and simulate the manipulator, which has determined whether the motion trajectory is accurate and whether the motion is stable and reliable. As a result, the MATLAB software is used to simulate the motion of the manipulator between two points. It can be seen from the curve of displacement, velocity and acceleration that the manipulator runs smoothly and reliably.
A framework of modelling slip-controlled crack growth in polycrystals using crystal plasticity and XFEM
Authors: Zhang P. , Lu S. , Baxevanakis K.P. , Zhao L.G. , Yu T.Y. , Zhou R.X. 
Published: May 2021

Abstract
Short cracks tend to develop at high and irregular rates compared to macroscopic cracks, making the prediction of fatigue life a challenging task. In this work, a numerical framework combining crystal plasticity model and the Extended Finite Element Method (XFEM) is applied to study the slip-controlled short crack growth in a polycrystal superalloy RR1000. The model is calibrated from experiments and used to evaluate short crack growth paths and rates. Two fracture criteria are used and compared: the onset of fracture is controlled by the total and individual cumulative shear strain respectively, and the crack grows either perpendicular to the direction of maximum principal strain or along crystallographic directions.
Research on the origin of solid super-slip and friction based on Raman spectroscopy
Authors: Zhang Ruijie 
Published: May 2021

Abstract
It is estimated that about 1 / 3 ~ 1 / 2 of the world’s energy consumption is caused by friction and wear. About 80% of the parts of general machinery and equipment are scrapped due to wear. In China, the annual loss caused by friction is more than 4 trillion. Therefore, to explore the origin of friction and realize solid super sliding has become a key point of people’s attention. But the basic scientific principle and mechanism of friction origin are difficult to explore, so how to give a reasonable method to solve this problem is particularly important. This paper focuses on the use of Raman spectroscopy to observe the solid super slip phenomenon and phonon dissipation, through Raman spectroscopy to determine the orientation of molecules on the friction interface, detect the related properties of two-dimensional materials, as well as crystal defects and their apparent morphology to explore the origin of friction, and to reduce the energy loss caused by friction.
Residual Value Evaluation of Operating Pure Electric Vehicles Based on Machine Learning
Authors: Wang Yujiu , Huang Miaohua , Chen Kailun 
Published: May 2021

Abstract
In view of the current imperfect second-hand evaluation system for new energy vehicles, there are limitations such as simple evaluation models, strong subjectivity, and large evaluation differences. This paper establishes the residual value evaluation model for operating pure electric vehicles, combining actual vehicle operation and maintenance data and establishes the residual value rate evaluation model based on the XGBoost algorithm and Boosted Trees enhanced algorithm. The multi-dimensional feature data of vehicle type, service time, mileage and region are extracted by feature engineering, and the evaluation system of residual value rate correction coefficient is established based on AHP. Finally, based on residual value rate evaluation model and the residual value rate correction coefficient system model to optimize the replacement cost method evaluation model, thereby constructing a complete residual value evaluation model. The model is based on actual vehicle operating data and machine learning algorithms, which has strong pertinence and real-time for the residual value evaluation of pure electric vehicles.
Research of uneven arc burning of parallel necks of DC fuse
Authors: Yin Fan , Shen Bing , Wu Zhuang Jin 
Published: May 2021

Abstract
When breaking low current, DC fuse is prone to voltage drop. It is caused by uneven arc burning between parallel necks. The problem of uneven arc burning in parallel slows down the breaking speed of the fuse, and in severe cases causes the fuse to overheat and arc spray. To solve this problem, this paper establishes a mathematical model of fuse arc, a commutation model between parallel necks and a pre-arc time model of necks. Based on Matlab, the current of each branch is calculated as well as temperature of necks. Then this paper explains the cause of uneven parallel arcing and analyzes the influence of the machining error and current on the phenomenon. Finally this paper calculates the minimum current density that fuse can arc evenly in parallel under different machining errors, and the conclusion can be used to guide the design of DC fuse.
Failure analysis of phase B pull rod of HGIS circuit breaker operating mechanism in 220 kV Substation
Authors: Lyu Lei , Chen Hao , Zhang Yanfei , Bai Haolun 
Published: May 2021

Abstract
The B-phase pull rod of HGIS circuit breaker operating mechanism in a 220kV substation was broken at the root. The broken pull rod was analyzed by macro examination, metallographic examination, chemical composition analysis, fracture morphology analysis and impact test to find out the reason for the fracture. The results showed that: 1. Due to the improper heat treatment in the manufacturing process, the metallographic structure of B-phase pull rod appeared network ferrite and widmanstatten structure, which made the material brittle and impact toughness lower than the standard requirements; 2. The content of alloy elements Cr, Ni and Ni were significantly higher than the standard requirements, which reduced the plasticity and toughness of the material; 3. The low temperature of substation environment led to the decrease of material toughness and the viscosity of the lubricant decreased, causing the transmission parts to jam. The joint action of three factors led to cleavage fracture of B-phase pull rod in the stress concentration area.
Fatigue failure and launch safety assessment of gun barrel
Authors: Zheng J , Li H J , Wu B 
Published: May 2021

AbstractHundreds or thousands of projectiles have been fired through a gun barrel. Catastrophic fatigue failure of gun barrel due to cyclic loadings by the stresses induced by the combination of high pressure and temperature combustion gas, and projectile with the rotating band interaction with the bore surface, has not yet been understood. In this paper, laboratory hydraulic fatigue tests on simulated gun barrel were performed on MTS Land. The experimental results show that there is an inherent relation between crack propagation in thick-walled tube and the external surface hoop and axial strains. This fact suggests that fatigue failure of gun barrel should be likely prevented by monitoring the external surface strains of the gun barrel and stopping continued firing before a major crack growing up to the critical size.
Beam collimation scheme of laser wireless power supply system for high potential monitoring node of power transmission and transformation
Authors: Feng Huang , Hui Huang , Hui Deng , Yang Tianyi , Zhang Xiangyu 
Published: May 2021

Abstract
Laser wireless power supply technology has the advantages of high energy density, good directionality, small transmitting and receiving aperture, convenient and flexible installation and deployment. It is very suitable for power supply for sensors or mobile electrical equipment in complex high potential environment, such as patrol UAV. Because the beam quality of high-power semiconductor laser is far worse than that of other types of lasers, when it is used as the transmitter of beam shaping system, it must be equipped with corresponding beam shaping system to obtain laser beam with uniform spot, appropriate size and small divergence angle, so as to ensure that the photoelectric cell module has high conversion efficiency and meet the needs of long-distance laser transmission. In this paper, a beam collimation scheme based on aspheric lens group is designed, which integrates optical devices with low cost, reduces the energy loss in the process of laser transmission, and obtains laser beam with certain intensity uniformity. The test shows that the collimator can better meet the parameter requirements of the collimation system.
A nonlinear model between life cycle cost, service time and recycling quality level of waste engine parts under uncertain environment
Authors: Shi Junli , Ma Mingyang , Ma Yundong , Liu Huanyu , Ma Qinyi 
Published: May 2021

Abstract
Engine is the core of auto parts. It has great economic and social benefits for retired engines and their parts by remanufacturing. However, in recycling process, the uncertainty of quality status of retired engines leads to the uncertainty of life cycle cost, which makes it difficult for technicians to evaluate the cost. In order to address the problem mentioned, this study sets up a nonlinear model between the life cycle cost, service time and the quality level of used engine parts by considering damage degree in recycling process of used engine parts as a research index and takes 50 heavy-duty engine connecting rods as an example, which provides a theoretical basis for remanufacturing enterprises to evaluate the cost and determine the remanufacturing process accurately.
Research on an Improved Induction Power-taking Method for Smart Grid Monitoring Equipment
Authors: Yang Mengqin , Yang Jun 
Published: May 2021

Abstract
The development of smart cities is inseparable from the support of smart grids. Transmission lines are the bloodline of the smart grid. Due to the geographical environment and insulation conditions of the transmission lines, the power supply of its monitoring equipment cannot directly transfer electrical energy from the cable. The low-pressure end is transferred to the high-pressure end. In order to ensure the smooth operation of the smart grid, the development of an online monitoring device that can continue to work reliably in different environments is a prerequisite to ensure the effective operation of the transmission line[1]. Aiming at the technical bottleneck of monitoring equipment, this article improves the conventional induction power extraction method, and proposes an induction power extraction method based on parallel resonance, by matching the capacitor in the secondary winding of the magnetic core with the corresponding excitation inductance, parallel resonance occurs, thereby increasing the equivalent impedance of the damping branch where the magnetic core is located, so that the load can obtain more power through another branch. Finally, an electromagnetic core electromagnetic simulation experiment was carried out by using Ansoft Maxwell simulation software to verify the effectiveness of the method.
Effect of two-stage aging on hardness and electrical conductivity of as-extruded 7075 aAluminum Alloy
Authors: Cao Fenghong , Qin Zhaohui 
Published: May 2021

Abstract
The effect of two-stage aging on the microstructure and properties of as-extruded 7075 aluminum alloy was studied by means of hardness, conductivity and microscope. The results show that: in the process of solution and primary aging, with the increase of heat treatment time, the hardness and electrical conductivity of the alloy have little improvement, but there is a strong linear correlation between hardness and electrical conductivity, that is, the change of hardness and electrical conductivity presents the same trend; after two-stage aging treatment, with the extension of aging time, the hardness of the alloy first increases, reaches the peak value, and then decreases gradually, the hardness and conductivity have a strong negative linear correlation; and with the increase of aging temperature and aging time, the hardness of the alloy decreases by 9.6%, while the conductivity increases by 18.6%.
Diaokou River Estuarine Sediment Movement Numerical Simulation Analysis Based on two Dimensional Numerical Model
Authors: Ma Liangchao , Jiang Caodong , Li Dongfeng , Zhang Hongwu , Li Zihao 
Published: May 2021

Abstract
The sediment movement and deposition diffusion regularity of the Diaokou River are related to the safety and stability of the northern coast and coastal ports of the Yellow River Delta, and the deposition of sediment in the estuary will lead to the extension of the river and the increase of river resistance. As a result, the water level of the Yellow River estuary and the lower reaches of the Yellow River rises, which has a negative impact on the flood control safety of the lower reaches of the Yellow River. Therefore, it is of great significance to study the sediment deposition and diffusion law of the Diaokou River into the sea. Using the verified two-dimensional numerical model of marine sediment of estuary rivers, the sediment movement of Diaokou River into the sea is calculated, and the marine dynamic characteristics such as tidal current and tide in the sea area near the Diaokou River into the sea are analyzed. The spatial and temporal distribution of sediment concentration in sediment movement and the increase of sediment deposition thickness in sediment movement are consistent with the analysis results of measured data.
Study on the influence of tunnel construction on existing tunnel below by above-crossing tunnel
Authors: Liu Chun , Zhang Qing , Liu Heng 
Published: May 2021

Abstract
During the construction of the above-crossing tunnel, the surrounding rock of the existing tunnel will be disturbed in different degrees due to the different spacing between the upper tunnel and the existing tunnel. In order to study the regular pattern between the surface deformation of the existing tunnel surrounding rock and the tunnel spacing, the surrounding rock deformation of 10 groups of existing tunnels with different spacing is studied by numerical simulation based on the project of the upper loop section of Chongqing rail transit line 9. The results show that the uplift deformation of the vault of the existing tunnel will be caused by the construction of the upper double-track tunnel, and the final deformation of the existing tunnel is in the shape of “M“. The maximum displacement of the existing tunnel decreases first and then increases with the increase of the transverse distance of the upper crossing tunnel, but the maximum displacement of the existing tunnel does not change much; As the vertical distance between the new tunnel and the existing tunnel increases, the maximum displacement of the existing tunnel decreases linearly within the 3L vertical distance. It gradually stabilized after 3L, indicating that the existing tunnels beyond 3L are almost unaffected by new tunnels.
Online estimation of state of health for lithium-ion batteries in electric vehicles based on voltage integral and temperature
Authors: Chen Kailun , Li Qizhong , Wang Yujiu , Huang Miaohua 
Published: May 2021

Abstract
In order to achieve accurate online State of health estimation of power battery, this paper proposes a method based on voltage integration and temperature. Based on the NASA ternary lithium battery accelerated life test, three groups of battery experimental data are divided according to the difference in temperature and discharge rate. According to the single battery data and battery experimental data required to record in the Chinese national standard documents, the feasibility of voltage integration as a characterization of battery health is verified. Then we discussed the charging and discharging behavior of electric vehicles and combine the Particle Swarm Optimization algorithm to select the voltage integral of the fixed voltage interval in the charging stage as the equivalent health factor of the battery health state, and establish a battery health state estimation model based on the Gaussian process regression with the temperature and voltage integral as input. The proposed method is verified by experimental data. The proposed method is suitable for online estimation of battery health status under different temperatures and different discharge rates. The root mean square error and average absolute error of battery health status estimation are both less than 1.4%.
Exploration of the safety management and maintenance of machinery manufacturing and processing equipment
Authors: Wu Guoming 
Published: May 2021

Abstract
With the rapid development of the economy, various industries are also rapidly growing and progressing, and the machinery manufacturing industry has also made greater breakthroughs. If various industries can achieve the goal of automatic production of machinery, mechanical equipment will be a crucial factor. The machinery manufacturing industry has a lot of room for development, and machinery manufacturing technology has also made tremendous progress. If the machinery and equipment produced by the machinery manufacturing industry become more and more excellent, it needs to try to meet the production needs of all walks of life, and improve the quality of manufacturing equipment. The current problems in the process must be solved, such as equipment failure, safety management.
Instrument Transformers Detection and Calibration with Synchronized Phasor Measurements
Authors: Peng Zhang , Hao Liu 
Published: May 2021

Abstract
Instrument transformers with deviation can lead to biased measurements. It causes problems for various applications that use voltage and current measurements. This paper presents a method for detecting and calibrating instrument transformers using synchronized phasor measurements, while the validity of the proposed method is verified via simulation. It is shown that the proposed method can evaluate the instrument transformers and all the Ratio Correction Factors (RCFs) of instrument transformers can be calculated, which can improve the accuracy of measurements. The proposed approach is robust to system uncertainty and noise.
Motion Simulation Analysis of the Horizontal Sealing Device for the Bulk Material Packaging Machine Based on SOLIDWORKS Motion
Authors: Ning Tingzhou , Zhang Yao , Fu Ling 
Published: May 2021

Abstract
In the past, the horizontal sealing mechanism of the bulk material packaging machine has a cam type and a cylinder type. The cylinder type horizontal sealing mechanism has a great impact when the speed changes, while the cam type horizontal sealing mechanism will cause noise and vibration. In this paper, the three-dimensional model of horizontal sealing device for bulk material packaging machine is carried out by SOLIDWORKS software, and the motion simulation analysis is carried out by using the add-in SOLIDWORKS motion. The results show that the acceleration of the horizontal sealing head for the horizontal sealing device occurs in 1/4 and 3/4 of the entire movement cycle. The horizontal sealing device can adjust the speed to meet the horizontal sealing requirements of different packaging bags. The horizontal sealing device of the bulk material packaging machine designed in this paper provides a reference for improving the packaging efficiency of products.
Cause analysis and preventive measures of 500kV shunt reactor bushing failure
Authors: Yang Xuefei , Yang Youtian , Zhang Gongliao , Yao Ribin , Lv Lifan 
Published: May 2021

Abstract
In response to a recent 500kV line shunt reactor high-voltage bushing failure event in a station, This article examines and analyzes the objects and protection actions after the casing is disassembled. It was found that the cause of the casing failure was caused by the arc igniting the insulating oil in the casing after the main insulation of the casing was discharged. Finally, corresponding preventive measures are proposed from the perspective of on-site operation and maintenance.
Research on the Influence of Device Thermal Equivalent Model on the Temperature Field of Infrared Hot Air Reflow Soldering
Authors: Yin Yutian , Ji Chenyang , Gong Yubing 
Published: May 2021

Abstract
Infrared hot air reflow soldering is an important process in SMT assembly process. The temperature field of infrared hot air reflow soldering of PCBA will directly affect the reliability of solder joints. The different simplified equivalent models have a certain influence on the temperature field of infrared hot air reflow soldering PCBA, which is mainly reflected in accuracy and efficiency. This paper studies the influence of three different thermal models on the temperature field of reflow soldering PCBA, and selects four groups of points in the same position of the three models, and comprehensively compares their temperatures. The results show that the maximum temperature deviation of the three models is as high as 7℃ in the soldering zone and 4℃ in the cooling zone, and the temperature difference is small. It can be concluded that the complex solder ball model can be used for high precision applications, and the simplified single-layer solder model and the thermal equivalent model can be used for low precision applications. These conclusions provide some references for the modeling of infrared hot air reflow soldering.