bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Difference of Gold Content Results of Electroplated Hard Gold Products
Authors: Yang Tingting , Wang Xuan , Zhu Yong , Yang Xihan , Li Lansen , Huang Wei , Li Simeng , Xu Tianchen , Li Miao , Wu Jing , Deng Junfa , Shen Jiani 
Published: July 2023

Abstract
The results of inductively coupled plasma spectrometry (ICP) and fire assay for the determination of gold content in electroplated hard gold products were compared, and the reasons for the differences were explored by transmission electron microscope, differential scanning synchronous thermal analyzer, high-frequency infrared carbon sulfur analyzer, etc. The result shows that the difference between the results of inductively coupled plasma spectrometry and fire assay is mainly due to the deposition of light elements such as K and Na and non-metallic elements such as C and S in the electroplating process caused by the complex electroplating liquid system. The above elements are not involved in the test of inductively coupled plasma spectrometry, so the final gold content is higher than the true value.
Study on The Method for Predicting The Explosion Source Point Based on The Characteristics of Shock Wave
Authors: Hou Feiyu , Wang Changli , Zhang Xin , Tian Haocheng , Li Kang , Bai Fengtao 
Published: July 2023

Abstract
To improve the accuracy in predicting the blast initiation position in tests from the measured data, a method of computing the blast source coordinates based on the average velocity of the blast shock and the corresponding correction and iteration methodology is proposed, and the accuracy of the method is verified and validated by comparing with the available data. The results show that: the accuracy of the method is good and its reliability is also high, and a spherical charge data correction method is proposed based on the characteristics of the shock wave, which can effectively improve the prediction accuracy. Using it, the coordinate error of the explosion source point is reduced from 0.656m to 0.084m, and the maximum relative error is reduced from 4.95% to 0.31%. The coordinate error of the dynamic explosion example is 1.68m, and the maximum relative error is 16.1%. The study found that the error of the original data has a great influence on prediction accuracy, and to ensure the high accuracy of the prediction results, the data with excessive errors should be excluded.
Research on Reliability of CNC Machine Tools Based on Sectional Model Involving Two Weibull Distributions
Authors: Chen Bingkun , Wang Zhiqiong , Zhang Yingzhi 
Published: July 2023

Abstract
To study the failure distribution rule of CNC machine tools and accurately fit the distribution model of failure time, the field test failure data from a series of CNC machine tools are analyzed in this paper. A sectional model involving two Weibull distributions is used to fit the failure time of CNC machine tools. The D-test method is used to examine the fit of the model. By comparing the goodness of fit with the ordinary Weibull distribution model, it is finally verified that the sectional model involving two Weibull distributions is more consistent with the failure data distribution rule of the CNC machine tools.
Research on Non-contact Bolt Preload Monitoring Based on DIC
Authors: Liu Zhenyao , Wang Decheng , Cheng Peng , Zang Yong 
Published: July 2023

Abstract
Bolt preload is a key parameter of the reliability of bolt connection. Traditional bolt preload detection generally uses torque wrench or high-precision strain sensor. In this paper, a new method of non-contact preload monitoring is realized by measuring the digital image of bolt elongation. A bolt tensile test device is designed, and the results of laser triangulation and three-dimensional point tracking are compared with those of optical measurement. The embedded load cell is used to monitor the bolt preload. The test results of M18 bolts with different bolt lengths and grades are evaluated. and it is found that the test values are close to the theoretical calculation, which can be used to predict the pretightening force.
Numerical simulation of the extruded process of Cased Telescoped Ammunition
Authors: Li Xiaofeng , Liang Lin , Mei Shuai 
Published: July 2023

Abstract
Compared with traditional guns, the cartridge belt of the Cased Telescope Ammunition (hereinafter referred to as CTA) is far away from the rifling when it is fired, which leads to a greater impact force in the process of extrusion, and further affects the barrel life and internal ballistic performance. A finite element model of the coupled projectile launching dynamics was established based on the elastic-plastic theory to study the mechanical characteristics of the extrusion process. The dynamic extrusion process of the conventional and CTA artillery projectile was simulated numerically, the corresponding data such as the extrusion velocity, extrusion resistance and the stress in the slope chamber were obtained, and the extrusion characteristics of the CTA artillery projectile were compared and analyzed. The results show that compared with the conventional artillery of the same caliber, the extrusion velocity and the extrusion resistance of the CTA guns are increased by 87.6% and 33.5%. The calculated results can provide a theoretical reference for the internal ballistics and structural design of the CTA guns.
Simulation of Auto Parts Polishing Control Strategy Based on PID Control
Authors: Tian Haopeng 
Published: July 2023

Abstract
With the large increase in automobile production, the demand for automobile parts is also increasing day by day. Aluminum alloy is the most widely used material in automobile parts. The production process of aluminum alloy parts has been automated, but the polishing process is still mainly manual. The high cost and low efficiency of manual polishing restrict the development of parts production technology. Therefore, it is imperative to develop a set of automatic polishing systems for aluminum alloy parts. Robot application in the polishing field has become a trend, but the force/bit coupling relationship in the polishing process of a robot is complicated, which brings great difficulty to the control of the polishing force. To solve the above problems, the key to obtaining stable polishing quality is to realize the force/bit decoupling of robot polishing and control the output constant polishing force. In this paper, an end-effector is used to realize the decoupling of force and position, and a new constant-force polishing control strategy is proposed to improve the automatic control level of robot polishing aluminum alloy auto parts. According to the nonlinear characteristics of the end-effector mathematical model and the feedback linearization characteristics of the backstepping method, a new type of backstepping PID constant force controller is designed, and the control flow is set up for simulation analysis. Simulink was used to build the simulation process and set up a reasonable controller gain for simulation verification. The simulation results of end-effector output polishing force under different strategies show that the reverse PID control has better response speed and anti-interference ability than the simple reverse control.
Fault Diagnosis Method of Planetary Gearbox Based on ISSA-VME and Multi-scale Fuzzy Entropy
Authors: Li Rongda , Xu Ke , Zhang Qing , Zhu Haifeng 
Published: July 2023

Abstract
To solve the problem of noise interference and difficulty in feature extraction of vibration signals of planetary gearbox, propose a fault diagnosis method of planetary gearbox based on improved sparrow search algorithm optimized variational mode extraction (ISSA-VME) and multi-scale fuzzy entropy (MFE). The vibration signal was decomposed by ISSA-VME, and the multi-scale fuzzy entropy of the original signal was calculated according to the IMF component. The fault feature set composed of MFE was applied to the SVM classifier optimized by the improved sparrow search algorithm for fault pattern recognition. The experimental results demonstrate that compared with ICEEMDAN and VMD methods, ISSA-VME has a better effect and higher efficiency on vibration signal decomposition. The identification rate of missing teeth, cracks, wear, and other faults of planetary gearbox sun gear by the proposed method reaches 97.50%.
Kinematics and Dynamics Simulation of Lower Limb Exoskeleton Walking Assist Mechanism
Authors: Zhao Yixuan , Li Haonan , Li Zheng , Wu Shuqin , Wang Yiming , Chai Chenwen 
Published: July 2023

Abstract
To solve the problem of rehabilitation training for patients with limited mobility of lower limbs, a scheme of lower limb exoskeleton walking assistance mechanism was proposed. The D-H model of the walking assist mechanism is established, and the forward kinematics is solved. The exoskeleton workspace is analyzed by the Monte Carlo method. The kinematics and dynamics simulation analysis of the walking assist mechanism is completed by using ADAMS software, and the rationality of the kinematics and dynamics performance is verified. The results show that the lower limb exoskeleton walking assist mechanism can meet the requirements of movement space, movement performance, and dynamic performance of patients with lower limb movement limitation and meet the basic needs of normal human wearing. The research results lay a foundation for the structural optimization of the following lower limb exoskeleton walking assist mechanism.
Machining Accuracy Allocation of Shaft System Considering Vibration and Cost
Authors: Shi Zhenyi , Sun Tao , Ma Zhenlai , Yu Wanbo , Shu Peng , Zhang Ji 
Published: July 2023

Abstract
In some important equipment such as vessels, the requirements for vibration reduction and cost-effectiveness of centrifugal pumps are becoming more and more stringent. It becomes really essential to present a method to assign manufacturing accuracy for shaft system assembly considering vibration and cost. A numerical model of the pump shaft system is developed to analyze the residual unbalance of the pump shaft system. The finite element model was verified through prototype tests. A machining accuracy allocation scheme is proposed by using an orthogonal design, and the cost and vibration intensity of the shaft system generated by vibration are evaluated. Based on this, a method to distribute shaft system machining accuracy is proposed to control the cost as much as possible while ensuring the vibration. Through orthogonal design, multiple sets of key parameter combinations are obtained, the vibration response of the shaft system under the parameter combination is calculated, and the contribution of each shaft system error to the shaft frequency vibration is analyzed. Combining the relative machining cost of the shaft system under different parameter combinations, the optimal allocation of the key parameters of the shaft system is completed based on vibration evaluation and relative cost.
Design and Analysis of A Two-stage Bionic Flapping Wing Aircraft
Authors: Fu Xiaokun , Hao Yongping , Ma Minghui , Zheng Xuyang 
Published: July 2023

Abstract
To develop an aircraft with a certain load capacity, high lift, and high bionics, a two-stage bionic flapping wing aircraft was designed according to the physiological structure of large birds. Firstly, the degrees of freedom of the transmission mechanism of flapping wing aircraft are calculated, and the dimensions of each component of the aircraft are determined. Secondly, we use the design software NX to draw the three-dimensional model of the aircraft. Then, the ADAMS software is used to simulate the dynamics of the aircraft, and the flapping amplitude and angular velocity changes during the flapping process are obtained, which verifies the rationality of the three-dimensional model design of the aircraft. Finally, a prototype of flapping wing aircraft is made. Experiments show that the flapping wing aircraft designed has good flapping stability. And the expectation is realized.
Study Effect of HIP & Heat Treatment on MIM Porous Tool Steel SKD11
Authors: Wu Xiaowei , Lan Fang 
Published: July 2023

Abstract
Hard tool steel SKD11 had a lot of industrial practical applications because it had super mechanical properties such as wear resistance and toughness. There is a trend to manufacture components with competitive costs. The wear resistance and hardness of the sintered components are insufficient to meet the cutter and dies’ strict requirements. The HIP process can further reduce pore size, quantity, and even distribution of pores of as-sinter blanks. As a result, the higher density, lower porosity, and high hardness of components can be obtained without obvious growing of grain size. After heat-treatment and subzero treatment, hardness increased up to HRC58-61, and wear resistance significantly improved.
Optimal Design of Stepping Self-moving Belt Tail
Authors: Hu Kaiyu , Yang Kangxin 
Published: July 2023

Abstract
This paper introduces the tail part of the belt conveyor, which is used to transport materials during the operation of the heading face and its forward form is a step forward. A bridge conveyor transfer machine is carried above the frame of the stepping self-moving belt tail, which is overlapped with the tail of the machine to realize material transfer. According to the force analysis during the movement of the lap joint trolley, the tail frame of the machine is optimized to form the optimal design parameters.
Research on Deceleration Technology of Rocket Sled Double Track Sled
Authors: Xiao Jun , Zhang Lin-rui , Xue Qiang , Geng Qiang 
Published: July 2023

Abstract
Aiming at the shortcomings of water brake in the deceleration recovery test of double-track sled, the reverse rocket deceleration was applied to the recovery of double-track sled. A deceleration scheme of rocket sled double track sled car is designed to improve the safety of double track sled car. Firstly, according to the requirements of sliding distance and water entry speed of sled, the deceleration resistance is designed and calculated, and the reverse rocket is selected. However, the sled car is designed according to the dimensions of the reverse thrust rocket, and the installation position and way of the reverse thrust rocket are determined. At last, according to the deceleration trajectory and the parameters of recoil rocket, the control mode and ignition position of recoil rocket are designed. The simulation results show that the deceleration effect of reverse rocket is obvious. This control method is simple and feasible. The reverse rocket deceleration method can be applied to the recovery of double track sled.
Study on flame cutting process of thick stainless-clad steel
Authors: Deng Chunyin , Chen Guoxing , Wu Shuhui , Lu Zhuang , Liu Shengyong , Su Liangliang , Zhao Ying , Gao Wenju 
Published: July 2023

Abstract
In general, three different types of processes can be utilized to cut thick stainless-clad steel: waterjet cutting, mechanical cutting, and thermal cutting (plasma, flame, and EDM cutting). Because stainless steel contains a lot of Cr, Ni, and other elements with high ignition and melting temperatures, flame cutting is not recommended for direct cutting of stainless steel. Three different stainless-clad steel specimen thicknesses were prepared for this study, and cutting experiments were conducted utilizing the flame-cutting procedure. The tests demonstrate that using suitable flame-cutting parameters can yield the optimal cutting process parameters and successfully cut thick stainless-clad steel.
Simulation Study of Aircraft Active-Active Hydroelectric Hybrid Power Drive Unit
Authors: Mo Wei , Li Wei , Lu Yueliang 
Published: July 2023

Abstract
The Power Drive Unit (PDU) is the power source of the aircraft high-lift system (HLS), which converts hydraulic or electric energy into mechanical energy for output, and deflects the flap/slat through the transmission lines to increase the wing area to improve lift. Two sets of hydraulic motor subsystems working simultaneously are used in the Active-Active PDU of traditional aircraft to improve the reliability of the system. In this paper, an Active-Active Hydroelectric Hybrid Power Drive Unit (HPDU) is designed with a fixed-displacement hydraulic motor and a permanent magnet synchronous motor, the fundamental composition of the HPDU is introduced, the mathematical model of main components is analyzed, the HPDU is modeled based on AMESim, and the function and operation performance are investigated by simulation. The results show that the HPDU can realize the functional design requirements such as forward and reverse rotation and the performance design requirements such as withstanding sudden load within the rated load range during running.
A Novel Design of a Built-in V-Rotor Ultra-Efficient PMSM Based on Multiple Air Slots
Authors: Liu Xin , Wang Bulai , Yang Mengzhen 
Published: July 2023

Abstract
According to indicators, the New V-Rotor Permanent Magnet Motor (NVRPM) for compressors with a rated power of 22 kW and a rated speed of 3000 rpm is optimally designed. Because of the large number of permanent magnets in the V-type PM motor, the magnetic leakage between rotor poles will increase, and its air gap magnetic field contains large harmonic components, which is easy to increase the loss and reduce the efficiency. The structure of the initial V-shaped rotor was optimized by adding multiple air slots and cosine non-uniform air gaps on the rotor surface. Through the finite element simulation of electromagnetic characteristics of NVRPM, it is proved that the improvement of the new motor structure can reduce the loss, weaken the cogging torque, and decrease the torque ripple, and the simulation efficiency is up to 96%, and its operation area is wide and efficient. Finally, the results show that the optimization design of the NVRPM structure is feasible.
08 steel numerical simulation study on the cold forging of buffer seat
Authors: Lv Longlong , Cai Yujun , Dong Xiaochuan , Wu Chuan 
Published: July 2023

Abstract
For the problem of uneven hardness in the specified area of the buffer seat, we analyze the reasons for this problem. With the goal of promoting hardness uniformity in the specified area of the product, the friction coefficient and punch pressing speed were selected as the influencing factors, simulation experiments were designed, and the results were obtained through multiple simulations. The simulation results show that the processing conditions are that the friction coefficient is not greater than 0.2 and the pressing speed of the punch is 0.2 mm/sec, which are the process solutions to make the hardness of the product uniform. Moreover, compared to the effects of several other variables, the pressing speed has the greatest influence on the hardness deviation of the final product.
Mesh Stiffness Models for Modified Straight Bevel Gears without and with Slice Coupling
Authors: Shu Ruizhi , Chen Siyu , Ge Shuaishuai , Tan Rulong , Yin Qin 
Published: July 2023

Abstract
The analysis of the dynamics of gear systems is based on the determination of the time-varying mesh stiffness (TVMS). The infinitesimal approach was used to slice the straight bevel gear’s teeth. After that, the beam deformation theory was combined to determine the stiffness components of each tooth segment. On this basis, the meshing stiffness models with and without slice coupling were constructed using the methods of accumulative integral potential energy and slice coupling, respectively. Lastly, the results of the suggested methodology were compared to those of the finite element analysis to ensure accuracy. The result shows that both analytical methods can solve the TVMS of straight bevel gears accurately and quickly.
Design of a high-accuracy time-to-digital converter based on dual-edge signals
Authors: Xiao Yuan , Liang Huaguo , Jin Liyu , Wang Yuchuan , Shao Zhiwei , Wang Yue , Lu Yingchun 
Published: July 2023

Abstract
Among numerous time-to-digital converters (TDC), tapped
delay line (TDL) is the most commonly used architecture. However,
its dead time of more than two cycles is inefficient for
applications with high measurement rates. Limited by the device
process, the delay of each cell in the TDL exhibits a random and
uneven distribution, degrading the linearity of the TDC. In this
study, a dual-edge TDL structure is proposed. By improving original
pulse-holding circuit, the propagated signal injected into the fine
measurement chain is alternately switched between rising and falling
edge signals to decrease the dead time to one cycle. The
nonlinearity problem is alleviated by an enhanced tapped sampling
sequence circuit. A dual-edge “1” count encoder is introduced to
effectively simplify the difficulty of addressing the bubble
problem. Bit-by-bit calibration and a moving average filter are
adopted to improve accuracy. The proposed scheme has been verified
on a Xilinx Kintex-7 FPGA platform. The resolution (least
significant bit, LSB1) is 12.07 ps when the
propagated signal in the TDL is the rising edge. The differential
nonlinearity (DNL) is [-0.81,0.93] LSB1, and the
integral nonlinearity (INL) is between
[-2.33,2.19] LSB1. At the falling edge, the
resolution (LSB0) is 11.90 ps, between
[-0.73,0.98] LSB0 and
[-2.46,1.83] LSB0 for DNL and INL, respectively. In
addition, the accuracy reaches 15.25 ps after multiple measurements
for different time intervals separately.
Adiabatic bunch compression in storage rings from self wakes generated in Cherenkov waveguides
Authors: Antipov S.A. , Agapov I. , Zagorodnov I. , Lemery F. 
Published: July 2023

Abstract
Equilibrium bunch lengths typical to modern day light sources of tens of picoseconds limit the spectral reach of superradiant approaches for exploring materials and biological samples. In particular, generation of terahertz radiation seems appealing for pump-probe experiments.
Taking advantage of self-wakes generated by carefully chosen structure one can control the bunch length and shape the bunch profile to increase significantly the high-frequency spectral components. Numerical analysis indicates the presence of self-consistent steady states that can be obtained with passive corrugated or dielectric structures. This approach has potential applications for generating superradiant terahertz radiation and pulse shaping in circular accelerators.