bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Power Quality Evaluation Method for High Energy-consuming Enterprises
Authors: Liu Yu , Liu Junde , Yang Bo , Ning Liaoyi , Zhu Xiangbo , Wang Xue , Bian Shenghua 
Published: March 2021

Abstract
With the increase of the voltage level of the power system, the demand for electric energy of high energy-consuming enterprises continues to increase, which puts forward higher requirements on the power quality. As power quality problems become more and more prominent, how to manage power quality scientifically and reasonably has attracted more and more attention from power quality workers. At the same time, users have increased their power quality requirements and the continuous development of power marketization. To achieve comprehensive power quality management, it is necessary to have a scientific, accurate, and standardized assessment of power quality. In-depth understanding and understanding of power quality, attach great importance to the harm and impact of power quality degradation on the operation of the power supply system, and it is particularly urgent to achieve comprehensive power quality management.
Application and Optimization Design of Titanium Alloy in Sports Equipment
Authors: Li Ming , Pan Yang , Zou Yunpeng 
Published: March 2021

Abstract
Titanium (Ti) was discovered in 1789. Norway and the United States began to produce titanium dioxide with the sulfuric acid method in 1908, the titanium sponge was prepared by the sponge titanium in the laboratory for the first time in 1910, and the United States Dupont company used the magnesium method to produce tons of titanium sponge in 1948, which marks the beginning of the industrial production of titanium sponge. Titanium and its alloys are one of the most promising light alloy structural materials in the 21st century due to their advantages of low density, high specific strength and specific stiffness, corrosion and fatigue resistance, high temperature resistance and weldability. In recent years, the world titanium industry and titanium processing technology has developed rapidly. The production and consumption of sponge titanium, wrought titanium alloy and ferroalloy processed materials have reached a very high level, and their application fields have been extended to almost all military and civilian industrial sectors. This paper focuses on the application of titanium alloy in sports equipment, and the optimization design of titanium alloy sports equipment.
Dynamic simulation method of adjustable nozzle considering clearance fit
Authors: Zhu Haitian , Jin Xin , Zhang Zhongqing , Zhou Kai , Li Chaojiang 
Published: March 2021

Abstract
Aiming at the motion stagnation and local damage failure of a 2D needled Cf/SiC adjustable nozzle during operation, the motion performance of the nozzle and the contact stress at the key parts were studied. A dynamic simulation method of the nozzle with adjustable nozzle considering clearance fit was established, and the throat contraction process was analyzed by a simulation example. Firstly, the critical analysis positions of the nozzle were determined by trial calculation, and the model was simplified and the mesh was optimized. Then, the simulation was carried out under the boundary conditions involving multiple fields. The motion characteristics of the nozzle throat during the throat contraction process were analyzed due to the velocity results, and the stress state and failure state at the key position of the nozzle during the impact process were finally determined.
The research of compressibility of compressed air foam
Authors: Chen Y , Chen T , Fu X C , Bao Z M , Hu C 
Published: March 2021

Abstract
The compressibility of compressed air foam was an important mechanical parameter in hydrodynamic calculations. The compression coefficient was set by the theoretical model in the current study of foam computational fluid mechanics. Here are many types of fire foam and each of them is different with different compressible performance. The compression coefficient obtained by theoretical calculation has a certain error and the experimental method test is needed. In this study, the equipment for measuring the foam compressibility was designed and developed. The compressibility of compressed air foam was preliminary studied in this article.
Analysis of Cracking Causes of P91 Welding Seam of High Pressure Steam Guide Pipe of Supercritical Unit
Authors: Li Xiuneng , Hou Shuang , Han Lizhe , Yan He , Yang Chao , Tian Zhiyong 
Published: March 2021

Abstract
A 600MW supercritical unit in a thermal power plant has been in operation for 63,000 hours, and a P91 weld leak occurred between the high-pressure steam guide pipe and the high-pressure governor valve. After macroscopic morphology analysis, alloy composition analysis, metallographic structure observation, and microhardness test analysis, it is found that the cracking of the base metal and weld on the high-pressure speed control valve is caused by structural stress and welding stress, which leads to cracking due to creep. The crack originated in the fine-grained area of the heat-affected zone, and it has been operating in a high-temperature operating environment for a long time. The P91 weld on the high-pressure steam guide tube produces creep holes in the fine-grained heat-affected zone, which gradually grow to form creep cracks, and eventually lead to cracks and leakage. Therefore, the failure of pipeline cracking is caused by the joint action of tensile stress and type IV crack.
Design and Control of High Precision two Axis Servo Scanning System in Space
Authors: Li Jing , Zhang Ai , Wang Qingying , Lin Zhe 
Published: March 2021

Abstract
A high precision direct drive control two axis servo scanning system in space is designed and developed. Based on the requirement of technical indicators, the high-precision direct drive control two axis servo scanning system is divided into an rotating telescope and a half angle mirror servo system. The design and analysis of the servo system’s structural design, shafting accuracy and motor options are carried out. Taking the half angle mirror servo system as an example, the electrical structure of servo system is expounded, and a compound control strategy based on all digital control drive and high precision photoelectric encoder is established, which directly drives PMSM. The circuit design and working process of servo control module are described in detail. The test results show that the speed stability performance of the scanning system can reach ±0.28%, and the servo precision can reach ±16″, and it has the characteristics of long life, anti pollution, etc, which can meet the requirements of the space high precision and long life scanning system.
Durability Test Bench Design for Electric Lock of Sliding Door
Authors: Yao Zhipeng , Lu Wei , Yao Jia , Lin Feng , Zhu Fengming 
Published: March 2021

Abstract
With the rapid development of automobile industry, electric door locks have widely used in various vehicle doors, especially for sliding doors. Among all performances, durability performance for electric locks is virtual for safety, so miniaturized durability test bench has been designed in the research according to the national standard of electric lock. Firstly, four-bar linkage mechanism has been adopted as the main actuator for the motion track achievement, the real motion track of sliding door can be guaranteed through the verification of ADAMS simulation. Secondly, the compression test has been carried out to calculate the reaction force of door sealing strips, thus the resistance device of test bench for simulating reliable locking process of electric lock has been designed. The miniaturized durability test bench can replace the existing durability test method which only performed by the whole vehicle testing, thus providing a low-cost and reliable test device for relevant manufacturers.
Identification Method of Key Risk Control Points in Mechanical Product Assembly Process
Authors: Ju Pinghua , Xu Wenlin , Gu Haodong , Ran Yan 
Published: March 2021

Abstract
In order to improve the assembly process quality of mechanical products, a structuralized decomposition method of Function-Movement-Action (FMA) was used to obtain the meta-action (MA) of minimum assembly granularity of mechanical products. Secondly, taking the performance index of the moving layer as the object of assembly process quality analysis, the state space model of the hybrid type MA was established, and the relationship models between the quality of the serial, parallel and hybrid type assembly process and the internal influencing factors were given. Then, the Partial Least Squares Regression (PLSR) method was used to solve the problem of multicollinearity and small sample among the influencing factors of each MA, and the key risk control points in the assembly process were obtained by the importance index analysis of variable projection. Finally, the effectiveness of the proposed method is proved by taking a numerical control turntable as an example.
Meshing efficiency analysis of double helical gears considering tribo-dynamic coupling effect
Authors: Wang Jietian , Lin Tengjiao , Yang Jin 
Published: March 2021

Abstract
In order to obtain accurate meshing efficiency of double helical gears, a calculation method of sliding friction power loss is proposed considering the tribo-dynamic coupling effect. Based on the mixed elastohydrodynamic lubrication (EHL) theory, the initial friction coefficient of tooth surface is obtained and the friction excitation is calculated. Considering the tribo-dynamic coupling effect, a sixteen-degree-of-freedom tribo-dynamic model of double helical gear pair is established, including time-varying mesh stiffness, friction excitation, backlash and transmission error. The tribo-dynamic behaviours of gear pair are analysed before and after coupling, and then the sliding friction power loss and meshing efficiency of double helical gears are obtained. The research results show that after tribo-dynamic coupling, the friction coefficient and friction excitation of double helical gear pair increase, and the meshing efficiency decreases. The meshing efficiency of gear pair increases with the increase of helix angle and pressure angle, and decreases with the increase of surface roughness.
Welding procedure Research of Niobium Heat Exchanger
Authors: Jiang Chengjun , Zhang Xiaoli , Du Yannan , Wang Wei 
Published: March 2021

Abstract
The weldability of R04200 niobium tube-to-tubesheet is analyzed. The macroscopic examination, penetration testing, hydrostatic testing and metallographic examination are tested by the method of GTAW. The results show that specific welding structures with He-Ar mixed gas as shielding gas can improve the arc stiffness, thermal efficiency and penetration. It expresses the great significance of formulating the welding methods guidance of niobium pressure vessels.
Design and Implementation of Ultrafast Broadband Sweep Source based on AD9914
Authors: Cai Kaida , Zhang Zhongyang , Huang Qingchun , Xiao Jing 
Published: March 2021

Abstract
To address a technical difficulty of long scanning cycle of broadband (100 MHz~900 MHz) frequency sweep source, an ultrafast broadband sweep source was designed based on the basic principle of direct digital-frequency synthesis (DDS) theory by using the high-performance DDS chip AD9914. During the design, the DSP28335 chip was used as the control device. The designed source can output 100MHz~900 MHz swept-frequency signals and it can realize sawtooth wave frequency-modulated signals in the shortest cycle (8us) by configuring the digital ramp generator in the chip. Moreover, a microstrip stepped impedance low-pass filter was designed using ADS to eliminate spurious signals in the direct synthesizer and decrease the in-band attenuation, thus making the curve flatter. According to final test and experimental data analysis, the designed sweep source has a large output broadband, short sweeping cycle and strong inhibition of spurious signals. It possesses great application values.
Optical Design of A CaF2-free 5× Flat-field Apochromatic Metallographic Micro-objective with Long Working Distance
Authors: Han Haimei 
Published: March 2021

Abstract
Based on the apochromatic system theory, an innovative CaF2-free 5× plan apochromatic metallographic micro-objective with long working distance was designed using the OSLO software through the iterative optimization technique. The designed metallographic microscope objective used the relevant photographic field lens as the initial structure. The final lens structure is composed of 7 lenses of 4 components in coaxial array. The object surface is imaged at infinity through an optical system. According to analysis results of the design, this metallographic microscope objective has following characteristics. Firstly, all lens are CaF2-free and manufactured by optical glass produced. Secondly, it can achieve flat-field chromatic aberration. Thirdly, it has a large field of view and long working distance.
Finite element reduction modeling and vibration analysis of mistuned coating thickness blisk
Authors: Kuang Ziqi , Shi Pingyi , Wu Zhengqiang , Bi Jun , Zhu Pailong 
Published: March 2021

Abstract
The application of hard coating damping technology to the blades ofblisk can effectively reduce the vibration stress and improve its service life. In this paper, a three-dimensional eight-node laminated incompatible element is proposed, which only needs the node coordinates of the structure without the coating. In the coating damping design process, it could avoid reconstructing the finite element mesh when changes the coating thickness. Based on the cyclic symmetry algorithm and the SNM method, a finite element reduction model to analyze the vibration characteristics of the coated blisk with coating thickness mistuning was established andverified by ANSYS. The results indicate that the proposed finite element model can be used to analyze the vibration characteristics with the changed coating thicknessand it shows great consistence with the result of ANSYS. On the other side, the SNM still has high accuracy when the coating thickness varies from 0 mm to 0.3 mm.
Experimental investigation and numerical simulation of the stress and deformation behavior for selective laser sintering of PA6
Authors: Zhou Mengyuan , Han Yuchen , Si Liang , Li Maoyuan 
Published: March 2021

Abstract
The uneven temperature field caused by the local instantaneous heating of the laser generates the thermal stress during the selective laser sintering. The stress causes the deformation of parts, affecting the precision and mechanical properties. However, it’s difficult to directly measure the stress history and deformation behavior during processing through experimental methods due to its ultra-high temperature and closed cavity. In this paper, the effects of laser power and scanning speed on the stress field and deformation of polyamide 6 by selective laser sintering were systematically investigated. The results showed that as the laser power increased or the scanning speed decreased, the z-direction stress and deformation of the specimens increased. Based on the inherent strain method, the deformation behavior of large-size parts was evaluated and in good agreement with experiments, which can guarantee the accuracy of the model and predict the deformation of parts.
Effects of External Heat Flux during Orbital Period of Spacecraft on Operating Characteristics of Loop Heat Pipe
Authors: Yang Tao , Zhao Shilei , Gao Teng , Zhao Zhenming , Zhang Ping 
Published: March 2021

Abstract
Effects of external heat flux during orbital period on operating characteristics of loop heat pipe were discussed through a thermal vacuum experimental study based on the orbit of remote sensing satellite. Results demonstrate that changes external heat flux of orbit causes periodic fluctuation of temperature on the heat delivery surface of loop heat pipe (LHP), thus causing period changes of state of working media in the LHP. Changes of state of working media further lead to “backflow” of working media, thus causing adverse impacts on stable operation of LHP. The adverse effects of backflow on operation of LHP were verified through a thermal vacuum experiment. Research conclusions have high guidance to the in-orbit application of LHP.
A False Bank Accounts Detection Method Based on Naive Bayesian Network
Authors: Wan Weiqing , Li Weihong 
Published: March 2021

Abstract
At present, more and more cases of economic fraud are based on false bank accounts. Due to the limitation of the bank’s technology and ability to verify the true identity of customers, the online verification system of banks can only check the authenticity of the ID card, while the consistent verification of people and cards can only be completed manually by bank tellers. It is easy to produce errors if the consistency is judged by the teller’s manual naked eye. In this paper was proposed a method of constructing a naive Bayesian network classification model by automatically detect the authenticity of bank accounts to avoid the problem of economic fraud of false bank accounts, and verified the feasibility of this method through specific examples. The experimental results show that the method which has certain theoretical and practical significance, and provides reference for the detection of other false accounts.
Research on modal analysis method of Multiple Units car body in the preparation conditions
Authors: Li Ya-Na , Li Shuo 
Published: March 2021

Abstract
The first-order vertical bending frequency is an important parameter to evaluate the vibration performance of car body in the preparation conditions. Increasing its frequency value can avoid the resonance between the car body and the bogie frame, reduce the vibration, and improve the running stability and riding comfort. Due to the low first-order vertical bending frequency, combined with layout optimization of equipment under vehicle and structure optimization, the optimal equipment layout scheme and the thickness of the key parts were obtained based on the refined modeling. The first-order vertical bending frequency of car body was increased from 7.63Hz to 8.35Hz, which was increased by 9.4%.
The Research and Implementation in Digital Transformation of Manufacturing Enterprises
Authors: Di Peng 
Published: March 2021

Abstract
This article introduces in detail the typical problems that exist in digital transformation of manufacturing enterprises. It describes the specific methods and strategies for manufacturing enterprises to achieve digital transformation from two aspects: the application of digital resources outside the enterprises and the internal value chain throughout the enterprise. Combined with the implementation case of a specific manufacturing enterprise, it demonstrates the process of the enterprise’s digital transformation.
Structure Optimization and Verification of Portable Intelligent Gauge Calibrator
Authors: Chen Hao , Sun Xiao Guang , Zhu Hui Chen 
Published: March 2021

Abstract
Portable intelligent gauge calibrator is a new type of gauge calibrator to replace the traditional gauge calibrator. It can effectively solve the problems of traditional gauge calibrator, such as unable to carry out on-site measurement, too large volume, low degree of intelligence and so on. In view of the problem that the maximum stress of the connector of the horizontal measuring platform is too large in the trial operation of the portable intelligent gauge calibrator, this paper puts forward a solution combining topology optimization with practical experience. The test shows that the method is effective and feasible.
Vibration synchronization intelligent control with trajectory tracking
Authors: Wu Shilling , Zhang Nan , Jia Yijun 
Published: March 2021

Abstract
Based on the dynamic model of the double-mass vibrating mechanical system, the adaptive control theory is introduced to study the motor control synchronization problem in the vibrating mechanical system. First, the dynamic model of the dual-mass nonlinear vibration system is studied, and the overall relationship between the motor motion and the vibration system is analyzed. Then, a dual-motor adaptive control strategy is designed, so that the parameters in the control system can be intelligently adjusted with the synchronization state of the motors, and the synchronization stability and motion trajectory between the motors are studied. Lyapunov stability criterion is used to verify the stability of the synchronous control system. Finally, MATLAB/Simulink is used to simulate the effectiveness of the dual-motor adaptive control system, which proves that the system has good robustness. Through research, it is found that the dual-motor vibration synchronization adaptive control strategy can keep the motors in the dual-mass nonlinear vibration system with good synchronization effects, and the system has good robustness. The research content can provide a certain theoretical reference for the research and design of multi-motor synchronous machinery.
A Contactless Measurement Instrument Based on Fusion of A Single-Point Laser Range Finder and A VIO System
Authors: Yuan Xinran , Liu Gang , Sun Boyang , Li Yanhui 
Published: March 2021

Abstract
To improve the safety and convenience of the traditional measurement instruments (such as Total station, Laser tracker), while reducing the system cost, a contactless measurement instrument consists of a single-point laser range finder (LRF) and a tracking module (a VIO system providing the measurement system 6DoF poses) is proposed in this paper. Its measuring procedure includes three steps: 1) Obtain the calibrated relative position parameters from a 3D position of the LRF. 2) Determine the remote target 3D point positions by fusing the measurement value of LRF. 3) In order to improve measurement accuracy, design a practical case-specific framework by analysing two typical measurement situations. This allows us to measure all scale factor information such as distance, height and clearance of a spatial structure in a convenient or portable way. Through the remote 3D point positions estimation experiment, the contactless measurement instrument exhibits the capability to satisfy the need of majority measurement applications for indoor architecture.
Effect of Volume Fraction Whiskers on Tensile and Thermal Expansion Properties of Mg2B2O5 Whisker-reinforced Aluminum Composite
Authors: Zhang Lei , Qiu Peng , Li Bin 
Published: March 2021

Abstract
This paper prepared magnesium borate whisker reinforced aluminum matrix composites by extrusion casting, and studied the effects of the volume fraction of the reinforced phase on the mechanical properties, thermal expansion properties and microstructure of the composites. The test results show that the reinforced magnesium borate whisker in the composite can be uniformly dispersed in the aluminum matrix to improve the strength. With the increase of the volume fraction, the strength of the composite material increases and the plasticity decreases. When the whisker volume fraction is 30%, the strength of the composite material reaches the maximum, with its tensile strength reaching 244 MPa and elastic modulus 107.6 GPA. When the whisker volume fraction is 20%, the composite has the best plasticity and the fracture elongation is 0.47%. The thermal expansion curve of the composite shows that the increase of whisker volume fraction will reduce the thermal expansion coefficient of the composite.