bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcranial ultrasound stimulation modulates the interhemispheric balance of excitability in human motor cortex
Authors: Ren Liyuan , Zhai Zhaolin , Xiang Qiong , Zhuo Kaiming , Zhang Suzhen , Zhang Yi , Jiao Xiong , Tong Shanbao , Liu Dengtang , Sun Junfeng
Published: January 2023

Background. Low-intensity transcranial ultrasound stimulation (TUS) could induce both immediate and long-lasting neuromodulatory effects in human brains. Interhemispheric imbalance at prefrontal or motor cortices generally associates with various cognitive decline in aging and mental disorders. However, whether TUS could modulate the interhemispheric balance of excitability in human brain remains unknown. Objective. This study aims to explore whether repetitive TUS (rTUS) intervention can modulate the interhemispheric balance of excitability between bilateral motor cortex (M1) in healthy subjects. Approach. Motor evoked potentials (MEPs) at bilateral M1 were measured at 15 min and 0 min before a 15 min active or sham rTUS intervention on left M1 and at 0 min, 15 min and 30 min after the intervention, and the Chinese version of brief neurocognitive test battery (C-BCT) was conducted before and after the intervention respectively. Cortical excitability was quantified by MEPs, and the long-lasting changes of MEP amplitude was used as an index of plasticity. Results. In the active rTUS group (n = 20), the ipsilateral MEP amplitude increased significantly compared with baselines and lasted for up to 30 min after intervention, while the contralateral MEP amplitude decreased lasting for 15 min, yielding increased laterality between bilateral MEPs. Furthermore, rTUS intervention induced changes in some C-BCT scores, and the changes of scores correlated with the changes of MEP amplitudes induced by rTUS intervention. The sham rTUS group (n = 20) showed no significant changes in MEPs and C-BCT scores. In addition, no participants reported any adverse effects during and after the rTUS intervention, and no obvious temperature increase appeared in skull or brain tissues in simulation. Significance. rTUS intervention modulated the plasticity of ipsilateral M1 and the interhemispheric balance of M1 excitability in human brain, and improved cognitive performance, suggesting a considerable potential of rTUS in clinical interventions.
Research on Direct Measurement to Spray Resistance Test of Prismatic Planing Hull
Authors: Shi Sheng-zhe , Jiang Ting , Wang Fan , Zheng Xiao-long
Published: January 2023

To obtain spray resistance directly, a prismatic planing hull test was conducted in a towing tank in static water. The characteristic angles of the standing line and leading edge line of the spray zone were obtained through the fixed flight test of the whole prismatic planing hull. The prismatic planing hull was divided into front and rear parts along the standing line, and then the fixed flight state test of the split planing hull was carried out, and the spray resistance was directly measured by the front planing hull. The results show that the percentage of splash resistance in the total resistance is from 15.83 % to 30.10 % under the condition of high-speed planing; Split planing hull model test is an effective method for direct measurement of spray resistance.
Finite element analysis of complete structure of tower cranes
Authors: Cheng Baozhong , Yang Bo , Wang Dianxi , Duan Mingyu
Published: January 2023

In order to ensure the safety and stability of the tower crane in operation, the static and dynamic characteristics of the QTZ100 tower crane in typical working conditions are analyzed by the finite element method, so as to verify the safety of its use and put forward targeted suggestions for the optimization of cranes. The results show that the equivalent stress is less than the ultimate design stress of the tower crane, and there is stress concentration in the plate connected between the upper turntable and the lifting arm. The frequency of the fully loaded motor is far from the normal operating frequency of the tower. The horizontal root displacement of the lifting arm corresponding to the peak displacement response is relatively large. The buckling factor of the tower crane is higher than the empirical value. Therefore, to meet the strength and stability requirements of the tower crane, the connection between the upper turntable and the lifting arm should be strengthened. The motor will not resonate with the tower crane when it is fully loaded, and the dynamic rigidity is poor when it works at the frequency corresponding to the peak value. The buckling factor is higher, so the stability is better.
Microstructure Evolution and Interfacial Reaction of Cu/SAC305/Cu and Co-P/SAC305/Cu Solder Joints under High Current Density
Authors: Long Ting , Chen Yuqian , Fan Tao , Rong Jing , Chen Tao , Yang Donghua
Published: January 2023

The size of solder joints in electronic packaging is gradually decreasing, which directly leads to a sharp increase in the current density experienced by the solder joints. Therefore, it is of great significance to study the effect of electromigration on the interface of the lead-free solder. In this paper, the effect of electromigration on the microstructure of Cu UBM and Co-P UBM solder joints was compared. By comparing the morphological changes of CoSn3 and Cu6Sn5 at the interface, combined with the calculation of the thickness of the intermetallic compound, it was found that the consumption rate of Co-P UBM in the solder joint was much lower than that of the Cu substrate. Moreover, when the Co-P UBM is completely consumed, the consumption rate of the Cu substrate is also significantly reduced.
Analysis of Point Contact Isothermal Elastohydrodynamic Lubrication Characteristics of a New Type of Trigeminal Universal Coupling for Automobile
Authors: Xu Yutian , Yao Chuanqing , Yang Yan.
Published: January 2023

This thesis designed a new type of trigeminal universal coupling structure that changes the original surface contact sliding friction into point contact rolling friction. We analyzed the characteristics of isothermal elastohydrodynamic lubrication to ensure new construction on the drive shaft stability, reliability, and durability. First, we established a contact model of the improved new structure and analyzed the isothermal elastohydrodynamic characteristics of the point contact. Then we studied the input shaft frequency, load, deflection angle, and lubrication characteristics. Research indicated that the other being equal, the faster the input shaft frequency could lead to a thicker oil film, a higher oil film pressure, and a higher secondary pressure peak. The higher load could cause the thinner oil film thickness, the lower oil film pressure, the later position where the pressure begins to increase, and the less obvious second pressure peak. The greater deflection angle could bring about the thicker oil film thickness, the higher oil film pressure, the earlier position where the pressure began to increase, and the earlier position at which the secondary pressure peak was located. This phenomenon was more pronounced in the contact center area.
Comparison of the Measurement Results of PIV with Different Tracer
Authors: Mao Yuhong , Yang Lufeng , Chen Chao , Wang Yue
Published: January 2023

Particle Image Velocimetry (PIV) was used to measure the solenoidal vector field of the Taylor-Couette flow with different tracers. It can be seen that both of them, the polyamide and flocs can be a suitable performance tracer particles for PIV in flow field measurement. The results indicated that the instantaneous velocity vector maps obtained with different tracer particles which could denote the characteristics of the flow structure, the size and the vortex centers of the vortex. At the meantime, the experimental results demonstrated that the velocity vector obtained by the flocs generated in real-time as tracer particles was similar with suitable performance to those obtained by polyamide.
Research on the influence of cutter roll optimization of rotary tiller on its Operation performance
Authors: Wu Tiebin , Cai Wangfei , Song XinBin , Tan Yawen
Published: January 2023

Rotary tillers often have shallow plowing depth and serious leakage problems in the specific working process, resulting in a decrease in the rate of soil breaking and stubble breaking, causing damage to mechanical devices. In this paper, we conducted a field test on the popular self-propelled rotary tiller to obtain the changes in the operating Indexes of various types of knife roller operation with time under three types of tillage environments; we conducted a force analysis and finite element analysis on the IT245 rotary tiller to obtain the stress effect and deformation of the rotary tiller during the operation of the cutter roll; we aimed to study the operating performance and working mechanism of the rotary tiller through test and simulation to explore the path of optimizing the cutter roll.
Study on X-ray testing of buried polyethylene pipeline thermal fusion welding
Authors: Li Qiang , Li Weihan , Li Yanfeng , Yang Jie
Published: January 2023

Thermal fusion welding is a common method for high-density polyethylene (HDPE) pipelines. However, defects are easy to occur at the joints in the welding process, causing hidden danger. In this study, HDPE pipes with thermal fusion welding defects were made and the X-ray technology was used for detection. The results show that the testing effects of different defects are quite different. The X-ray cannot detect cold-welding defects. The weld seam of the over-welding in the negative is narrowed. Besides, the unfilled holes collapse during welding, resulting in poor detection results. The filled holes can be detected.
Gate Ringing Analysis and Driving Circuit Design of GaN HEMT
Authors: Fu Beinan , Xu Mochen , Dong Baolei , Liu Tao
Published: January 2023

GaN HEMT can operate at a high switching frequency because of its characteristics, but there are also related problems. This paper analyzes the negative effects of switching oscillations of GaN HEMT, introduces the design criteria of its driving circuit, and analyzes the causes of the Miller effect and gate ringing under the influence of high-frequency parasitic parameters. Then, the corresponding suppression strategies for the above two phenomena are given, and the design of the driving circuit is introduced. Finally, the validity and rationality of the designed driving circuit are verified by experiments.
Research on Dynamic Characteristics Analysis Method of Spindle-Flywheel Rotor System of Inertia Friction Welding Machine
Authors: Jin Quan , Sun Baoyu , Zhang Gang , Guan Yingjun
Published: January 2023

A rotor is a special vibration system whose mechanical characteristics change with rotating speed. Taking the spindle-flywheel rotor system of inertia friction welding machine as the research object, in order to explore the variation law of critical speed and the unbalanced response of rotor system at different node positions, according to the special form of the spindle-flywheel rotor system, the combined flywheel set is simplified as a node of a lumped mass model, and the Riccati transfer matrix method and finite element method are used to calculate respectively. The error of the Riccati transfer matrix method is less than 4% compared with the finite element method, which proves the rationality of an equivalent flywheel node. Compared with the finite element method, the Riccati transfer matrix method, which simplifies the flywheel model, not only ensures accuracy but also shortens the calculation time. This method is obviously more suitable for calculating the spindle-flywheel rotor system model of an inertial friction welding machine. In addition, this method can also calculate the unbalanced response. When the unbalanced mass distribution is closer to the head end of the spindle, the unbalanced response vibrates more strongly at the second-order natural frequency, and the rotor response during vibration can be predicted.
Effect of vacuum sealing on corrosion resistance of high-velocity arc sprayed coating
Authors: Deng Chunyin , Lu Zhuang , Lu Haifeng , Liu Chenwei , Wu Shuhui , Qin Enwei
Published: January 2023

Thermal spray coatings commonly have pores and micro cracks in their structure. Corrosive medium will pass through pores and micro cracks in corrosive conditions and damage the substrate, leading to coating failure and reduced service life. In this study, vacuum impregnation sealing (VIS) and conventional impregnation sealing (CIS) were used to seal high-velocity arc-sprayed NiCr-based coatings. The cross-sectional microstructure of the coating and its porosity are observed by optical microscopy. Energy spectrometry and scanning electron microscopy were used to measure the sealant’s penetration depth. corrosion behavior was studied by neutral salt spray testing and electrochemical methods. The results showed that the average depth of sealant penetration by VIS is 275 m, almost three times greater than that of CIS. Better corrosion resistance was indicated in the coating sealed by VIS, which had a smaller corrosion current density and a more noticeable passivation zone than the coating sealed by CIS. The coating sealed by VIS showed no rust stains after 432 hours in the salt spray corrosion environment, but the coating sealed by CIS showed corrosion rust spots after 96 hours. The coating sealed by VIS appeared to have greater corrosion resistance, providing experimental support for its use in engineering.
Effect of different top electrodes on dielectric properties of Pb0.3Sr0.7TiO3thin film
Authors: Hou Shuang , Li Xiuneng , Gu Zhehan , Xu Liang , Liu Kai , Mao Xueyin , Jian Hongwei , Yuan Qiaoqiao
Published: January 2023

The PST thin films with different top electrodes were prepared by magnetron sputtering and Sol-gel, respectively. The effects of different top electrodes on Dielectric and Tunable Properties of the films were studied. It is found that the comprehensive properties of the PST films can be improved by using suitable top electrodes. When the dielectric tuning amount of PST thin films using Au/Cr dielectric tuning value is 71.4%, the dielectric loss is 0.02004, and the figure of merit (FOM) is 35.7, which has optimal dielectric properties. At the same time, the purpose of replacing precious metals (Au) with cheap metals (Cu) is realized.
Method for Detecting Electrical Interface in Sea Area Based on Active Electric Field
Authors: Chen Cong , Wu Xu , Yang Jingxuan , Sun Jiaqing
Published: January 2023

To obtain the direction and distance of the electrical interface in the sea, the active electric field of the electric dipole and two three-component electric field intensity sensors are used to detect them. First, the structure design of the active electric field detection device is given, and then a method for active electric field detection of the electrical interface in the sea area is proposed, that is, the effect of the electrical interface on the active electric field is equivalent to the effect of the mirror electric dipole, locating the position of the mirror dipole can be done by measuring the change of the field strength, and then the interface parameters can be determined according to the symmetrical relationship between the position of the mirror dipole and the source dipole. Both simulation analysis and laboratory test results show that the interface detection method is feasible. The related research provides new ideas for target detection in the sea.
Study on the influence of layout angle on static stiffness and longitudinal grip of tread blocks
Authors: Zhou Shenghao , Wang Shuogui
Published: January 2023

The static stiffness and longitudinal grip of the tread block are important parameters of the tire, affecting the performance of the tire, such as braking, steering, noise, and side slip properties. In order to study the influence of the layout angle of the tread block on the static stiffness and longitudinal grip of the tread block, a theoretical model of the change of the static stiffness of the tread block with the layout angle is introduced, which is considered the effect of the compression on the deformation under sliding conditions. A finite element model of the static stiffness of the tread block changing with the layout angle is established in ABAQUS, and the conclusions obtained are in good agreement with the theoretical model. On this basis, the changes in the longitudinal grip of the tread block under different layout angles are explored, and the longitudinal grip of the tread block is increased and then decreased with the increase of the layout angle, and the increase rate before reaching the peak is less than the decrease rate after reaching the peak. Comparing and analyzing the shear stress nephogram of the load-bearing slip tread block under different layout angles, it is found that when the layout angle changes, the shear stress of the tread block will be redistributed according to certain characteristics, thus affecting the longitudinal grip of the tread block.
Loose bolt detection method based on wavelet packet decomposition with CNN
Authors: Xing Yuhua , Geng Huan
Published: January 2023

Loose bolts in PV mounts can affect the smooth operation of the system. If the loose bolts are not detected in time, the PV modules may fall off and cause the mounts to collapse in serious cases. The ultrasonic wavelet packet decomposition (WPD) combined with convolutional neural network (CNN) is proposed as a detection method to address the problem that the ultrasonic signal collected when the bolt is loose indistinctively. First, the ultrasonic signal with bolt loosening information is decomposed into four layers of wavelet packets to extract the energy composition of the feature vectors of each sub-band signal; second, the CNN model is designed and the network is trained with the feature vectors as samples; finally, the discrimination of bolt loosening conditions is achieved. The feasibility of the method is verified through experiments, and the experimental results show that the accuracy of the model is improved from 95.64% to 99.92% compared with the original data training model, and from 86.96% to 99.92% compared with the support vector machine (SVM).
Design of a battery early warning system based on the single-chip microcomputer
Authors: Yan Chengen
Published: January 2023

There is countless news of disasters caused by battery damages, such as explosions, electricity leaks, and thermal runaways each year, resulting in millions of dollars of losses, which highlights the scarcity of an effective damage detection system. However, early-stage damages cannot be detected by current detection methods accurately. This design uses the LTC6811-1 chip to monitor the current and voltage data of the cell and then transmits the data to the ATMEGA328-AU single chip, where the data are processed before being displayed on a PC screen. The principle of detecting damages is to compare the fluctuations in detected data with the pre-set data, i.e., the voltage and current data of discharges of a standard normal cell. If the fluctuation is significantly different in a short time, the cell is considered to be damaged. This offers a new alternative for battery monitoring with earlier warning messages sent and improved details about the damage.
Compressed Sensing: Theory and Applications
Authors: Wang Hanbo
Published: January 2023

Compressed sensing is a new technique for solving underdetermined linear systems. Because of its good performance, it has been widely used in academia. It is applied in electrical engineering to recover sparse signals, especially in signal processing. This technique exploits the signal’s sparse nature, allowing the original signals to recover from fewer samples. This paper discusses the fundamentals of compressed sensing theory, the research progress in compressed sensing signal processing, and the applications of compressed sensing theory in nuclear magnetic resonance imaging and seismic exploration acquisition. Compressed sensing allows for the digitization of analogue data with inexpensive sensors and lowers the associated costs of processing, storage, and transmission. Behind its sophisticated mathematical expression, compressed sensing theory contains a subtle idea. Compressed sensing is a novel theory that is an ideal complement and improvement to conventional signal processing. It is a theory with a high vitality level, and its research outcomes may substantially influence signal processing and other fields.
Effect of different parameters on processing efficiency in electrochemical machining
Authors: Zhou Guanlin , Adayi Xieeryazidan , Shang Zhongsheng
Published: January 2023

To explore the influence of different processing parameters on the efficiency of electrochemical machining and the surface morphology, the influence of different processing parameters on the removal of spikes was simulated by COMSOL Multiphysics simulation software. And combined with experiments, the influence of different processing parameters on electrochemical machining micro-surface was analyzed and compared. The results showed that the removal amount increased with the increase of machining voltage, machining time, and electrolyte concentration, and decreased with the increase in the machining gap. The appropriate processing parameters not only reduce the surface roughness from 2.56μm to 0.57μm, but also change the difference between the surface micro high point and the micro low point from 280μm to 170μm, and the finishing effect is greatly improved.
Research on digital soft start method of boost DC-DC switching power supply
Authors: Li Mengli , Guo Zhongjie , Qiu Ziyi , Shi Hao
Published: January 2023

Due to the progress of science and technology and the rapid development of the economy, human performance requirements for electronic products are getting higher and higher. Therefore, it is necessary to study a Boost-type DC-DC converter with high conversion efficiency, miniaturization, strong stability, and fast start speed. Currently, there are many ways to solve the DC-DC switching power supply problem. By analyzing the switching power supply, an efficient digital soft start method for boosting DC-DC switching power supply. This method adopts programmable digital technology. By precharging the output capacitor with the multiplexed substrate switching circuit, the output current rises steadily, and the soft start effect of the switching power supply is achieved. Based on the 0.18um BCD process, the test shows that when the input voltage is 3.7 V, the output voltage is 4.6 V, and the duty ratio is 20%, the soft start time is 210 us when the PVT changes and the steady rise of the output voltage does not produce the surge current phenomenon. Through theoretical analysis and experimental verification, the proposed method has the obvious advantages of simple structure, strong stability, low power consumption, and fast starting speed.
A Divide and Conquer Strategy to Deadlock Prevention in AMS with a Multitype of Resources using Resource Petri Nets
Authors: Yuan Hongpeng
Published: January 2023

The divide and conquer strategy in this paper is used to investigate the deadlock prevention of the AMS modeled by Resource-oriented Petri net when multitype resources are introduced. Based on the production process circuits, the plant ROPN model is divided into an idle subnet, an autonomous subnet, and some independent topologies. By adding liveness enforcing controllers to each topology, deadlock-free AMS can be achieved. It is shown that if the ROPN satisfies the separation condition, the computational effort of the controller will be greatly reduced. The proposed method is illustrated with the large AMS example.
Simulation and Experiment Research on Abrasive Wear of the Ship Mechanical Seal
Authors: Jin Yong , Ouyang Wu , Liu Zihao , Zhou Jianhui
Published: January 2023

The wear of friction pair resulting from seawater particles will inevitably bring marine tail shaft mechanical seal in the process of work, and abrasive wear will increase the static ring wear, resulting in the leakage of the mechanical seal. In this paper, through finite element simulation analysis of abrasive wear with different particle sizes and abrasive wear tests under different static ring materials, it is concluded that larger abrasive particle sizes will increase the deformation and residual stress on the surface of static ring materials, thus increasing the amount of wear, and the surface of softer static ring materials will be more serious. Also, if the particle size is too large, the particle concentration of the friction surface will decrease, and the wear will decrease.
Implicit Lyapunov Function-based Formation Control for Heterogeneous Vehicular Platoons with Time Delays
Authors: Chen Xiyan , Zheng Xinlei , Zhai Chunjie , Chen Chuqiao , Zimenko Konstantin A. , Wang Hongkui , Yin Haibing , Yan Chenggang
Published: January 2023

In order to lower the drivers’ driving pressure and improve traffic efficiency, academic and industrial interest in the cooperative adaptive cruise control (CACC) system has been substantial. In this research, we use the Implicit Lyapunov Function (ILF) technique to develop a switching controller for HVPs with temporal delays. The constant time headway strategy is utilized to construct the HVPs error model first. Then, the implicit Lyapunov function is used to develop the switching controller. Finally, the conditions of internal stability and string stability are obtained. The suggested switching controller has been shown to maintain internal and string stability in simulations involving heterogeneous vehicle platoons.
Principle and Experimental Study of Flow Noise Reduction for Underwater Vehicle Hull-Mounted Sonar
Authors: Fu Renqi , Shen Wenmiao , Hou Jue , Lou Wanxiang
Published: January 2023

When the underwater vehicle is sailing at high speed, the noise of flow becomes one of the principal background noises of the hull-mounted sonar, and suppressing the flow noise is an important way to further develop the detection execution of the hull-mounted sonar. In this paper, by establishing a physical model for the analysis of flow noise, The theoretical calculation of the fluctuating level of noise acquired by a plane element sensor imbedded in an rubbery layer is performed, and the impact of different wave-number filter elements such as sensor receiving area and rubbery layer on reducing turbulent noise is discussed, and then, the effectiveness of the flow noise reduction is verified through the measurement in a large-scale flow noise test tunnel.
Application of Adaptive Integral Robust Controller in Laser Galvanometer Motor
Authors: Li Guo-wang , Huang Shi-hao , Cai Xinjian
Published: January 2023

High-speed motion control of the galvanometer has become a very important part of laser processing. Due to the parameter uncertainty of the galvanometer itself, non-linearity can affect the friction compensation effect. In this paper, we propose to reduce the steady-state tracking error of the galvanometer system by means of an integral control term, while estimating the friction behavior using a nonlinear modified LuGre observer. Then an adaptive integral robust control scheme is used to eliminate the effects of nonlinear friction and external disturbances. And the stability of the galvanometer system is proved by the Lyapunov theorem. Simulation verification by MATLAB shows that the control scheme proposed in this paper can accurately follow the system commands. And the controller can effectively suppress the effects of unknown disturbances and parameter uncertainties compared with traditional control strategies. The simulation results show that the proposed control scheme significantly improves the response speed and tracking accuracy of the galvanometer system.
Bolts looseness detection in construction machinery
Authors: Song Yancheng , Liu Guangjun , Wang Yunfei
Published: January 2023

Bolt connections have increasingly wide applications in the mechanical industry, such as civil construction, construction machinery, etc. However, along with the vibration of the mechanical operation, bolt looseness is unavoidable and thus can lead to severe consequences. Therefore, the detection of loose bolts deserves an in-depth study. However, conventional bolt looseness detection techniques require a lot of time and labor, and direct contact sensor-based detection techniques are sensitive to interference from the surroundings. To tackle these challenges mentioned above, this work proposes a vision-based bolt looseness detection method, with the advantages of low cost, easy deployment, and non-contact. Specifically, an innovative attention mechanism is introduced into the Yolov4 framework to improve the accuracy and speed of bolt detection. Each bolt image is cropped by the recognition result of the detector, then the bolt contour is extracted by edge detection, and the bolt is determined to be loose or not based on the angle of bolt rotation. Comprehensive experiments in real-world settings verify the effectiveness and efficiency of the proposed method.
Study on the detection method of HDPE electro-fusion welding defect based on X-ray technology
Authors: Li Qiang , Li Weihan , Lu Qi , Li Yanfeng , Yang Tao
Published: January 2023

Electro-fusion welding is a common method for high-density polyethylene (HDPE) pipes. It has a high degree of automation and mature technology. However, during the welding process, various buried defects are easily generated. In this paper, HDPE pipes with welding defects were processed, and X-ray technology was used to detect the defects. The results show that: The X-ray detection technology is sensitive to the defects of sockets and ultralight clay-filled holes. But it is difficult to distinguish the size of the holes. Unfilled holes are partially fused during the welding process, which makes them difficult to detect. In addition, the defects of cold-welding and unscratched oxide skin cannot be detected.
Design and Simulation of a New Type of Speed-ratio Bladeless Supercharger Mechanism
Authors: Zhao Jie , Wang Zhicheng , Zhu Mengfan
Published: January 2023

Aiming at the problems of complex machining and impeller structural strength of traditional centrifugal compressors, a new speed-ratio bladeless supercharging mechanism is proposed. The results show that the system pressure of the new structure increases with the increase of the rotating speed of the disk; while the maximum pressure of the outer cavity and the maximum pressure of the system change in a curve with the difference of the disk wall clearance, the diameter of the disk and the number of pipes in the disk. Based on the results of theoretical and simulation analysis, a bladeless pressurized structure test platform was established. The test results show that the working medium pressurization measured at the outlet of the mechanism is 0.1Mpa, and the experimental results have a high degree of agreement with the theoretical analysis.
Simulation research on hydrodynamic performance of wave glider airfoil
Authors: Wang Ganlin , Zhu Liucun , Wan Hong , Wang Jiyue , Deng Haofeng , He Congwei
Published: January 2023

To improve the wave energy utilization rate of the wave glider as the research goal, research on the improvement of the hydrodynamic performance of the airfoil of the wave glider was carried out. First, we extract the bionic airfoil A and the standard airfoil C and draw the design airfoil B and the regular airfoil D. Secondly, using ANSYS Fluent, the hydrodynamic performance of the four airfoils under different inflow velocities and angles of attack is studied. Finally, data analysis shows that under the same attack angle, the lift coefficient, drag coefficient, and lift-drag ratio of the airfoil are not affected by the incoming flow velocity. Under the same incoming flow velocity, when the attack angle is 5°-13°, the bionic wing Type A is slightly better than the design airfoil B, obviously better than the standard airfoil C and regular airfoil D. Considering the hydrodynamic performance and material cost, it can be seen that the B airfoil is the optimal airfoil in this study. The comparative analysis of four airfoils provides a research basis for improving the wave energy utilization rate of the wave glider.
Bearing Fault Diagnosis Based on Prime Mean Spectral Segmentation Kurtogram
Authors: Dai Bing , Peng Yingjie , Lin Ning , Wang Peng
Published: January 2023

The spectrum-based fault feature extraction method for industrial equipment can avoid the problems of modal aliasing and end effects caused by mode decomposition in the time domain. This paper proposes a kurtogram constructed based on prime mean spectral segmentation. The preset framework realizes fast spectral segmentation, and the multivariate segmentation mode provides a more reasonable distribution of center frequency and bandwidth. The precise location and diagnosis of faults can be achieved by scanning shocks in each frequency band by spectral negentropy. Simulation signals and bearing fault experimental signals verify the performance of the algorithm.
Design of an autonomous navigation system for emergency disposal robots at radioactive waste sites under extreme climatic conditions
Authors: Peng Tianlin , Tang Dewen , Wu Jianing
Published: January 2023

There are many factors of environmental hazards that endanger the lives of personnel at radioactive waste sites after sudden extreme weather disasters, and the use of robotic substitutes can effectively safeguard the lives of personnel. For the situation where the environmental information of radioactive waste sites is unknown and there are many variables, an autonomous navigation system of emergency disposal robots with strong resilience and stability is designed. First, an algorithm based on the Rao-Blackwellized particle filtering theory is used in the autonomous navigation system to achieve more accurate robot positioning and map building through four processes: prediction, correction, resampling, and map building. Second, the traditional path planning algorithm combined with road information is added to Hopfield neural network to achieve deep analysis of complex road conditions. Finally, the intelligent voice interaction function is added to the navigation system to realize the robot’s interaction and real-time monitoring and feedback. The experimental results show that the emergency disposal robot has high accuracy in positioning, navigation, obstacle avoidance, etc., can respond quickly in unexpected situations and can carry out effective voice interaction.
Research on the automatic release function of electronic handover orders in distribution networks based on RPA
Authors: Bian Qiaoyan , Huang Di , Luo Shaojie , Zheng Weiyan , Yan Xingping
Published: January 2023

RPA is a new type of artificial intelligence virtual process automation robot. After several years of development, it has been widely used in various fields that need process automation. Studying the application of process automation in the power industry can solve mechanical and repetitive work problems by replacing the repetitive tasks and work processes performed manually with digital means. This paper introduces the Research and Development contents and specific process of an automatic release tool of electronic handover orders for distribution networks based on RPA, which can simulate the standardization of manual work process by pre-set program operation instructions, to speed up business process flow and reduce human investment.
A predictive Algorithm for Boost PFC Operating in Mixed Conduction Mode
Authors: Niu Junhao , Miao Hongtang
Published: January 2023

The traditional PFC control adopts the PI algorithm of the double-loop structure, but the PI parameter designed at this time is aimed at the inductor current continuous mode (CCM). When the PFC enters a heavy or light load, the converter inevitably enters the inductor current discontinuous mode (DCM). If the control parameters of CCM are still used at this time, the system may become unstable and reduce load response speed. Therefore, an optimized predictive current control is proposed, which calculates the duty cycle in CCM and DCM separately in advance, and then adopts the corresponding optimal duty cycle according to the detected inductor current conduction mode. With this algorithm, the PFC can operate in mixed conduction mode. It has a wider load range and faster load response speed than PI. Finally, through PLECS, the algorithm is verified by simulation.
Research on Real-Time Data Transmission and Feature Analysis Technology of Smart Tool Holder
Authors: Yan Jie , Huang Yigong , Song Lei
Published: January 2023

Cutting force, vibration, and cutting temperature are the significant characteristics of the cutting process for real-time monitoring and optimization. Smart tool holder technology is one of the key technologies to effectively monitor the cutting process. In order to realize real-time monitoring of the cutting process, a data transmission and processing technology based on the smart tool holder is proposed. First, a data transmission scheme based on socket communication technology is developed. Then, a data transmission format based on Modbus protocol and BCD code is proposed. Finally, the feature analysis technology of real-time data is discussed for the requirements of real-time control and optimization of process parameters. The proposed technology is conducive to improving the data processing efficiency of the data transmission process of the smart tool holder and is of great significance to the standardization of data transmission based on the smart tool holder.
Research on robotic end positioning based on fuzzy PID control
Authors: Liu Yunzhong , Jiang Hong , Zhang Xiangfeng
Published: January 2023

The existing traditional proportional-integral-derivative (PID) control robot has low-end positioning accuracy, which cannot meet the needs of accurately placing the molding die in the current automatic coal pen production process. To address this problem, this paper proposes a fuzzy strategy PID control method based on fuzzy strategy, aiming to improve the accuracy and robustness of the system when the manipulator grasps the mounding mold. Firstly, a manipulator motor control model is established to derive the parameters of the manipulator control system; secondly, the fuzzy control strategy is applied to adjust the PID control parameters in real time to improve the dynamic stability of the system. Finally, the control system is simulated, and field experiments are conducted to verify the accuracy of robotic end positioning. The experimental results show that the fuzzy PID control system has a shorter response time, better anti-interference ability, and better stability than the traditional PID control and achieves the accuracy requirements of coal pen automation production.
Node Importance Recognition Algorithm Based on the Correlation Degree Transmission Contribution Matrix
Authors: Lin Shengnan , Li Shuai , Su Yang
Published: January 2023

Based on the importance identification of nodes in a directed weighted network, a node importance recognition algorithm based on the correlation transmission contribution matrix is proposed. The proposed algorithm comprehensively considers the transmission ability of nodes, the correlation degree between nodes and adjacent nodes or indirectly related nodes, and the contribution degree between nodes to construct the correlation degree transmission contribution matrix. This paper combined the algorithm with the node efficiency of the local range of node importance and finally combined it with the global importance index intermediary number centrality to comprehensively evaluate the importance of nodes in the network. For the nodes with only incoming edges in the network, the product of the node mediator centrality and the correlation degree contribution matrix is calculated as the node importance. For nodes with only outgoing edges in the network, the product of node mediator centrality, degree value and node self-efficiency is calculated as node importance. Conducting experimental simulation analysis of the ARPA directed-weighted networks shows that the deliberate attack based on the algorithm results hits the network more obviously, which further proves the effectiveness and accuracy of the proposed algorithm.
Operational scenario of first high luminosity LHC run
Authors: Tomás R , Arduini G , Baudrenghien P , Brüning O , Bruce R , Buffat X , Calaga R , Cerutti F , Maria R De , Dilly J , Efthymiopoulos I , Giovannozzi M , Hermes P D , Iadarola G , Jones R , Kostoglou S , Lindström B , Maclean E H , Métral E , Mounet N , Papaphilippou Y , Persson T H B , Pugnat T , Redaelli S , Sterbini G , Timko H , Veken F Van der , Wenninger J , Zerlauth M
Published: January 2023

A new scenario for the first operational run of the High Luminoisty LHC (HL–LHC) era (Run 4) has recently been developed to accommodate a period of performance ramp-up to achieve an annual integrated luminosity close to the nominal HL–LHC design target. The operational scenario in terms of beam parameters and machine settings, as well as the different phases to reach optimal performance, are described here along with the impact of potential delays to key hardware components.
Summary of numerical noise studies for Electron-Ion Collider strong-strong beam-beam simulation
Authors: Luo Y , Xu D , Hao Y , Qiang J , Berg J S , Blaskiewicz M , Fischer W , Gamage R , Gu X , Huang H , Hoffstaetter G , Kewisch J , Lovelace H , Montag C , Morozov V , Nisson E , Peggs S , Ptitsyn V , Satogata T , Willeke F
Published: January 2023

The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with design luminosities up to 1 × 1034cm−2s−1 in center mass energy range of 20-140 GeV. We studied the planned electron-proton collisions using a Particle-In-Cell (PIC) based Poisson solver in strong-strong beam-beam simulation. We observed a much larger proton emittance growth rate than in weak-strong simulation. To understand the numerical noise and its impact on strong-strong simulation results, we carried out extensive studies to identify all possible causes for artificial emittance growth and quantify their contributions. In this article, we summarize our study activities and findings. This work will help us better understand the simulated emittance growth and the limits of the PIC based strong-strong beam-beam simulation.
Detector solenoid compensation in the EIC electron storage ring
Authors: Xu D , Luo Y , Berg J Scott , Lovelace H , Tepikian S , Wu Q , Xiao B , Avronsart J , Witte H , Blaskiewicz M , Montag C , Willeke F , Gamage B R , Morozov V , Hao Y
Published: January 2023

The Electron-Ion Collider (EIC) uses crab cavities to restore the geometrical luminosity loss associated with the large crossing angle. Due to space limitations, the detector solenoid cannot be compensated locally. This paper presents the lattice design to compensate the detector solenoid effects without interfering with the crab cavities. Skew quadrupoles are employed to avoid additional crab cavities. The correction scheme is checked by beam-beam simulation.
Field enhanced compact S-band gun employing a pin cathode
Authors: Bazrafshan R , Fakhari M , Rohwer T , Flöttmann K , Matlis N H , Kärtner F X
Published: January 2023

S-band RF-guns are highly developed for production of low emittance relativistic electron bunches, but need powerful klystrons for driving. Here, we present the design and first experimental tests of a compact S-band gun, which can accelerate electrons up to 180 keV powered by only 10 kW from a compact rack-mountable solid-state amplifier. A pin-cathode is used to enhance the RF electric field on the cathode up to 100 MV/m as in large-scale S-band guns. An electron bunch is generated through photoemission from a flat copper surface on the pin ex-cited by a UV laser pulse followed by a focussing solenoid producing a low emittance bunch with 0.1 mm mrad transverse emittance for up to 100 fC bunch charge. We are currently in the conditioning phase of the gun and first experiments show good agreement with simulations. The compact gun will serve three purposes: (i) it can be used directly for ultrafast electron diffraction; (ii) as an injector into a THz booster producing 0.3 MeV to 2 MeV electron bunches for ultrafast electron diffraction; (iii) The system in (ii) serves as an injector into a THz linear accelerator producing a 20 MeV beam for the AXSIS X-ray source project.
Beam orbit shift due to BPM thermal deformation using machine learning
Authors: Chen Kemin , Wang Faya , Wang Guanliang , Wang Zhe , Hosaka Masahito , Guo Lei , Xu Wei
Published: January 2023

Stabilizing beam orbit is critical for advanced synchrotron radiation light sources. The beam orbit can be affected by many sources. To maintain a good orbit stability, global orbit feedback systems (OFB) has been widely used. However, the BPM thermal deformation would lead to BPM misreading, which can not be handled by OFB. Usually, extra diagnostics, such as position transducers, is needed to measure the deformation dependency of BPM readings. Here, an alternative approach by using the machine operation historic data, including BPM temperature, insertion device (ID) gaps and corrector currents, is presented. It is demonstrated at Hefei Light Source (HLS). The average orbit shift due to BPM thermal deformation is about 34.5 μm/°C (horizontal) and 20.0 μm/°C (vertical).
Dependence of CsK2Sb photocathode performance on the quality of graphene substrate film
Authors: Guo L , Goto K , Yamaguchi H , Yamamoto M , Takashima Y
Published: January 2023

A high-performance photocathode is required to advanced accelerators and electron microscopes. In particular, the CsK2Sb photocathode is of interest because it has features such as low emittance, excitability with visible light, and high quantum efficiency (QE). Generally, the CsK2Sb photocathode is produced by depositing a cathode element on a substrate, so that the cathode performance strongly depends on the surface condition of the substrate. We have found graphene as reusable substrate, which has the property of being chemically inactive. In this study, graphene film quality dependence of CsK2Sb photocathode performance was evaluated. Specifically, CsK2Sb photocathode was deposited using different quality graphene film substrates and their QE values and uniformity were compared. The quality of graphene films was analyzed using X-ray Photoelectron Spectroscopy (XPS) and X-ray Absorption Spectroscopy (XAS). We found that the graphene film can be cleaned by heating at 500 deg. The QE of the cathode on a good quality graphene film was higher and more uniform than that on a poor quality graphene film.
Start-to-end simulations for bunch compressor and THz SASE FEL at PITZ
Authors: Lueangaramwong A , Li X , Boonpornprasert P , Krasilnikov M , Stephan F
Published: January 2023

The magnetic bunch compressor was designed as part of a THz accelerator source being developed at the Photo Injector Test facility at DESY in Zeuthen (PITZ) as a prototype for pump-probe experiments at the European XFEL. As an electron bunch is compressed to achieve higher bunch currents for the THz source, the beam dynamics in the bunch compressor was studied by numerical simulations. A start-to-end simulation optimizer including coherent synchrotron radiation (CSR) effects has been developed by combining the use of ASTRA, OCELOT, and GENESIS to support the design of the THz source prototype. In this paper, we present simulation results to explore the possibility of improving the performance of the THz FEL at PITZ by using the developed bunch compressor.