bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long-term Variation of the Solar Polar Magnetic Fields at Different Latitudes
Authors: Yang Shuhong , Jiang Jie , Wang Zifan , Hou Yijun , Jin Chunlan , Song Qiao , Luo Yukun , Li Ting , Zhang Jun , Zhang Yuzong , Zhou Guiping , Deng Yuanyong , Wang Jingxiu 
Published: June 2024

Abstract
The polar magnetic fields of the Sun play an important role in governing solar activity and powering fast solar wind. However, because our view of the Sun is limited in the ecliptic plane, the polar regions remain largely uncharted. Using the high spatial resolution and polarimetric precision vector magnetograms observed by Hinode from 2012 to 2021, we investigate the long-term variation of the magnetic fields in polar caps at different latitudes. The Hinode magnetic measurements show that the polarity reversal processes in the north and south polar caps are non-simultaneous. The variation of the averaged radial magnetic flux density reveals that, in each polar cap, the polarity reversal is completed successively from the 70° latitude to the pole, reflecting a poleward magnetic flux migration therein. These results clarify the polar magnetic polarity reversal process at different latitudes.
Heat and particle exhaust in high-performance plasmas in Wendelstein 7-X
Authors: Gao Yu , Geiger Joachim , Jakubowski Marcin W. , Pandey Arun , Bozhenkov Sergey , Feng Yuhe , Endler Michael , Baldzuhn Jürgen , Perseo Valeria , Kremeyer Thierry , Schlisio Georg , Puig Sitjes Aleix , Otte Matthias , Naujoks Dirk , Krychowiak Maciej , König Ralf , Zhang Daihong , Szepesi Tamás , Kocsis Gábor , Cseh Gábor , Buzás Attila , Pisano Fabio , Knieps Alexander ,   the W7-X Team
Published: June 2024

Abstract
The paper reports for the first time the heat and particle exhaust at the plasma boundary through various edge diagnostics for the high-performance plasma obtained after pellet injection on Wendelstein 7-X. The plasma density at the edge is found to be reduced by a factor of 2 in the high-performance phase, supporting the previously reported density peaking at the plasma centre. The plasma beta effect on the magnetic topology is reflected by the appearance of the second strike line, which is well understood with simulation. However, during the rapid decay phase of the enhanced confinement, a transient localized heat flow of up to 16 MW m−2 is observed at the leading edge of a poorly cooled divertor component, which has not been understood but raises concerns about machine safety.
RSU-Net: An Attention U-Net for Martian Rock Segmentation
Authors: Tian Pengzhi , Yao Meibao 
Published: June 2024

Abstract
Since rocks may collide with the rover or wear tires during the exploration mission of the Mars probe, and may contain rich geological information, identifying rocks in the scene is crucial for the navigation and obstacle avoidance of the Mars probe. Additionally, since the communication between the Mars rover and the earth is often intermittent and delayed during missions, it needs a certain degree of autonomy. Deep learning technologies such as semantic segmentation and target detection can meet this requirement to a certain extent, which facilitates the enhancement of safety and efficiency for the Mars rover. Rock segmentation is to divide the pixels of the rock from the image. However, the texture of the rock is often close to the texture of the surrounding sand, and some parts may be covered, so it is difficult to identify it correctly. To this end, this paper proposed RSU-Net (Rock Segmentation U-Net) and RSU-Net-L, which combine the SENet attention mechanism, and the latter achieves higher computational efficiency and inference speed by compressing the number of channels on the basis of the former. In addition, this paper established a dataset, MarsRock, for Mars rock segmentation to help the Mars rover for visual navigation. Its images come from “Tianwen-1”, which contains 1194 images, and each image has a corresponding rock label. And our experiments on the MarsRock dataset show that RSU-Net can achieve 99.07% accuracy and 67.71% F1-score. RSU-Net-L can achieve 98.99% accuracy and 66.67% F1-score while diminishing the number of parameter count by 43.7% and the number of FLOPs by 43.6%, while the FPS can reach 12.01 on a single RTX6000-24GB GPU.
Fast 3D Reconstruction for Unknown Space Targets via Neural Radiance Field
Authors: Lu Chenxi , Yu Meng , Cui Hutao 
Published: June 2024

Abstract
In this study, a novel residual space object 3D model reconstruction approach is proposed. First, several low-cost CubeSats are assigned to carry out multi-view image capture in the vicinity of the space target, yielding a series of images with relative pose information. Then, a fast 3D reconstruction approach based on NeRF is introduced, in which real-time performance and reconstruction quality are improved for fast on-board 3D reconstruction. Finally, a simulation test is designed to verify the performance of the proposed method, results show that the proposed NeRF-based method is superior to traditional method in terms of reconstruction speed and texture richness.
Optimization Design of Mechanical Properties of Frame Plate Structure for Aircraft Repair Based on Genetic Algorithm
Authors: Meng Xiangrui , Ma Yongbin , Guo Ziwen , Fan Junling , Deng Zichen 
Published: June 2024

Abstract
Designing options for aircraft frame plate repair often relies on experience. Development of optimization technique is necessary to obtain optimal design for aircraft frame plate structure. In this paper, a method to optimize the repair parameters using genetic algorithm is proposed for the structural repair of aircraft frame plate. In the design process, the parameters of the reinforced piece are considered, including the type, length, width, thickness, and the layout of the rivets. Compared with the traditional genetic algorithm, the algorithm based on this paper considers the crossover between species and so on, so it can find the optimal solution in a wider design space. The finite element software ABAQUS combined with Python tool is used for parametric modelling and calculation, and the residual stress values of the repaired part is used as the objective function. Finally, a repaired aircraft frame plate structure with best static and dynamic properties is obtained.
An Inductance-Capacitance Measurement Method Based On Auto-Balancing Bridge
Authors: Liu Kang , Zhou Chengning , Chen Xueying , Wang Fu 
Published: June 2024

Abstract
Modern measurement modules are extremely demanding on the hardware and must accurately capture the relevant parameters of capacitance and inductance. The inductance and its quality factor, capacitance and its loss angle tangent value are very important parameters, but also the current testing difficulties. To efficiently and accurately measure the inductance and its quality factor, capacitance and its loss angle tangent, this paper developed a capacitance-inductance testing method based on automatic balanced bridge circuit. Firstly, based on the DSP development board, test capacitance and inductance by switching dip switches; Then, the use of self-excited oscillation method to generate a fixed frequency sinusoidal signal, through the amplifier to increase the amplitude of its signal, and the use of adder to the signal to provide a certain bias to meet the amplitude requirements; Finally, based on the automatic balanced bridge method, through the full-wave rectification plus filter will be converted into the average of the signal to be tested, and then use the amplifier circuit to control the average value of the signal to be tested, and then use the amplifier circuit to control the average value. Then use the amplifier circuit to control the average value within the AD sampling range, and use the micro-controller to collect the test amplitude, phase and other related parameters. The test results show the effectiveness of the proposed method.
Active Packet Dropout Kalman Filter Based Diagnosis Scheme For Liquid Rocket Engines With Measurement Fault
Authors: Zhang Zhenzhen , Zhang Xiaoguang , Chen Hui , Ma Meng 
Published: June 2024

Abstract
Various faults of the liquid rocket engine (LRE) threaten the safety of space launches. The LRE system faults are challenging to detect and isolate owing to sensor faults. In this paper, an active packet dropout Kalman filter (APD-KF) based method is proposed for solving the problem of LRE system fault detection and isolation (FDI) under measuring fault. Sensor faults are isolated firstly based on distributed extended multiple model adaptive estimation (EMMAE) scheme, and the sensor fault detection isolation (FI) result are then transformed to the package drop matrix and inserted into the system fault factor estimation process to discard fault measurement information. Experimental results based on data from simulation are used to decorate the efficiency of the method. This study may help to improve LRE health management and reduce launch risk by solving the problem of LRE system FDI with measurement fault.
Numerical study on ultrasonic detection of cracks in metallic structures with variable cross-sectional thickness
Authors: Wang Yan , Feng Rongxin , Hameed Muhammad Saqib , Zhang Shuai , Xu Jifeng , Zheng Kaihong 
Published: June 2024

Abstract
The metal structures are widely used in aerospace engineering, especially in joints and spars. The safety of these parts is important to ensure the safe service of the whole structures. The ultrasonic wave is a traditional technique to detect cracks in metals. However, it is usually difficult to find all the cracks because of its difficulty in variable directions of the crack and the irregular shapes of the metals. This paper aims to address the challenge of detecting cracks in metallic structures with varying cross-sectional thicknesses using ultrasonic methods. The research investigates the behavior of ultrasonic longitudinal and transverse waves as they propagate through aluminum plates with variable cross sections. Additionally, it examines how cracks in different orientations influence these wave types. The theoretical analyses are performed which explore the reflection of oblique incidence waves and the diffraction of ultrasonic waves when they encounter semi-infinite cracks. Subsequently, numerical simulations are performed to validate the theoretical findings and to detect both horizontal and vertical cracks within metal plates of varying cross-sectional thicknesses. The findings indicate that both longitudinal and transverse waves are effective in identifying the location of damage caused by horizontal cracks. However, when it comes to vertical cracks, only transverse waves are successful in detecting their precise location. From the research of this paper, transverse ultrasonic wave is suggested to detect cracks in metal structures with irregular cross sections.
Research on Load Control Of Main Bearing Based on Isfd Principle
Authors: Wang Ye , Guo Jie , Sun Xiewen 
Published: June 2024

Abstract
The main bearing load of the internal combustion engine is one of the main excitation sources that cause the vibration and radiation noise of the body structure. By reducing the main bearing load transmitted from the main bearing cap to the body, the vibration and noise of the internal combustion engine can be effectively reduced. In this paper, the main bearing cap damper is designed based on the principle of integral squeeze film damper (ISFD), and the load is controlled on the transmission path of the main bearing load. The main bearing load measurement scheme is designed. The load changes of the main bearing cap before and after the installation of the main bearing cap damper are measured experimentally. The load control effect of the main bearing cap damper is analyzed and verified.
Dynamic Simulation Analysis of Aviation Gear Transmission Based on Rough Tooth Surface
Authors: Sun Xiewen , Wei Huirong , Wang Ye 
Published: June 2024

Abstract
In order to explore the influence of tooth surface microstructure on the dynamics of aviation gear transmission, this paper describes the profile of aviation gear considering rough surface based on fractal theory. With the help of the established gear fractal contact model, the dynamic parameters such as time-varying friction coefficient, time-varying meshing stiffness and transmission error of rough tooth surface are characterized. The nonlinear dynamic model of aviation gear is established to solve the dynamic response of smooth and rough tooth surface. The dynamic meshing force, dynamic friction force, vibration time domain and frequency domain diagram are obtained, and the corresponding experiments are carried out. The simulation and experimental results show that the fluctuation range of the dynamic simulation results of aviation gear transmission based on rough tooth surface will be larger, and it has a certain degree of disorder, which is closer to the experimental results.
Drive Control Technology of Dual Three Phase Permanent Magnet Synchronous Motor for Electric Propulsion Aircraft
Authors: Kuang Zhi , Wang Yining , Duan Xiaoli , Wu Donghua , Cui Shumei 
Published: June 2024

Abstract
Green aviation is one of the effective ways to cope with future oil energy shortages and improve the atmospheric environment. As the executing mechanism of electric propulsion aircraft, the fault tolerance and safety of the electric drive system are the primary considerations. This article uses dual three-phase permanent magnet synchronous motors (PMSM) to drive propellers to provide power for electric propulsion aircraft. Firstly, the working principle of the propellers is analyzed, and a simulation model of the propellers is established using Simulink; Secondly, the space vector control method of dual three-phase PMSM is elaborated, and two different forms of space vector control are compared. At the same time, a vector control model of dual three-phase PMSM is established, and the third harmonic content of dual three-phase PMSM under two different space vectors is compared through simulation. Finally, establish a simulation model of dual three-phase PMSM driving propeller, compare the motor phase current and driving performance of different vector control methods, and analyze the advantages and disadvantages of different vector control methods.
Optimization design of rotor system with squeeze film damper
Authors: Shengxi Jia , Junyi Chen , Mi Yan , Hao Zhang , Xiaotao Tian 
Published: June 2024

Abstract
For the rotor system with squeeze film damper (SFD), an optimization design method based on eccentricity iteration was proposed. In this method, ANSYS is used to calculate the dynamic characteristics of the rotor, and Isight is used to solve the optimization design problem. The position of bearing, the position of disks and the support stiffness of SFD was selected as design variables. The optimization design of a double-disk flexible rotor system with SFD was performed, and a series of comparative experiments were carried out. The experimental results show that: after optimization, the amplitude response of the two disks is only 0.052 mm and 0.08 mm respectively when the rotor system passes through the critical speed, and the reaction response of the two supports is only 35 N and 34.2 N respectively. The experimental results demonstrate the effectiveness of the method. It can be used as a general method to deal with the engineering problems of optimal design of complex rotor system with SFD. The optimal design result of the rotor system is that the stiffness of the elastic support is reduced to the minimum, and the position of the two disks is close to the support on the premise that the critical speed satisfies the constraint.
Minimum nonprobabilistic entropy deconvolution for fault diagnosis of rolling element bearings
Authors: Zhu Yuanhang , Zi Yanyang , Chen Zhenyi , Shi Zhen , Zhao Yuhao 
Published: June 2024

Abstract
The blind deconvolution methods (BDMs) is one of the most common methods for fault diagnosis of rolling bearings, and it is essential to maintain the safe and reliable operation of mechanical equipment. However, noise interference and the need for prior periods limit the scope of application of the BDMs. In this paper, a new minimum nonprobabilistic entropy deconvolution (MNPED) method is proposed. According to the correlation between fault impact and non-Gaussianity, the Gaussian membership function in fuzzy set theory is used to map the sample points to the membership degree of Gaussian distribution, and then the nonprobabilistic entropy (NPE) is formed to measure the impact characteristics of the signal. Then NPE is incorporated into the iterative process of solving the filter coefficient. Finally, the target signal and the optimal filter coefficient are selected based on the criterion of minimum NPE. MNPED is capable of adaptively extracting the periodic pulse of a signal without requiring prior knowledge of the period, even in the presence of strong noise interference. The effectiveness and robustness of the proposed approach are validated through simulation and experimental data.
Numerical simulation and experimental analysis of foreign object impact on aero-engine fan rotor blade
Authors: Zhang Shuai , Dong Jiang 
Published: June 2024

Abstract
The detection and identification of fan rotor foreign object impact events during the working process of aero-engines are crucial to the safety and security of aircraft flight. Through the numerical simulation method based on finite element and the foreign object impact test platform to simulate the process of real engine impact by foreign objects, the rule of fan rotor blade foreign object impact and the monitoring and identification method were studied. Meanwhile, aiming at the problems of high difficulty and low accuracy in identifying the impact of foreign objects on the fan by the airborne parameters and added vibration parameters, the non-contact vibration measurement method based on blade tip timing was used to obtain the blade vibration displacement under different fan speed, foreign matter mass and impact velocity. The numerical simulation and experimental results show that the change trend of the vibration displacement of the rotor tip of the fan is consistent with that of the numerical simulation. And with the increase of the foreign object projectile mass, the vibration displacement of the blade tip caused by the impact of the foreign object on the fan blade increases. In addition, the impact velocity of the foreign object has little effect on the vibration displacement of the blade tips after impact. Furthermore, the vibration displacement of the blade tip caused by the impact of foreign objects first increases and then decreases with increasing speed.
Development of a mathematical model for the prediction of drill quality in voice-activated ultrasonic vibration assisted drilling process.
Authors: Bhuiyan Shah Alam , Patwari Anayet U , Navid Wasib Ul , Morshed Rahman Maruf , Showkhin Sakib 
Published: June 2024

Abstract
In different industries, drilling quality play an important role in the success of operations by producing millions of quality drilled parts. The production of high-quality parts at the lowest possible cost to the manufacturer is the primary goal of contemporary process and assembly industries. To assess the quality index of drilling holes; circularity index and surface roughness are important metrics. In order to produce better drilled parts at lower prices, this study work attempts to determine the key process variables using voice acting modules to investigate the induced vibrations effects that have the greatest impact on surface roughness and circularity index in a vertical CNC drilling machine. In order to forecast the surface roughness and circularity index of drilled holes within a given operational range, a mathematical model has been proposed by adopting a coupled algorithm using design expert and statistical approach. As an experimental design technique, Response Surface Methodology with small central composite design is used to enable the evaluation of various process parameters related with machining and vibration parameters and their effects on surface roughness and circularity index. The created model is improved using statistical tools to ensure the best match to the experimental data. It has been observed with the increase of RPM and vibration frequency the surface roughness increases up to a certain limit and then decrease whereas with the increase feed the surface roughness increases. But in terms of circularity index with the increase of the process parameters the plotted graph trends under perturbation analysis shows the similar pattern CI decreases up to a certain limit and then increases.
Study on bearing capacity and damage mode of carbon fiber composite J-type structures in oilfield completion tool connections
Authors: Lu Daosheng , Sun Yongtao , Zou Wei , Cheng Wenjia 
Published: June 2024

Abstract
Carbon fiber composite structures have a broad application prospect in oilfield completion tool module connection. However, the material failure mechanism is still unclear. In this paper, the mechanical properties and failure mode of T700/7901 composite J-type structure are investigated from experimental and finite element perspectives. Firstly, the load-carrying and failure properties of the structure were analyzed through typical mechanical property experiments such as tensile, bending, and compression, and the fiber, matrix damage, and delamination damage are the main reasons for the failure of the mechanical properties of the material. Secondly, a numerical model of the progressive damage ontological relationship of the composite material was established, and the accuracy of the model was verified by combining the experimental results. Based on the above study, this paper proposes the failure mechanism and optimization of composite J-type, which provides useful guidance for the design of fiber composite structures for oilfield completion tool types in the future.
Study on mechanical properties of bolted connection structure of carbon fiber resin matrix composites at low temperature
Authors: Ren Xiaoyang , Li Xiaoming , Huang Heyuan 
Published: June 2024

Abstract
This article focuses on the impact of low temperature environments that composite materials may face in engineering applications. Through experimental testing, the bearing capacity of carbon fiber resin based composite bolted structures at -100 ℃ and 25 ℃ was obtained, and a continuous damage model (CDM) was established. The damage evolution mechanism of bolted connection structures between metal and carbon fiber resin matrix composites at -100 °C and 25 °C was elucidated through numerical simulation. Research has shown that the ultimate load of the structure at -100 °C is 3.99% lower than that at room temperature, and the failure mode of the composite material structure at low temperature is transverse fracture along the hole edge, which is different from the compression tensile fracture along the nail hole section at room temperature.
Design and Implementation of Simulation Training System for Ground Maintenance Pannel of a Certain Type of Aircraft
Authors: Wang Yizun , Zhou Qiting 
Published: June 2024

Abstract
According to the design requirements of ground maintenance pannel simulation training system of a certain type of aircraft, a set of training system with the functions of ground handling practice, aircraft maintenance operation training and PMA interactive operation training is developed. The system design fully considers the requirements of generalization and modularization design. The function division of each module is clear, the signal interface is clear, and one of the modules can be replaced quickly to facilitate the positioning and elimination of failure. It has the dual expansibility of training task and training model, and can continuously add training task package, including procedure training, troubleshooting guidance training, etc., and can adapt to change in aircraft state.