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Acta Mechanica Sinica 2023年第3期39卷 168-184页

作者：张昆鹏畅兆敏郝淑英张琪昌冯晶晶 Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Schoolof MechanicalEngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384China Tianjn Key Laorary of Noninearynamics and Conto Soolof MhancalEngineeringTinjin UnverTianjn 30002China

本文设计一类新型的指数型变截面梁式微陀螺,变截面指数梁的宽度与长度的关系为指数函数变化的形式,且指数梁的截面变化因子小于等于零,梁的厚度随梁长仍保持不变.考虑了曲率非线性和惯性非线性对系统的影响,利用扩展哈密顿原理、单模... 详细信息

本文设计一类新型的指数型变截面梁式微陀螺,变截面指数梁的宽度与长度的关系为指数函数变化的形式,且指数梁的截面变化因子小于等于零,梁的厚度随梁长仍保持不变.考虑了曲率非线性和惯性非线性对系统的影响,利用扩展哈密顿原理、单模近似法和拉格朗日微分方程,建立了指数型变截面梁式非线性陀螺仪的振动控制方程、边界条件和非线性离散化模型,且考虑了陀螺仪驱动和检测两个方向上直流电压和交流电压对系统响应的影响,采用ADM法求解陀螺仪系统在不同截面变化因子下的静态响应,利用多尺度法对系统的非线性离散化模型进行摄动求解,分析各个参数对陀螺仪动态响应的影响规律.结果表明,随着截面变化因子的增大,指数梁陀螺仪的吸合电压和一阶固有频率逐渐增加,并呈现近似线性的变化规律.通过调节指数梁截面变化因子,可以控制科氏力响应峰值频率和检测峰值频率的差值.利用指数梁陀螺仪系统的硬化非线性特征,当交流电压施加在指数梁厚度方向时,选择合适的指数截面变化因子、阻尼比和交流电压,可以使指数梁式陀螺仪系统获得更好的带宽性能及线性可测范围;当交流电压施加在指数梁宽度方向,选取合适的截面变化因子,不仅可以获得较高的系统灵敏度性能,同时增加陀螺仪对外部输入角速度的线性可测范围.

关键词： Exponential beam Micro-gyroscope Nonlinear characteristics Bandwidth Sensitivity

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Mechanical properties and microstructure evolution of T2 copper in multimodal ultrasonic vibration assisted micro-compression

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材料科学技术（英文版） 2025年第5期208卷 152-163页

作者： Weiqiang Wan Zidong Yin Guangchao Han Ming Yang Jitao Hu Fuchu Liu Linhong Xu Wei Bai Hui Chen School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Graduate School of System Design Tokyo Metropolitan UniversityTokyo 191-0065Japan Graduate School of System Design Tokyo Metropolitan UniversityTokyo 191-0065Japan School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Shenzhen Research Institute China University of GeosciencesShenzhen 518057China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Shenzhen Research Institute China University of GeosciencesShenzhen 518057China School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Shenzhen Research Institute China University of GeosciencesShenzhen 518057China Shenzhen Huazhong University of Science and Technology Research Institute Shenzhen 518000China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

Multimodal ultrasonic vibration(UV)assisted micro-forming has been widely investigated for its advan-tages of further reducing forming loads and improving forming ***,the influence mecha-nism of different UV modes on microstructure evolution and mechanical properties was still ***-timodal UV assisted micro-compression tests on T2 copper with different grains and sample sizes were conducted in this *** microstructure evolution for different UV modes was observed by *** results showed that the true stress reduction caused by UV was increased sequentially with tool ultrasonic vibration(TV),mold ultrasonic vibration(MV)and compound ultrasonic vibration(CV).The region of grain deformation was shifted along the direction of UV,and the MV promoted the uniform distribution of deformation *** grain refinement,fiber streamline density,grain deformation and rotation degree were further enhanced under CV,due to the synergistic effect of TV and ***,a coupled theoretical model considering both acoustic softening effect and size effect was proposed for describing the mechanical *** a physical model of dislocation motion in different UV modes was developed for describing the microstructure *** maximum error between the theoretical and experimental results was only 2.39％.This study provides a theoretical basis for the optimization of UV assisted micro-forming process.

关键词： Multimodal ultrasonic vibration Microstructure evolution Acoustic softening Size effect Coupling mechanism

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On the Accuracy and Efficiency of the reactor Operation Digital Twin for Parameter Identification and State Estimation

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SSRN 2023年

作者： Hong, Lizhan Gong, Helin Ji, Hongjun Lu, Jialiang Li, Han Li, Qing Paris Elite Institute of Technology Shanghai Jiao Tong University Shanghai200240 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610041 China

Accurate and efficient online parameter identification and state estimation are crucial to leveraging Digital Twin simulations for optimizing the operation of near-carbon-free nuclear energy systems. In previous works, we have developed the idea of reactor Operation Digital Twin (RODT). However, non-differentiabilities and discontinuities arise when employing some machine learning based surrogate forward models, challenging traditional gradient-based inverse methods and their variants. This study investigates deterministic and metaheuristic algorithms and further develops hybrid algorithms to address such issues. An efficient modular RODT software framework is presented incorporating these methods into its post-evaluation module for comprehensive comparison. Methods are rigorously assessed based on convergence profiles, stability with respect to noise, and computational performance. Numerical results demonstrate that the hybrid KNNLHS algorithm delivers the optimal balance of accuracy and efficiency for real-time online applications. Meanwhile, algorithms like FSA, DE and ADE exhibit slower yet highly accurate performance. This work advances RODT methodologies to harness machine learning and systems modelling for improved reactor monitoring, systematic diagnosis of off-normal events, lifetime management strategies, etc. The developed modular software and novel optimization methods presented offer pathways to realize the full potential of RODT for transforming energy engineering practices. © 2023, The Authors. All rights reserved.

关键词： State estimation

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Target-background feature blocks and aberrance repressed correlation filters for real-time UAV tracking

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Signal, Image and Video Processing 2025年第7期19卷 1-11页

作者： Jia, Yunwei Liu, Bo Liu, Zhenzhong Wang, Tianyang Yv, Kaiying Wang, Shuo Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

In recent years, Unmanned Aerial Vehicle (UAV) tracking technology has been widely applied in fields such as agriculture and aviation. However, due to limitations in UAV computational resources and battery life, deep learning-based tracking algorithms are difficult to deploy directly. Therefore, efficient and robust tracking methods based on Discriminative Correlation Filters (DCF) have become the mainstream for UAV tracking. The traditional DCF method updates the model with a fixed step size, making it prone to contamination, while the boundary effect further limits its tracking capability. To address the issue of model contamination, an appearance model update and masking mechanism was designed, introducing feature confidence and overall confidence thresholds to evaluate the quality of features and images. Features and images with poor quality are masked, and the learning rate is reduced to prevent model contamination. This paper proposes the Target-Background Feature Block and Aberrance Repressed Correlation Filter (TBFBARCF), which introduces target and background regularization terms into the spatial filter to mitigate boundary effects and incorporates an aberrance repression regularization term into the temporal aberrance repressed filter to reduce response map aberrance. The two filters mutually constrain each other and are jointly trained. Experiments conducted on three challenging datasets, OTB100, UAV123, and UAVDT, demonstrate that the TBFBARCF tracker outperforms 11 other DCF-based trackers. Its average precision and average success rate reach 0.756 and 0.62, respectively, and it operates at a speed of 36.6 frames per second (FPS) on a CPU platform. © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2025.

关键词： Drones

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Effect of Hydrogen, Helium and Dose Rate on the Evolution of Dislocation Loop in Pure Iron During In-Situ Irradiation

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SSRN 2024年

作者： Wu, Mengjie Huang, Jiyong Cao, Ziqi Ding, Yifan Zhong, Qinghong Zhao, Yanli Ran, Guang College of Energy Xiamen University Xiamen361102 China Fujian Research Center for Nuclear Engineering Xiamen361102 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China

Simulating neutron irradiation with ion irradiation requires considering the comprehensive effects of hydrogen, helium and dose rate to fully understand the microstructure evolution of material in an irradiated environment. Here, the characterization and evolution of dislocation loops in pure iron were investigated under heavy ion irradiation with four different injected gas ion types (Fe+, Fe+ & H2+, Fe+ & He+ and Fe+ & H2+ & He+) and under Fe+ & He+ irradiation with four different dose rates using in-situ transmission electron microscopy at 723 K. Compared to the Fe+ single-beam irradiation, the additional injection of H or He, or co-injecting H & He, mainly promoted the nucleation of dislocation loops at the early stage of irradiation and enhanced loop growth after that. Among them, the simultaneous irradiation of Fe+ & H2+& He+ triple beams were most pronounced. Moreover, Fe+ & H2+ & He+ triple-beam irradiation resulted in the highest fraction of loops and the highest ratio of the rotation of loop habit-plane. Under Fe+ & He+ dual-beam irradiation, the results demonstrated that as the dose rate increases, the loop density increased and the loop size decreased. Moreover, the fraction of loops at low dose rate was noticeably greater than that at high dose rate. The results of the current work provide important references for a better understanding of the effectiveness of ion irradiation in simulating neutron irradiation. © 2024, The Authors. All rights reserved.

关键词： Neutron irradiation

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Analysis of the impact of long-term service of inverter devices on electromagnetic compatibility

Analysis of the impact of long-term service of inverter devi...

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china Power Supply Society Electromagnetic Compatibility Conference (CPEMC)

作者： Ruiheng Zhang Xuejun Pei Jin Meng Hongming Fan Peng Zhou Yuzhang Yuan Power Electronics and Energy Management Key Laboratory Ministry of Education of China Huazhong University of Science and Technology Wuhan China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

ISBN: (数字)9798331509552

ISBN: (纸本)9798331509569

Taking the IGBT power module of the inverter device as the research object, finite element analysis technology was used to explore the influence of long-term service on the thermal characteristics and stress-strain of the IGBT module. At the same time, the influence of service aging on the electromagnetic compatibility performance of the device was studied, and the finite element simulation results were verified through accelerated aging experiments. The results showed that during the long-term operation of the IGBT module, due to the different thermal expansion coefficients of its materials, strain differences were found, ultimately leading to an increase in its ground capacitance, resulting in an increase in the amplitude of the common mode conducted noise of the device by 3dBμA in the frequency band after 20MHz. This study will provide theoretical guidance for the electromagnetic compatibility design of inverter devices for long-term service.

关键词： Insulated gate bipolar transistors Performance evaluation Accelerated aging Electromagnetic compatibility Fatigue Inverters Thermal noise Finite element analysis Thermal stresses Strain

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Mechanical Properties and Thermal Shock Resistance of SrAl_(2)Si_(2)O_(8) Reinforced BN Ceramic Composites

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无机材料学报 2024年第10期39卷 1182-1188页

作者： WANG Bo CAI Delong ZHU Qishuai LI Daxin YANG Zhihua DUAN Xiaoming LI Yanan WANG Xuan JIA Dechang ZHOU Yu International Joint Laboratory of Advanced Nanomaterials of Heilongjiang Province College of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Key Laboratory of Advanced Structural-Functional Integration Materials School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China China Resources Cement Technology R&D Co. LtdGuangzhou 510000China The First Military Representative Office of the Army Equipment Department in Beijing Beijing 100072China The Fourth System Design Department Fourth AcademyChina Aerospace Science and Industry Corporation LimitedBeijing 100048China School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Hexagonal boron nitride(h-BN)ceramics have become exceptional materials for heat-resistant components in hypersonic vehicles,owing to their superior thermal stability and excellent dielectric ***,their densification during sintering still poses challenges for researchers,and their mechanical properties are rather *** this study,SrAl_(2)Si_(2)O_(8)(SAS),with low melting point and high strength,was introduced into the h-BN ceramics to facilitate the sintering and reinforce the strength and ***,BN-SAS ceramic composites were fabricated via hot press sintering using h-BN,SrCO_(3),Al_(2)O_(3),and SiO_(2) as raw materials,and effects of sintering pressure on their microstructure,mechanical property,and thermal property were *** thermal shock resistance of BN-SAS ceramic composites was *** show that phases of as-preparedBN-SAS ceramic composites are h-BN and h-SrAl_(2)Si_(2)O_(8).With the increase of sintering pressure,the composites’densities increase,and the mechanical properties shew a rising trend followed by a slight *** a sintering pressure of 20 MPa,their bending strength and fracture toughness are(138±4)MPa and(1.84±0.05)MPa·m^(1/2),*** sintered at 10 MPa exhibit a low coefficient of thermal expansion,with an average of 2.96×10^(-6) K^(-1) in the temperature range from 200 to 1200℃.The BN-SAS ceramic composites prepared at 20 MPa display higher thermal conductivity from 12.42 to 28.42 W·m^(-1)·K^(-1) within the temperature range from room temperature to 1000℃.Notably,BN-SAS composites exhibit remarkable thermal shock resistance,with residual bending strength peaking and subsequently declining sharply under a thermal shock temperature difference ranging from 600 to 1400℃.The maximum residual bending strength is recorded at a temperature difference of 800℃,with a residual strength retention rate of 101%.As the thermal shock temperature difference increase,the degree of oxida

关键词： BN matrix composite hot-press sintering mechanical property thermal shock resistance service reliability

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Gap and Glitch Simulation for Taiji Data Challenge 6

Gap and Glitch Simulation for Taiji Data Challenge

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6th International Conference on Information Communication and Signal Processing, ICICSP 2023

作者： Jiafeng, Zhang Xiaodong, Peng Mengyuan, Zhao Peng, Xu Pengzhan, Wu Chen, Gao Xiaoshan, Ma National Space Science Center Chinese Academy of Sciences Key Laboratory of Electronics and Information Technology for Space System Beijing China Institute of Mechanics Chinese Academy of Sciences Beijing China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China

ISBN: (纸本)9798350339994

Simulating the detection process of a space-based gravitational wave (GW) measurement system is crucial for the task demonstration, design, operation and data processing. Gaps and glitches, which are common types of abnormal events in the detection process, are an important part of data simulation. This paper explores two gap models and three glitch models, provides a comprehensive overview of these models. The implementation of these models in Taiji Data, the simulation data of the Taiji program, is designed. Dedicated software modules were developed to incorporate the gap and glitch models into the simulation process. The impact of adding gap and glitch to the measurement is illustrated and analyzed. Finally, the time-series simulation detection data of space GWs that integrates gap and glitch models has been obtained, providing support for promoting the improvement of the detection data processing capabilities. © 2023 IEEE.

关键词： Gap simulation Glitch simulation Space gravitational wave detection Taiji Data

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Digital-Based Inverse design for Ultra-Compact Power Splitter on LNOI

Digital-Based Inverse Design for Ultra-Compact Power Splitte...

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2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023

作者： Zhou, Lingjun Ma, Hansi Nie, Xiaomin Li, Yunchen He, Zhixue Wang, Lei Li, Ke Zhang, Fan Peng Cheng Laboratory Shenzhen China School of Electronic and Computer Engineering Peking University Shenzhen China Center of Material Science National University of Defense Technology Changsha China State Key Laboratory of Advanced Optical Communication System and Networks School of Electronics Peking University Beijing China

ISBN: (纸本)9798350312614

We propose and experimentally demonstrate an ultra-compact and efficient power splitter on LNOI. The device is realized through the inverse design of a digital meta-structure and occupies a small footprint of only 4.8×4.8μm2. The measured results show that the insertion losses are below 2.5dB across the wavelength band of 1500-1560 nm, and the power imbalance between the two output ports is within 0.3 dB. © 2023 IEEE.

关键词： inverse design LNOI power splitter

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Review of Research Advances in CFD Techniques for the Simulation of Urban Wind Environments

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Fluid Dynamics & Materials Processing 2022年第2期18卷 449-462页

作者： Pengfei Ju Mingrui Li Jingying Wang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education(Tianjin University of Technology) Tianjin300384China School of Energy and Power Engineering Shandong UniversityJinan250061China Shandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology&Equipment Shandong UniversityJinan250061China

Computational fluid dynamics(CFD)has become the main method for the prediction of the properties of the external wind environment in cities and other urban contexts.A review is presented of the existing literature in terms of boundary conditions,building models,computational domains,computational grids,and turbulence *** specific issues,such as the accuracy/computational cost ratio and the exploitation of existing empirical correlations,are also examined.

关键词： Computational fluid dynamics wind environment pre-processing settings

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