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npj Materials Degradation 2025年第1期9卷 1-13页

作者： Fang, Huanjie Wang, Wenqian Yu, Jianhao Wang, Yongxin He, Xiaodong Di, Chongqing Pu, Jibin Nishimura, Kazuhito Wang, Weize State Key Laboratory of Advanced Marine Materials Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of Sciences No.1219 Zhongguan West Road Ningbo315201 China Qianwan Institute of CNITECH Zhongchuang 1st Road Zhongchuang Park Qianwan New Area Ningbo315336 China Key Laboratory of Pressure System and Safety Ministry of Education School of Mechanical and Power Engineering East China University of Science and Technology No.130 Meilong Road Shanghai200237 China

Accompanied with working condition of advanced aero-engine becoming harsh, the state-of-art 6–8 wt.% Y2O3-stabilized-zirconia (YSZ) thermal barrier coatings (TBCs) degradation aroused by environmental deposits (CMAS and molten salt) has attracted growing concerning. In this context, attack behavior of CMAS+NaVO3 mixtures (CN) on YSZ TBCs was studied by experimental investigation and computational simulation to gain insights into the mechanism behind thermos-chemical degradation. Results from conventional TBCs/the melt interaction test showed that the molten CN exhibited superior permeability than CMAS counterpart, with infiltration depth exceeding 350 μm within 0.5 h. Additionally, accelerated precipitation of Y-rich c-ZrO2 grains was exclusively noted in CN-corroded specimen, potentially attributable to the decrease in Y-solubility. Microstructural evolution of YSZ particles in ceramic particles/the melt interaction test indicated an enhanced thermos-chemical corrosiveness of CN, and this phenomenon was further elucidated through a corresponding DFT simulation, which implicated that promoted transport behavior may be the underlying cause. © The Author(s) 2025.

关键词： Chemical attack

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Study on sintering parameters and bonding mechanism of Cu@Ag preform via electromagnetic compaction for power electronics

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Journal of Alloys and Compounds 2025年 1030卷

作者： Liu, Li Wang, Qian Robertson, Stuart Chen, Chuantong Liu, Changqing Zhou, Zhaoxia Tuo, Chengjiong Ma, Haojie Nong, Liting Cao, Xueqiang Chen, Zhiwen School of Materials Science and Engineering Wuhan University of Technology Hubei Wuhan China The Institute of Technological Science Wuhan University Hubei Wuhan China State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Heilongjiang Harbin China Loughborough Materials Characterisation Centre Loughborough University Leicestershire Loughborough United Kingdom Flexible 3D System Integration Laboratory SANKEN Osaka University Osaka Japan

This study investigates the low-temperature sintering and stress-assisted bonding mechanisms of Cu@Ag composite preforms fabricated via electromagnetic compaction (EMC) technology. Experimental results show that the sintering temperature, pressure, time, and internal stress significantly enhance their bonding quality, achieving a high shear strength of up to 52.01 MPa. Molecular dynamics (MD) simulations reveal that internal stress promotes plastic deformation of Cu@Ag core-shell particles, accelerates atomic diffusion, and facilitates recrystallization, reducing the required bonding energy during sintering. Consequently, this combined effect enables directly effective bonding at low temperatures without the need for intermetallic compound formation or organic solvents. These findings highlight the potential of Cu@Ag preforms as reliable die-attach materials for next-generation power electronics. © 2025 Elsevier B.V.

关键词： Preforming

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Application of Parallel Mechanism in Varistructured Quadruped/Biped Human-carrying Walking Chair robot

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International Journal of Automation and computing 2013年第5期10卷 447-454页

作者： Ling-Feng Sang Hong-Bo Wang Dian-Fan Zhang Zhen-Hua Tian Fu-Hai Deng De-Lei Fang Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Science and Technology Research Institute Yanshan University

For the existing problems of walking chair robot such as simple function,lower bearing capacity and not walking in complex environment,a novel varistructured quadruped / biped human-carrying walking chair robot is *** proposed robot could be used as biped and quadruped walking chair *** the conversion of the walking chair robot from the quadruped to the biped or vice versa,6-UPS and 2-UPS＋UP（U,P and S are universal joint,the prismatic pair,and sphere joint,respectively） parallel mechanisms are selected as the leg mechanism of the biped walking robot and quadruped walking robot,*** the screw theory and theory of mechanism,the degrees of freedom of the leg mechanism and the body mechanism in diferent motion states are computed so as to meet the requirements of mechanism *** motion characteristics of the 2-UPS＋UP parallel mechanism which is the key part of the walking chair robot are ***,the workspace of the moving platform is drawn and the efect of the structural parameters on the workspace volume is ***,it is found that the volume of the workspace of the moving platform is bigger when the side length ratio and the vertex angle ratio of the fxed platform and the moving platform which are isosceles triangles are close to *** study provides a theoretical foundation for the prototype development.

关键词： Human-carrying walking chair robot parallel leg mechanism degree of freedom varistructure workspace kinematics

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Organophosphate esters in Tianshan glacier runoff: Occurrence, degradation, risk, and flux

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Fundamental Research 2025年

作者： Zeng, Jiamin Chai, Lei Wang, Xiaoping Fu, Jianjie Fu, Jie Li, Zhongqin Jia, Yufeng Zhou, Yunqiao Dong, Huike Gong, Ping State Key Laboratory of Tibetan Plateau Earth System Resources and Environment (TPESRE) Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China School of Environment Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Hangzhou 310024 China College of Earth and Environmental Sciences Lanzhou University Lanzhou 730000 China State Key Laboratory of Cryospheric Science/Tianshan Glaciological Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China College of Geography and Environment Science Northwest Normal University Lanzhou 730070 China

Organophosphate esters (OPEs) are a class of chemicals of emerging concern. However, little is known about the environmental behavior, transformation and ecological risk of OPEs in mid-latitude glacial environments. This study investigated the concentration and composition characteristics of organophosphate triesters (tri-OPEs) and organophosphate diesters (di-OPEs) in the runoff of Urumqi No. 1 Glacier and Koxkar Glacier in the Tianshan Mountains, and estimated the output of them from glacial rivers. The total concentration of tri-OPEs (Σ₁₃tri-OPEs) was 8565 pg/L in glacier surface meltwater and 6568 pg/L in proglacial rivers. Di-OPEs exhibited lower concentrations, with 99 pg/L and 117 pg/L (Σ₁₀di-OPEs) in glacier surface meltwater and proglacial rivers, respectively. Tri-OPEs exhibited clear diurnal variations, which are presumed to be related to environmental temperature, while di-OPEs did not show an obvious trend. Although risk quotients (RQs) indicated that the concentrations of OPEs pose minimal risk to the glacier aquatic environment, the Toxicological Priority Index (ToxPi) score results showed that tris(2-chloroethyl) phosphate (TCEP) has the highest priority and therefore requires more attention. The total output flux of OPEs (Σ₁₃tri-OPEs and Σ₁₀di-OPEs) in glacial rivers throughout the entire Tianshan region was estimated to be ∼847 kg/year. Given the continuity of glacial melting and the accumulation of emerging pollutants in glaciers, the process of melting poses an increasing risk to freshwater resources, warranting heightened attention. © 2024

关键词： Flux estimation Organophosphate esters Pollutant prioritization Risk assessment Runoff variation

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A combined-observation pose correction method for enhancing tracking accuracy in visual measurement systems

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Measurement: Journal of the International Measurement Confederation 2025年 253卷

作者： Yan, Kang Zheng, Jun Chen, Shangjian Wang, Jiangfeng Jin, Fengxin Dai, Ming Liu, Weiyuan Tang, Weihao Bi, Yunbo State Key Laboratory of Fluid Power and Mechatronic System School of Mechanical Engineering Zhejiang University 866 Yuhangtang Road Zhejiang Hangzhou310027 China CO. LTD Zhejiang Overseas High-level Talents Innovation Park 998 Wenyi West Road Zhejiang Hangzhou310027 China Qiushi Academy for Advanced Studies College of Computer Science and Technology Zhejiang University 38 Zheda Road Zhejiang Hangzhou310027 China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical Engineering Zhejiang University 866 Yuhangtang Road Zhejiang Hangzhou310027 China

Non-contact full-field 3D measurement and reconstruction using visual binocular tracking is crucial for many contemporary applications. However, accuracy limitations arise in long-range tracking due to low confidence in depth pose estimation. To address this, we propose a pose correction method using two binocular tracking units (TUs) in a perpendicular configuration. In the system, depth tracking from one unit is correlated to lateral tracking from the other unit through their relative pose. During fusion, lateral information takes precedence due to re-projection constraints, enabling the system to operate with high confidence in nearly any tracking direction. This approach not only improves tracking accuracy but also reduces spatial accuracy variations compared to conventional tracking systems. The proposed method is an optimization framework that leverages predictive models and corresponding loss functions. It estimates the combined tracking pose for each frame and the global relative poses between units using projection data from both TUs. Our system exhibits a maximum relative RMSE of 0.0074%, markedly lower than that of separate TU systems (0.0155–0.1153%). Furthermore, it achieves average reductions in spatial accuracy variation of 57.2% and 38.9% compared with individual TU systems. © 2025 Elsevier Ltd

关键词： 3D reconstruction Combined observation Hybrid measurement Pose tracking Stereo vision

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A CGAN-LSTM-Based Framework for Time-Varying Non-Stationary Channel Modeling

arXiv

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arXiv 2025年

作者： Guo, keying He, Ruisi Yang, Mi Zhang, Yuxin Ai, Bo Zhang, Haoxiang Han, Jiahui Chen, Ruifeng School of Electronics and Information Engineering Beijing Jiaotong University Beijing100044 China State Key Laboratory of Advanced Rail Autonomous Operation Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing100044 China China Academy of Industrial Internet Ministry of Industry and Information Technology Beijing China Institute of Computing Technology China Academy of Railway Sciences Corporation Limited Beijing100081 China

Time-varying non-stationary channels, with complex dynamic variations and temporal evolution characteristics, have significant challenges in channel modeling and communication system performance evaluation. Most existing methods of time-varying channel modeling focus on predicting channel state at a given moment or simulating short-term channel fluctuations, which are unable to capture the long-term evolution of the channel. This paper emphasizes the generation of long-term dynamic channel to fully capture evolution of non-stationary channel properties. The generated channel not only reflects temporal dynamics but also ensures consistent stationarity. We propose a hybrid deep learning framework that combines conditional generative adversarial networks (CGAN) with long short-term memory (LSTM) networks. A stationarity-constrained approach is designed to ensure temporal correlation of the generated time-series channel. This method can generate channel with required temporal non-stationarity. The model is validated by comparing channel statistical features, and the results show that the generated channel is in good agreement with raw channel and provides good performance in terms of non-stationarity. Copyright © 2025, The Authors. All rights reserved.

关键词： Long Term Evolution (LTE)

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Hull forms of small high-speed wave-piercing monohull crafts and hydrodynamics study

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Journal of Hydrodynamics 2019年第4期31卷 814-826页

作者： Cheng-zhu Wei Ying-hui Li Xiao-feng Liang Hong Yi State Key Laboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration MOE Key Laboratory of Marine Intelligent Equipment and System Shanghai Jiao Tong University Shanghai 200240 China

Wave-piercing design is a revolution in hull design for small high-speed boats to operate in adverse sea conditions. To study hydrodynamics of the small high speed wave piercing monohull craft systematically, four typical small high-speed wave-piercing monohull crafts were developed, and validated CFD methods were adopted to calculate hull resistances and motions. The resistances and hull motions of these high-speed wave piercing monohull crafts in calm water and waves were obtained and compared. Obvious operating differences can be observed. High-speed wave piercing monohull crafts with slender and twisted planing hulls have smaller resistance at high speed, but the dynamic effects increase as sea conditions worsen. The high-speed wave-piercing monohull craft with a slim multi-chine hull maintains in waves for softer hull motions but suffers the disadvantages of larger resistance. The high-speed wave piercing monohull craft with a triangular hull shows no obvious advantages compared with the other types.

关键词： Small high-speed wave-piercing monohull craft resistance hull motions

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Operation and Force Analysis of the Guide Wire in a Minimally Invasive Vascular Interventional Surgery robot system

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Chinese Journal of Mechanical Engineering 2015年第2期28卷 249-257页

作者： YANG Xue WANG Hongbo SUN Li YU Hongnian Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University School of Mechanical Engineering University of Jinan Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Faculty of Science and Technology Bournemouth University

To develop a robot system for minimally invasive surgery is significant,however the existing minimally invasive surgery robots are not applicable in practical operations,due to their limited functioning and weaker perception.A novel wire feeder is proposed for minimally invasive vascular interventional *** is used for assisting surgeons in delivering a guide wire,balloon and stenting into a specific lesion *** contrasting those existing wire feeders,the motion methods for delivering and rotating the guide wire in blood vessel are described,and their mechanical realization is presented.A new resistant force detecting method is given in *** change of the resistance force can help the operator feel the block or embolism existing in front of the guide *** driving torque for rotating the guide wire is developed at different *** the CT reconstruction image and extracted vessel paths,the path equation of the blood vessel is *** the shapes of the guide wire outside the blood vessel,the whole bending equation of the guide wire is *** is a risk criterion in the delivering *** process can make operations safer and man-machine interaction more reliable.A novel surgery robot for feeding guide wire is designed,and a risk criterion for the system is given.

关键词： minimally invasive wire feeder force analysis moment of inertia risk criterion

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Measurement-Based Non-Stationary Markov Tapped Delay Line Channel Model for 5G-Railways

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IEEE Antennas and Wireless Propagation Letters 2025年

作者： Zhang, Xuejian He, Ruisi Yang, Mi Ding, Jianwen Chen, Ruifeng Gao, Shuaiqi Qi, Ziyi Zhang, Zhengyu Ai, Bo Zhong, Zhangdui Beijing Jiaotong University State Key Laboratory of Advanced Rail Autonomous Operation The School of Electronics and Information Engineering The Frontiers Science Center for Smart High-speed Railway System Beijing100044 China Beijing Jiaotong University School of Electronics and Information Engineering Beijing100044 China Henan High Speed Railway Operation and Maintenance Engineering Research Center Zhengzhou451460 China China Academy of Railway Sciences Corporation Ltd. Institute of Computing Technology Beijing100081 China

5 G for Railways (5G-R) is globally recognized as a promising next-generation railway communication system designed to meet increasing demands. Channel modeling serves as foundation for communication system design, with tapped delay line (TDL) models widely utilized in system simulations due to their simplicity and practicality and serves as a crucial component of various standards like 3GPP. However, existing TDL models applicable to 5G-R systems are limited. Most fail to capture non-stationarity, a critical characteristic of railway communications, while others are unsuitable for the specific frequency bands and bandwidths of 5G-R. In this paper, a channel measurement campaign for 5G-R dedicated network is carried out, resulting in a measurement-based 5-tap TDL model utilizing a first-order two-state Markov chain to represent channel non-stationarity. key model parameters, including number of taps, statistical distribution of amplitude, phase and Doppler shift, and state transition probability matrix, are extracted. The correlation between tap amplitudes is also obtained. Finally, the accuracy of model is validated through comparisons with measurement data and 3GPP model. These findings are expected to offer valuable insights for design and link-level simulation of 5G-R systems. © 2025 IEEE.

关键词： Markov chains

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Narrower atomic filter at 422.7 nm based on thermal Ca beam

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Chinese Science Bulletin 2014年第28期59卷 3543-3548页

作者： Zhichao Xu Xiaobo Xue Duo Pan Xiaogang Zhang Wei Zhuang Jingbiao Chen State Key Laboratory of Advanced Optical Communication System and Network School of Electronics Engineering and Computer Science Peking University

So far, the only Ca magneto-optic atomic filters reported are based on a heated Ca cell, and the transmission spectrum obtained is double-peaked with 3 GHz effective passband limited by Doppler broadening. A magneto-optic atomic filter with single-peaked transmission spectrum of sub-Doppler bandwidth based on the thermal Ca atomic beam is firstly experimentally demonstrated. The fast Ca dipole transition(1S0–1P1) at 422.7 nm, which matches a strong solar Fraunhofer line, was utilized. A folded ninebeam traveling wave configuration is employed, and the maximum transmission efficiency is measured to be 7.3 %.A sub-Doppler transmission bandwidth of 590 MHz, much narrower than the 2.2 GHz Doppler width in the heated atomic cell, is obtained for the first time.

关键词：原子束过滤器纳米多普勒加宽钙传输效率原子滤波器多普勒宽度

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