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A digital image correlation method for strain measurement using higher-order X-ray optical field components

Optics and Laser technology 2025年 189卷

作者： Li, Zixin Su, Yong Li, Jia Yuan, Yajun Xiao, Yu Xu, Feng CAS Key Laboratory of Mechanical Behaviour and Design of Materials Department of Modern Mechanics CAS Center for Excellence in Complex System Mechanics University of Science and Technology of China Anhui Hefei230027 China School of Biomedical Engineering Anhui Medical University Hefei230032 China

To achieve highly sensitive characterization of internal material strain fields, this study proposes a digital image correlation strain field measurement method based on higher-order X-ray optical field *** method utilizes random gratings to modulate the X-ray optical field, extracts the information of higher-order field components during material deformation based on the discrepancy between the theoretical transmission model and the experimental measurement, and combines the extracted information with Digital Image Correlation (DIC) technology to achieve precise measurement of internal material strain *** to the experimental comparison and verification, the relative displacement difference between the deformation field distribution obtained by the proposed method and the results of the traditional absorption phase method in the non-boundary and stress concentration area proves that the correlation information of the higher order components can truly reflect the deformation characteristics of the ***, compared to traditional methods, this method demonstrates higher sensitivity in strain field characterization. Particularly in the measurement of shear strain at crack tips, its computational results align more closely with linear elastic fracture mechanics theoretical predictions, providing a novel experimental approach for studying material damage evolution and failure mechanisms. © 2025 Elsevier Ltd

关键词： Crack tips

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Mofs-Derived Cu/Carbon Membrane as Bi-Functional Catalyst: Improving Catalytic Activity in Detection and Degradation of Pfoa Via Regulation of Reactive Cu Species

SSRN

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SSRN 2023年

作者： Hou, Chen Chen, Fang Cheng, Daozhen Zou, Shengyang Wang, Jianzhi Shen, Mengxia Wang, Yang College of Bioresources Chemical and Materials Engineering Shaanxi University of Science and Technology Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development Key Laboratory of Paper Based Functional Materials of China National Light Industry National Demonstration Center for Experimental Light Chemistry Engineering Education Xi’an710021 China Key Laboratory for Green Chemical Process of Ministry of Education Hubei Key Laboratory for Novel Reactor and Green Chemistry Technology Hubei Engineering Research Center for Advanced Fine Chemicals School of Chemical Engineering and Pharmacy Wuhan Institute of Technology Wuhan430073 China

Developing bi-functional materials to simultaneously detect and degrade persistent pollutant perfluorooctanoic acid (PFOA) is of significant importance for environmental and human health. In this study, a copper-based mimic enzyme colorimetric detecting sensor coupling with solar photo-electro-Fenton degradation (SPEF) system was built based on Cu/carbon nanofiber (CNF-Cu/C) membrane. Self-supporting flexible CNF-Cu/C membrane was successfully prepared by solvothermal method with further secondary seed growth and in-situ thermal reduction. Based on calcination temperature regulation, the obtained CNF-Cu/C membrane derived from MOFs/polyacrylonitrile (HKUST/PAN) membrane was characterized by 3D carbon fiber network dispersed with porous carbon skeleton embedded copper species, which exhibited good dispersibility, cycling stability and excellent electrical conductivity. With excellent peroxidase-like activity, CNF-Cu/C can rapidly detect PFOA based on the inhibition of color reaction of tetramethylbenzidine (TMB) with detection limit of 0.133 μM. Furthermore, CNF-Cu/C also exhibited outstanding optical properties and oxygen redox reaction (ORR) activity, and the removal efficiency of PFOA in Cu-SPEF system reached 98.22% within 180 min under optimal conditions. Based on the results of free radical quenching experiment, EPR experiment and HPLC-MS experiments, the degradation mechanism and degradation path of PFOA by SPEF system were further speculated. © 2023, The Authors. All rights reserved.

关键词： Membranes

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Effect of residual pore on the performance of UN kernel TRISO particle fuel 14

Effect of residual pore on the performance of UN kernel TRIS...

引用

14th International Nuclear Fuel Cycle Conference, GLOBAL 2019 and Light Water reactor Fuel Performance Conference, TOP FUEL 2019

作者： Liu, Shichao Chen, Ping Zhou, Yi Pang, Hua Xi, Yong Tang, Changbing Zhao, Yanli Qiu, Xi Guo, Zixuan Nuclear power institute of China Science and Technology on Reactor System Design Technology Laboratory Changshun Stress No.1 Chengdu Sichuan610200 China

The thermal-mechanical performance of uranium nitride (UN) tri-isotropic (TRISO) particle with residual pore used in Light Water reactor (LWR) was investigated. The effect of pore size and location on the performance of inner dense pyrolytic carbon (IPyC) layer, SiC layer and outer dense pyrolytic carbon (OPyC) layer was studied. The dimensional changes, fission gas release and internal pressure of the fuel particle layers were calculated. Residual pore size can affect the stress distribution of coated layers obviously. The residual pore especially the big ones may be the source of cracks on the SiC layer, which can break or loss the capacity of SiC layer. Residual pore location has little influence on the stress distribution of the coated layer. In order to maintain the fission retention capacity of TRISO particle, the big residual pore should be avoided during fabrication process. Copyright © GLOBAL 2019 - International Nuclear Fuel Cycle Conference and TOP FUEL 2019 - Light Water reactor Fuel Performance *** rights reserved.

关键词： Silicon carbide

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Contrastive Learning for Robust Android Malware Familial Classification

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IEEE Transactions on Dependable and Secure Computing 2022年 1-14页

作者： Wu, Yueming Dou, Shihan Zou, Deqing Yang, Wei Qiang, Weizhong Jin, Hai National Engineering Research Center for Big Data Technology and System Services Computing Technology and System Lab Hubei Engineering Research Center on Big Data Security School of Cyber Science and Engineering Huazhong University of Science and Technology Wuhan China Shanghai Key Laboratory of Intelligent Information Processing School of Computer Science Fudan University Shanghai China University of Texas at Dallas Dallas USA National Engineering Research Center for Big Data Technology and System Services Computing Technology and System Lab Cluster and Grid Computing Lab School of Computer Science and Technology Huazhong University of Science and Technology Wuhan China

Due to its open-source nature, Android operating system has been the main target of attackers to exploit. Malware creators always perform different code obfuscations on their apps to hide malicious activities. Features extracted from these obfuscated samples through program analysis contain many useless and disguised features, which leads to many false negatives. To address the issue, in this paper, we demonstrate that obfuscation-resilient malware family analysis can be achieved through contrastive learning. The key insight behind our analysis is that contrastive learning can be used to reduce the difference introduced by obfuscation while amplifying the difference between malware and other types of malware. Based on the proposed analysis, we design a system that can achieve robust and interpretable classification of Android malware. To achieve robust classification, we perform contrastive learning on malware samples to learn an encoder that can automatically extract robust features from malware samples. To achieve interpretable classification, we transform the function call graph of a sample into an image by centrality analysis. Then the corresponding heatmaps can be obtained by visualization techniques. These heatmaps can help users understand why the malware is classified as this family. We implement IFDroid and perform extensive evaluations on two datasets. Experimental results show that IFDroid is superior to state-of-the-art Android malware familial classification systems. Moreover, IFDroid is capable of maintaining a 98.4% F1 on classifying 69,421 obfuscated malware samples. IEEE

关键词： Semantics

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Anti-Fatigue Nanomechanics in the Pre-Cracked Graphene-Copper Artificial Nacre Under Cyclic Tension

SSRN

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SSRN 2023年

作者： Liu, Xiaoyi Xu, Yunfei Shi, Jinchun Zhu, YinBo Zhang, Sen Wu, HengAn Mechanics+X Laboratory Chengdu Development Center of Science and Technology China Academy of Engineering Physics Chengdu610200 China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics CAS Center for Excellence in Complex System Mechanics University of Science and Technology of China Hefei230027 China

The fatigue performance of pre-cracked graphene-copper artificial nacre (GrCu nacre) under cyclic tensile loading is investigated using theoretical analysis and molecular dynamics (MD) simulations. Mechanical models are proposed to describe the fatigue performance of GrCu nacre, which agree well with MD simulations. Compared with nanocomposites consisting of large graphene sheets, graphene fragments cannot improve the ultimate strength of GrCu nacre, but significantly improve its fatigue limit. This anti-fatigue effect is dominated by the graphene-copper interfaces with van der Waals interactions, which can be adjusted by tailoring the architectural parameters of GrCu nacre. The ultimate strength of nacre decreases as the volume fraction of graphene increases. The fatigue limit of GrCu nacre decreases as the length of graphene fragments increases, and can be approximately described by a quadratic function of interlayer repeat spacing. An anomalous weakening effect occurs when the in-plane distance between graphene fragments is less than 2 nm, while this effect can be ignored when it is higher than 2 nm. The fatigue ratio of common metals is ~0.4, whereas that of GrCu nacre is generally higher than 0.9. These underlying mechanisms and theoretical models can improve the fundamental understanding of the fatigue performance of composites with incoherent interfaces, as well as the bottom-up design of graphene-metal nanocomposites. © 2023, The Authors. All rights reserved.

关键词： Molecular dynamics

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Few-shot gearbox fault diagnosed based on meta-learning and time convolution network

Few-shot gearbox fault diagnosed based on meta-learning and ...

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Chinese Automation Congress (CAC)

作者： Yuan Dai Yanghui Ou Junwei Hu Zuowei Ping Xinghua Xu Yong Zhang School of Information Science and Engineering Wuhan University of Science and Technology Wuhan China Wuhan Second Ship Design and Research Institute Wuhan China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

In order to resolve the problem that the traditional fault diagnosis methods can not accurately diagnose under complex working conditions and few fault data, a fault diagnosis method based on meta-learning and time convolution network (TCN) is proposed in this paper. Firstly, Ensemble Empirical Mode Decomposition-Independent Component Analysis (EEMDICA) is used to denoise the original signals under different working conditions, and the acquired signals are randomly sampled to form meta tasks according to the meta-learning protocol. Through the TCN model training, the priori knowledge is obtained by optimizing the initialization parameters. The knowledge is used to improve accuracy in unforeseen condition tasks. Finally, simulation experiments are carried out on the gearbox dataset. The results indicate that the method has advantages in solving the fault classification problem of few shot gearbox under complex working conditions.

关键词： Employee welfare Fault diagnosis Training Protocols Automation Convolution Task analysis

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A fast calculation method for three-impulse contingency return trajectory during the near-moon phase based on differential algebra

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Chinese Journal of Aeronautics 2025年第4期 290-308页

作者： Lin LU Haiyang LI Tianshan DONG Wanmeng ZHOU College of Aerospace Science and Technology National University of Defense Technology Hunan Key Laboratory of Intelligent Planning and Simulation for Aerospace Missions Beijing Institute of Spacecraft System Engineering China Astronaut Research and Training Center

Aimed at the demand of contingency return at any time during the near-moon phase in the manned lunar landing missions,a fast calculation method for three-impulse contingency return trajectories is ***,a three-impulse contingency return trajectory scheme is presented by combining the Lambert transfer and maneuver at the special ***,a calculation model of three-impulse contingency return trajectories is ***,fast calculation methods are proposed by adopting the high-order Taylor expansion of differential algebra in the twobody trajectory dynamics model and perturbed trajectory dynamics ***,the performance of the proposed methods is verified by numerical *** results indicate that the fast calculation method of two-body trajectory has higher calculation efficiency compared to the semi-analytical calculation method under a certain accuracy *** to its high efficiency,the characteristics of the three-impulse contingency return trajectories under different contingency scenarios are further analyzed *** findings can be used for the design of contingency return trajectories in future manned lunar landing missions.

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Ray-Tracking Simulation and Analysis of Propagation for Typical Scene of High Speed Maglev 21

Ray-Tracking Simulation and Analysis of Propagation for Typi...

引用

21st IEEE International Conference on Communication technology, ICCT 2021

作者： Kewei, Chen Hongbo, Liu Jiaqi, Liang Qintao, Liu Naval University of Engineering College of Electronic Engineering Wuhan China Naval University of Engineering National Key Laboratory of Science and Technology on Vessel Integrated Power System Wuhan China

ISBN: (纸本)9781665432061

The propagation of 38 GHz and 3.5 GHz in typical scenarios of high-speed maglev train is studied. Referring to the magnetic field configuration of Shanghai Maglev, the viaduct and tunnel scenes are modeled and simulated. The propagation characteristics at 38GHz and 3.5GHz are compared in terms of receiving power and Doppler frequency shift, and the broadband path loss and delay spectrum parameters are modeled, which provides suggestions for the design of high-speed data transmission communication system. © 2021 IEEE.

关键词： Magnetic levitation

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Enhanced Adaptive Disturbance Observer for Sensorless Control of PMSM With Multi-harmonics Suppression Characteristics

引用

IEEE Journal of Emerging and Selected Topics in Power Electronics 2025年

作者： Qin, Qinghai Yi, Xinqiang Yu, Zhongjun Yu, Haitao Fang, Shuhua Southeast University School of Electrical Engineering Nanjing210096 China Naval University of Engineering National Key Laboratory of Science and Technology on Vessel Integrated Power System Wuhan430033 China East Lake Laboratory Wuhan430202 China

The inverter nonlinearity and spatial flux harmonics inevitably result in the back electromotive force (BEMF) harmonics in permanent magnet synchronous motor (PMSM), which deteriorates the performance of the model-based sensorless control. To settle the problem, this article proposes an enhanced adaptive disturbance observer by reconstructing the observer structure based on the pre-designed enhanced complex coefficient filter (ECCF). An ECCF with specific harmonic filtering capability based on conventional complex coefficient filter and multi-frequency suppression module is pre-constructed. Based on the reverse design method, the structure of the conventional disturbance observer is reconstructed into the desired ECCF structure. Multi-harmonics can be suppressed without cascading additional filtering networks after the conventional BEMF observers. The sensorless control algorithm studied is verified by the comparative experiments on a 1 kW PMSM platform. © 2013 IEEE.

关键词： Sensorless control

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A transient fiuid–structure interaction analysis strategy and validation of a pressurized reactor with regard to loss-ofcoolant accidents

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Nuclear science and Techniques 2020年第6期31卷 11-21页

作者： Ying-Chao Ma Xie-Lin Zhao Xian-Hui Ye Nai-Bin Jiang Jin-Xiong Zhou State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an 710049China Key Laboratory of Nuclear Reactor System Design Technology Nuclear Power Institute of ChinaChengdu 610200China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China

A loss-of-coolant accident(LOCA)is one of the basic design considerations for nuclear reactor safety analysis.A LOCA induces propagation of a depressurization wave in the coolant,exerting hydrodynamic forces on structures viafiuid–structure interaction(FSI).The analysis of hydrodynamic forces on the core structures during a LOCA process is *** describe the implementation of a numerical strategy for prestressed *** consists of an initialization and a restarted transient analysis process,all implemented via the ANSYS Workbench by system coupling of ANSYS and *** strategy is validated by making extensive comparisons of the pressures,displacements,and strains on various locations between the simulation and reported *** approach is appealing for dynamic analysis of other prestressed structures,owing to the good popularity and acknowledgement of ANSYS and Fluent in both academia and industry.

关键词： Loss-of-coolant accident(LOCA) Fluid–structure interaction(FSI) Finite element method Prestressed structure Structural dynamics

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