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2019 International Conference on Optoelectronic science and Materials, ICOSM 2019

作者： Yang, Xiaoning Liu, Yuming Wang, Zhihao Li, Yu Wang, Jinghu Zhang, Yongtai Beijing Institute of Spacecraft Environment Engineering Beijing100084 China Science and Technology on Reliability and Environment Engineering Laboratory Beijing100084 China

Due to high energy electron radiation in space, Spacecraft internal charging will occur, which will cause deep dielectric electrostatic discharge and cause the most serious anomalies, that is, those that have resulted in the loss of mission. Because spacecraft internal charging is accompanied with X-ray bremsstrahlung, it is possible to mitigate inner dielectric electrostatic discharge by using nonlinear conductivity material induced by X-ray radiation. It shows that the conductivity of ZnO materials increases with the increase of X-ray radiation dose rate. At low X-ray radiation dose rate, the conductivity of ZnO increases linearly with the increase of X-ray dose rate. At high X-ray radiation dose rate, the conductivity of ZnO is saturated gradually. The conductivity of ZnO with high original resistivity varies more widely with the dose rate of X-ray, which is more suitable for spacecraft internal charging protection. © Published under licence by IOP Publishing Ltd.

关键词： X rays

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reliability evaluation of DCFP in k/n system considering shock threshold descending 30

Reliability evaluation of DCFP in k/n system considering sho...

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30th European Safety and reliability Conference, ESREL 2020 and 15th Probabilistic Safety Assessment and Management Conference, PSAM 2020

作者： Zhu, Guixia Yang, Tianyu Chen, Ying Research Institute of Nuclear Power Operation China Science and Technology on Reliability and Environmental Engineering Laboratory Beihang University China

ISBN: (纸本)9789811485930

In the industrial design process, redundant methods are often used to improve the reliability of the system, for example the k-out-of-n system. Also, degradation and overstress failure exist in the many systems where operation load and environmental conditions are complex. They can cause DCFP (Dependent Competing Failure Process). However, the components in k-out-of-n system often have load-sharing effects, and the failure correlation caused by them may increase the joint failure probability of the system and reduce the reliability of the system. Moreover, systems may experience the mutual effect of the degradation and catastrophic failure caused by shock because of DCFP. After considering the load sharing effect and DCFP in k-out-of-n system, system reliability evaluation becomes more difficult. This paper analyses the relationship about descending of threshold between the interaction of shock process and degradation process from failure behaviour rules. System modelling method and failure probability evaluation are based on considering the impact of load-sharing effects and DCFP in k-out-of-n system. The study considers three mechanisms of descending load threshold: 1) degradation failure threshold descending caused by random shock process;2) shock failure threshold descending caused by random shock process;3) shock failure threshold descending caused by degradation process. Finally, this paper studies the reliability of the system by simulating the case of a voltage regulator system by considering load-sharing effects and DCFP to evaluate the influence of threshold decrease on k-out-of-n system. Copyright © ESREL2020-PSAM15 *** by Research Publishing, Singapore.

关键词： reliability

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Modeling Task Time Duration Using the Hunter Dynamic Human reliability Analysis FrameworK

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Proceedings of the Human Factors and Ergonomics Society Annual Meeting 2022年第1期66卷 1612 - 1616页

作者： Ronald L. Boring Thomas A. Ulrich Jooyoung Park Jeeyea Ahn Roger Lew Human Factors and Reliability Department Idaho National Laboratory Idaho Falls Idaho USA Nuclear Engineering Ulsan National Institute of Science and Technology Ulsan Republic of Korea Virtual Technology and Design Program University of Idaho Moscow Idaho USA

The Human Unimodel for Nuclear technology to Enhance reliability (HUNTER) is simulation software for modeling the human portion of risk. HUNTER is built on a framework that separately models individual, task, and environmental factors. As a dynamic human reliability analysis (HRA) method, it affords advantages over traditional static or worksheet-based HRA approaches, such as the ability to model what-if scenarios and produce outputs beyond human error probabilities. In this paper, a validation was conducted of HUNTER task time estimates vs. empirical data collected for a steam generator tube rupture scenario. The HUNTER model produced using GOMS-HRA task-level primitives yielded timing results very closely aligned to empirical reference data for base and complex conditions, suggesting the tool holds promise for HRA requiring time estimation.

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A Low Frequency Fiber Vibration Acceleration Sensor Based on Long Period Fiber Grating and Double-Clamped Beam

SSRN

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SSRN 2022年

作者： Zhang, Limu Zhang, Wei Liu, Qishi Sun, Xiaoyan Hu, Youwang Duan, Jian State Key Laboratory of High Performance Complex Manufacturing College of Mechanical and Electrical Engineering Central South University Changsha410083 China Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory Guangzhou510610 China

In this paper, we have designed, fabricated and characterized a fiber sensor for the measurement of low frequency vibration acceleration. The sensor structure based on a double-clamped beam and a long period fiber grating (LPFG) that inscribed in single mode fiber (SMF) by femtosecond laser. The LPFG stick tightly on top surface of the beam and its transmission spectrum changes with beam bending enabling vibration acceleration *** experimental results suggest that the sensor has an accurate and flat frequency response over a certain range of 1.5~10Hz, and the maximum frequency response error measured experimentally is 4.4%. The maximum measurable acceleration is 0.3g and the maximum acceleration sensitivity measured experimentally is 2.8mW/g with a linearity greater than 99.6%. The temperature drift of the sensor is 0.001g/°C and it also has good anti-interference ability and reliability at the same time. © 2022, The Authors. All rights reserved.

关键词： Single mode fibers

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Constructing a One-Dimensional Long-Short Hybrid Carbon Skeleton as Separator Modifier for Dendrite-Free Li-S Batteries

SSRN

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SSRN 2022年

作者： He, Yusen He, Zongke Jin, Qianwen Yang, Tai Zhao, Yan Li, Qiang State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Materials Science and Engineering Hebei University of Technology Tianjin300130 China Hebei Provincial Key Laboratory of Green Chemical Technology and High Efficient Energy Saving School of Chemical Engineering and Technology Hebei University of Technology Tianjin300130 China

The shuttling effect of polysulfides and the uncontrollable evolution of dendritic lithium, which occur individually in each electrode, obstruct the development of lithium-sulfur battery in practical conditions. With the intention of exploring a simple integrated method to solve above-mentioned issues, we use one-dimension long-short carbon nanofiber-nanotube with rich active sites to construct 3D scaffold architecture as an effective modifier on the separator, developing a symmetrically modified separator with hierarchically porous Li+ channels. The weaving carbon nanofibers with vertically-rooted carbon nanotube tentacles are conducive to both long-range and short-range electric conduction. In addition, the 3D carbon nanofiber-nanotube structure can reduce the local current density and induce uniform lithium nucleation. Meanwhile, coexisting metallic nanoparticles and abundant doping systems act as the adsorptive, electrocatalytic and lithiophilic sites to achieve high efficiency in the processes of sulfur electrochemistry and dendrite-free lithium conversion. Because of these advantageous characteristics, the Li-S cells based on the double-sided modified separator achieve reliable Li/S electrochemistry including a highly specific capacity of 1044.1 mAh g-1 over 100 cycles at 0.2 C, an excellent rate performance of up to 3 C, as well as an areal capacity of up to 4.38 mAh cm-2 under increased sulfur loading of 5.5 mg cm-2. Moreover, the Li-S pouch cell using this symmetric separator modification strategy exhibits excellent cycling stability, demonstrating broad application prospects in the flexible energy storage area. © 2022, The Authors. All rights reserved.

关键词： Lithium sulfur batteries

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Revealing the Crack Propagation Behavior of Weldment Under Cyclic Loadings by Combining Crystal Plasticity Finite Element and Xfem

SSRN

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SSRN 2024年

作者： Zhou, Dewen Wang, Xiaowei Li, Heng Kang, Zitong Zhang, Tianyu Chen, Yefeng Zhang, Xiancheng Gong, Jianming Tu, Shantung School of Mechanical and Power Engineering Nanjing Tech University Nanjing211816 China Reliability centered Manufacturing Research Institute Nanjing Tech University Nanjing211816 China Key Laboratory of Pressure Systems and Safety Ministry of Education East China University of Science and Technology Shanghai200237 China

In this paper, different types of crack propagation behavior in P92 welded joint are simulated under low cycle fatigue and creep-fatigue interaction loadings using crystal plasticity finite element coupled with the eXtended Finite Element Method (XFEM). The geometric discontinuity is introduced by net slip and utilized as the crack propagation criterion. The inherent limitations for simulating crack growth within the XFEM were modified. The result shows that the cracks in heat affected zone grow faster than that in the welded zone. Short crack propagation dominated by dislocation activity takes approximately 4 to 5 grains, followed by long crack propagation which is unrelated to dislocation activity and the growth direction kept an angle to the loading direction (45o-51o). For type IV cracking (fastest propagation speed), the crack favorably grows on the slip system (101) [ 11] and (0 1) [111]. The increased strain amplitude and the introduction of the dwell period accelerate the crack growth rate. Experimentally observed crack growth features like the deflections within grains and at grain boundaries, retardation at grain boundaries are captured. © 2024, The Authors. All rights reserved.

关键词： Crack propagation

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Rectangular carbon nitrides C4N monolayers with a zigzag buckled structure: Quasi-one-dimensional Dirac nodal lines and topological flat edge states

arXiv

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arXiv 2024年

作者： Li, Linyang Li, Jialei Yu, Yawei Song, Yuxuan Li, Jia Liu, Xiaobiao Peeters, François M. Chen, Xin Liu, Guodong School of Science Hebei University of Technology Tianjin300401 China School of Science Henan Agricultural University Zhengzhou450002 China Centre for Quantum Metamaterials HSE University Moscow101000 Russia Department of Physics University of Antwerp Groenenborgerlaan 171 AntwerpB-2020 Belgium Thermal Science Research Center Shandong Institute of Advanced Technology Jinan250103 China State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Materials Science and Engineering Hebei University of Technology Tianjin300130 China

Due to the flexibility of C and N atoms in forming different types of bonds, the prediction of new two-dimensional (2D) carbon nitrides is a hot topic in the field of carbon-based materials. Using first-principles calculations, we propose two C4N monolayers with a zigzag buckled (ZB) structure. The ZB C4N monolayers contain raised-C (raised-N) atoms with sp3 hybridization, different from the traditional 2D graphene-like carbon nitride materials with sp2 hybridization. Interestingly, the band structures of the ZB C4N monolayers exhibit quasi-one-dimensional (quasi-1D) Dirac nodal line that results from the corresponding quasi-1D structure of the zigzag carbon chains, which is essentially different from the more common ring-shaped nodal line. The quasi-1D Dirac nodal line exhibits the following features: (i) gapless Dirac points, (ii) varying Fermi velocity, and (iii) slightly curved band along the high-symmetry path. All these features are successfully explained by our proposed tight-binding model that includes interactions up to the third nearest-neighbor. The Fermi velocity of the 2D system can reach 105 m/s, which is promising for applications in high-speed electronic devices. The topological flat band structure determined by the Zak phase and band inversion of the corresponding 1D system is edge-dependent, which is corresponding to the Su-Schrieffer-Heeger model, providing to rich physical phenomena. Copyright © 2024, The Authors. All rights reserved.

关键词： Monolayers

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A Robust Agatston Score for Coronary Artery Calcium Scoring from Non-ECG-Gated CT with Different Reconstruction Kernels

A Robust Agatston Score for Coronary Artery Calcium Scoring ...

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IEEE International Symposium on Biomedical Imaging

作者： Shuo Zhang Xinmei Su Quanlong Feng Zifeng Wu Zhenghua Xu State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Health Sciences and Biomedical Engineering Hebei University of Technology China DeepWise AI Lab Beijing China School of Information and Electronics Beijing Institute of Technology Beijing China College of Land Science and Technology China Agricultural University Beijing China

A coronary artery calcium score (CACS) is a vital measure to screen individuals at risk for early coronary heart disease. However, as the main evaluation system of CACS, the Agatston score computed from CT images via HU-thresholding may vary significantly even for the same individual as the protocol of image acquisition changes (e.g., reconstruction kernels). This may harm the compatibility of CACS, when evaluated in different health facilities at different times. To tackle this issue, we propose the robust Agatston score (RAS), wherein we predict the calcification level per pixel via deep learning, rather than directly thresholding the HU value from CT images, as we do for the classic Agatston score. In this way, we make the CACS more robust to the change of acquisition protocols, and let the comparison among CACS from various sources easier. Experimental results show that our method can improve the CACS level accuracy from 64.21% to 95.78%. Code is available at https://***/lucas-dw/ras.

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Hybrid Reinforced Medical Report Generation with M-Linear Attention and Repetition Penalty

arXiv

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arXiv 2022年

作者： Xu, Wenting Xu, Zhenghua Chen, Junyang Qi, Chang Lukasiewicz, Thomas State Key Laboratory of Reliability and Intelligence of Electrical Equipment Tianjin Key Laboratory of Bioelectromagnetic Technology and Intelligent Health Hebei University of Technology China College of Computer Science and Software Engineering Shenzhen University China Department of Computer Science University of Oxford United Kingdom

To reduce doctors’ workload, deep-learning-based automatic medical report generation has recently attracted more and more research efforts, where deep convolutional neural networks (CNNs) are employed to encode the input images, and recurrent neural networks (RNNs) are used to decode the visual features into medical reports automatically. However, these state-of-the-art methods mainly suffer from three shortcomings: (i) incomprehensive optimization, (ii) low-order and unidimensional attention mechanisms, and (iii) repeated generation. In this article, we propose a hybrid reinforced medical report generation method with m-linear attention and repetition penalty mechanism (HReMRG-MR) to overcome these problems. Specifically, a hybrid reward with different weights is employed to remedy the limitations of single-metric-based rewards. We also propose a search algorithm with linear complexity to approximate the best weight combination. Furthermore, we use m-linear attention modules to explore high-order feature interactions and to achieve multi-modal reasoning, while a repetition penalty applies penalties to repeated terms during the model’s training process. Extensive experimental studies on two public datasets show that HReMRG-MR greatly outperforms the state-of-the-art baselines in terms of all metrics. We also conducted a series of ablation experiments to prove the effectiveness of all our proposed components. We also performed a reward search toy experiment to give evidence that our proposed search approach can significantly reduce the search time while approximating the best performance. Copyright © 2022, The Authors. All rights reserved.

关键词： Reinforcement learning

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Ablation behavior of in-situ Cr7C3-CrSi2 composite coating prepared by plasma spraying

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Ceramics International 2025年

作者： Jia, Shi-tong Yang, Yong Zhao, Hong-jian Wang, Xing-yu Wang, Yan-wei Shao, Yu-xuan Ma, Yu-duo Gao, Peng-yue Gao, Sheng-yong Li, Ai-min Zhang, Huan-huan Hebei Key Laboratory of New Functional Materials School of Materials Science and Engineering State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of Technology Tianjin300401 China Hebei Huabei Diesel Engine Co. Ltd Hebei Province Shijiazhuang050081 China Key Laboratory of Hebei Province on High Temperature Alloy Regeneration Technology Zhong Hang Shang Da Superalloys Co. Ltd Hebei Province Xingtai054800 China Department of Chemical and Materials Engineering University of Alberta EdmontonABT6G 2H5 Canada

A Cr7C3-CrSi2 composite coating with excellent ablation resistance was successfully prepared on a graphite substrate by plasma spraying Cr-SiC composite powder. The ablation behavior and mechanism of the Cr7C3-CrSi2 composite coating ablated by plasma jetting (about 10000 °C) were investigated. The Cr7C3-CrSi2 composite coating demonstrated remarkable resilience against 80 s of the plasma jet ablation, maintaining its integrity. The primary factor contributing to the remarkable ablation resistance of the Cr7C3-CrSi2 composite coating was the formation of a dense Cr2O3-SiO2 composite oxide layer during the process of resisting high-temperature ablation. The dense Cr2O3-SiO2 composite oxide layer was generated on the surface of the Cr7C3-CrSi2 composite coating, with the oxidized product, SiO2, filling the pores of the Cr2O3, thereby preventing damage caused by the penetration of oxygen. © 2025

关键词： Ablation

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