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14th IEEE Global reliability and Prognostics and Health Management Conference, PHM-Hangzhou 2023

作者： Tian, Yu Li, Ruiying Wang, Yuanyuan Ma, Ji Song, Yeqing School of Reliability and Systems Engineering Beihang University Beijing China Science and Technology on Reliability and Environmental Engineering Laboratory Beijing100191 China Deep Space Exploration Laboratory Beijing100194 China

ISBN: (纸本)9798350301359

Satellite handover frequently occurs on low-earth-orbit (LEO) satellite communication systems, and it affects system availability. However, existing studies neglected such an impact. To solve the problem above, this paper proposed a topology modeling method, in which the satellite dynamic operation is divided into small time slices to simplify the system, and the earth ground is divided into grids to abstract the ground user's communication requirement. Then, the service availability is defined according to the key performance parameter of the communication service, delay, and a Monte Carlo-based availability assessment method is addressed with the consideration of the satellite handover. Finally, a case is used to analyze how satellite handover strategies affect service availability. and suggestions are given to improve system availability. © 2023 IEEE.

关键词： low-earth-orbit satellite communication system Monte Carlo satellite handover service availability

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Degradation Evaluation of Neutron Irradiation Effect on AlGaN/GaN Metal-Insulator- Semiconductor High Electron Mobility Transistors 25

Degradation Evaluation of Neutron Irradiation Effect on AlGa...

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25th International Conference on Electronic Packaging technology, ICEPT 2024

作者： Duan, Xiaoyue Li, Pinbo He, Liang Shi, Yijun Chen, Xinghuan Ni, Yiqiang Liu, Jun He, Zhiyuan Chen, Yiqiang School of Electrical Engineering University of South China Science and Technology on Reliability Physics and Application of Electronic Component Laboratory Hengyang China Science and Technology on Reliability Physics and Application of Electronic Component Laboratory Guangzhou China School of Electrical Engineering University of South China Hengyang China School of Integrated Circuits Guangdong University of Technology Guangzhou China

ISBN: (纸本)9798350353808

We investigate the degradation effects of neutron irradiation on AIGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) in this work. The performance of the devices is characterized through relevant electrical current-voltage (I-V) test and capacitance- voltage (C-V) test. The result indicates that the electrical parameter of the device degrades after neutron irradiation, such as positive shift of threshold voltage, reduction in output drain current, and the increase of the on-resistance. Additionally, combining with the frequency-dependent conductance method, it displays that shallow energy level- interface states at the AIGaN/GaN heterojunction increase, along with slightly shifting to deeper energy level after neutron irradiation. Neutron irradiation introduces more interface states and increase the scattering which degrading the carrier concentration and mobility, causing related degradation on electrical performances. This study provides useful reference value for the application of GaN-based devices in the aerospace. © 2024 IEEE.

关键词： Gallium nitride

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Fault Feature Recognition Of Satellite Power System Based On Incremental Learning 15

Fault Feature Recognition Of Satellite Power System Based On...

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15th IEEE Global reliability and Prognostics and Health Management Conference, PHM-Beijing 2024

作者： Li, Zhipeng Yang, Yang Dong, Yanchen Zhu, Baolong Suo, Mingliang School of Reliability and Systems Engineering Beihang University Beijing100191 China No.31850 Unit People's Liberation Army of China Beijing102200 China Jinan250353 China Institute of Reliability Engineering National Key Laboratory of Science and Technology on Reliability and Environmental Engineering School of Reliability and Systems Engineering Beihang University Beijing100191 China

ISBN: (纸本)9798350354010

In modern communications and technology, satellite power systems play a central role, and their reliability and fault diagnosis technology are increasingly important. Traditional fault diagnosis methods mainly include signal processing and model-based methods, but they are often inefficient and have limited accuracy when processing complex data sets. This paper proposes a feature selection algorithm based on incremental learning to improve the efficiency and accuracy of fault diagnosis. Its advantage is that it can only evaluate the newly added feature set without the need to reprocess the entire data set, thus optimizing the feature selection process and significantly improving the efficiency and response speed of the algorithm. In order to verify its effectiveness, this article selected 8 public data sets and 4 satellite power system simulation data sets for testing. Then, widely used algorithms are introduced to compare with the algorithm proposed in this article for a more comprehensive comparative analysis. By comparing the differences in running time and classification accuracy of the algorithms, it is concluded that the algorithm proposed in this article can significantly reduce the running time while maintaining or improving the classification effect, verifying the feasibility of the algorithm. © 2024 IEEE.

关键词： Satellite communication systems

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Effects of the windshield inclination angle on head/brain injuries in car-to-pedestrian collisions using computational biomechanics models

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Transportation Safety and Environment 2024年第2期6卷 1-12页

作者： Fang Wang Mingliang Wang Lin Hu Ke Peng Jiajie Yin Danqi Wang Liangliang Shi Zhou Zhou School of Automotive and Mechanical Engineering Changsha University of Science and TechnologyChangsha 410114HunanChina Hunan Province Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle Changsha University of Science and TechnologyChangsha 410114HunanChina State Key Laboratory of Vehicle NVH and Safety Technology China Automotive Engineering Research Institute Co.Ltd.Chongqing 401122China Division of Neuronic Engineering KTH Ro y al Institute of TechnologyStockholm 14152Sweden

Car-to-pedestrian collision(CPC)accidents occur frequently,and pedestrians often suffer serious head/brain *** major cause is the primary impact with the ***,we use an umerical sim ulation method to study the influence of the windshield in-clination angle of a passenger car on pedestrian head/brain injury due to CPC *** range of the windshield inclination angle was set at 24°-50°,with an interval of 2°.The results show that the windshield angle significantly affects the pedestrian kine-matics and exerts different effects on the head injury when evaluating with various head injury *** the head peak linear/rotational acceleration and acceleration-based head injury criterion(HIC)/rotational injury criterion(RIC),the predictions at the secondary impact stage have no clear relationship with the windshield angle(R^(2)=0.04,0.07,0.03 and 0.26,respectively)and their distributions are *** the primary impact,the peak linear acceleration and HIC show a weak trend of first decreasing and then increasing with the increasing of the windshield angle,and the rotational acceleration and RIC tend to remain relatively *** the cum ulative strain dama ge measure(CSDM)criterion,the predictions at the primary impact are slightly lower than those at the secondary impact,and the trend of first decreasing and then increasing with the increase in the windshield angle is observed at both impact *** the windshield inclination angle is approximately 32°-40°,the head injury severity in both impact phases is generally lower than that predicted at other windshield angles.

关键词： car-to-pedestrian collision(CPC) head/brain injury head injury criterion(HIC) windshield inclination angle computa-tional biomechanics model(CPCBM)

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Health Assessment and RUL Prediction of Aeroengine Under Multiple Working Conditions

Health Assessment and RUL Prediction of Aeroengine Under Mul...

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International Conference on Guidance, Navigation and Control, ICGNC 2022

作者： Zhang, Yan Liu, Xue Ma, Jian Institute of Reliability Engineering Beihang University Beijing100191 China Science and Technology Laboratory on Reliability and Environmental Engineering Beihang University Beijing100191 China School of Reliability and System Engineering Beihang University Beijing100191 China

ISBN: (纸本)9789811966125

Health assessment and remaining useful life (RUL) prediction are the focus of Prognostics Health Management (PHM). Highly accurate assessment and prediction affects the effectiveness of maintenance decision. Aeroengine is the key equipment of aircraft, and its health state and remaining life need special attention. However, complicated working conditions restrict the accuracy of prediction, and there are few researches on solving the engine health state under multiple conditions. Therefore, this paper proposes a method of engine health assessment and life prediction under multiple working conditions. Firstly, the degradation sensitive parameters are selected based on fitting function method. Then, based on the Maximum Mean Difference (MMD) method, the integrated multi-cycle health index is constructed. Finally, Gated Recurrent Unit (GRU) and segmental fusion mechanism are established to predict the remaining useful life under multiple conditions. The model is verified by C-MAPSS dataset, the average prediction accuracy of engine is improved by 13.07% on average compared with several mainstream deep learning models. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Engines

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Fault Diagnosis for Flight Control System Based on Contrastive Learning

Fault Diagnosis for Flight Control System Based on Contrasti...

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International Conference on Guidance, Navigation and Control, ICGNC 2022

作者： Zhou, An Cheng, Yujie Song, Dengwei Institute of Reliability Engineering Beihang University Beijing100191 China Science and Technology Laboratory on Reliability and Environmental Engineering Beihang University Beijing100191 China School of Reliability and Systems Engineering Beihang University Beijing100191 China

ISBN: (纸本)9789811966125

Flight control system is responsible for stabilizing flight attitude, maintaining flight trajectory and improving flight performance. It is an important system of aircraft. This paper proposed a method based on contrastive learning to solve low fault diagnosis accuracy and poor feature-extraction ability of fault diagnosis model due to few quantity of fault data in aircraft flight control system. Inspired by contrastive learning, multi-scale expansion based on white noise is carried out for original data firstly. Secondly, contrastive sample matching based on fault information is constructed by using the expanded data set. Then, this paper constructs a fault diagnosis model based on Siamese neural net taking sample pairs as input and the contrastive constraint between sample pairs is beneficial for improving feature extraction ability of the model. Finally, simulation data of flight control system based on AMEsim/Simulink co-simulation model are used to compare the fault diagnosis method based on contrastive learning with common fault diagnosis methods. The result proves the feasibility and effectiveness of the proposed method. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Flight control systems

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Hydrogel-based catalysts for hydrogen generation by the hydrolysis of B–H compounds under external physical fields

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Journal of Energy Chemistry 2023年第11期86卷 518-535,I0011页

作者： Chunling Qin Wenliu Wu Hassanien Gomaa Shuai Wu Cuihua An Qibo Deng Ning Hu Key Laboratory of Hebei Province on Scale-span Intelligent Equipment Technology School of Mechanical Engineeringand School of Materials Science and EngineeringHebei University of TechnologyTianjin 300401China State Key Laboratory of Reliability and Intelligence Electrical Equipment Hebei University of TechnologyTianjin 300130China Advanced Equipment Research Institute Co. Ltd.Of HEBUTTianjin 300401China

Hydrogen is a popular clean high-energy-density ***,its utilization is limited by the challenges toward low-cost hydrogen production and safe hydrogen ***,these issues can be addressed using promising hydrogen storage materials such as B–H *** stored in B–H compounds can be released by hydrolysis at room temperature,which requires catalysts to increase the rate of the ***,several effective approaches have been developed for hydrogen generation by catalyzing the hydrolysis of B–H *** review summarizes the existing research on the use of nanoparticles loaded on hydrogels as catalysts for the hydrolysis of B–H ***,the factors affecting the hydrolysis rate,such as temperature,p H,reactant concentration,and type of nano particles,were ***,the preparation methods(in situ reduction,one-pot method,template adsorption,etc.)for the hydrogel catalysts and the types of loaded catalysts were ***,the hydrogel catalysts that can respond to magnetic fields,ultrasound fields,optical fields,and other physical fields are ***,the issues and future developments of hydrogel-based catalysts are *** review can inspire deeper investigations and provide guidance for the study of hydrogel catalysts in the field of hydrogen production via hydrolysis.

关键词： Hydrogel Nanoparticlec atalyst B-H compounds Hydrolysis reaction External physical field

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Dimethylammonium cation stabilizes all-inorganic perovskite solar cells

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Journal of Semiconductors 2023年第3期44卷 4-8页

作者： Zuolin Zhang Mengjia Li Jie Sun Cong Chen Jiangzhao Chen Liming Ding State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Materials Science and EngineeringHebei University of TechnologyTianjin 300401China Key Laboratory of Optoelectronic Technology&Systems(MoE) College of Optoelectronic EngineeringChongqing UniversityChongqing 400044China Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China Macao Institute of Materials Science and Engineering(MIMSE) Macao University of Science and TechnologyMacao 999078China

Facing the poor environmental stability of traditional methylammonium or formamidinium-based lead halide per-ovskites,scientists turn their attention to inorganic lead hal-ide perovskites(ILHPs)with narrow bandgaps,excellent thermal stability and reduced ion migration compared to their organic/inorganic counterparts[1−4].Up to now,the PCEs for ILHP solar cells exceed 21%[5].Especially,the preferred black ILHP(***3)with the smallest bandgap of~1.7 eV and single-halide composition for avoiding phase separation is crucial for high-performance single-junction solar cells and can be applied in tandem devices as the top cells[6,7].However,small Cs+(167 pm)in CsPbI3 with a tolerance factor close to 0.8 is unsuitable for the 3D PbI3-framework[8].The mis-matched size of cations will induce lattice strain and the per-ovskite spontaneously transforms to undesired non-photoact-ive yellow phase(δ-phase,like NH4CdCl3)(Fig.1(a))[9,10].There-fore,improving lattice symmetry and reducing lattice strain are the strategies for inhibiting the phase transition of ILHPs.

关键词： inorganic perovskite ammonium

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The degradation of perovskite precursor

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Journal of Semiconductors 2023年第10期44卷 3-6页

作者： Mengjia Li Lixiu Zhang Cong Chen Jiangzhao Chen Liming Ding State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Materials Science and EngineeringHebei University of TechnologyTianjin 300401China Key Laboratory of Optoelectronic Technology&Systems(MoE) College of Optoelectronic EngineeringChongqing UniversityChongqing 400044China Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China Macao Institute of Materials Science and Engineering(MIMSE) Macao University of Science and TechnologyMacao 999078China

Perovskite solar cells(PSCs)are taking a leading position in thin-film optoelectronic devices due to their excellent optical,physical and electrical properties[1-4].Nevertheless,the stability issue of metal halide perovskite precursor solution severely retards the future industrialization of PSCs[5-7].In stoichiometry,slight solution composition change will induce severe degradation of device performance.

关键词： perovskite halide film

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Response of partitioning to cooling rate for different solutes in aluminum alloys

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Journal of Materials science & technology 2024年第18期185卷 155-164页

作者： Jiang You Cheng Wang Dong Qiu Si-Yu Chen Ze-Tian Liu Hui-Yuan Wang National Key Laboratory of Automotive Chassis Integration and Bionics Jilin UniversityChangchun 130025China Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering Jilin UniversityChangchun 130025China State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Material Science and EngineeringHebei University of TechnologyTianjin 300130China Center for Additive Manufacturing School of EngineeringRMIT UniversityMelbourneVIC 3001Australia

It is commonly recognized that the cooling rate has a substantial effect on solute partitioning and its resultant microsegregation during *** classical dendrite tip undercooling theory clarifies the mitigation of microsegregation by increasing the cooling ***,most of the studies focused on binary alloys,leaving an open question as to whether the microsegregation of different solutes in a multi-component alloy system exhibits a relieving degree similar to increasing cooling *** a widely used 6022-type Al alloy(Al-0.76Mg-0.93Si-0.2Fe)as a model alloy,the current study reveals that the microsegregation of Mg gets alleviated to the greatest extent,followed by those of Si and Fe when the cooling rate increases from 5 to 128 K/*** phenomenon is attributed to the solute-based difference in response to partitioning to cooling rate(denoted as Rk).We propose a theoretical equation to quantify Rk,and the R_(k)values of solute Mg,Si,and Fe successfully explain the rank of solute partitioning in ***,a broad range of R_(k)values of other commonly used alloying elements in Al alloys were calculated and ranked,delivering a handy tool to predict the microsegregation behavior and sol-ubility of different solute elements upon sub-rapid solidification,which is consistent with experimental *** framework can also be extended to other multi-component alloy systems.

关键词： Solidification Cooling rate Microsegregation Aluminum alloys Solute partitioning

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