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IEEE/IAS Industrial and Commercial Power System Asia (I&CPS Asia)

作者： Yuan Min Zhen Xing Xueni Ding Hui Li Ran Yao Wei Lai Cheng Yang Wenxing Han Yannan Yuan Key Laboratory of Nuclear Reactor System Design Technology ChengDu China State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China Chongqing University Chongqing China

Multi-chips parallel IGBT module is widely used in new energy power grid connection, flexible AC and DC transmission, electric vehicles and charging devices, rail transit electric traction and other fields, and the reliability of their operation is very important. Therefore, how to select the characteristic parameters that can characterize the aging state of multi-chips parallel IGBT device is particularly important for system active operation and maintenance and reliability improvement. This paper takes the widely used multi-chips parallel IGBT module as the research object. According to the failure mode of bond wire lift-off, the degradation law of electrothermal and magnetic characteristic parameters in the aging failure process of the multi-chips parallel IGBT module was studied, and finally the magnetic flux density was selected as the aging state monitoring parameter of the multi-chips parallel IGBT module.

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Microstructure Characterization and Failure Mechanism of Laser Welded Nuclear-grade FeCrAl Alloy 10

Microstructure Characterization and Failure Mechanism of Las...

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2023 10th International Conference on Advanced Manufacturing technology and Materials Engineering, AMTME 2023

作者： Zhan, Yaqi Niu, Yitian Hu, Yanying Zhang, Ruiqian Ma, Xianfeng Liu, Jinping Feng, Yingchao Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen University Guangdong Zhuhai519082 China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of China Chengdu Sichuan610041 China Key Laboratory for Highly Efficient and Intelligent Welding of China National Nuclear Corporation China Nuclear Industry 23 Construction Co. Ltd Beijing101300 China

FeCrAl alloy is considered a new type of promising accident-tolerant fuel cladding material. Laser welding technology, which has been widely applied in the connection of various metal materials, uses a high energy density laser heat source with the advantages of efficiency and precision. However, due to the inherent characteristic of high speed, the laser weld is generally exposed to rapid solidification, resulting in the inevitable formation of defects such as coarse grain size and porosity in the weld. The presence of pores is a troublesome question because they will reduce the bearing area of the joint and accelerate the initiation of cracks, resulting in a significant reduction of the tensile strength. Based on these considerations, in this study, the effect of pores on laser-welded nuclear-grade FeCrAl alloy is investigated by quasi-in-situ tensile testing, and the fracture mechanism of the joint is revealed. The maximum ultimate tensile strength measured by the experiment is 550 MPa, and the elongation of welds is 9.6%. In addition, there are obvious stress concentrations and cracking phenomena generated in the vicinity of a pore. The joint is eventually fractured in the fusion line near the fusion zone. A large number of pores can be found at the fracture failure position from the fracture morphology observation, indicating that the pores are presumably to be the intrinsic reason for the cracking of the welded joints. © Published under licence by IOP Publishing Ltd.

关键词： Welds

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A Discrete Numerical Study of the Effect of the Thickness and the Porosity of the Sand Cushion on the Impact Response Due to the Rockfall

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Computer Modeling in Engineering & sciences 2022年第3期130卷 1683-1698页

作者： Song Yuan Peng Zhao Liangpu Li Xibao Wang Jun Liu Bo Zhang Sichuan Communication Surveying&Design Institute Co. Ltd.Chengdu610065China Key Laboratory of Deep Underground Science and Engineering(Ministry of Education) College of Architecture and EnvironmentSichuan UniversityChengdu610065China Institute of New Energy and Low-Carbon Technology Sichuan UniversityChengdu610065China Institute of Science and Technology China Three Gorges CorporationBeijing100038China

The prevention and the reduction of the rockfall are the common measures of the prevention and the reduction of *** the rock-shed resists the impact of the rockfall,the force that acts on the structure consists of the cushion dead load and the impact-induced load,of which the dynamic process of the propagation of the impactinduced load is ***,we conducted a numerical study to investigate the impact of the *** the highly discrete characteristic of the sand,we developed a numerical model on the basis of the discrete element method(DEM).The numerical model,which simulation results were validated by the results of real-scale experiments,was used to investigate the dynamic response of the impact force of the rockfall and the transmission of the impact force under the different magnitude of the falling height and the different thickness of the sand *** results of our study indicated that the cushion thickness had little effect on the impact of the rockfall,and the dense sand cushion generated higher impact force than did the loose sand *** the high thickness enhanced the buffer performance of the sand cushion,the additional force induced by the dead load of sand cushion was ***,to determine the appropriate thickness of the sand cushion,we suggested designers consider the buffer performance and the dead load of the sand *** analysis presented in this paper provided a practical estimation of the impact-induced force of the thick sand cushion.

关键词： Rockfall impact DEM sand cushion thickness porosity impact force bottom force

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Natural Graphene Plasmonic Nano-Resonators for Highly Active Surface-Enhanced Raman Scattering Platforms

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Energy & Environmental Materials 2023年第5期6卷 269-280页

作者： Xiaoqiang Feng Zhiduo Liu Guanglin Zhang Shan Zhang Shuiping Huang Zhengyi He Genwang Wei Siwei Yang Yangguang Zhu Caichao Ye Cheng-Te Lin Guqiao Ding Gang Wang Department of Microelectronic Science and Engineering School of Physical Science andNingbo UniversityNingbo 315211China State Key Laboratory of Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Academy for Advanced Interdisciplinary Studies&Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China

Highly sensitive and uniform three-dimensional(3D)hybrid heterogeneous structures for use in surface-enhanced Raman scattering(SERS)experiments were fabricated by sequentially decorating high-quality,ultra-clean,graphene quantum dots(GQDs)and Ag nanoparticles(Ag-NPs)onto ***-difference time-domain calculations and scanning Kelvin probe microscopy were used to verify that the Ag-NPs/GQDs/3D-graphene system facilitates substantial electromagnetic enhancement(due to the occurrence of two kinds of"gaps"between the Ag-NPs that form 3D"hot spots")and additional chemical enhancement(in detecting someπ-conjugated molecules).The SERS mechanism was explored in further detail via experimental analysis and confirmed by performing theoretical *** large surface area of the 3D substrate(due to the large specific surface areas of the GQDs and 3D-graphene)results in a better enrichment effect which helps produce lower detection *** particular,the detection limits obtained using the Ag-NPs/GQDs/3D-graphene platform can reach 10^(-11)M for rhodamine 6G,10^(-10)M for methylene blue and dopamine,and 10^(-7)M for tetramethylthiuram disulfide and methyl parathion in apple juice(these are superior to most of the results reported using graphene-based SERS substrates).In summary,the 3D-platform Ag-NPs/GQDs/3D-graphene/Si shows outstanding SERS *** therefore has excellent application prospects in biochemical molecular detection and food safety monitoring.

关键词： Ag-NPs/GQDs/3D-graphene chemical enhancement dopamine Electromagnetic enhancement

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Striking a growth–defense balance:Stress regulators that function in maize development

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Journal of Integrative Plant Biology 2024年第3期66卷 424-442页

作者： Shiyi Xie Hongbing Luo Wei Huang Weiwei Jin Zhaobin Dong Maize Engineering and Technology Research Center of Hunan Province College of AgronomyHunan Agricultural UniversityChangsha 410128China State Key Laboratory of Maize Bio-breeding National Maize Improvement CenterFrontiers Science Center for Molecular Design BreedingChina Agricultural UniversityBeijing 100193China Tianjin Key Laboratory of Intelligent Breeding of Major Crops Fresh Corn Research Center of BTHCollege of Agronomy&Resources and EnvironmentTianjin Agricultural UniversityTianjin 300384China

Maize(Zea mays)cultivation is strongly affected by both abiotic and biotic stress,leading to reduced growth and *** has recently become clear that regulators of plant stress responses,including the phytohormones abscisic acid(ABA),ethylene(ET),and jasmonic acid(JA),together with reactive oxygen species(ROS),shape plant growth and *** their well established functions in stress responses,these molecules play crucial roles in balancing growth and defense,which must be finely tuned to achieve high yields in crops while maintaining some level of *** this review,we provide an in-depth analysis of recent research on the developmental functions of stress regulators,focusing specifically on *** unraveling the contributions of these regulators to maize development,we present new avenues for enhancing maize cultivation and growth while highlighting the potential risks associated with manipulating stress regulators to enhance grain yields in the face of environmental challenges.

关键词： stress regulators maize development ABA ET JA ROS

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design of low-weight, small-size and high-efficiency equalization circuits based on switched-capacitors 4

Design of low-weight, small-size and high-efficiency equaliz...

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2022 4th International Conference on Electronic Engineering and Informatics, EEI 2022

作者： Ding, Yanhong Zhao, Xin Li, Kun Liu, Qing Shi, Gengxin School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China China Electronics Technology Group Corporation Tianjin China

ISBN: (纸本)9783800759231

An any cell to any cell equalization circuit, which is based on switched capacitors and energy bus, is proposed in this paper. In this equalization topology, any high voltage cell can directly transfer the power to any low voltage cell through energy bus. With the increasing miniaturisation and integration of circuit boards, the topology proposed in this paper reduces the size of the circuit by varying the capacitance and frequency in order to further reduce the area and weight of the circuit. At the same time compared with the equalization circuit using transformers or inductance devices, this circuit has the characteristics of low cost, low-weight, small-size, easy integration and simple control scheme and it is suitable for applictions such as aerospace and unmanned aerial vehicles. The feasibility of the circuit topology is verified by formula demonstration and simulation results. © VDE VERLAG GMBH ∙ Berlin ∙ Offenbach.

关键词： Cells

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3D/4D additive-subtractive manufacturing of heterogeneous ceramics

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Journal of Materials science & technology 2024年第34期201卷 210-221页

作者： Guo Liu Xinya Lu Xiaofeng Zhang Yan Zhao Shenghui Yi Jingjun Xu Yuqi Zhan Jianan Yin Chengcheng Feng Zhifeng Zhou Peiyu Wang Zhou Chen Yunhu He Siyao Chen Pengchao Liu Jun Zuo Yu Dai Jian Wu Sida Liu Jian Lu Centre for Advanced Structural Materials City University of Hong Kong Shenzhen Research InstituteGreater Bay Joint DivisionShenyang National Laboratory for Materials ScienceShenzhen 518057China CityU-Shenzhen Futian Research Institute Shenzhen 518045China Hong Kong Branch of National Precious Metals Material Engineering Research Center City University of Hong KongHong Kong 999077China Department of Mechanical Engineering City University of Hong KongHong Kong 999077China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China National Engineering Laboratory for Modern Materials Surface Engineering Technology&The Key Lab of Guangdong for Modern Surface Engineering Technology Institute of New MaterialsGuangdong Academy of ScienceGuangzhou 510650China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Faculty of Materials Science Shenzhen MSU-BIT UniversityShenzhen 518100China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Physics and Materials Nanchang UniversityNanchang 330031China

The manufacturing of heterogeneous high-temperature material components is challenging for use in practical ***-dimensional(3D)printing provides solutions to programmable constructing ceramic ***,the development of heterogeneous ceramics is limited by low flexibil-ity of heterogeneity,geometrical complexity,structural resolution,manufacturing efficiency,and mate-rial *** this study,we demonstrated flexible and rapid approaches for fabricating complicated and precise heterogeneous ceramics by shape-changing(4D)or shape-keeping(3D)additive-subtractive manufacturing(ASM)*** shape-changing strategy for heterogeneous ceramics was achieved by global ceramization of heterogeneous precursors,while the shape-keeping strategy for heterogeneous ceramics was achieved by local receramization of homogeneous *** element analysis(FEA)simulations of the influence of the thermal shrinkage dominant in the shape-changing strategy on the shape deformation of heterogeneous ceramics could be valuable predictions of the experimental *** 3D/4D ASM methods are generic for high-temperature materials and extendable to metallic and dia-mond materials.

关键词： 3D/4D printing Additive-subtractive manufacturing Heterogeneous ceramics Elastomer-derived ceramics Local receramization

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Chern Number Tunable Quantum Anomalous Hall Effect in Compensated Antiferromagnets

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Physical Review Letters 2025年第11期134卷 116603-116603页

作者： Wenhao Liang Zeyu Li Jiaqi An Yafei Ren Zhenhua Qiao Qian Niu International Centre for Quantum Design of Functional Materials CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics and Department of Physics University of Science and Technology of China Hefei Anhui 230026 China Department of Physics The Hong Kong University of Science and Technology Clear Water Bay Hong Kong China Hefei National Laboratory University of Science and Technology of China Hefei 230088 China Department of Physics and Astronomy University of Delaware Newark Delaware 19716 USA

We propose to realize the quantum anomalous Hall effect (QAHE) in two-dimensional compensated antiferromagnets without net spin magnetization. We consider antiferromagnetic MnBi2Te4 as a concrete example. By breaking the parity-time (PT) symmetry of even-layer MnBi2Te4, we find that the system can host the QAHE with a nonzero Chern number. We show that by controlling the antiferromagnetic spin configuration—for example, down/up/up/down that breaks PT symmetry—tetralayer MnBi2Te4 can host a Chern number |C|=1. Such spin configuration can be stabilized by pinning the spin orientations of the surfaces. Furthermore, via tuning the on-site orbital energy and vertical electric fields, we find rich QAHE phases with tunable Chern number of |C|=1,2,3. In addition, we reveal that the edge states are layer selective and primarily located at the boundaries of the bottom and top layers. Our Letter not only proposes a scheme to realize Chern number tunable QAHE in antiferromagnets without net spin magnetization but also provides a platform for layer-selective dissipationless transport devices.

关键词： Antiferromagnetism

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Preparation and characterization of novel indoor usage of wood-plastic composites from polypropylene/recycled rice straw

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Taiwan Journal of Forest science 2021年第4期35卷 337-349页

作者： Lin, Sheau-Horng Chou, Chuen-Shii Department of Wood Science and Design National Pingtung University of Science and Technology Xuehfu Rd. Neipu Township Pingtung90201 Taiwan CPowder Technology RandD Laboratory Department of Mechanical Engineering National Pingtung University of Science and Technology Xuehfu Rd. Neipu Township Pingtung912 Taiwan

Most wood-plastic composites (WPCs) are fabricated using thermoplastics and sawdust (or other natural fibers). In this study, we used polypropylene (PP) and recycled rice straw (RS) as raw materials to prepare 22 types of WPCs for indoor use. We also incorporated chemical agents to enhance resistance to UV light, coupling capability, and flame retardancy. We then assessed how the PP/RS ratio and the addition of chemical agents affected the density of the resulting WPCs and the water-absorption rate (WAR), length-swelling rate (LSR), and microstructure. We also performed a thermogravimetric analysis, evaluated the weathering performance and flame retardancy, and measured the release of organic volatile matter (formaldehyde) to determine whether the proposed WPCs meet established standards for indoor usage. Samples prepared without a coupling agent exhibited increased WAR and LSR values with an increase in the content of recycled RS powder (24- h soaking test). Samples prepared with a coupling agent presented increased WAR values with an increase in soaking time when the content of recycled RS powder exceeded 50 phr (indicates the percentage of additives in rubber (or resin)) (28-day soaking test). The best composites evaluated in this study were self-extinguishing (limited oxygen index (LOI) = 27) and flameproof (based on V-0 criteria), exhibited low formaldehyde release (0.07 mg/L), and presented no differences in appearance before and after weathering tests. © 2021 Taiwan Forestry Research Institute. All rights reserved.

关键词： Polypropylenes

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Simulation of Rain Attenuation to Electromagnetic Wave Propagation

Simulation of Rain Attenuation to Electromagnetic Wave Propa...

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2022 International Applied Computational Electromagnetics Society Symposium, ACES-China 2022

作者： Hui, Tan Ling-Yun, Zhang Yi-Fu, Zhao Yu-Jia, Si Science and Technology on Electromagnetic Compatibility Laboratory China Ship Development and Design Center Wuhan430064 China Wuhan University of Technology School of Naval Architecture Ocean and Energy Power Engineering Wuhan430063 China

ISBN: (纸本)9781665452366

This paper applies computation method of rain attenuation and simulates the effect of rain attenuation to electromagnetic wave propagation. This paper provides attenuation features of different rain strength to different frequency electromagnetic wave, analyses the regulation of attenuation features, and draws the conclusions. © 2022 IEEE.

关键词： Electromagnetic wave propagation

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