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SSRN 2022年

作者： Huang, Danqiang Dai, Jianfeng Li, Zengpeng Wen, Xinchao Feng, Wei Liu, Hui School of Science Lanzhou University of Technology Gansu Lanzhou730050 China State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology Gansu Lanzhou730050 China Key Laboratory of Solar Power System Engineering Jiuquan Vocational Technical College Gansu735000 China

Hollow ZnFe2O4/carbon-based nanocomposite absorbers were successfully synthesized using a simple one-pot solvothermal process. Different methods were used to study the physical structure, microstructure, functional groups, and magnetic properties of the composite absorbers. The addition of different carbon-based nanomaterials improves the wave absorption properties in different ways. It not only improves the absorption strength, but also increases the effective absorption bandwidth. According to research findings, a maximum reflection loss of −37.47 dB was obtained for pure hollow ZnFe2O4 at 1.6 mm, −49.17 dB for ZnFe2O4/rGO at 3.6 mm, −40.31 dB for ZnFe2O4/MWCNTs at 4.8 mm, and −27.64 dB for ZnFe2O4/MWCNTs/rGO at 1.9 mm. The excellent electromagnetic wave absorption is attributed not only to the magnetic loss of the ferrite and the dielectric loss of the carbon-based nanomaterials, but also to the interfacial polarization between the different materials and the dipolar polarization of the residual functional groups. © 2022, The Authors. All rights reserved.

关键词： Iron compounds

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Probabilistic Power Flow Considering Static Characteristics of Power system with Large-Scale Offshore Wind Power 6

Probabilistic Power Flow Considering Static Characteristics ...

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6th International Conference on Power and Renewable Energy, ICPRE 2021

作者： Peng, Sui Lou, Yuanyuan Yu, Hao Chen, Honglin Zuo, Zhengmin Zhang, Zhangliang Zhou, Xinyu Tang, Junjie China Southern Power Grid Company Limited Grid Planning and Research Center Guangdong Power Grid Corporation Guangzhou China Chongqing University State Key Laboratory of Power Transmission Equipment System Security and New Technology Chongqing China

ISBN: (纸本)9781665449618

Offshore wind power is the frontier field of renewable energy development. The realization of large-scale offshore wind power (LSOWP) integration and high-efficiency consumption is conducive to improving wind power utilization efficiency and investment benefits in power industry. Firstly, Nataf transformation is utilized to generate samples of Pearson correlated offshore wind speed which obey two-parameter Weibull distribution. Besides, the power of conventional generators and loads are presented with their static characteristics. Then, an unified extended power flow model including system frequency is established. Finally, the proposed method has been tested on modified IEEE 39-bus system. Monte Carlo method is utilized to analyze the impact arisen from LSOWP integration on system operation status under multi-scenarios. And this paper mainly focuses on the distribution of steady-state frequency and branch MW flows. © 2021 IEEE.

关键词： Correlation methods

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Experimental study on the effect of brake shoe pressure on wheel wear and fatigue damage behavior during tread braking

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Wear 2025年 571卷

作者： Su, Jiabao Ding, Haohao Wang, Wenjian Huang, Xiaoqing Zhang, Shuyue Lewis, Roger Meli, Enrico Liu, Qiyue Zhou, Zhongrong Tribology Research Institute State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610031 China Mechanical Industry Key Laboratory of Damage Mechanism and Protection Technology for High-speed Friction Pairs Southwest Jiaotong University Chengdu610031 China Baowu Group Masteel Rail Transit Materials Technology Co. Ltd Maanshan243010 China Department of Mechanical Engineering The University of Sheffield Mappin Street Sheffield S1 3JD United Kingdom University of Florence via Santa Marta 3 Tuscany Florence50139 Italy

The widespread adoption of tread braking has made it necessary to study the wear and fatigue damage behavior of wheels under the combined action of brake shoes and rails. This study aims to investigate the influence of brake shoe pressure on wheel damage with an innovative small-scale test rig, the ‘shoe-wheel-rail contact machine’. Two contact modes were designed: shoe-wheel contact and shoe-wheel-rail contact. The results indicated that, with the increase in brake shoe pressure, both the wear loss of the wheel and braking temperature increased significantly. However, compared to the shoe-wheel contact, the wheel wear and fatigue damage were more severe after the shoe-wheel-rail contact, and they were more sensitive to changes in the brake shoe pressure. Notably, under the shoe-wheel-rail contact, wheel fatigue damage was dominated by sub-surface cracks, whereas almost no fatigue cracks were observed under the shoe-wheel contact. Furthermore, when the braking temperature reaches 350 °C, the synergistic effect of the braking temperature and the plastic deformation caused by wheel-rail rolling contact induced the refinement of the microstructure of the wheel material. © 2025 Elsevier B.V.

关键词： Fatigue crack

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Research on PD monitoring and location method of automatic directional substation

Research on PD monitoring and location method of automatic d...

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2021 International Conference on Information technology and Intelligent Control, CITIC 2021

作者： Hou, Jie Zhang, Yanjun Xu, Su Zhang, Ruiqiang Li, Jiqiang Xu, Changjian Baotou Power Supply Bureau of Inner Mongolia Electric Power Co.Ltd Inner Mongolia Autonomous Region 014000 China State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing400044 China

The accurate positioning of partial discharge can effectively avoid the occurrence of insulation failure of power equipment, but most of the existing positioning devices are fixed antenna array, which is difficult to achieve multi angle discharge monitoring in space, and the positioning method is single and the positioning accuracy is not high. Therefore, this paper proposes an automatic directional monitoring device for partial discharge source, and proposes a precise positioning method based on fixed point iteration method. With this positioning method as the main method and the automatic directional device as the auxiliary method, the spatial multi angle positioning of partial discharge source is realized. Firstly, PD signal recognition algorithm is used to identify the fault of PD signal, and then the steering gear rotation angle is determined by the angle correlation calculation formula, so as to accurately identify the position and direction of PD source. On this basis, four antenna array positioning algorithm is used to accurately locate PD source. Finally, through the field simulation test, it is found that the angle error of automatic orientation is 3°. The position error of PD source is 0.19m, which verifies the feasibility of the proposed method and device. © 2021 Institute of Physics Publishing. All rights reserved.

关键词： Antenna arrays

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Continuous Perception Garment Classification Based on Optical Flow Variation

Continuous Perception Garment Classification Based on Optica...

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IEEE International Conference on robotics and Biomimetics

作者： Li Huang Tong Yang Yu Zhang Rongxin Jiang- Xiang Tian Yaowu Chen Institute of Advanced Digital Technologies and Instrumentation Zhejiang University Hangzhou China State Key Laboratory of Industrial Control and Technology Zhejiang University China Zhejiang Provincial Key Laboratory for Network Multimedia Technology Hangzhou China Ministry of Education of China Embedded System Engineering Research Center Hangzhou China

ISBN: (纸本)9781665481106

A novel continuous perception garment classification mechanism is proposed in this paper, with the aim to identify the correct category of the garment from a set of known categories. It has been observed that due to the severe folding and overlapped texture of garments, treating a video of the continuous deformation of cloth as a set of disordered static figures would be ineffective which leads to low classification precision performed by an image-based garment classifier. In contrast, a high-level decision making module that leverages the classification results of each single image would significantly increase the algorithm performance. In this paper, we incorporate the optical flow variation of deformable cloth between consecutive configurations as a representative of how it is traversing within the confidence interval of the image-based classifier. We claim that it is not the number of video frames but the sum of optical flow variation of the garment configuration between consecutive frames having the same category label that constitutes the belief of garment classification. In other words, if two consecutive visual appearances of the garment could be identified as the same category by the image-based classifier, then the more diverged that two configurations are, the more confident that the garment is correctly identified. Experimental comparisons between the state-of-the-art algorithm and the proposed algorithm in a public dataset have been provided which prove the validity of the proposed algorithm.

关键词： Visualization Biomimetics Clothing Decision making Robot sensing systems Classification algorithms Task analysis

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Mwcnts Wrapped in Hollow with Open Holes of Cofe2o4 as High-Performance Electromagnetic Wave Absorbers

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SSRN 2022年

作者： Huang, Danqiang Dai, Jianfeng Qing, Wang Liu, Hui Li, Zengpeng School of Science Lanzhou University of Technology Gansu Lanzhou730050 China State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology Gansu Lanzhou730050 China Key Laboratory of Solar Power System Engineering Jiuquan Vocational Technical College Gansu735000 China

A multi-component, special structure of electromagnetic wave absorber produces significant electromagnetic wave absorption performance because of excellent impedance matching. In this work, CoFe2O4@CNTs composites are prepared. CoFe2O4 exhibits a hollow and open-hole shape with a rough surface, and this structure facilitates more electromagnetic wave absorption. The incorporation of multiwalled carbon nanotubes (MWCNTs) leads to dipole polarization and when wrapped around CoFe2O4 particles, increases the interface loss. The influence of the filler-loading ratio on the microwave absorption performance of wax-based absorbers is thoroughly investigated. The highest electromagnetic wave absorption performance is obtained at 25% filling with a minimum reflection loss (RLmin) of −36.52 dB at a thickness of 1.9 mm and effective absorption bandwidth (EAB) is 3GHz. In this study, a method is proposed for creating high-performance electromagnetic wave absorbers. © 2022, The Authors. All rights reserved.

关键词： Iron compounds

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Magnetic Properties and Exchange Coupling Effects of Srfe12o19@Mfe2o4 (M=Co, Ni, Zn) as Hard-Soft Magnetic Ferrite Core-Shell Nanofibres

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SSRN 2022年

作者： Huang, Danqiang Wen, Xinchao Dai, Jianfeng Feng, Wei Liu, Hui Li, Zengpeng School of Science Lanzhou University of Technology Gansu Lanzhou730050 China State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology Gansu Lanzhou730050 China Key Laboratory of Solar Power System Engineering Jiuquan Vocational Technical College Gansu 735000 China

In this study, SrFe 12 O 19 @MFe 2 O 4 (M=Co, Ni, Zn) core-shell nanofibers were fabricated by coaxial electrostatic spinning. The composites obtained at an annealing temperature of 900 °C are composed of SrFe 12 O 19 in pure phase and MFe 2 O 4 (M=Co, Ni, Zn) in different spinels. Sr@Ni and Sr@Zn, fibers all exhibit a unique core-shell structure, while Sr@Co fibers are connected by a lamellar structure. The single-phase hysteresis lines for each composite indicate the presence of exchange coupling effects between the hard/soft magnetic composite phases. The magnetic properties of the composites change as the soft magnetic material in the shell layer changes. Sr@Co has the highest Ms (69.43 emu/g) and Mr (33.82 emu/g), whereas Sr@Zn has the highest Hc (2927 Oe). The switching plant curves indicate that the best exchange coupling of the three groups of samples is for Sr@Co. The magnetic properties of the composites are explained in terms of the nanofibre diameter, the exchange coupling between the two phases and the nature of the soft magnetic phase itself. It is shown that the exchange coupling of composites is closely related to the type of composite. © 2022, The Authors. All rights reserved.

关键词： Nanofibers

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Deep Learning Based Vehicular Millimeter-Wave Channel Prediction Using Visual Information

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IEEE Antennas and Wireless Propagation Letters 2025年

作者： Wang, Shirui He, Ruisi Yang, Mi Ai, Bo Zhang, Xuejian Zhong, Zhangdui Zhang, Haoxiang Han, Jiahui Liu, Bingcheng 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 Ministry of Industry and Information Technology China Academy of Industrial Internet Beijing100044 China Chinese Academy of Sciences Aerospace Information Research Institute Beijing100094 China

Millimeter-wave channel prediction requires detailed and accurate environmental information due to challenges of non-line-of-sight transmission and severe reflection and scattering. Image information conveniently reflects real-time changes of physical environment and provides a promising solution for millimeter-wave channel modeling. However, research on millimeter-wave channel prediction based on RGB images is still in its exploratory stage. Meanwhile, RGB images introduce new influencing factors, such as visual angle changes, leading to inaccurate prediction. This article proposes a millimeter-wave channel prediction model based on propagation knowledge and visual information, which enhances original RGB image features while combining manual features from specific domain prior knowledge in propagation. Experimental results show that the proposed model outperforms traditional RGB image-based prediction for a multi-scenario, multiview fused dataset, achieving a symmetric mean absolute percentage error as low as 4.16%. In addition, the proposed model demonstrates enhanced stability and interpretability. © 2002-2011 IEEE.

关键词： Prediction models

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Size-Fractionated Distribution of Glycerol Dialkyl Glycerol Tetraether Core Lipids in Surface Sediments of a Large-River Delta-Front Estuary

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SSRN 2023年

作者： Wang, Jinpeng Zhao, Bin Yao, Peng State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control South China Institute of Environmental Sciences Ministry of Ecology and Environment of the People’s Republic of China Guangzhou510530 China Key Laboratory of Marine Eco-Environmental Science and Technology First Institute of Oceanography Ministry of Natural Resources Qingdao266061 China Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Ocean University of China Qingdao266100 China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and Technology Qingdao266237 China

Glycerol dialkyl glycerol tetraether core lipids (GDGTs) are microbial biomarkers ubiquitously distributed in terrestrial and marine soils/sediments. Dispersal and fate of GDGTs in an estuary largely depends on sediment grain size, however, their size distribution remains poorly understood. Here, surface sediments collected from the Changjiang Estuary were separated into five size fractions ( 125 µm) and analyzed for GDGTs as well as total organic carbon (TOC) and its stable isotopic composition, and lignin phenols, to investigate the size and spatial distributions of these parameters in the estuarine system. The contents of isoprenoidal GDGTs (iso-GDGTs) were more abundant in the finest fractions and in off-estuary sites. The contents of branched GDGTs (br-GDGTs) were high not only in the finest fractions but also in large fractions (> 32 μm fractions). And thus, br-GDGTs are mainly deposited near the estuary along with coarse particles, but a part of br-GDGTs attached to fine particles can be selectively transported off the estuary. Differentiated distributions of iso-GDGTs and br-GDGTs among size fractions and selective dispersal of these sediments resulted in a sharp decrease of the branched and isoprenoid tetraether (BIT) index from the estuary (~0.52) to the shelf (~0.16). Although BIT values of these sediments were relatively high (> 0.1), the occurrence of co-variation of br-GDGTs and crenarcheaol in estuarine sediments was likely due to the association of different GDGTs in sediments that have different size compositions, and could still imply in-situ production of br-GDGT. Among size fractions, OC fractions derived from the BIT index (fsoil-BIT) was significantly correlated with fterrestrial OC based on a mixing model, indicating that BIT tracked a broader pool of terrestrial OC than just soil OC. More work is needed to further clarify the applicability of BIT in estuaries as a proxy for OC sources. © 2023, The Authors. All rights reserved.

关键词： Glycerol

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Quantum Interference between Photons and Single Quanta of Stored Atomic Coherence

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Physical Review Letters 2022年第8期128卷 083605-083605页

作者： Xingchang Wang Jianmin Wang Zhiqiang Ren Rong Wen Chang-Ling Zou Georgios A. Siviloglou J. F. Chen Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology Shenzhen 518055 China International Quantum Academy (SIQA) and Shenzhen Branch Hefei National Laboratory Futian District Shenzhen 518055 China State Key Laboratory of Precision Spectroscopy School of Physics and Electronic Science East China Normal University Shanghai 200241 China Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan 030024 Shanxi China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei 230026 Anhui China Guangdong Provincial Key Laboratory of Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China

Essential for building quantum networks over remote independent nodes, the indistinguishability of photons has been extensively studied by observing the coincidence dip in the Hong-Ou-Mandel interferometer. However, indistinguishability is not limited to the same type of bosons. For the first time, we hereby observe quantum interference between flying photons and a single quantum of stored atomic coherence (magnon) in an atom-light beam splitter interface. We demonstrate that the Hermiticity of this interface determines the type of quantum interference between photons and magnons. Consequently, not only the bunching behavior that characterizes bosons is observed, but counterintuitively, fermionlike antibunching as well. The hybrid nature of the demonstrated magnon-photon quantum interface can be applied to versatile quantum memory platforms, and can lead to fundamentally different photon distributions from those occurring in boson sampling.

关键词： Electromagnetically induced transparency Quantum description of light-matter interaction Quantum optics Single photon sources Atomic ensemble Atom & ion cooling Coherent control Photon counting

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