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A Novel Approach of Electromagnetic Compatibility Conducted Susceptibility Analysis Based on Gaussian Even Pulse Signal

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Chinese Journal of Electronics 2024年第2期33卷 472-478页

作者： Youwei MENG Yanhua PENG Haoyang ZHANG Lilin LI Donglin SU The School of Electronic and information Engineering Beihang University The institute of Electromagnetic Compatibility Technology Beihang University The research institute for frontier science Beihang University

The purpose of the electromagnetic compatibility conducted susceptibility test for interconnected cables in the system is to evaluate its ability to operate acceptably when subjected to interference. We propose a novel conducted susceptibility analysis approach: by injecting the Gaussian even pulse signal, we find that the susceptibility threshold of the system shows two different patterns with the change of signal parameters; then we locate the cause of the susceptibility of the device by analyzing the threshold level curves. The effectiveness of the proposed approach is verified by testing with devices containing digital modules such as navigation receivers. The proposed approach facilitates a deeper understanding of the susceptibility mechanism of systems and their appropriate electromagnetic compatibility design.

关键词： Analytical models Navigation Interference Receivers Electromagnetic compatibility Physical layer Time-domain analysis

Enhancing thermoelectric performance of p-type SnTe through manipulating energy band structures and decreasing electronic thermal conductivity

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Rare Metals 2024年第7期43卷 3232-3241页

作者： Xin Qian Hao-Ran Guo Jia-Xin Lyu Bang-Fu Ding Xing-Yuan San Xiao Zhang Jiang-Long Wang Shu-Fang Wang Hebei Key Lab of Optic-Electronic information and Materials College of Physics Science and TechnologyHebei UniversityBaoding 071002China College of Electron and information Engineering Hebei UniversityBaoding 071002China research institute for frontier science Beihang UniversityBeijing100191China

SnTe has received considerable attention as an environmentally friendly alternative to the representative thermoelectric material of ***,excessive hole carrier concentration in SnTe results in an extremely low Seebeck coefficient and high thermal conductivity,which makes it exhibit relatively inferior thermoelectric *** this work,the thermoelectric performance of p-type SnTe is enhanced through regulating its energy band structures and reducing its electronic thermal conductivity by combining Bi doping with CdSe ***,the carrier concentration of SnTe is successfully suppressed via Bi doping,which significantly decreases the electronic thermal ***,the convergence and flattening of the valence bands by alloying CdSe effectively improves the effective mass of SnTe while restraining its carrier ***,a maximum figure of merit(ZT) of~ 0.87 at 823 K and an average ZT of~ 0.51 at 300-823 K have been achieved in Sn_(0.96)Bi_(0.04)Te-5%*** results indicate that decreasing the electronic thermal conductivity is an effective means of improving the performance of thermoelectric materials with a high carrier concentration.

关键词： Thermoelectric materials SnTe Energy band structure Electronic thermal conductivity ZT value

An Improved Z-buffer Accelerated PO Method for EM Scattering from Electrically Large Targets

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Chinese Journal of Electronics 2024年

作者： Jiangfei BAI Shunchuan YANG Donglin SU School of Electronics and information Engineering Beihang University research institute for frontier science Beihang University

The physical optical(PO) method is widely used to solve the electromagnetic scattering problems involved electrically large structures, in which each surface element is required to determine whether it is blocked by others. It may suffer from the computational efficiency issue through elementwise shadowing testing. In this paper, an efficient Z-buffer based shadowing testing method is proposed to accelerate this procedure. In the proposed method,all triangular facets are first mapped to a grid plane as the Z-buffer method, and for each grid cell, all projected triangles intersecting it are recorded. Then, rigorous shadowing testing is made for all facets recorded in the grid where the centroid of each triangle is projected. It can avoid a large number of redundant operations for pairs of triangles with no occlusion relation, which lead to the same accuracy as the traditional rigorous shadowing testing method with significantly efficiency improvement. Four numerical examples are carried out to validate its accuracy and efficiency.

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Study on the Impact of Imbalance between Transmission Lines on Crosstalk: a Novel Perspective of Displacement Current

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Chinese Journal of Electronics 2024年

作者： Xiaozhu LU Lingnan SONG Hui XU Donglin SU School of Electronics and information Engineering Beihang University research institute for frontier science Beihang University

This paper systematically studies the impact of imbalances between adjacent lines and effects on crosstalk. A novel perspective of displacement current is introduced to analyze and explain the simulated observations. The imbalances caused by coupling between single-single, single-differential, and differential-differential lines are studied and analyzed by considering the near-field coupling through the generated displacement currents. Measurements are conducted for various cases of coupled adjacent lines. An equivalent model considering the variation of displacement current with geometrical parameters is also proposed, and the corresponding coupling coefficients are extracted based on simulations to characterize the impact of imbalances. The methods and results presented in this paper provide useful guidelines for designing high-speed circuit layouts with closely spaced transmission lines.

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Multi-faceted spatio-temporal network for weather-aware air traffic flow prediction in multi-airport system

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Chinese Journal of Aeronautics 2024年第7期37卷 301-316页

作者： Kaiquan CAI Shuo TANG Shengsheng QIAN Zhiqi SHEN Yang YANG School of Electronic and information Engineering Beihang UniversityBeijing 100191China State Key Laboratory of CNS/ATM Beijing100191China institute of Automation Chinese Academy of SciencesBeijing 100190China research institute for frontier science Beihang UniversityBeijing 100191China

As one of the core modules for air traffic flow management,Air Traffic Flow Prediction(ATFP)in the Multi-Airport System(MAS)is a prerequisite for demand and capacity balance in the complex meteorological *** to the challenge of implicit interaction mechanism among traffic flow,airspace capacity and weather impact,the Weather-aware ATFP(Wa-ATFP)is still a nontrivial *** this paper,a novel Multi-faceted Spatio-Temporal Graph Convolutional Network(MSTGCN)is proposed to address the Wa-ATFP within the complex operations of ***,a spatio-temporal graph is constructed with three different nodes,including airport,route,and fix to describe the topology structure of ***,a weather-aware multi-faceted fusion module is proposed to integrate the feature of air traffic flow and the auxiliary features of capacity and weather,which can effectively address the complex impact of severe weather,e.g.,***,to capture the latent connections of nodes,an adaptive graph connection constructor is *** experimental results with the real-world operational dataset in Guangdong-Hong Kong-Macao Greater Bay Area,China,validate that the proposed approach outperforms the state-of-the-art machine-learning and deep-learning based baseline approaches in performance.

关键词： Air traffic control Graph neural network Multi-faceted information Air traffic flow prediction Multi-airport system

Effect of Ni content on the wear behavior of Al-Si-Cu-Mg-Ni/SiC particles composites

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 374-383页

作者： Yanyu Liu Lina Jia Wenbo Wang Zuheng Jin Hu Zhang School of Materials science and Engineering Beihang UniversityBeijing 100191China Ningbo institute of Technology Beihang UniversityNingbo 315100China Qingdao research institute of Beihang University Qingdao 266000China research institute for frontier science Beihang UniversityBeijing 100191China

In recent years,the addition of Ni has been widely acknowledged to be capable of enhancing the mechanical properties of Al-Si ***,the effect of Ni on the wear behaviors of Al-Si alloys and Al matrix composites,particularly at elevated temperat-ures,remains an understudied *** this study,Al-Si-Cu-Mg-Ni/20wt%SiC particles(SiCp)composites with varying Ni contents were prepared by using a semisolid stir casting *** effect of Ni content on the dry sliding wear behavior of the prepared compos-ites was investigated through sliding tests at 25 and 350℃.Results indicated that theθ-Al_(2)Cu phase gradually diminished and eventually disappeared as the Ni content increased from 0wt%to 3wt%.This change was accompanied by the formation and increase inδ-Al_(3)CuNi andε-Al_(3)Ni phases in *** hardness and ultimate tensile strength of the as-cast composites improved,and the wear rates of the composites decreased from 5.29×10^(−4)to 1.94×10^(−4)mm^(3)/(N∙m)at 25℃and from 20.2×10^(−4)to 7×10^(−4)mm^(3)/(N∙m)at 350℃with the increase in Ni content from 0wt%to 2wt%.The enhancement in performance was due to the presence of strengthening network structures and additional Ni-containing phases in the ***,the wear rate of the 3Ni composite was approximately two times higher than that of the 2Ni composite due to the fracture and debonding of theε-Al_(3)Ni *** wear,delamination wear,and oxidation wear were the predominant wear mechanisms of the investigated composites at 25℃,whereas delamination wear and oxid-ation wear were dominant during sliding at 350℃.

关键词： Al matrix composite microstructure sliding test high temperature wear mechanism

Continuous preparation of strong and tough PVA nanocomposite fibers by mechanical stretching-assisted salting-out treatment

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Nano research 2024年第4期17卷 3156-3163页

作者： Hang Chen Guangze Yang Yingzhi Sun Yichao Xu Mingjie Liu Key Laboratory of Bioinspired Smart Interfacial science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China research institute for frontier science Beihang UniversityBeijing 100191China International research institute for Multidisciplinary science Beihang UniversityBeijing 100191China

Polymer composite fibers with superior properties such as excellent combined strength and toughness and biocompatibility can be used in high-tech applications of braided protective devices and smart wearable,however the research of high-performance polymer composite fiber remains in the infant *** we present a strategy to produce strong and tough anisotropic polymer nanocomposite fibers with orientedly aligned salt rods using mechanical stretching-assisted salting-out *** prepared nanocomposite fibers have a tensile strength of up to 786±2.7 MPa and an elongation at break of 81%,and the anisotropic fibers exhibit good transmission of mechanical vibration in the longitudinal direction with high *** the fabrication process,the salt builds up into oriented rods during the directional salting process,and the polymer is confined to the 150 nm domain between the rods after the solvent is completely evaporated,giving the nanocomposite fibers superior mechanical *** presented strategy can be applied to the continuous mass production of nanocomposite fibers and is also generalizable to other polymer nanocomposites,which could extend the applicability of nanocomposite fibers to conditions involving more demanding mechanical loading and mechanical vibration transmission.

关键词： poly(vinyl alcohol)(PVA)nanofibers oriented structure ultrastrong and stiff mechanical vibration transmission salting out continuous production

Indium-based electrocatalysts for CO_(2) reduction to C1 products

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Chinese Chemical Letters 2024年第6期35卷 134-145页

作者： Qin Cheng Ming Huang Qingqing Ye Bangwei Deng Fan Dong research Center for Carbon-Neutral Environmental&Energy Technology Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China Yangtze Delta Region institute(Huzhou)&institute of Fundamental and frontier sciences University of Electronic Science and Technology of ChinaHuzhou 313000China Suzhou Industrial Technology research institute of Zhejiang University Suzhou 215163China

Electrocatalytic CO_(2) reduction at mild conditions is a promising strategy to transform greenhouse gases into fuels or value-added chemicals to solve the increasingly serious environmental and energy *** most crucial factor in determining the CO_(2) reduction performance is to develop efficient electrocatalysts with high selectivity and *** the various electrocatalysts,indium-based catalysts have attracted extensive attention due to their non-toxicity,low cost,and high formic acid/formate *** this work,we comprehensively review the recent development and research progress of indium-based electrocatalysts for CO_(2)*** reaction mechanism,reaction pathways,structure-activity relationship,and strategies to enhance the activity of CO_(2)RR on indium-based catalysts have also been briefly presented and ***,the existing challenges and future developments for indium-based highperformance catalysts for CO_(2)RR are proposed.

关键词： Electrocatalytic CO_(2) reduction In-based catalysts Formate Reaction mechanism Structure-activity relationship

Quantized anomalous Hall resistivity achieved in molecular beam epitaxy-grown Mn Bi2Te4 thin films

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National science Review 2024年第2期11卷 24-32页

作者： Yunhe Bai Yuanzhao Li Jianli Luan Ruixuan Liu Wenyu Song Yang Chen Peng-Fei Ji Qinghua Zhang Fanqi Meng Bingbing Tong Lin Li Yuying Jiang Zongwei Gao Lin Gu Jinsong Zhang Yayu Wang Qi-Kun Xue Ke He Yang Feng Xiao Feng State Key Laboratory of Low Dimensional Quantum Physics Department of Physics Tsinghua University institute of Physics Chinese Academy of Sciences School of Materials science and Engineering Tsinghua University Beijing Academy of Quantum information sciences frontier science Center for Quantum information Hefei National Laboratory Southern University of science and Technology

The intrinsic magnetic topological insulator MnBi2Te4provides a feasible pathway to the high-temperature quantum anomalous Hall（QAH） effect as well as various novel topological quantum phases. Although quantized transport properties have been observed in exfoliated MnBi2Te4thin flakes, it remains a big challenge to achieve molecular beam epitaxy（MBE）-grown MnBi2Te4thin films even close to the quantized regime. In this work, we report the realization of quantized anomalous Hall resistivity in MBE-grown MnBi2Te4thin films with the chemical potential tuned by both controlled in situ oxygen exposure and top gating. We find that elongated post-annealing obviously elevates the temperature to achieve quantization of the Hall resistivity, but also increases the residual longitudinal resistivity, indicating a picture of high-quality QAH puddles weakly coupled by tunnel barriers. These results help to clarify the puzzles in previous experimental studies on MnBi2Te4and to find a way out of the big difficulty in obtaining MnBi2Te4samples showing quantized transport properties.

关键词： intrinsic magnetic topological insulator quantized anomalous Hall resistivity molecular beam epitaxy quantized transport property