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An improved initial rotor position estimation method using high-frequency pulsating voltage injection for PMSM

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Defence Technology（防务技术） 2024年第3期33卷 19-29页

作者： Yang Jiang ming cheng School of Electrical Engineering Southeast UniversityNanjing 210096China

High frequency pulsating voltage injection method is a good candidate for detecting the initial rotor position of permanent magnet synchronous ***,traditional methods require a large number of filters,which leads to the deterioration of system stability and dynamic *** order to solve these problems,a new signal demodulation method is proposed in this *** proposed new method can directly obtain the amplitude of high-frequency current,thus eliminating the use of filters,improving system stability and dynamic performance and saving the work of adjusting filter *** addition,a new magnetic polarity detection method is proposed,which is robust to current measurement ***,experiments verify the effectiveness of the method.

关键词： Initial position detection Signal demodulation algorithm Magnetic polarity detection Filter elimination

Residual stress distribution in thin diamond films and its effects on preparation of thick freestanding diamond films using DC arc plasma jet operated at gas recycling mode

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 255-259页

作者： LI cheng-ming Sch. of Mat. Sci. and Eng. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Diamond films produced by chemical vapor deposition show excellent properties. The residual stress distribution of diamond thin films deposited by DC arc plasma jet at recycling mode was analyzed by line shifts of micro Raman spectroscopy. The results show that the compressive residual stress concentrates at the film's edge. The experimental observations show that cracks initiate at the edge of the diamond thick wafer and then propagate towards the center. The residual stress of diamond films increases with the increase of methane concentration and deposition temperature. The difference of adhesion in close area causes more shear stress and brings about the two sides of crack being not at same level. To suppress crack probability, it is favourable for increasing the film thickness and selecting a substrate with lower coefficient of thermal expansion and lower adhesion. The effects of the residual stress distribution on thick diamond films detachment were discussed.

关键词： Cracking Diamond films Residual stress

A bioinspired strategy for assembling graphene oxide sheets into high-performance graphene films

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Science China Chemistry 2018年第12期61卷 1475-1476页

作者： Hui-ming cheng Tsinghua-Berkeley Shenzhen Institute Tsinghua University Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Since 2004,graphene has attracted intense attention from the scientific and industrial communities due to its extraordinary properties,such as ultrahigh strength and remarkable electrical *** production of high-quality gra- phene materials can be achieved by chemical vapor deposition and chemical exfoliation,and their applications have been widely explored [1-3].

关键词： bioinspired strategy assembling graphene oxide sheets graphene films

High-quality graphene films produced by freezestretching alignment

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Science China Materials 2021年第5期64卷 1302-1303页

作者： Hui-ming cheng Shenzhen Geim Graphene Center Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Monolayer graphene has the highest tensile strength,Young’s modulus, and electrical conductivity of known materials, and it is expected to be used in aerospace,automobiles, flexible electronics, etc. [1]. However, the extraordinary properties of graphene are on the molecular level and have not been realized when assembled into macroscopic materials.

关键词： stretching modulus conductivity

Two-dimensional ambipolar van der Waals heterostructures enabling in-sensor computing for high-accuracy image recognition

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Science China Materials 2022年第9期65卷 2611-2612页

作者： Hui-ming cheng Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

A traditional image recognition system is separately composed of a photodetector and a processing *** photodetector first detects a target light signal,then converts the detected light signal to an electrical signal,a... 详细信息

关键词： computing image system

D2ANet:Difference-aware attention network for multi-level change detection from satellite imagery

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Computational Visual Media 2023年第3期9卷 563-579页

作者： Jie Mei Yi-Bo Zheng ming-ming cheng TMCC CSNankai UniversityTianjin 300350China State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Recognizing dynamic variations on the ground,especially changes caused by various natural disasters,is critical for assessing the severity of the damage and directing the disaster ***,current workflows for disaster assessment usually require human analysts to observe and identify damaged buildings,which is labor-intensive and unsuitable for large-scale disaster *** this paper,we propose a difference-aware attention network(D2ANet)for simultaneous building localization and multi-level change detection from the dual-temporal satellite *** the differences in different channels in the features of pre-and post-disaster images,we develop a dual-temporal aggregation module using paired features to excite change-sensitive channels of the features and learn the global change *** the nature of building damage caused by disasters is diverse in complex environments,we design a difference-attention module to exploit local correlations among the multi-level changes,which improves the ability to identify damage on different *** experiments on the large-scale building damage assessment dataset xBD demonstrate that our approach provides new state-of-the-art *** code is publicly available at https://***/mj129/D2ANet.

关键词： change detection building localization sate-llite imagery dual-temporal aggregation difference attention

Metre-size single-crystal graphene becomes a reality

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Science Bulletin 2017年第15期62卷 1039-1040页

作者： Hui-ming cheng Tsinghua-Berkeley Shenzhen Institute Tsinghua University Shenzhen 518055 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Center of Excellence in Environmental Studies (CEES) King Abdulaziz University Jeddah 21589 Saudi Arabia

*** Liu of Peking University,a well-known graphene researcher and also one of the authors for the work[1]highlighted here,has always said,‘‘Fabrication determines the future'.I *** growth of large-area high-quality ... 详细信息

关键词：石墨大规模生产铜基材料单晶化学气相沉积 Ni合金北京大学器件应用

Dual Frequency Transformer for Efficient SDR-to-HDR Translation

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Machine Intelligence Research 2024年第3期21卷 538-548页

作者： Gang Xu Qibin Hou ming-ming cheng Tianjin Media Computing Center College of Computer ScienceNankai UniversityTianjin300000China

The SDR-to-HDR translation technique can convert the abundant standard-dynamic-range (SDR) media resources to high-dynamic-range (HDR) ones, which can represent high-contrast scenes, providing more realistic visual experiences. While recent vision Transformers have achieved promising performance in many low-level vision tasks, there are few works attempting to leverage Transformers for SDR-to-HDR translation. In this paper, we are among the first to investigate the performance of Transformers for SDR-to-HDR translation. We find that directly using the self-attention mechanism may involve artifacts in the results due to the inappropriate way to model long-range dependencies between the low-frequency and high-frequency components. Taking this into account, we advance the self-attention mechanism and present a dual frequency attention (DFA), which leverages the self-attention mechanism to separately encode the low-frequency structural information and high-frequency detail information. Based on the proposed DFA, we further design a multi-scale feature fusion network, named dual frequency Transformer (DFT), for efficient SDR-to-HDR translation. Extensive experiments on the HDRTV1K dataset demonstrate that our DFT can achieve better quantitative and qualitative performance than the recent state-of-the-art methods. The code of our DFT is made publicly available at https://***/CS-GangXu/DFT.

关键词： Standard-dynamic-range to high-dynamic-range(SDR-to-HDR)translation Transformer dual frequency attention(DFA) frequency-aware feature decomposition efficient model

Analytical Solution of a Fractional-slot Double-layer-winding Open-slot Vernier Permanent Magnet Machine with Tooth Tips

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Chinese Journal of Electrical Engineering 2024年第2期10卷 44-58页

作者： Weibing Wang ming cheng School of Electric Power Engineering Nanjing Institute of TechnologyNanjing 211167China School of Electrical Engineering Southeast UniversityNanjing 210096China

An analytical solution(ANA)for a fractional-slot double-layer-winding open-slot vernier permanent magnet(VPM)machine with tooth tips is *** vector potential equations are analytically solved using the technique of variable separation in four subdomains in a two-dimensional polar coordinate *** on the solved magnetic vector potential,the flux density distribution,torque,flux linkage,inductance,electromotive force(EMF)and power factor are analytically *** 18-slot/32-rotor-pole prototype is analyzed,and the results match well with the finite element analysis(FEA),which validates that the ANA consumes less time than ***,the tooth tips are optimized using the ANA to improve the average ***,the ANA can be used to evaluate the demagnetization withstand capabilities of permanent *** material utilization,slot-filling factor,EMF,and torque are compared between the models with three and four ***,an experimental prototype is constructed and tested,and the results validate the ANA.

关键词： Analytical solution magnetic field vernier permanent magnet machine subdomain optimization demagnetization