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New polyhydroxylated metabolite derived from biotransformation of diosgenin by the white-rot fungus Coriolus versicolor

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Chinese Chemical Letters 2010年第4期21卷 446-448页

作者： wu, Guang Wei Li, Xiao Jun gao, Yi Jia, Yuan gao, jin Ming NW A&F Univ Coll Sci Yangling 712100 Shaanxi Peoples R China Natl Engn Res Ctr Phytochem W China Yangling 712100 Shaanxi Peoples R China

Microbial transformation of diosgenin(1) was carried out with the white-rot fungus,Coriolus versicolor.A new polyhydroxyl metabolite,(25R)-spirost-5-ene-3β,7β,21-triol(2),was obtained as a result of *** structure wa... 详细信息

关键词： (25R)-Spirost-5-ene-3β 7β 21-triol Coriolus versicolor Diosgenin Microbial biotransformation Biocatalysis

一种适用于混合三端直流输电线路的故障定位方法

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西安交通大学学报 2025年第1期59卷 37-46页

作者：高淑萍杨莉莉武心宇周晋宇宋国兵西安科技大学电气与控制工程学院西安710054 西安市电气设备状态监测与供电安全重点实验室西安710054 西安交通大学电气工程学院西安710049

针对因结构复杂导致的混合三端直流输电线路故障定位困难的问题,提出了一种结合变分模态分解算法与改进卷积神经网络(CNN)的故障定位方法(VMD-CNN)。首先,利用PSCAD/EMTDC软件构建混合三端直流输电系统模型,获得故障电流数据,应用克拉... 详细信息

针对因结构复杂导致的混合三端直流输电线路故障定位困难的问题,提出了一种结合变分模态分解算法与改进卷积神经网络(CNN)的故障定位方法(VMD-CNN)。首先,利用PSCAD/EMTDC软件构建混合三端直流输电系统模型,获得故障电流数据,应用克拉克变换对其解耦,获取故障电流的线模分量;其次,对得到的线模分量进行变分模态分解(VMD),得到多个本征模态函数(IMF)分量,选取特征信息最丰富的IMF分量作为VMD-CNN模型的输入;然后,利用高效的分类模型支持向量机(SVM)判别故障发生的区域,将提取到的IMF分量作为SVM输入进行训练学习,可以准确判断出故障发生区域;最后,搭建VMD-CNN模型进行故障定位,挖掘出行波信号中蕴藏的故障信息,同时通过麻雀搜索算法优化CNN中的超参数,实现混合三端直流输电线路的精确定位。仿真结果表明:过渡电阻为100Ω,不同故障位置情况下的定位相对误差均在0.17%以内;故障位置为460 km,不同过渡电阻情况下的定位相对误差均在0.25%以内;过渡电阻为50Ω,不同故障类型情况下的相对误差均在0.3%以内。所提方法能够提升不同故障位置、过渡电阻和故障类型下的定位准确性。

关键词：混合三端直流输电故障定位变分模态分解卷积神经网络麻雀搜索算法

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NETWORK-CONNECTED UAV COMMUNICATIONS

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China Communications 2018年第5期15卷 I0003-I0005页

作者： Yong Zeng Shi jin Qihui wu Feifei gao the National University of Singapore the faculty of the National Mobile Communications Research Laboratory Southeast University the College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics the Department of Automation Tsinghua University

Unmanned aerial vehicles(UAVs)have found fast growing applications in recent years,such as for cargo delivery,precision agriculture,aerial monitoring,video streaming,traffic control,rescue and search,and communication... 详细信息

关键词：连接网络通讯 UAV 精确农业交通控制天线搜索

An Asynchronous Clustering and Mobile Data Gathering Schema Based on Timer Mechanism in Wireless Sensor Networks

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Computers, Materials & Continua 2019年第3期58卷 711-725页

作者： jin Wang Yu gao Wei Liu Wenbing wu Se-Jung Lim Hunan Provincial Key Laboratory of Intelligent Processing of Big Data on Transportation School of Computer&Communication EngineeringChangsha University of Science&TechnologyChangsha410114China School of Information Science and Engineering Fujian University of TechnologyFuzhou350000China College of Information Engineering Yangzhou UniversityYangzhou225000China Department of Computer Engineering Chonnam National UniversityYeosu596597Korea.

Recently,Wireless sensor networks(WSNs)have become very popular research topics which are applied to many *** provide pervasive computing services and techniques in various potential applications for the Internet of Things(IoT).An Asynchronous Clustering and Mobile Data Gathering based on Timer Mechanism(ACMDGTM)algorithm is proposed which would mitigate the problem of“hot spots”among sensors to enhance the lifetime of *** clustering process takes sensors’location and residual energy into consideration to elect suitable cluster ***,one mobile sink node is employed to access cluster heads in accordance with the data overflow time and moving time from cluster heads to *** experimental results display that the presented method can avoid long distance communicate between sensor ***,this algorithm reduces energy consumption effectively and improves package delivery rate.

关键词： Internet of things wireless sensor networks clustering mobile data collection timer.

Two-Dimensional Animal-Like Fractals in Thin Films

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Chinese Physics Letters 1996年第2期13卷 121-124页

作者： gao Hong-jun XUE Zeng-quan wu Quan-de PANG Shi-jin Beijing Laboratory of Vacuum Physics Chinese Academy of SciencesBeijing 100080 Department of Radio-Electronics Peking UniversityBeijing 100871

we present a few unique animal-like fractal patterns in ionized-clnster-beam deposited fullerene-tetracyanoquinodimethane thin *** fractal patterns consisting of animal-like aggregates such as"fishes"and"quasi-seahorses"have been characterized by transnission electron *** results indicate that the sall aggregates ofthe aninmal-like body are composed of many single crystals whose crystalline directions are generally *** formation of tle fractal patterns can be attributed to the cluster-diffusion-lirnited aggregation.

关键词： aggregation fractal crystalline

THE DAVIES METHOD FOR HEAT KERNEL UPPER BOUNDS OF NON-LOCAL DIRICHLET FORMS ON ULTRA-METRIC SPACES

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Acta Mathematica Scientia 2020年第5期40卷 1240-1248页

作者： jin gao Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

We apply the Davies method to give a quick proof for the upper estimate of the heat kernel for the non-local Dirichlet form on the ultra-metric space. The key observation is that the heat kernel of the truncated Dirichlet form vanishes when two spatial points are separated by any ball of a radius larger than the truncated range. This new phenomenon arises from the ultra-metric property of the space.

关键词： heat kernel ultra-metrie Davies method

Printable elastic silver nanowire-based conductor for washable electronic textiles

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Nano Research 2020年第10期13卷 2879-2884页

作者： Hong-wu Zhu Huai-Ling gao Hao-Yu Zhao jin Ge Bi-Cheng Hu jin Huang Shu-Hong Yu Division of Nanomaterials&Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleInstitute of EnergyHefei Comprehensive National Science CenterCAS Center for Exclilence in NanoscienceDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China

Printable elastic conductors promote the wide application of consumable electronic textiles (e-textiles) for pervasive healthcare monitoring and wearable computation. To assure a clean appearance, the e-textiles require a washing process to clean up the dirt after daily use. Thus, it is crucial to develop low-cost printable elastic conductors with strong adhesion to the textiles. Here, we report a composite elastic conductor based on Ag nanowires (NWs) and polyurethane elastomer. The composite could be dispersed into ink and easily printed onto textiles. One-step print could form robust conductive coatings without sealing on the textiles. Interestingly, the regional concentration of Ag NWs within the polyurethane matrix was observed during phase inversion, endowing the elastic conductor with a low percolation threshold of 0.12 vol.% and high conductivity of 3,668 S·cm^−1. Thanks to the high adhesion of the elastic conductors, the resulted e-textiles could withstand repeated stretching, folding, and machine washing (20 times) without obvious performance decay, which reveals its potential application in consumable e-textiles.

关键词： printable elastic conductor electronic textiles washability phase inversion silver nanowires

A Novel Oscillating Chemical Reaction Using Ninhydrin as Single Organic Substrate

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Chinese Chemical Letters 2006年第1期17卷 77-80页

作者： Fu Wei YANG jin Zhang gao wu YANG Kan Jun SUN Institute of Chemistry Northwest Normal University Lanzhou 730070

A novel oscillating chemical reaction using ninhydrin as a single organic substrate was represented in this paper. It distinguished from the classically catalyzed BZ oscillating chemical reaction due to there was no active methene （CH2=） and/or enol structure in the ninhydrin molecule, which served as single organic substrate. This suggested that the substrates used in catalyzed BZ reaction were not always the organic compounds containing active methene （CH2=） and/or enol structure and bromination process in this kind of catalyzed chemical oscillating reaction was not also necessary.

关键词： Single organic substrate active methene enol structure oscillating chemical reaction.

Improved MIMO-OFDM scheme for the next generation WLAN

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Journal of Systems Engineering and Electronics 2013年第1期24卷 52-59页

作者： Zhanji wu Xiang gao School of Information and Communication Engineering Beijing University of Posts and Telecommunications

The research and application of wireless local area networks （WLAN） technology are in a stage of rapid development. It has been one of research focuses of the wireless communications field. Through the use of enhanced single-user （SU）/multi-user （MU） multiple input multiple output （MIMO）-orthogonal frequency division multiplexing （OFDM） technology, the next generation WLAN IEEE 802.1 lac dramatically increases the throughput. An improved MIMO-OFDM scheme based on modulation diversity is proposed for the next generation WLAN. It uses two-dimensional modulation diversity to the current IEEE 802.11ac transmission scheme. Through the space-time-frequency component inter- leaver and the rotational modulation, the proposed scheme ex- hibits high spectral efficiency and low error rate in fading channels. The simulation results show that the proposed scheme significantly outperforms the SU/MU MIMO-OFDM scheme in the current IEEE 802.11 ac standard, which is up to 5 dB.

关键词： wireless local area networks (WLAN) I EEE 802.1 lac modulation diversity multiple input multiple output (MIMO) orthog- onal frequency division multiplexing (OFDM).