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Terahertz narrow bandstop, broad bandpass filter using double-layer S-shaped metamaterials

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Science China(Information Sciences) 2013年第12期56卷 132-138页

作者： LIANG LanJu JIN BiaoBing WU JingBo ZHOU GaoChao ZHANG YongGang TU XueCou JIA Tao JIA XiaoQing CAO ChunHai KANG Lin XU WeiWei CHEN Jian College of Optoelectronics engineering Zaozhuang University Research Institute of Superconductor electronics (RISE) School of Electronic Science and EngineeringNanjing University

In this study,double-layer S-shaped metamaterials(MMs)are analyzed by terahertz time-domain *** materials exhibit narrow bandstop and broad bandpass transmission properties at both horizontal and vertical electric-feld polarizations.A 117%increase in the unloaded quality factor is experimentally observed for these *** center frequency is approximately 0.45 THz,with a 3-dB bandwidth of 0.52 THz from 0.20 to 0.72 THz at normal *** measured average insertion loss is 0.5 dB with a ripple of 1 *** results show that double-layer S-shaped MMs are efective in designing tunable terahertz devices.

关键词： metamaterial terahertz flter double-layer S-shaped material transmission

Coronavirus Pandemic Analysis Through Tripartite Graph Clustering in Online Social Networks

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Big Data Mining and Analytics 2021年第4期4卷 242-251页

作者： Xueting Liao Danyang Zheng Xiaojun Cao Department of Computer Science Georgia State UniversityAtlantaGA 30302USA Suzhou Key Laboratory of Advanced optical Communication Network Technology School of Electronic and Information EngineeringSoochow UniversitySuzhou 215006China

The COVID-19 pandemic has hit the world *** reaction to the pandemic related issues has been pouring into social platforms,such as *** public officials and governments use Twitter to make policy *** keep close track of the related information and express their concerns about the policies on *** is beneficial yet challenging to derive important information or knowledge out of such Twitter *** this paper,we propose a Tripartite Graph Clustering for Pandemic Data Analysis(TGC-PDA)framework that builds on the proposed models and analysis:(1)tripartite graph representation,(2)non-negative matrix factorization with regularization,and(3)sentiment *** collect the tweets containing a set of keywords related to coronavirus pandemic as the ground truth *** framework can detect the communities of Twitter users and analyze the topics that are discussed in the *** extensive experiments show that our TGC-PDA framework can effectively and efficiently identify the topics and correlations within the Twitter data for monitoring and understanding public opinions,which would provide policy makers useful information and statistics for decision making.

关键词： COVID-19 clustering online social network Twitter

Longest Paths and Cycles in Connected Claw-Free Graphs

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Transactions of Tianjin University 2004年第3期10卷 221-224页

作者：李明楚李旭东 school of electronic Information engineering Tianjin University Tianjin 300072 China

A graph is called claw-free if it does not contain a claw as its induced *** this paper, we prove the following results:1)If G is a 2-connected claw-free graph on n vertices,then for any vertex v and any two distinct vertices x and y in V(G)-{v},G has a path containing v and all neighbors of v and connecting x and y;2) Let C be the longest cycle in a 3-connected claw-free graph G and H a component of G-C,and if H is connected but not 2-connected,then there exist nonadjacent vertices u and v in H such that |V(C)|≥(3(d(u)+)d(v))-2.

关键词： longest path cycle claw-free graph

Optimization of Power Dissipation in Pipelined Analog-to-Digital Converter

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Transactions of Tianjin University 2004年第4期10卷 280-284页

作者：徐江涛姚素英赵毅强张为李树荣张生才 school of electronic Information engineering Tianjin UniversityTianjin 300072China

Power optimization for pipelined analog-to-digital converter(ADC) was studied. Operational principle of pipelined ADC was discussed and noise voltage caused by two important thermal noise sources, sampling switch and amplifier,was quantitatively analyzed. Method used to minimize power and the values under simple model were presented. Power can be saved by making the sampling and feedback capacitors scale down in the *** the size of capacitors was limited by thermal noise in high resolution *** equivalent circuits of the two important thermal noise sources were *** noise was optimally distributed among the pipeline stages,and the relationship between scaling factor and closed loop gain was obtained for minimum power *** closed loop gain was 2 or 4 in pipeline ADC, and the corresponding scaling factor was (1.217) and *** results can serve as useful guidelines for designers to minimize the ADC′s power consumption.

关键词： pipelined ADC sampling switches resolution thermal noise

Measurement of Rotatory Optics Element in Tensor Dielectric Matrix for Rotatory optical Fiber

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Transactions of Tianjin University 2005年第2期11卷 115-118页

作者：刘敬浩张晓帆李华舟鲍振武 school of electronic Information engineering Tianjin University Tianjin 300072 China

The rotatory optics element in the tensor dielectric coefficient matrix is an important para-(meter) for analyzing and calculating a rotatory optical fiber by electromagnetic theory. But the mea-(surement) of rotatory optics element is difficult for the rotatory optical fiber. A simple principle and method for measuring rotatory optics element are put forward in this paper. Firstly by using electromagnetic theory it was demonstrated that the rotatory optics element has a simple linear relation with the rotatory angle, and then the rotatory optics element has a simple linear relation with the magnetic field strength (or bias current in the helix coil) . Secondly a measurement system for the rotatory optics element in the rotatory optical fiber was designed. Using the measurement system the rotatory element can be obtained by measuring the bias current simply.

关键词： rotatory optics element tensor dielectric coefficient rotatory optic fiber polarized light

Wide-field optical sizing of single nanoparticles with 10 nm accuracy

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Science China(Physics,Mechanics & Astronomy) 2021年第9期64卷 56-66页

作者： Yang Liu Yan Kuai Qiwen Zhan Joseph R.Lakowicz Douguo Zhang Advanced Laser Technology Laboratory of Anhui Province Department of Optics and Optical EngineeringUniversity of Science and Technology of ChinaHefei 230026China school of optical-Electrical and Computer engineering University of Shanghai for Science and TechnologyShanghai 200093China Center for Fluorescence Spectroscopy Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimore 21201USA

There is an increasing demand for new technologies to rapidly measure individual nanoparticles in situ for applications,including early-stage diagnosis of human diseases and environmental ***,we demonstrate a label-free wide-field optical microscopy capable of sizing dispersed non-luminescent dielectric nanoparticles(with diameters down to 22 nm)with 10 nm *** technique utilizes enhanced nanoparticle-perturbed scattering by surface plasmons created on a gold *** the meantime,an azimuthal rotation illumination module is installed on this microscope and a differential image processing technique is carried *** relationship between the scattering intensity and the particle size was experimentally measured with good consistency with the theoretical *** capability of precise measurement of the size of dispersed nanoparticles within a larger field of view in a label-free,non-invasive and quantitative manner may find broad applications involving single nanoparticle chemistry and physics.

关键词： plasmonic microscopy label-free imaging single nanoparticle optical sizing imaging and sensing

Effect of Cu addition on corrosion resistance and shape memory effect of Fe-14Mn-5Si-9Cr-5Ni alloy

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中国有色金属学会会刊：英文版 2009年第1期19卷 149-153页

作者：胡保全白培康董治中程军 school of Materials Science and engineering North University of China National Key Laboratory for electronic Measurement Technology North University of China school of Materials Science and engineering Tianjin University

The modification of Fe-14Mn-5Si-9Cr-5Ni shape memory alloys(SMAs) by copper addition was carried out, aiming at further enhancing its corrosion resistance. The results of electrochemical potentiodynamic measurement and immersion test show that copper can remarkably improve the corrosion resistance in Cl- solution. Otherwise, it is found that copper cannot markedly affect the mechanical properties nor the shape memory effect(SME). As for the effects of copper on Fe-Mn-Si based alloys, the austenite strengthening is one of the key factors to improve SME.

关键词： FeMnSiCrNi合金形状记忆效应力学性能热处理

Sealing Effect of KAl(SO_(4))_(2)Solution on the Corrosion Resistance of Anodized Aluminum Alloy

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Journal of Wuhan University of Technology(Materials Science) 2022年第1期37卷 104-109页

作者： CHENG Jie DONG Peng school of Electrical engineering Nanjing Vocational University of Industry TechnologyNanjing 210023China Crystal Physics Research Center Nanjing University of Posts and TelecommunicationsNanjing 210023China College of electronic and optical engineering&College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210023China

The 2024 anodized aluminum alloy film was sealed by KAl(SO_(4))_(2)solution and the effect of sealing on corrosion resistance was investigated by means of potentiodynamic polarization curves,electrochemical impedance spectroscopy,and X-ray photoelectron *** experimental results show that the optimal parameters for KAl(SO_(4))_(2)sealing are 35℃,with the pH value of 8,the concentration of 8 g/L,and the sealing time of 3 *** corrosion resistance of the KAl(SO_(4))_(2)sealed sample can be significantly improved than that of unsealed one,and is obviously superior to that of the conventional hydrothermal sealed ***,X-ray photoelectron spectroscopy demonstrates that more Al(OH)_(3)will be formed in the process of KAl(SO_(4))_(2)sealing,which will shrink the diameter of the microporous and therefore results in the excellent corrosion resistance.

关键词： aluminum alloy anodic oxidation KAl(SO_(4))_(2)solution sealing corrosion resistance

Notifiable infectious disease surveillance with data collected by search engine

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Journal of Zhejiang University-Science C(Computers and electronics) 2010年第4期11卷 241-248页

作者： Xi-chuan ZHOU1,Hai-bin SHEN2 (1Department of Information Science and electronic engineering,Zhejiang University,Hangzhou 310027,China) (2school of Electrical engineering,Zhejiang University,Hangzhou 310027,China) Department of Information Science and electronic engineering Zhejiang University Hangzhou China school of Electrical engineering Zhejiang University Hangzhou China

Notifiable infectious diseases are a major public health concern in China,causing about five million illnesses and twelve thousand deaths every *** detection of disease activity,when followed by a rapid response,can reduce both social and medical impact of the *** aim to improve early detection by monitoring health-seeking behavior and disease-related news over the ***,we counted unique search queries submitted to the Baidu search engine in 2008 that contained disease-related search *** we counted the news articles aggregated by Baidu's robot programs that contained disease-related *** found that the search frequency data and the news count data both have distinct temporal association with disease *** adopted a linear model and used searches and news with 1–200-day lead time as explanatory variables to predict the number of infections and deaths attributable to four notifiable infectious diseases,i.e.,scarlet fever,dysentery,AIDS,and *** the search frequency data and news count data,our approach can quantitatively estimate up-to-date epidemic trends 10–40 days ahead of the release of Chinese Centers for Disease Control and Prevention(Chinese CDC)*** approach may provide an additional tool for notifiable infectious disease surveillance.

关键词： Notifiable infectious diseases Disease surveillance Search engine