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Persistent Currents and Edge States in a Quasi-One-Dimensional Mesoscopic Ring with a Screened Interaction

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Communications in Theoretical Physics 2002年第5期38卷 621-628页

作者： HE Guang-Ping li hua-zhong Advanced Research Center Zhongshan University Guangzhou 510275 China Advanced Research Center Zhongshan University Guangzhou 510275 China

The effect ofthe edge state on the persistent current in quasi-1D mesoscopic rings with a screened interactionwhich exists only between nearest-neighboring particles is studied with the Hartree-Fock approximation. The theoreticalvalue of the current magnitude is greatly enhanced by both the edge state and the Coulomb interaction, and pinningthe electrons into a lattice is good for the enhancement if screening happens. In high dimensional systems the screeningeffect can make the interacting range show anisotropy, and create a tendency of gathering for particles with a repulsivepotential.

关键词： strongly correlated electron systems, persistent currents, edge states

Critical Dimension for Stable Self-Gravitating Stars in AdS

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Communications in Theoretical Physics 2009年第8期52卷 255-260页

作者： li zhong-hua CAI Rong-Gen Department of Physics China West Normal University Nanchong 637002 China Key Laboratory of Frontiers in Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences P.O. Box 2735 Beijing 100190 China

We study the self-gravitating stars with a linear equation of state, P = aρ, in AdS space, where a is a constant parameter. There exists a critical dimension, beyond which the stars are always stable with any central energy density; below which there exists a maximal mass configuration for a certain central energy density and when the central energy density continues to increase, the configuration becomes unstable. We find that the critical dimension depends on the parameter a, it runs from d = 11.1429 to 10.1291 as a varies from a = 0 to 1. The lowest integer dimension for a dynamically stable self-gravitating configuration should be d = 12 for any a E [0, 1] rather than d = 11, the latter is the case of self-gravitating radiation configurations in AdS space.

关键词： critical dimension self-gravitating star AdS space

Successful isolation of Helicobacter pylori after prolonged incubation from a patient with failed eradication therapy

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World Journal of Gastroenterology 2009年第12期15卷 1528-1529页

作者： Yan Yin li-hua He Jian-zhong Zhang Department of Diagnosis National Institute for-Communicable Disease Control and Prevention Chinese Center for Disease Control and Prevention Beijing 102206 China

Helicobacter pylori(H pylori),a gastric pathogen,is a major cause of chronic gastritis and peptic ulcer disease,and is an important risk factor for the development of gastric *** of the bacterium from gastric biopsy is essential for the determination of drug resistance of H ***,the isolation rates of H pylori from infected individuals vary from 23.5%to 97% due to a number of factors such as biopsy preparation,cultural environment,medium and the method *** the present case,we found that a prolonged incubation period of up to 19 d allowed successful isolation of H pylori from a patient who received triple therapy that failed to eradicate the bacterium.

关键词： Helicobacter pylori Isolation Eradication

MIMO-OFDM channel estimation method utilizing correlation in time domain for B3G-TDD uplink

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The Journal of China Universities of Posts and Telecommunications 2007年第2期14卷 23-27页

作者： ZHOU Ming-yu li li-hua JIANG Jun zhong Ming-hua TAO Xiao-feng Wireless Technologies Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China

This article proposes a simple pilot-aided channel estimation method based on correlation in time domain for multiple-input and multiple-output olthogonal frequency division multiplexing （MIMO-OFDM） systems. Pilot symbols in all transmit antennas are generated from different circular shifting of a certain sequence. Through once correlation, the receiver can obtain time-domain pulse responses for channel fading from all transmit antennas to a certain receive antenna, from which channel estimation in frequency domain can be obtained. Beyond 3G time-division duplex （B3G-TDD） uplink is introduced, and the channel estimation method is used in it. Theoretical analysis and simulation are both carried out. Mean square error （MSE） performance shows that the method can exhibit precise estimation. Complexity analysis proves it requires very low complexity. System simulation result shows that it guarantees the performance of B3G-TDD uplink very well.

关键词： multiple-input and multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) channel estimation time-domain pulse response

Phylogeographic relationships of the southern green stink bug Nezara viridula （Hemiptera： Pentatomidae）

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Insect Science 2010年第5期17卷 448-458页

作者： Min li zhong-hua Fan Ji-Meng hua Chun-Jing Niu Chun-Xuan li Wen-Jun Bu Institute of Entomology College of Life Sciences Nankai University Tianjin China

The sequences of 16S rDNA, cytochrome oxidase subunit I （CO1） and cytochrome b （Cyt b） genes from nine field collections （seven provinces in China： Guangxi, Hubei, Guangdong, Guizhou, Zhejiang, Hunan, Jiangxi, and also southern and northern part oflran）, plus the sequences of Africa, Europe, Americas and Japan obtained form GenBank were used to re-analyse the genetic variation in the southern green stink bug Nezara viridula （linnaeus）. The phylogeographic re-analysis by using four algorithms （N J, MP, ML and Bayesian） showed three main lineages. The Iranian haplotypes fell into lineage II formed from Europe and America, rather than in lineage III from Asia; the Chinese haplotypes fell into the Asian clade. Our results suggested that African and non-African gene pools have been isolated since the Miocene era with the molecular clock calibrations for Heteroptera mtDNA, and not since the Pliocene as mentioned previously. The corresponding age of the separation of the eastern and western Asia clades is estimated to be 4.0-1.6 million years ago, coinciding with the Pliocene-Pleistocene epoch and with acute rising events in the Tibet Plateau locates in the western China, which may have formed the barriers observed today.

关键词： COI Cyt b 16S rDNA Nezara viridula phylogeographie

An extended processing scheme for coherent integration and parameter estimation based on matched filtering in passive radar

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第11期15卷 1071-1085页

作者： Xin GUAN li-hua zhong Dong-hui HU Chi-biao DING Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences University of Chinese Academy of Sciences

In passive radars, coherent integration is an essential method to achieve processing gain for target detection. The cross ambiguity function(CAF) and the method based on matched filtering are the most common approaches. The method based on matched filtering is an approximation to CAF and the procedure is:(1) divide the signal into snapshots;(2) perform matched filtering on each snapshot;(3) perform fast Fourier transform(FFT) across the snapshots. The matched filtering method is computationally affordable and can offer savings of an order of 1000 times in execution speed over that of CAF. However, matched filtering suffers from severe energy loss for high speed targets. In this paper we concentrate mainly on the matched filtering method and we use keystone transform to rectify range migration. Several factors affecting the performance of coherent integration are discussed based on the matched filtering method and keystone transform. Modified methods are introduced to improve the performance by analyzing the impacts of mismatching, precision of the keystone transform, and discretization. The modified discrete chirp Fourier transform(MDCFT) is adopted to rectify the Doppler expansion in a multi-target scenario. A novel velocity estimation method is proposed, and an extended processing scheme presented. Simulations show that the proposed algorithms improve the performance of matched filtering for high speed targets.

关键词： Keystone transform Matched filtering MDCFT Mismatching Passive radar Velocity estimation

Theory and technology of preventing water from flooding roadways

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Journal of China University of Mining and Technology 2008年第4期18卷 500-503页

作者： CAO Sheng-gen HOU Shi-song li zhong-hua State Key Laboratory of Coal Resource and Mine Safety School of Mining Engineering China University of Mining ＆Technology Xuzhou Jiangsu 221116 China

According to the principle of effective stress action of rock and soil, we established a mechanical model of water flooding into roadways,analyzed the constitutive relation of hydrodynamic pressure and contact pressure of rock and soil and discovered that the process of pre-grouting of a roadway curtain is a dynamically balancing process in which effective stress keeps gradually in- creasing and pore water pressure gradually declines. In such a grouting process, the initial water plugging effect is realized when the effective stress and total stress reaches equilibrium. A rigid-flexible packing layer is designed behind the brickwork to increase the effective stress and reduce pore water pressure in order to have a permanent water proof performance. This provides a theoretical basis for roadway driving and permanent water prevention. The monitoring and application results show that the initial and perma- nent waterproof theory has provided an effective method for roadway driving and making it waterproof.

关键词： roadway curtain grouting first- waterproof rigid-flexible layer permanent water prevention

Hepatitis C Virus Infection Caused by Infrequent Exposure in China Should Be of Concern

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Virologica Sinica 2020年第4期35卷 481-485页

作者： Xin-Cheng Qin li-hua zhong li-Ying Zhu Alexander Plyusnin Yong-Zhen Zhang State Key Laboratory of Infectious Disease Prevention and Control Department of ZoonosesNational Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China Department of Infectious Diseases The Fourth Hospital of Harbin Medical UniversityHarbin 150081China Department of Virology Haartman InstituteUniversity of Helsinki00014 HelsinkiFinland Shanghai Public Health Clinical Center&Institute of Biomedical Sciences Fudan UniversityShanghai 200433China

Dear Editor,Hepatitis C Virus(HCV)infection is a huge public health problem globally,because it can lead to adverse long-term clinical *** China,the population has experienced a skyrocketing growth of HCV infections b... 详细信息

关键词： al. frequent clinical

Side Information-Based Stealthy False Data Injection Attacks Against Multi-Sensor Remote Estimation

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 1054-1056页

作者： Haibin Guo zhong-hua Pang Chao li the Key Laboratory of Fieldbus Technology and Automation of Beijing North China University of TechnologyBeijing 100144China

Dear Editor,This letter investigates a novel stealthy false data injection(FDI)attack scheme based on side information to deteriorate the multi-sensor estimation performance of cyber-physical systems(CPSs).Compared with most existing works depending on the full system knowledge,this attack scheme is only related to attackers'sensor and physical process *** design principle of the attack signal is derived to diverge the system estimation ***,it is proven that the proposed attack scheme can successfully bypass the residual-based ***,all theoretical results are verified by numerical simulation.

关键词： estimation scheme system