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Distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in surface water and sediments from Baiyangdian Lake in North China

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Journal of Environmental Sciences 2011年第10期23卷 1640-1649页

作者： Guohua Dai Xinhui liu gang liang Xu Han liu Shi Dengmiao Cheng Wenwen Gong State Key Laboratory of Water Environment Simulation School of Environment Beifing Normal University Beifing 100875 China

Persistent organochlorine compounds, including hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polychlorinated biphenyls （PCBs） were analyzed in surface water and sediments from Balyangdian Lake, North China. Total concentrations of HCHs, DDTs and PCBs in surface water were in the range of 3.13-10.60, 4.05-20.59 and 19.46-131.62 ng/L, respectively, and total concentrations of HCHs, DDTs and PCBs in sediments were 1.75-5.70, 0.91-6.48 and 5.96-29.61 ng/g dry weight, respectively. Among the groups of HCHs （sum of α-HCH, β-HCH, y-HCH and 6-HCH） and DDTs （sum of DDT, DDD and DDE）, the predominance of β-HCH, DDE and DDD in water and sediment samples was clearly observed. This observation suggested that β-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD. For PCBs, penta-, hexa- and hepta-chlorinated congeners were the most abundant compounds in the both phases. Furthermore, the partitioning of chlorinated compounds between sediment and water was investigated to understand their transport and fates in aquatic ecosystems. The results indicated that average logs of organic carbon-normalized sediment-water partition coefficients （logK∝） for OCPs varied between 3.20 and 5.53, and for PCBs, logK∝ values ranged from 3.19 to 5.57. The observed logK∝ was lower than their equilibrium logK∝ predicted from linear model, which may be attributed to the solubility enhancement effect of colloidal matter in water phase and the disequilibrium between sediment and water.

关键词： oranochlorine pesticides polychlorinated biphenyls water sediment Baiyangdian Lake North China

Noise Effects on Oscillator Network of Transcription Regulators

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Communications in Theoretical Physics 2002年第10期38卷 497-502页

作者： WANG Xian-Ju AI Bao-Quan liu Guo-Tao liu liang-gang Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China

Based on the model describing the regulation of the PRM operator region of λ phage proposed by Jeff Hastyet al., we study the noise effects on the oscillator network. We find that the additive noise cannot change the period andthe amplitude of the relaxation oscillator, but in the multiplicative case, the period of the relaxation oscillator increasesto a constant value with the increase of the strength of noise, and the amplitude of the relaxation oscillator also showsincreases with the increase of the strength of noise. This novel results suggest that an external multiplicative noise sourcecould be used to control gene expression.

关键词： gene control, noise strength, oscillator

Obstacle Effects on One-Dimensional Translocation of ATPase

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Communications in Theoretical Physics 2002年第7期38卷 121-124页

作者： WANG Xian-Ju AI Bao-Quan liu liang-gang Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China

We apply a general random walk model to the study of the ATPase's one-dimensional translocation along obstacle biological environment, and show the effects of random obstacles on the ATPase translocation along single stranded DNA. We find that the obstacle environment can reduce the lifetime of ATPase lattice-bound state which results in the inhibition of ATPase activity. We also carry out the ranges of rate constant of ATPase unidirectonal translocation and bidirectional translocation. Our results are consistent with the experiments and relevant theoretical consideration, and can be used to explain some physiological phenomena.

关键词： random walk, average statistical time, obstacle

Current Reversal Due to Coupling Between Asymmetrical Driving Force and Ratchet Potential

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Communications in Theoretical Physics 2006年第4期45卷 637-640页

作者： AI Bao-Quan XIE Hui-Zhang liu liang-gang School of Physics and Telecommunication Engineering South China Normal University Guangzhou 510631 China Department of Physics South China University of Technology Guangzhou 510641 China Department of Physics Zhongshan University Guangzhou 510275 China

Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potentlal are the two ways of inducing a net current. It is found that the competition of the spatial asymmetry of potential with the temporal asymmetry of the external force leads to the phenomena like current reversal The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.

关键词： current reversal correlation ratchet competition

The Influence of the Renormalization Condition to the Equation of State of the Nuclear Matter

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Communications in Theoretical Physics 2001年第7期36卷 65-70页

作者： CHEN Wei AI Bao-Quan ZHENG Xiao-Ping liu liang-gang Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China

In the relativistic σ-ω model, the influences of the parameters b, c, d in the potential U(σ) = (1/2!)bo2 -+-(1/3!)cσ3+(1/4!)dσ4 to the incompressibility, effective mass and binding energy of the nuclear matter are studied in *** calculation of equation of state of nuclear matter shows that the values of b, c, d depend on the renormalization condition, we also find that a soft equation of state of nuclear matter can be obtained in a suitable renormalization condition, and the experimental incompressibility coefficient can be reproduced. These results are also used to study the thermal properties of hot A-resonant nuclear ***-interaction of σ meson, renormalization, hot and dense hadronic matter

关键词： equation of state,

Structural and Spacial Characters of Neutron Star in Relativistic σ-ω Model

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Communications in Theoretical Physics 2006年第5期45卷 853-857页

作者： WEN De-Hua HU Jian-Xun liu liang-gang Department of Mathematics Zhongshan University Guangzhou 510275 China Department of Physics South China University of Technology Guangzhou 510641 China Department of Physics Zhongshan University Guangzhou 510275 China

The analytical and numerical solutions of structure and curvature of two kinds of static spherically symmetric neutron stars are calculated. The results show that Ricci tensor and curvature scalar cannot denote the curly character of the space directly, however, to static spherically symmetric stars, these two quantities can present the relative curly degree of the space and the matter distribution to a certain extent.

关键词： static spherically symmetric star neutron star structure curvature scalar

Noise-Induced Transition in a Voltage-Controlled Oscillator Neuron Model

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Communications in Theoretical Physics 2008年第7期50卷 257-260页

作者： XIE Hui-Zhang liu Xue-Mei AI Bao-Quan liu liang-gang LI Zhi-Bing Department of Physics Sun Yat-Sen University Guangzhou 510275 China School of Physics South China University of Technology Guangzhou 510640 China School of Physics and Telecommunication Engineering South China Normal University Guangzhou 510631 China Faculty of Information Technology Macao University of Science and Technology Macao China

In the presence of Gaussian white noise,we study the properties of voltage-controlled oscillator neuronmodel and discuss the effects of the additive and multiplicative *** is found that the additive noise can accelerate andcounterwork the firing of neuron,which depends on the value of central frequency of neuron itself,while multiplicativenoise can induce the continuous change or mutation of membrane potential.

关键词： Gaussian white noise transition voltage-controlled oscillator neuron model

Semiglobal Stabilization via Output-feedback for a Class of Uncertain Nonlinear Systems

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自动化学报 2013年第12期39卷 2154-2159页

作者： liu Meng-liang liu Yun-gang School of Control Science and Engineering Shandong UniversityJinan 250061 China

这份报纸为不明确的非线性的系统的一个班经由产量反馈认为 semiglobal 是稳定。与存在结果不同，在调查下面的系统拥有更严肃的非线性和实质地增加产量反馈的困难的未知控制系数控制器设计。联合 backstepping 方法和产量反馈支配途径... 详细信息

这份报纸为不明确的非线性的系统的一个班经由产量反馈认为 semiglobal 是稳定。与存在结果不同，在调查下面的系统拥有更严肃的非线性和实质地增加产量反馈的困难的未知控制系数控制器设计。联合 backstepping 方法和产量反馈支配途径，稳定控制器的 semiglobal 明确地被给，它能保证靠近环的系统在设计参数的适当选择下面完成 semiglobal asymptotic 稳定性。一个模拟例子验证理论结果和建议途径。

关键词：不确定非线性系统输出反馈控制器半全局镇定全局渐近稳定性全局稳定控制系数参数选用闭环系统

Non-abelian Collective Excitations in Nonlinear Quark-Gluon Plasma Media

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Chinese Physics Letters 2000年第9期17卷 643-645页

作者： ZHENG Xiao-Ping HOU De-Fu liu liang-gang LI Jia-Rong Institute of Particle Physics Huazhong Normal UniversityWuhan 430079 Department of Physics Zhongshan UniversityGuangzhou 510275

We have studied the effect of the third-order density fluctuations in the medium on the collective excitations in quark-gluon *** show that the nonlinear response of a quark-gluon plasma medium leads to non-Abelian collective *** present two kinds of non-Abelian oscillation solutions which respectively correspond to weakly and strongly nonlinear coupling of field components in the color *** also show that the weakly nonlinear solution is similar to the Abelian-like one but has a frequency shift,which is of order g^(2)T,from the eigenfrequency.

关键词： space. weakly collective