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2./3D-QSAR comparative study on mutagenicity of nitroaromatics

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Science china Chemistry 2005年第3期48卷 246-252页

作者： WANG xiaodong1, LIN Zhifen2. YIN Daqiang1, LIU Shushen1 & WANG Liansheng1 1. state key Laboratory of Pollution Control and Resources Reuse, School of the Environment at Nanjing {2., Nanjing 2.0093, china 2. key Laboratory of Tropical Marine Environmental dynamics, South china Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,china state key Laboratory of Pollution Control and Resources Reuse School of the Environment at Nanjing University Nanjing China key Laboratory of Tropical Marine Environmental dynamics South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China

Nitroaromatics are typical toxic organic pollutants and are ubiquitous in environment with diverse structures. They are widely used in many industries and formed during many natural and anthropogenic processes. Most of these pollutants are potentially carcinogenic and the as-sessment and prediction of the mutagenicity of nitroaromatics are of great interest. In this paper the structure-mutagenicity relationships of 2.9 nitroaromatics are investigated by molecular or-bital theory based classic structure-activity relationships and comparative molecular field analysis (CoMFA). A comparison is undertaken in respect of the interpretation of mechanism and predic-tive ability for these two categories of QSAR approaches and highly predictive QSAR models have been developed.

关键词： nitroaromatics, mutagenicity, mechanism, 3D-QSAR, CoMFA.

Exact stationary solutions independent of energy for strongly nonlinear stochastic systems of multiple degrees of freedom

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Science china(Technological Sciences) 2009年第8期52卷 2424-2431页

作者： HUANG ZhiLong1,2.& JIN xiaoLing1 1 department of Mechanics, Zhejiang university, Hangzhou 31002., {2. 2.The state key Laboratory of Fluid Power Transmission and Control, Zhejiang university, Hangzhou 31002., {2. department of Mechanics Zhejiang University The state key Laboratory of Fluid Power Transmission and Control

A new procedure is proposed to construct strongly nonlinear systems of multiple degrees of freedom subjected to parametric and/or external Gaussian white noises, whose exact stationary solutions are independent of energy. Firstly, the equivalent Fokker-Planck-Kolmogorov (FPK) equations are derived by using exterior differentiation. The main difference between the equivalent FPK equation and the original FPK equation lies in the additional arbitrary antisymmetric diffusion matrix. Then the exact stationary solutions and the structures of the original systems can be obtained by using the coefficients of antisymmetric diffusion matrix. The obtained exact stationary solutions, which are generally independent of energy, are for the most general class of strongly nonlinear stochastic systems multiple degrees of freedom (MDOF) so far, and some classes of the known ones dependent on energy belong to the special cases of them.

关键词： exact stationary solution nonlinear stochastic system equivalent system independent of energy

Stochastic stability of quasi-integrable Hamiltonian systems with time delay by using Lyapunov function method

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Science china(Technological Sciences) 2010年第3期53卷 703-712页

作者： LING Quan 1,JIN xiaoLing 1 &HUANG ZhiLong 2.1 department of Mechanics,Zhejiang university,Hangzhou 31002.,{2. 2.state key Laboratory of Fluid Power Transmission and Control,Zhejiang university,Hangzhou 31002.,{2. department of Mechanics Zhejiang University state key Laboratory of Fluid Power Transmission and Control Zhejiang University

The asymptotic Lyapunov stability of one quasi-integrable Hamiltonian system with time-delayed feedback control is studied by using Lyapunov functions and stochastic averaging ***,a quasi-integrable Hamiltonian system with time-delayed feedback control subjected to Gaussian white noise excitation is approximated by a quasi-integrable Hamiltonian system without time ***,stochastic averaging method for quasi-integrable Hamiltonian system is used to reduce the dimension of the original system,and after that the Lyapunov function of the averaged It equation is taken as the optimal linear combination of the corresponding independent first integrals in ***,the stability of the system is determined by using the largest eigenvalue of the linearized *** examples are used to illustrate the proposed procedure and the effects of delayed time on the Lyapunov stability are discussed as well.

关键词： Lyapunov stability Lyapunov function time delay stochastic averaging

Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of china

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Science china Earth Sciences 2009年第11期52卷 1813-1824页

作者： ZHU ShouBiao1,2.& CAI YongEn2.1 Institute of Crustal dynamics, china Earthquake Administration, Beijing 100085, china 2.department of Geophysics, Peking university, Beijing 100871, china Institute of Crustal dynamics China Earthquake Administration Beijing China department of Geophysics Peking University Beijing China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of china, earthquake occurred in the region where GPS observation station is most densely deployed in the world. The unprecedented GPS data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPS temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2.102. Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 34.7% caused by the viscous relaxation and 2..7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPS temporal series data Chi-Chi earthquake

Incoherent control of two classes of finite-level quantum systems

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Journal of Systems Engineering and Electronics 2011年第4期22卷 679-683页

作者： Chunlin Chen 1,2.and Zhenquan Qin 3,1.department of Control and System Engineering,Nanjing university,Nanjing 2.0093,P.R.{2. 2.state key Laboratory for Novel Software Technology,Nanjing university,Nanjing 2.0093,P.R.{2. 3.School of Software,Dalian university of Technology,Dalian 11662.,P.R.{2. department of Control and System Engineering Nanjing University Nanjing 210093 P. R. China state key Laboratory for Novel Software Technology Nanjing University Nanjing 210093 P. R. China School of Software Dalian University of Technology Dalian 116620 P. R. China

The incoherent control of finite-level quantum systems is investigated. Following a brief introduction to coherent control paradigms in quantum control, a control problem that can not be accomplished using only coherent control is presented. For such a control problem, it is proved that it can be accomplished using incoherent control based on projective measurement and coherent control for two classes of finite-level quantum systems, i.e., eigenstate controllable quantum systems and wavefunction controllable quantum systems.

关键词： quantum control eigenstate controllability wavefunction controllability coherent control incoherent control.

X-ray flares of γ-ray bursts: Quakes of solid quark stars?

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Science china(Physics,Mechanics & Astronomy) 2009年第2期52卷 315-320页

作者： XU Renxin1 & LIANG EnWei2.1 School of Physics and state key Laboratory of Nuclear Physics and Technology, Peking {2., Beijing 100871, china 2.department of Physics, Guangxi {2., Nanning 530004, china School of Physics and state key Laboratory of Nuclear Physics and Technology Peking University Beijing China department of Physics Guangxi University Nanning China

A star-quake model is proposed to understand X-ray flares of both long and short γ-ray bursts (GRBs) in a solid quark star regime. Two kinds of central engines for GRBs are available if pulsar-like stars are actually (solid) quark stars, i.e., the SNE-type GRBs and the SGR-type GRBs. It is found that a quark star could be solidified about 103 to 106 s later after its birth if the critical temperature of phase transi- tion is a few Metga-electron-volts, and then a new source of free energy (i.e., elastic and gravitational ones, rather than rotational or magnetic energy) could be possible to power GRB X-ray flares.

关键词： γ-rays bursts: X-rays neutron stars elementary particles

The refined theory of deep rectangular beams for symmetrical deformation

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 919-925页

作者： GAO Yang1 & WANG MinZhong2.1 College of Science, china Agricultural university, Beijing 100083, china 2.state key Laboratory for Turbulence and Complex Systems and department of Mechanics and Aerospace Engineering, Peking university, Beijing 100871, china College of Science China Agricultural University Beijing China state key Laboratory for Turbulence and Complex Systems and {2. of Mechanics and Aerospace Engineering Peking University Beijing China

Based on elasticity theory, various one-dimensional equations for symmetrical deformation have been deduced systematically and directly from the two-dimensional theory of deep rectangular beams by using the Papkovich-Neuber solution and the Lur'e method without ad hoc assumptions, and they construct the refined theory of beams for symmetrical deformation. It is shown that the displacements and stresses of the beam can be represented by the transverse normal strain and displacement of the mid-plane. In the case of homogeneous boundary conditions, the exact solutions for the beam are derived, and the exact equations consist of two governing differential equations: the second-order equation and the transcendental equation. In the case of non-homogeneous boundary conditions, the approximate governing differential equations and solutions for the beam under normal loadings only and shear loadings only are derived directly from the refined beam theory, respectively, and the correctness of the stress assumptions in classic extension or compression problems is revised. Meanwhile, as an example, explicit expressions of analytical solutions are obtained for beams subjected to an exponentially distributed load along the length of beams.

关键词： deep rectangular beams the refined theory symmetrical deformation the Papkovich-Neuber solution the Lur’e method

Identification of Hercynian shoshonitic intrusive rocks in central Hainan Island and its geotectonic implications

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Science Bulletin 2006年第20期51卷 2507-2519页

作者： xiE Caifu1, 2. ZHU Jinchu1, DING Shijiang3, ZHANG Yeming2. FU Tai’an2.& LI Zhihong2.1. state key Laboratory for Mineral Deposits Research and {2. of Earth Sciences, Nanjing university, Nanjing 2.0093, china 2. Yichang Institute of geology and Mineral Resources, Yichang 443003, china 3. Hainan Bureau of geology and Mineral Resources, Haikou 5702.6, china department of Otolaryngology University Hospital VU P.O. Box 7057 1007 MB Amsterdam The Netherlands state key Laboratory for Mineral Deposits Research and {2. of Earth Sciences Nanjing University Nanjing 210093 China

An identification has been made of some shoshonitic intrusive rocks in central Hainan Island recently. These rocks are K-rich (K2.=2.9%―5.1%, K2./Na2.=0.95―2.12., distinctly enriched in LILE and LREE, strongly depleted in Nb, Ta, and moder- ately depleted in Sr and Ti, with (87Sr/86Sr)i = 0.70859―0.7142. and ε Nd(t) = (?2.77―?7.49). They were derived from an EMⅡ-type mantle source. The enrichment process is related to metasomatism of depleted mantle caused by a great amount of fluid-melt released from oceanic crust and terri- genous sediments at great depth (eclogite facies) during the subduction of the South china plate under the Indochina-South china Sea plate in the Carbon- iferous–Early Permian. A SHRIMP U-Pb zircon dating yields a crystallization age of 2.2.7 Ma for the sho- shonitic intrusions, which is coeval with the strongly peraluminous granites found in central Hainan Island. These two kinds of rocks generally possess syn-intrusion ductile deformation structures. Thus they are considered to have been generated during the early stage (syn-thrust phase) of a post-collisional event. The primary magma of shoshonitic rocks was produced at a depth > 80 km by decompression- dehydration melting of previously enriched litho- spheric mantle wedge, phlogopite-bearing garnet peridotite, which was in turn caused by the break-off of a descendent slab and upwelling of a hot as- thenosphere. The rising of melts was accompaniedby crustal contamination and crystallization fractiona- tion (AFC). Combining with other related data, it is proposed that the southwards subduction and amal- gamation of the South china plate with the Indo- china-South china Sea plate took place at ca. 2.7- 2.8 Ma, which was a part of the convergence proc- ess of the Pangea supercontinent. The suture zone was probably located along the line of Song Ma-Beibu Gulf-north margin of the Yunkai Moun- tains-Wuyi Mountains.

关键词： SHRIMP U-Pb dating Hercynian shoshonitic intrusive rocks post-collisional event enriched mantle Hainan Island.

Asynchronous cooperative communication systems:A survey on signal designs

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Science china(Information Sciences) 2011年第8期54卷 1547-1561页

作者： WANG HuiMing 1,2.& xiA xiangGen 3 1 School of Electronic and Information Engineering, xi’an Jiaotong university, xi’an 710049,china {2. key Laboratory of Integrated Services Networks, xidian university,xi’an 710049, china 3 department of Electrical and Computer Engineering,university of Delaware,Newark,DE 19716,USA School of Electronic and Information Engineering Xi"an Jiaotong University state key Laboratory of Integrated Services Networks Xidian University department of Electrical and Computer Engineering University of Delaware

Cooperative communications is a promising technique for future high speed wireless *** systems may be formulated as virtual multi-input multi-output (MIMO) systems where spatial/cooperetive diversity is a key advantage. However,different from MIMO systems,one of the major chal- lenges for cooperative communications systems is that the cooperative transmissions in cooperative systems may be neither time nor frequency synchronized,since the transmissions are from multiple cooperative nodes at different *** existing signal designs for co-located MIMO systems may not be able to collect the cooperative diversity in cooperative communications *** paper gives an overview of recent research efforts on combating the time and frequency asynchronism of the cooperative communication *** focus on the signal designs (or space-time codings/modulations) to achieve full cooperative diversity,and summarize some of the resent distributed space-timing coding and space-frequency coding techniques to combat timing errors and frequency offsets,and in the meantime to achieve full cooperative diversity,in both one-way and two-way cooperative networks.

关键词： cooperative communications time and frequency offsets space-time coding space-frequency codes full cooperative diversity linear receiver