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Formation of N-body polymer molecules through generalized stimulated Raman adiabatic passage

Physical Review A 2013年第4期87卷 043631-043631页

作者： Fu-quan Dou Li-bin Fu Jie Liu College of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 China School of Physics Beijing Institute of Technology Beijing 100081 China National Laboratory of Science and Technology on Computation Physics Institute of Applied Physics and Computational Mathematics Beijing 100088 China Key Laboratory of High Energy Density Physics Simulation Center for Applied Physics and Technology Peking University Beijing 100084 China

We investigate the creation of stable homonuclear and heteronuclear N-body polymer molecules from ultracold atoms via a generalized stimulated Raman adiabatic passage scheme. The atom-molecule dark-state solutions for the system are obtained and are found to satisfy universal algebraic equations. We discuss the linear instability and the adiabatic fidelity of the dark state. We also explore the effects of the interparticle interactions, the atomic number of the polymer, and external field parameters on the conversion process.

关键词： DARK states (Quantum optics) ADIABATIC processes MANY-body problem ATOMS ALGEBRAIC equations ATOMIC number

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Amyloid-β peptide (1-42) aggregation induced by copper ions under acidic conditions

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生物化学与生物物理学报（英文版） 2013年第7期45卷 570-577页

作者： Yannan Bin Xia Li Yonghui He Shu Chen Juan Xiang Institute of Surface Analysis and Biosensing College of Chemistry and Chemical Engineering Central South University Changsha 410083 China Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan 411201 China Institute of Surface Analysis and Biosensing College of Chemistry and Chemical Engineering Central South University Changsha 410083 China Institute of Surface Analysis and Biosensing College of Chemistry and Chemical Engineering Central South University Changsha 410083 China Key Laboratory of Resources Chemistry of Nonferrous Metals Ministry of Education Central South University Changsha 410083 China

It is well known that the aggregation of amyloid-β peptide (Aβ) induced by Cu2+ is related to incubation time, solution pH, and temperature. In this work, the aggregation of Aβ1–42 in the presence of Cu2+ under acidic conditions was studied at different incubation time and temperature (e.g. 25 and 37°C). Incubation temperature, pH, and the presence of Cu2+ in Aβ solution were confirmed to alter the morphology of aggregation (fibrils or amorphous aggregates), and the morphology is pivotal for Aβ neurotoxicity and Alzheimer disease (AD) development. The results of atomic force microscopy (AFM) indicated that the formation of Aβ fibrous morphology is preferred at lower pH, but Cu2+ induced the formation of amorphous aggregates. The aggregation rate of Aβ was increased with the elevation of temperature. These results were further confirmed by fluorescence spectroscopy and circular dichroism spectroscopy and it was found that the formation of β-sheet structure was inhibited by Cu2+ binding to Aβ. The result was consistent with AFM observation and the fibrillation process was restrained. We believe that the local charge state in hydrophilic domain of Aβ may play a dominant role in the aggregate morphology due to the strong steric hindrance. This research will be valuable for understanding of Aβ toxicity in AD.

关键词： amyloid-β peptide copper ions atomic force microscopy acidic pH morphology

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Enthalpies Estimation of Formation of Monosubstituted Alkanes by Interaction Potential Index

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Chinese Journal of Chemical Physics 2012年第2期25卷 153-160,I0003页

作者： Ya-xin Wu Chen-zhong Cao Hua Yuan School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China School of Chemistry and Chemical Engineering Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of EducationHunan University of Science and Technologyand Hunan Provincial University Key Laboratory of QSAR/QSPRXiangtan 411201China

The interaction potential index IPI（X） of 16 Br, C1, I, NO2, CN, CHO, COOH, CH3, CH： kinds of substituents X （X---OH, SH, NH2, ：CH2, C-CH, Ph, COCH3, COOCH3） were proposed, which are derived from the experimental enthalpies of formation △fHФ （g） values of monosubstituted straight-chain alkanes. Based on the IPI（X） and polarizability effect index, a simple and effective model was constructed to estimate the △fHФ （g） values of monosubstituted alkanes RX （including the branched derivatives）. The present model takes into account not only the contributions of the alkyl R and the substituent X, but also the contribution of the interaction between R and X. Its stability and prediction ability was confirmed by the results of leave-one-out method. Compared with previous reported studies, the obtained equation can be used to estimate enthalpies of formation for much more kinds of monosubstituted alkanes with less parameters. Thus, it is recommended for the calculation of the △fHФ（g） for the RX.

关键词： Interaction potential index Substituent Monosubstituted alkane Enthalpy offormation Polarizability effect index

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A two-dimensional numerical wave flume based on SA-MPLS method

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Acta Oceanologica Sinica 2012年第3期31卷 18-30页

作者： HUANG Xiaoyun LI Shaowu State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin 300072China School of Hydraulic Engineering Changsha University of Science and TechnologyChangsha410114China Water&Sediment Science and Water Hazard Prevention Hunan Provincial Key Laboratory Changsha University of Science and TechnologyChangsha 410114China

A spatially adaptive (SA) two-dimensional (2-D) numerical wave flume is presented based on the quadtree mesh system,in which a new multiple particle level set (MPLS) method is proposed to solve the problem of interface tracking,in which common intersection may be traversed by multiple *** using the adaptive mesh technique and the MPLS method,mesh resolution is updated automatically with time according to flow characteristics in the modeling process with higher resolution around the free surface and the solid boundary and lower resolution in less important *** model has good performance in saving computer memory and CPU time and is validated by computational examples of small amplitude wave,second-order Stokes wave and cnoidal *** results also indicate that standing wave and wave overtopping are also reasonably simulated by the model.

关键词： spatially adaptive quadtree mesh system multiple particle level set method numerical wave flume

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Error estimates of triangular mixed finite element methods for quasilinear optimal control problems

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Frontiers of Mathematics in China 2012年第3期7卷 397-413页

作者： Yanping CHEN Zuliang LU Ruyi GUO School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China College of Civil Engineering and Mechanics Xiangtan UniversityXiangtan 411105China School of Mathematics and Statistics China Three Gorges UniversityChongqing 404000China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Department of MathematicsXiangtan UniversityXiangtan 411105China

The goal of this paper is to study a mixed finite element approximation of the general convex optimal control problems governed by quasilinear elliptic partial differential equations. The state and co-state are approximated by the lowest order Raviart-Thomas mixed finite element spaces and the control is approximated by piecewise constant functions. We derive a priori error estimates both for the state variables and the control variable. Finally, some numerical examples are given to demonstrate the theoretical results.

关键词： A priori error estimate quasilinear elliptic equation generalconvex optimal control problem triangular mixed finite element method

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A DISCONTINUOUS GALERKIN METHOD FOR THE FOURTH-ORDER CURL PROBLEM

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Journal of computational Mathematics 2012年第6期30卷 565-578页

作者： Qingguo Hong Jun Hu Shi Shu Jinchao Xu School of Mathematical Science Peking University Beijing 100871 China LMAM and School of Mathematical Science Peking University Beijing 100871 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan University Xiangtan 411105 China Department of Mathematics Pennsylvania State University University Park PA 16802 USA

In this paper, we present a discontinuous Galerkin （DG） method based on the N@d@lec finite element space for solving a fourth-order curl equation arising from a magnetohy- drodynamics model on a 3-dimensional bounded Lipschitz polyhedron. We show that the method has an optimal error estimate for a model problem involving a fourth-order curl operator. Furthermore, some numerical results in 2 dimensions are presented to verify the theoretical results.

关键词： Fourth-order curl problem DG method Nedelec finite element space Errorestimate.

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The Parallel Generation of 2-D Hilbert Space-filling Curve on GPU

The Parallel Generation of 2-D Hilbert Space-filling Curve o...

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International Conference on Biomedical engineering and Informatics

作者： Chunsheng Feng Shi Shu Junxian Wang Zheng Li Hunan Key Laboratory for Computation & Simulation in Science and Engineering School of Mathematics and Computational Science Xiangtan University Xiangtan China

ISBN: (纸本)9781467311830

In this paper, we propose two parallel Hilbert Space-filling Curve(HSFC) generation algorithms BMIMp and SDDMp based on block matrix iteration method(BMIM) and state diagrams driver method(SDDM) in the CUDA parallel programming mode. Numerical results show that both of them obtain high parallel speedup. Especially, the speedup of BMIMp and SDDMp can reach 207 and 290 respectively for the 14-order HSFC. Furthermore, BMIMp outperforms SDDMp when considering the total computation time.

关键词： Hilbert Space-filling Curve block matrix iteration method state diagrams driver method CUDA C parallel computation

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Numerical Methods For Fractional Variational Problems Depending On Indefinite Integrals

Numerical Methods For Fractional Variational Problems Depend...

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第五届国际自动控制联合会分数阶导数及其应用会议

作者： Dongling Wang Aiguo Xiao Hunan Key Laboratory for Computation and Simulation in Scienceand Engineering Key Laboratory of Intelligent Computing &Information Processing of Ministry of Education University XiangtanHunan P.R.China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing & Information Processing of Ministry of Education University Xiangtan Hunan P.R.China

In this paper,the fractional variational integrators for fractional variational problems depending on indefinite integrals in terms of Caputo derivative are *** corresponding fractional discrete Euler-Lagrange equatio... 详细信息

关键词： Numerical Methods For Fractional Variational Problems Depending On Indefinite Integrals

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Magnetic Fluid Flows in Porous Media

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Chinese Physics Letters 2011年第8期28卷 198-201页

作者： LI Ming-Jun CHEN Liang Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematics and Computational ScienceXiangtan UniversityXiangtan 411105

The seepage law under a magnetic field is obtained by up-scaling the flow at the pore scale of rigid porous media,and the macroscopic equivalent model is also *** is proved that the macroscopic mass flow depends on the macroscopic magnetic force and the gradients of pressure and of magnetic pressure,as Zahn and Rosensweig have described in their *** permeability tensor is symmetric and positive.

关键词： macroscopic Porous magnetic

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A hybrid optimization algorithm for the multi-chromosomal reversal median problem

A hybrid optimization algorithm for the multi-chromosomal re...

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1st International Conference on engineering and Technology Innovation, ICETI 2011

作者： Zhang, Yi Zhang, Meng Department of Computer Science Jilin Business and Technology College Changchun 130062 China Military Simulation Technology Institute Air Force Aviation University Changchun130022 China Key Laboratory of Symbol Computation and Knowledge Engineering of Ministry of Education College of Computer Science and Technology Jilin University Changchun 130012 China

ISBN: (纸本)9783037853245

In this paper, we introduce a hybrid optimization algorithm with the Branch-and-Bound Method and the Ant Colony Optimization to solve the multi-chromosomal reversal median problem. We convert the large-scale genome into TSP maps at first. Then we use a hybrid optimization algorithm with the Branch-and-Bound Method and the Ant Colony Optimization to solve the problem. In our improved algorithm, we increase the search speed by implement multi-branch parallel search of ACO. Our extensive experiments on simulated datasets show that this median solver is efficient.

关键词： Ant colony optimization

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