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Existence theory for Rosseland equation and its homogenized equation

Applied Mathematics and Mechanics(English Edition) 2012年第12期33卷 1595-1612页

作者：张乔夫崔俊芝 State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of Sciences

The global boundness and existence are presented for the kind of the Rosseland equation with a general growth condition. A linearized map in a closed convex set is defined. The image set is precompact, and thus a fixed point exists. A multi-scale expansion method is used to obtain the homogenized equation. This equation satisfies a similar growth condition.

关键词： nonlinear elliptic equations fixed points mixed boundary conditions growthconditions maximal regularitys homogenized equation

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Comparative study on order-reduced methods for linear third-order ordinary differential equations

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Frontiers of Mathematics in China 2012年第6期7卷 1151-1168页

作者： Zhiru REN State Key Laboratory of Scientific/Engineering Computing Institute of ComputationalMathematics and Scientific/Engineering Computing Academy of Mathematics andSystems Science Chinese Academy of Sciences P. O. Box 2719 Beijing 100190 China

The linear third-order ordinary differential equation （ODE） can be transformed into a system of two second-order ODEs by introducing a variable replacement, which is different from the common order-reduced approach. We choose the functions p（z） and q（x） in the variable replacement to get different cases of the special order-reduced system for the linear third-order ODE. We analyze the numerical behavior and algebraic properties of the systems of linear equations resulting from the sine diseretizations of these special second-order ODE systems. Then the block-diagonal preconditioner is used to accelerate the convergence of the Krylov subspace iteration methods for solving the discretized system of linear equation. Numerical results show that these order-reduced methods are effective for solving the linear third-order ODEs.

关键词： third-order ordinary differential equation order-reduced method sine discretization preeonditioner Krylov subspace method

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Residual-based a posteriori error control for Space-time finite element approximations of parabolic optimal control problems

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PAMM 2014年第1期14卷

作者： Wei Gong Michael Hinze Zhaojie Zhou Institute of Computational Mathematics The State Key Laboratory of Scientific and Engineering Computing (LSEC) Academy of Mathematics and Systems Science Chinese Academy of Sciences. University of Hamburg Department of Mathematics Bundesstraße 55 20146 Hamburg. School of Mathematics Science Shendong Normal University 250014 Ji'nan China.

In this paper we investigate a space-time finite element approximation of parabolic optimal control problems. The first order optimality conditions are transformed into an elliptic equation of fourth order in space and second order in time involving only the state or the adjoint state in the space-time domain. We derive a priori and a posteriori error estimates for the time discretization of the state and the adjoint state. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

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Parallel finite element algorithms and adaptive mesh generation for solving nonlinear poisson-boltzmann equations

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Ruan Jian Xue Bao/Journal of Software 2013年第SUPPL.2期24卷 110-117页

作者： Xie, Yan Tu, Bin Lu, Ben-Zhuo Zhang, Lin-Bo The State Key Laboratory of Scientific and Engineering Computing Academy of Mathematics and Systems Science The Chinese Academy of Sciences Beijing 100190 China

This paper presents a parallel finite element algorithm based on the toolbox PHG for solving the nonlinear Poisson-Boltzmann equations for biomolecular systems. Previously TMSmesh, TransforMesh and ISO2Mesh were used to generate high resolution meshes. In this work a new method which combines mesh generation and adaptive mesh refinement is introduced to avoid complicated mesh generation steps. The new approach makes use of the capabilities of PHG in local mesh refinement and dynamic load balancing. The efficiency of the new method is demonstrated with a sphere model and the AChE system through both the decay of the a posteriori error estimates and the convergence of solvation-energy. In the meantime the method is also successfully applied to the Gramicidin Aion channel system. © Institute of Software Chinese Academy of Sciences.

关键词： Mesh generation

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Novel Retinex algorithm by interpolation and adaptive noise suppression

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Journal of Central South University 2012年第9期19卷 2541-2547页

作者：李武劲古博黄江涛王明辉 College of Computer Science Sichuan University College of Computer and Information Engineering Guangxi Teachers Education University Key Laboratory of Scientific Computing and Intelligent Information Processing of Guangxi Province (Guangxi University)

In order to improve image quality, a novel Retinex algorithm for image enhancement was presented. Different from conventional algorithms, it was based on certain defined points containing the illumination information in the intensity image to estimate the illumination. After locating the points, the whole illumination image was computed by an interpolation technique. When attempting to recover the reflectance image, an adaptive method which can be considered as an optimization problem was employed to suppress noise in dark environments and keep details in other areas. For color images, it was taken in the band of each channel separately. Experimental results demonstrate that the proposed algorithm is superior to the traditional Retinex algorithms in image entropy.

关键词： Retinex algorithm illumination estimation interpolation adaptive noise suppression

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Stochastic multi-symplectic wavelet collocation method for stochastic Hamiltonian Maxwell's equations

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AIP Conference Proceedings 2012年第1期1479卷 1753-1756页

作者： Jialin Hong Lihai Ji State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences P. O. Box 2719 100080 Beijing China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences100080 Beijing China

In this paper, we investigate the model of three-dimensional (3D) stochastic multi-symplectic Hamiltonian Maxwell's equations, and consider the stochastic multi-symplectic numerical methods of solving such equations. In particular, multi-symplectic wavelet collocation method (MSWCM) is applied to such equations. It is shown that this multi-symplectic numerical method preserves not only the multi-symplectic structure, but also discrete energy conservation law under perfectly electric conducting boundary conditions.

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Descope of the ALIA mission

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Journal of Physics: Conference Series 2015年第1期610卷

作者： Xuefei Gong Yun-Kau Lau Shengnian Xu Pau Amaro-Seoane Shan Bai Xing Bian Zhoujian Cao Gerui Chen Xian Chen Yanwei Ding Peng Dong Wei Gao Gerhard Heinzel Ming Li Shuo Li Fukun Liu Ziren Luo Mingxue Shao Rainer Spurzem Baosan Sun Wenlin Tang Yan Wang Peng Xu Pin Yu Yefei Yuan Xiaomin Zhang Zebing Zhou Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences No.55 Zhongguancun Donglu Beijing 100190 China Morningside Center of Mathematics Chinese Academy of Sciences No.55 Zhongguancun Donglu Beijing 100190 China State Key Laboratory of Scientific and Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences No.55 Zhongguancun Donglu Beijing 100190 China State Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences No.55 Zhongguancun Donglu Beijing 100190 China Max-Planck-Institut für Gravitationsphysik (Albert Einstein Institut) Am Mfühlenberg 1 D-14476 Potsdam Germany Theoretisch-Physikalisches Institut Friedrich-Schiller-Universität Jena Frobelstieg 1 D-07743 Jena Germany University of Chinese Academy of Sciences No.19A Yuquan Road Beijing 100049 China College of Applied Sciences Beijing University of Technology 100 Pingleyuan Beijing 100124 China Dongfanghong Small Satellite Company F12 Shenzhou Building No.31 Zhongguancun Nandajie Beijing 100081 China Max-Planck-Institut für Gravitationsphysik (Albert Einstein Institut) Callinstraße 38 D-30167 Hannover Germany National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Beijing 100012 China Department of Astronomy School of Physics Peking University No.5 Yiheyuan Road Beijing 100871 China The Kavli Institute for Astronomy and Astrophysics Peking University 5 Yiheyuan Road Beijing 100871 China Institute of Mechanics Chinese Academy of Sciences 15 Beisihuanxi Road Beijing 100190 China Astronomisches Rechen-Institut Zentrum für Astronomie Universität Heidelberg Mönchhofstrasse 12-14 69120 Heidelberg Germany School of Physics Huazhong University of Science and Technology 1037 Luoyu Road Wuhan 430074 China Institute of Theoretical Physics Chinese Academy of Sciences No.55 Zhongguancun Donglu Beijing 100190 China Mathematical Science Center Tsinghua Unive

The present work reports on a feasibility study commissioned by the Chinese Academy of Sciences of China to explore various possible mission options to detect gravitational waves in space alternative to that of the eLISA/LISA mission concept. Based on the relative merits assigned to science and technological viability, a few representative mission options descoped from the ALIA mission are considered. A semi-analytic Monte Carlo simulation is carried out to understand the cosmic black hole merger histories and the possible scientific merits of the mission options in probing the light seed black holes and their coevolution with galaxies in early Universe. The study indicates that, by choosing the armlength of the interferometer to be three million kilometers and shifting the sensitivity floor to around one-hundredth Hz, together with a very moderate improvement on the position noise budget, there are certain mission options capable of exploring light seed, intermediate mass black hole binaries at high redshift that are not readily accessible to eLISA/LISA, and yet the technological requirements seem to within reach in the next few decades for China.

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Car-Parinello molecular dynamics simulations of thionitroxide and S-nitrosothiol in the gas phase,methanol,and water——A theoretical study of S-nitrosylation

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Science China Chemistry 2012年第10期55卷 2081-2088页

作者： LIANG Juan CHENG ShangLi HOU JunWei XU ZhenHao ZHAO Yi-Lei State Key Laboratory of Microbial Metabolism School of Life Sciences and BiotechnologyShanghai Jiao Tong University Shanghai 200240China Shanghai Center for Systems Biomedicine Shanghai Jiao Tong UniversityShanghai 200240China MOE Laboratory of Scientific and Engineering Computing Shanghai Jiao Tong UniversityShanghai 200240China

A dilemma about whether thionitroxide radical (RSNHO) or S-nitrosothiol (RSNO) is observed in protein S-nitrosylation has arisen recently. To illustrate the effect of chemical environment on these structures, this paper presents quantum mechanical molecular dynamics of thionitroxide, and cis-and trans-S-nitrosothiols in the gas phase, methanol, and water. By using Car-Parrinello molecular dynamics (CPMD), we have observed that there is free rotation about the S-N bond at 300 K in thionitroxide, but no such rotation is observed for S-nitrosothiol. The C-S-N-O torsion angle distribution in thionitroxide is s-ignificantly dependent upon the surrounding environment, leading to either gauche-, cis-, or trans-conformation. In the case of S-nitrosothiol the C-S-N-O plane is twisted slightly by 5°-15° in the cis-isomer, while the periplanar structure is well-retained in the trans-isomer. The calculated results are in agreement with the X-ray crystallographic data of small molecular RSNO species. Interestingly, for both compounds, the CPMD simulations show that solvation can cause a decrease in the S-N bond length. Moreover, the oxygen atom of thionitroxide is found to be a good hydrogen-bond acceptor, forming an oxyanion-hole-like hydrogen bonding network.

关键词： quantum mechanical molecular dynamics S-nitrosylation thionitroxide S-nitrosothiol solvent effect

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Message from the IWPAPS 2012 workshop chairs

Proceedings - 2012 IEEE International Conference on Cluster ...

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Proceedings - 2012 IEEE International Conference on Cluster computing Workshops, Cluster Workshops 2012 2012年 xiii页

作者： Zhang, Linbo Zhang, Yunquan State Key Laboratory of Scientific and Engineering Computing CAS China Institute of Software CAS China

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Car-Parinello molecular dynamics simulations of thionitroxide and S-nitrosothiol in the gas phase,methanol,and water——A theoretical study of S-nitrosylation

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中国科学:化学 2012年第10期42卷 1497-1498页

作者： LIANG Juan1,CHENG ShangLi1,HOU JunWei1,XU ZhenHao1,2 & ZHAO Yi-Lei1,2,3* 1 State key laboratory of Microbial Metabolism,School of Life Sciences and Biotechnology,Shanghai Jiao Tong University,Shanghai 200240,China 2 Shanghai Center for Systems Biomedicine,Shanghai Jiao Tong University,Shanghai 200240,China 3 MOE laboratory of scientific and engineering computing,Shanghai Jiao Tong University,Shanghai 200240,China State Key Laboratory of Microbial Metabolism School of Life Sciences and Biotechnology Shanghai Jiao Tong University Shanghai 200240 China Shanghai Center for Systems Biomedicine Shanghai Jiao Tong University Shanghai 200240 China MOE Laboratory of Scientific and Engineering Computing Shanghai Jiao Tong University Shanghai 200240 China

A dilemma about whether thionitroxide radical(RSNHO) or S-nitrosothiol(RSNO) is observed in protein S-nitrosylation has arisen *** illustrate the effect of chemical environment on these structures,this paper presents quantum mechanical molecular dynamics of thionitroxide,and cis-and trans-S-nitrosothiols in the gas phase,methanol,and *** using Car-Parrinello molecular dynamics(CPMD),we have observed that there is free rotation about the S-N bond at 300 K in thionitroxide,but no such rotation is observed for *** C-S-N-O torsion angle distribution in thionitroxide is significantly dependent upon the surrounding environment,leading to either gauche-,cis-,or *** the case of S-nitrosothiol the C-S-N-O plane is twisted slightly by 5°-15° in the cis-isomer,while the periplanar structure is well-retained in the *** calculated results are in agreement with the X-ray crystallographic data of small molecular RSNO ***,for both compounds,the CPMD simulations show that solvation can cause a decrease in the S-N bond ***,the oxygen atom of thionitroxide is found to be a good hydrogen-bond acceptor,forming an oxyanion-hole-like hydrogen bonding network.

关键词： quantum mechanical molecular dynamics S-nitrosylation thionitroxide S-nitrosothiol solvent effect

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