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An Iterative Two-Grid Method of A Finite Element PML Approximation for the Two Dimensional Maxwell Problem

Advances in Applied Mathematics and Mechanics 2012年第2期4卷 175-189页

作者： Chunmei Liu Shi Shu Yunqing Huang Liuqiang Zhong Junxian Wang Hunan Key Laboratory for Computation&Simulation in Science and Engineering and Key Laboratory of Intelligent Computing&Information Processing of Ministry of Education Xiangtan UniversityHunan 411105China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

In this paper,we propose an iterative two-grid method for the edge finite element discretizations(a saddle-point system)of Perfectly Matched Layer(PML)equations to the Maxwell scattering problem in two ***,we use a fine space to solve a discrete saddle-point system of H(grad)variational problems,denoted by auxiliary system ***,we use a coarse space to solve the original saddle-point ***,we use a fine space again to solve a discrete H(curl)-elliptic variational problems,denoted by auxiliary system ***,we develop a regularization diagonal block preconditioner for auxiliary system 1 and use H-X preconditioner for auxiliary system *** we essentially transform the original problem in a fine space to a corresponding(but much smaller)problem on a coarse space,due to the fact that the above two preconditioners are efficient and *** with some existing iterative methods for solving saddle-point systems,such as PMinres,numerical experiments show the competitive performance of our iterative two-grid method.

关键词： Maxwell scattering edge finite element PML iterative two-grid method

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A linearly implicit conservative difference scheme for the space fractional coupled nonlinear Schrödinger equations

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Journal of computational Physics 2014年 272卷 644-655页

作者： Wang, Dongling Xiao, Aiguo Yang, Wei Department of Mathematics Northwest University Xi'an 710069 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing and oInformation Processing of Ministry of Education Xiangtan University Xiangtan Hunan 411105 China

In this paper, a linearly implicit conservative difference scheme for the coupled nonlinear Schrödinger equations with space fractional derivative is proposed. This scheme conserves the mass and energy in the discrete level and only needs to solve a linear system at each step. The existence and uniqueness of the difference solution are proved. The stability and convergence of the scheme are discussed, and it is shown to be convergent of order O(τ2 + h2) in the discrete l2 norm with the time step τ and mesh size h. When the fractional order is two, all those results are in accord with the difference scheme proposed for the classical non-fractional coupled nonlinear Schrödinger equations. Some numerical examples are also reported. © 2014 Elsevier Inc.

关键词： Linear systems

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An Efficient Proximity Point Algorithm for Total-Variation-Based Image Restoration

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Advances in Applied Mathematics and Mechanics 2014年第2期6卷 145-164页

作者： Wei Zhu Shi Shu Lizhi Cheng School of Mathematics and Computational Science Xiangtan UniversityXiangtan 411105HunanChina Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityXiangtan 411105HunanChina Department of Mathematics and Computational Science College of ScienceNational University of Defense TechnologyChangsha 410073HunanChina

In this paper,we propose a fast proximity point algorithm and apply it to total variation(TV)based image *** novel method is derived from the idea of establishing a general proximity point operator framework based on which new first-order schemes for total variation(TV)based image restoration have been *** current algorithms for TV-based image restoration,such as Chambolle’s projection algorithm,the split Bregman algorithm,the Berm´udez-Moreno algorithm,the Jia-Zhao denoising algorithm,and the fixed point algorithm,can be viewed as special cases of the new first-order ***,the convergence of the new algorithm has been analyzed at ***,we make comparisons with the split Bregman algorithm which is one of the best algorithms for solving TV-based image restoration at *** experiments illustrate the efficiency of the proposed algorithms.

关键词： Proximity point operator image restoration total variation first-order schemes.

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Legendre spectral Galerkin method for second-kind Volterra integral equations

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中国高等学校学术文摘·数学 2009年第1期4卷 181-193页

作者： Zhengsu WAN Yanping CHEN Yunqing HUANG Department of Mathematics Hunan Institute of Science and TechnologyYueyang 414006China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematics and Computational Science Xiangtan UniversityXiangtan 411105China

The Legendre spectral Galerkin method for the Volterra integral equations of the second kind is proposed in this *** provide a rigorous error analysis for the proposed method,which indicates that the numerical errors (in the L2 norm) will decay exponentially provided that the kernel function and the source function are sufficiently *** examples are given to illustrate the theoretical results.

关键词： Volterra integral equation Legendre spectral Galerkin method convergence

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Crystal Structures and Spectroscopy of Anti-2,4-bis(3-R-phenyl)pentane-2,4-diols (R = Me, SMe)

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Chinese Journal of Structural Chemistry 2012年第12期31卷 1713-1720页

作者：焦银春曹晨忠赵小林 School of Chemistry and Chemical Engineering Central South University School of Chemistry and Chemical Engineering Hunan University of Science and Technology Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education Hunan University of Science and Technology Hunan Provincial University Key Laboratory of QSAR/QSPR

Two anti-2,4-bis（3-R-phenyl）pentane-2,4-diols （1, R = Me; 2, R = SMe） have been synthesized and were characterized by X-ray diffraction, IR and UV spectra. X-ray diffractions indicate that intra- and intermolecular hydrogen bonding interactions form one-dimensional （ID） ribbons. The adjacent infinite I D ribbons result in 3D supramolecular structures. The dihedral angles between every two benzene rings in the two diols are 31.61（12） and 31.80（7）°, respectively. UV absorption spectra of the title compounds were recorded in MeOH, C2H5OH, CH3CN, n-BuOH and cyclohexane solvents with different dielectric constants.

关键词： crystal structure hydrogen bonds UV absorption solvent effect

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Design lithium storage materials by lithium adatoms adsorption at the edges of zigzag silicene nanoribbon: A first principle study

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Applied Surface science 2017年 406卷 161-169页

作者： Guo, Gang Mao, Yuliang Zhong, Jianxin Yuan, Jianmei Zhao, Hongquan Hunan Key Laboratory for Micro–Nano Energy Materials and Devices School of Physics and Optoelectronic Engineering Xiangtan University Hunan411105 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematics and Computational Science Xiangtan University Hunan411105 China Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing401120 China

First-principles spin-polarized calculations are performed to design lithium storage materials using the active edges of zigzag silicene nanoribbon (ZSiNR). We predict that edge-adsorption of Li adatoms on zigzag silicene nanoribbon is preferred in energy to form new type lithium storage materials. Significant charge transfer from Li adatoms to Si atoms at the edges of ZSiNR is found, indicating the main ionic interactions. It is found that the band structures of ZSiNR with Li adsorptions are sensitive with the variation of sites of adatoms at the two edges. Ferro-magnetic to antiferro-magnetic change is found in ZSiNR with symmetrical adsorption of Li adatoms at its two edges. Other unsymmetrical Li adsorptions at the edges of ZSiNR prefer to stay in ferro-magnetic state as that in narrow pristine ZSiNR. © 2017 Elsevier B.V.

关键词： Adsorption

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Synthesis of Novel Spiro Pyrrolidine and Pyrrolizine Derivatives by 1,3-Dipolar Cycloaddition

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中国化学(英文版) 2010年第7期28卷 1207-1211页

作者： Li Xiaofang Zheng Aiting Liu Bin Yu Xianyong Yi Pinggui Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education Hunan Province College Key Laboratory of QSAR/QSPR School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan Hunan 411201China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education Hunan Province College Key Laboratory of QSAR/QSPR School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan Hunan 411201

The 1,3-dipolar cycloaddition of azomethine ylides derived from isatin and amino acids viz. Sarcosine and proline to 2-arylmethylidene-5,6-dihydroimidazo[2,1-b]thiazol-3(2H)-ones afforded novel spiro pyrrolidines and pyrrolizidines regio- and stereoselectively in moderate yields. The products were characterized thoroughly by IR,MS, NMR together with elementary analysis.

关键词： spiroheterocycle 1,3-dipolar cycloaddition azomethine ylides dihydroimidazo[2,1-b]thiazol-3(2H)-one

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Identifying possible lncRNA-disease associations based on deep learning and positive-unlabeled learning

Identifying possible lncRNA-disease associations based on de...

引用

2022 IEEE International Conference on Bioinformatics and Biomedicine, BIBM 2022

作者： Peng, Lihong Huang, Liangliang Lu, Yuankang Liu, Guangyi Chen, Min Han, Guosheng Hunan University of Technology School of Computer Science Zhuzhou China Xiangtan University Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan China

ISBN: (纸本)9781665468190

lncRNAs are involved in many biological processes, and their mutations and disorders are closely related to many diseases. Identification of LncRNA-Disease Associations (LDAs) helps us understand the pathogenesis of diseases and improve their diagnosis and treatment. However, experiments to determine LDAs are expensive, so it is essential to exploit effective computational methods to screen possible LDAs. In this study, we developed an LDA prediction model (LDA-DLPU) based on deep learning and positive-unlabeled (PU) learning. First, LDA-DLPU extracted features of lncRNAs and diseases based on singular value decomposition and regression model. Second, it selected negative LDAs based on PU learning and graph autoencoder. Finally, it classified unknown lncRNA-disease pairs based on deep neural network. LDA-DLPU obtained the best performance on two datasets. We predict that BCYRN1 and IFNG-AS1 may associate with leukemia. © 2022 IEEE.

关键词： Diseases

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FETD Study of theWave Propagation in Chiral Metamaterials

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Advances in Applied Mathematics and Mechanics 2021年第1期13卷 191-202页

作者： Lei Yang Fuhao Liu Wei Yang Faculty of Information Technology Macao University of Science and TechnologyMacaoChina School of Mathematics and Computational Science Xiangtan UniversityXiangtanHunan 411105China Hunan Key Laboratory for Computation and Simulation in Science and Engineering and School of Mathematics and Computational Science Xiangtan UniversityXiangtanHunan 411105China

In this paper,we propose a finite element time-domain(FETD)method for the Maxwell’s equations in chiral metamaterials(CMMs).The time-domain model equations are constructed by the auxiliary differential equations(ADEs)*** source excitation method entitled total-field and scattered-field(TF/SF)decomposition technique is applied to FETD method for the first time in simulating the propagation of electromagnetic wave in CMMs,based on which a unified ADE-FETD-UPMLTF/SF scheme is proposed to simulate the wave in *** following properties of CMMs can be observed successfully from the numerical experiments based on our method,i.e.,the ability of the polarization rotation,and the negative phase *** amplitude of reflected wave can effectively be controlled by the physical parameters of CMMs.

关键词： Maxwell’s equations finite element time-domain(FETD) chiral metamaterials(CMMs).

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Synthesis of Novel Spiro Thiazolo[3,2-a]triazines via 1,3-Dipolar Cycloaddition of Azomethine Ylide

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Chinese Journal of Chemistry 2011年第1期29卷 97-101页

作者： Li, Xiaofang Liu, Haochong Zheng, Aiting Li, Zhikui Li, Guobin Yu, Xianyong Yi, Pinggui Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education Hunan Province College Key Laboratory of QSAR/QSPR School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan Hunan 411201 China

The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6（7H）-ones afforded novel dispiro[acenaphthylene-1,2’-pyrrolidine]-3＇,7″-[1,3]thiazolo[3,2-a][1,3,5]triazines in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis and X-ray crystallographic analysis. The results of experiment indicated that this 1,3-dipolar cycloaddition proceeded with high stereoselectivity and regioselectivity.

关键词： thiazolo[3,2-a]triazine 1,3-dipolar cycloaddition azomethine ylide spiroheterocycle

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