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Theoretical analysis and numerical simulation of acoustic waves in gas hydrate-bearing sediments

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Chinese Physics B 2021年第2期30卷 344-354页

作者： Lin Liu xiu-Mei zhang xiu-Ming Wang State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100149China Beijing Engineering Research Center of Sea Deep Drilling and Exploration Institute of AcousticsChinese Academy of SciencesBeijing 100190China

Based on Carcione-Leclaire model,the time-splitting high-order staggered-grid finite-difference algorithm is proposed and constructed for understanding wave propagation mechanisms in gas hydrate-bearing *** compressional waves and two shear waves,as well as their energy distributions are investigated in *** particular,the influences of the friction coefficient between solid grains and gas hydrate and the viscosity of pore fluid on wave propagation are *** results show that our proposed numerical simulation algorithm proposed in this paper can effectively solve the problem of stiffness in the velocity-stress equations and suppress the grid dispersion,resulting in higher accuracy compared with the result of the Fourier pseudospectral method used by *** excitation mechanisms of the five wave modes are clearly revealed by the results of ***,it is pointed that,the wave diffusion of the second kind of compressional and shear waves is influenced by the friction coefficient between solid grains and gas hydrate,while the diffusion of the third compressional wave is controlled by the fluid ***,two fluid-solid(gas-hydrate formation)models are constructed to study the mode conversion of various *** results show that the reflection,transmission,and transformation of various waves occur on the interface,forming a very complicated wave field,and the energy distribution of various converted waves in different phases is *** is demonstrated from our studies that,the unconventional waves,such as the second and third kinds of compressional waves may be converted into conventional waves on an *** propagation mechanisms provide a concrete wave attenuation explanation in inhomogeneous media.

关键词： gas hydrate-bearing sediments Carcione-Leclaire model time-splitting staggered-grid finite-difference slow-wave characteristics

Series Solution for Localization and Entanglement of an Exciton in a Quantum Dot Molecule by an ac Electric Field

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Communications in Theoretical Physics 2006年第2期45卷 357-362页

作者： LIN Chang zhang xiu-Lian College of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 China

The Schroedinger equation involving the phenomenon of the localization and entanglement for an exciton in a quantum dot molecule by an ac electric field is analytically investigated. New exact series solutions for the Schroedinger equation have been obtained for the first time. The analytical expressions can further describe the dynamical behaviors of an interacting electron-hole pair in a double coupled quantum dot molecule under an ac electric field accurately.

关键词： Schrodinger equation quantum dot molecule localization entanglement exact series solution

Hot deformation behavior and microstructure evolution of TiC–Al_2O_3/Al composites

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Rare Metals 2015年第10期34卷 725-730页

作者： Rui-Ying zhang Zhi-Ming Shi xiu-Mei zhang School of Materials Science and Engineering Inner Mongolia University of Technology Key Laboratory of Light Metal Materials

Hot compression behavior of TiC–Al2O3/Al composites was studied using the Gleeble-1500 system at a temperature range of 300–550 °C and at strain rate range of 0.01–10.00 s-1. The associated structural changes were studied by TEM observations. The results show that stress level decreases with deformation temperature increasing and strain rate decreasing, which can be represented by a Zener–Hollomon parameter in an exponent-type equation with hot deformation activation energy Q of 172.56 kJ·*** recovery occurs easily when strain rates are less than 10.00 s-1. Dynamic recrystallization can occur at strain rate of 10.00 s-1.

关键词： TiC–Al2O3/Al composites Hot deformation Flow stres

Synthesis and Crystal Structure of N, N'',N''-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) Amine

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Chinese Journal of Structural Chemistry 2005年第4期24卷 371-374页

作者： zhang xiu-Lian CHEN Xiao-Ming School of Chemistry and Chemical Engineering Sun Yat-Sen University Guangzhou 510275 China Department of Chemistry Guangdong Institute of Education Guangzhou 510310 China

N, N??, N??-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) amine (TOTIA) has been synthesized and characterized by X-ray crystallography, and its crystal is of monoclinic, space group P21/c with a = 6.0158(5), b = 16.3851(2), c = 31.6650(3) ?, β = 90.867(2)o, V = 3120.8(5) ?3, C39H36N4O3, Mr = 608.72, Dc = 1.296 g/cm3, Z = 4, F(000) = 1288, μ(MoKα) = 0.083 cm-1, R = 0.0641 and wR = 0.1615. The total reflections were 12598 and 5410 were independent, of which 3342 were observed with I > 2σ(I). There exist strong intramolecular hydrogen bonds between hy- droxy hydrogen atoms and azomethine nitrogen atoms, and obvious π-π stacking interaction between the phenyl rings of TOTIA.

关键词： crystal structure hydrogen bonds N,N′′,N′′-tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) amine

Theoretical Study on the Dark Oxidation Reaction Mechanism of Ethers

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Chinese Journal of Structural Chemistry 2006年第11期25卷 1402-1408页

作者： WANG Gui-xiu ZHU Rong-xiu zhang Dong-Ju LIU Cheng-Bu School of Chemistry and Chemical Engineering Shandong University Jinan 250100 China

The dark oxidation reactions of ethers including aether, isopropyl ether, phenyl isopropyl ether, and benzyl isopropyl ether have been studied by using density functional theory calculations. The structures of initial Contact charge transfer complexes （CCTCs）, transition states and caged radical intermediates have been located at the B3LYP/6-31G （d） level, The bonding nature of ethers with triplet 02 in CCTCs has been analyzed, and the detailed mechanism of dark oxidation reactions of ether is presented clearly.

关键词： ethers dark oxidation contact charge transfer complex reaction mechanism DFT

Analytical Study of Nonlinear Dust Acoustic Waves in Two-Dimensional Dust Plasma with Dust Charge Variation

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Communications in Theoretical Physics 2005年第2X期44卷 247-251页

作者： LIN Chang zhang xiu-Lian College of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 China

The nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation is analytically investigated by using the formally variable separation approach. New analytical solutions for the governing equation of this system have been obtained for dust acoustic waves in a dust plasma for the first time. We derive exact analytical expressions for the general case of the nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation.

关键词： nonlinear dust acoustic waves plasma formally variable separation approach exact analytical solution

Additive Maps Preserving Similarity of Operators on Banach Spaces

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Acta Mathematica Sinica,English Series 2006年第1期22卷 179-186页

作者： Jin Chuan HOU xiu Ling zhang Department of Mathematics Shanxi Teachers University Linfen 041004 P R. China

Let X be an infinite-dimensional complex Banach space and denote by B（X） the algebra of all bounded linear operators acting on X. It is shown that a surjective additive map Φ from B（X） onto itself preserves similarity in both directions if and only if there exist a scalar c, a bounded invertible linear or conjugate linear operator A and a similarity invariant additive functional ψ on B（X） such that either Φ（T） = cATA^-1 ＋ ψ（T）I for all T, or Φ（T） = cAT＊A^-1 ＋ ψ（T）I for all T. In the case where X has infinite multiplicity, in particular, when X is an infinite-dimensional Hilbert space, the above similarity invariant additive functional ψ is always zero.

关键词： Additive maps on operator algebras Similarity of operators Banach spaces

Whittaker Modules for the Derivation Lie Algebra of Torus with Two Variables

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Acta Mathematica Sinica,English Series 2016年第10期32卷 1177-1188页

作者： Hai Feng LIAN xiu Fu zhang Department of Mathematics Fujian Agriculture and Forestry UniversityFuzhou 350002P.R.China School of Mathematics and Statistics Jiangsu Normal UniversityXuzhou 221116P.R.China

Let L be the derivation Lie algebra of C[t1^±1 , t2^±1 ]. Given a triangle decomposition L = L＋ η ＋ L-, we define a nonsingular Lie algebra homomorphism φ ： L＋ → C and the universal Whittaker L-module We of type φ. We obtain all Whittaker vectors and submodules of We. Moreover, all simple Whittaker L-modules of type φ are determined.

关键词： Whittaker vector Whittaker module simple module derivation Lie algebra

Current research on electrospinning of silk fibroin and its blends with natural and synthetic biodegradable polymers

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Frontiers of Materials Science 2013年第2期7卷 129-142页

作者： Jian-Guang zhang xiu-Mei MO Biomaterials and Tissue Engineering Lab College of Chemistry Chemical Engineering & Biotechnology Donghua University Shanghai 201620 China

Silk fibroin （SF） is a kind of natural polymers with a great potential in biomedical application. Due to its good biocompatibility, biodegradability and minimal inflammatory reaction, SF is an excellent candidate for generating tissue engineering scaffolds. Electrospinning is a simple and effective method to fabricate nanofibers, which has several amazing characteristics such as very large surface area to volume ratio, flexibility in surface functionalities, and superior mechanical performance. The electro- spun nanofibers from SF and its blends have been used for varied tissue engineering. This paper will give a brief review about the structure, properties and applications of SF and blend nanofibers via electrospinning.

关键词： electrospinning nanofiber silk fibroin (SF) biodegradable polymer