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Quantitative amendment of high-field ^(13)C NMR spectra of coals

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chinese Science Bulletin 1997年第10期42卷 807-809页

作者： YANG Baolian, LI Liyun and YE ChaohuiLaboratory of Magnetic Resonance and Atomic and Molecular physics, wuhan {2. of physics and mathematics, chinese academy of sciences, wuhan 430071, china Laboratory of Magnetic Resonance and Atomic and Molecular physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan China

HIGH-RESOLUTION solid state 13C NMR spectroscopy has been a useful tool for the study of *** the use of cross polarization（CP）,magic angle spinning（MAS）and protonhigh-power decoupling（HPD）techniques,high-resolution solid state 13C NMR spectra ofcoals can be obtained and the coal aromaticity（fa）can be measured *** aromaticityis defined as the ratio of aromatic carbon atoms to the total carbon atoms in *** pa-

关键词： 13C NMR coal structure quantitative amendment.

Riemann boundary value problems and reflection of shock for the Chaplygin gas

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Science china mathematics 2012年第4期55卷 671-685页

作者： CHEN ShuXing 1,& QU AiFang 2.1 School of Mathematical sciences,Fudan University,Shanghai 2.0433,china 2.{2. institute of physics and mathematics,chinese academy of sciences,{2. 430071,china 1. School of Mathematical sciences Fudan University Shanghai 200433 China2. Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 China

In this paper,we study two-dimensional Riemann boundary value problems of Euler system for the isentropic and irrotational Chaplygin gas with initial data being two constant states given in two sectors respectively,where one sector is a quadrant and the other one has an acute vertex *** prove that the Riemann boundary value problem admits a global self-similar solution,if either the initial states are close,or the smaller sector is also near a *** result can be applied to solving the problem of shock reflection by a ramp.

关键词： Riemann boundary value problem reflection of shock Chaplygin gas wave interaction Eulersystem

ON THE WEIGHTED OCCUPATION TIME AND SUPPORT OF SUPER-BROWNIAN MOTION CONDITIONED ON NON-EXTINCTION

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Acta Mathematica Scientia 1999年第3期19卷 272-278页

作者：李炳章余旌胡 wuhan Univ Dept Math Wuhan 430072 Peoples R China Acad Sinica Wuhan Inst Phys & Math Wuhan 430071 Peoples R China

This paper investigates the property of super-Brownian motion conditioned on non-extinction. The authors obtain a representation of Laplace functional for the weighted occupation time of this class of processes. By th... 详细信息

关键词： super-Brownian motion non-extinction weighted occupation the support of measure

Randomization of Q_(p) spaces on the unit ball of C^(n)

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Science china mathematics 2005年第z1期48卷 306-317页

作者： LI Bo & OUYANG Caiheng Department of mathematics, State University of New York at Buffalo, Buffalo, NY 142.0, USA wuhan {2. of physics and mathematics, chinese academy of sciences, wuhan 430071, china SUNY Buffalo Dept Math Buffalo NY 14260 USA chinese Acad Sci Wuhan Inst Phys & Math Wuhan 430071 Peoples R China

In this paper, we study the random power series of several complex variables,and give some sufficient conditions for random power series to belong to Qp and Qp,0spaces by means of their characterizations of Carleson m... 详细信息

关键词： random power series, function spaces, the unit ball.

A RIGOROUS DERIVATION OF THE GROSS-PITAEVSKII HIERARCHY FOR WEAKLY COUPLED TWO-DIMENSIONAL BOSONS

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Acta Mathematica Scientia 2010年第3期30卷 841-856页

作者：刘创业 wuhan institute of {2. and mathematics Chinese Academy of Sciences

In this article, we consider the dynamics of N two-dimensional boson systems interacting through a pair potential N-1Va（xi -xj） where Va（x） = a^-2.（x/a）. It is well known that the Cross-Pitaevskii （GP） equation is a nonlinear SchrSdinger equation and the GP hierarchy is an infinite BBGKY hierarchy of equations so that if ut solves the GP equation, then the family of k-particle density matrices { k ut, k≥1} solves the GP hierarchy. Denote by ψN,t the solution to the N-particle Schrodinger equation. Under the assumption that a = N^-ε for 0 〈 ε 〈 3/4, we prove that as N→∞ the limit points of the k-particle density matrices of CN,t are solutions of the GP hierarchy with the coupling constant in the nonlinear term of the GP equation given by f V（x） dx.

关键词： Cross-Pitaevskii equation Boson system density matrix BBGKY hierarchy

Surface modification of γ-Al_2._3 by sodium ions

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chinese Science Bulletin 2001年第3期46卷 188-193页

作者： DENG Feng, YUE Yong, DU Youru, YE Chaohui, KONG Yuhua, WANG Guoxing & LI Xiaoding1. Laboratory of Magnetic Resonance and Atomic and Molecular physics, wuhan {2. of physics and mathematics, chinese academy of sciences, wuhan 430071, china 2. Hubei {2. of Chemistry, wuhan 430074, china Laboratory of Magnetic Resonance and Atomic and Molecular physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan China Hubei institute of Chemistry Wuhan China

1H/2.Na double resonance NMR techniques were employed to study the modification of surface hydroxyls on Y-Al2.3 by sodium ions. 1H-2.Na cross polarization (CP) experiment can resolve three kinds of sodium cations that are closely associated with surface hydroxyl groups, while the signal of deposited salt-Na2.O3, which is not connected to surface hydroxyl groups, is completely suppressed. 1H{2.Na} spin echo double resonance experiments reveal the surface modification in more detail. At low Na+ coverage (5%, 10%), the acidic hydroxyl groups are preferentially coordinated with sodium ions, while both the acidic and the basic hydroxyl groups are accessible for sodium ions at highcoordination that causes proton of the OH groups to be easily dissolved, which is evidenced by the fact that with calcination temperature of the catalysts increasing, the acidic hydroxyl groups are preferentially removed and only the basic hydroxyl groups remain when the calcination temperature is raised to 600℃.

关键词： surface modification γ-Al2.3 NMR hydrodesulfu-rization catalyst.

Natural abundant ^(15)N NMR detection of polypeptide and protein

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chinese Science Bulletin 1997年第19期42卷 1606-1611页

作者： HUANG He and MAO Xi’anwuhan institute of {2., chinese academy of sciences, wuhan 430071, china wuhan institute of {2. Chinese Academy of Sciences Wuhan China

THE ~15N NMR study is of general interest in the analysis of the protein conformations in solu-tions. When NMR is applied to the conformation study of macrobiomolecules, a heteronuclearmultiple quantum coherence (HMQC) spectrum of ~15N is usually measured first, so that theamide protons are assigned before other experiments, such as the total correlation

关键词： polypeptide and protein natural abundant 15N NMR heteronuclear multiple quantum coherence spectrum.

Behavior of gravity waves with limited amplitude in the vicinity of critical layer

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chinese Science Bulletin 2002年第18期47卷 1547-1550页

作者： WU Shaoping & Yl Fanwuhan institute of {2. and mathematics, chinese academy of sciences, wuhan 430071, china Department of Radio Science and Technology, wuhan University, wuhan 430072. china Department of {2., Huazhong Normal Univ wuhan institute of {2. and mathematics Chinese Academy of Sciences Wuhan China Department of physics Huazhong Normal University Wuhan China Department of Radio Science and Technology Wuhan University Wuhan China

By using the FICE scheme, a numerical simulation of three-dimensional nonlinear propagation of gravity wave packet in a wind-stratified atmosphere is presented. The whole nonlinear propagation process of the gravity wave packet is shown; the propagation behavior of gravity waves in the vicinity of critical layer is analyzed. The results show that gravity waves encounter the critical layer when propagating in the fair winds whose velocities increase with height, and the height of critical layer propagating nonlinearly is lower than that expected by the linear gravity waves theory; the amplitudes of gravity waves increase with height as a whole before gravity waves encounter the critical layer, but the increasing extent is smaller than the result given by the linear theory of gravity waves, while the amplitudes of gravity waves reduce when gravity waves meet the critical layer; the energy of wave decreases with height, especially at the critical layer; the vertical wavelength reduces with the height

关键词： gravity waves critical layer FICE scheme simulation.

POSITIVE SOLUTIONS FOR WEAKLY COUPLED NONLINEAR ELLIPTIC SYSTEMS

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Acta Mathematica Scientia 2010年第5期30卷 1577-1592页

作者：龙静杨健夫 wuhan institute of {2. and mathematics Chinese Academy of Sciences Graduate School Chinese Academy of Sciences Department of mathematics Jiangxi Normal University

In this article, we consider the existence of positive solutions for weakly coupled nonlinear elliptic systems {-△u＋u=（1＋a（x））｜u｜P-1u＋μ｜u｜a-2.｜v｜β＋λv in Rn,-△u＋u=（1＋b（x））｜v｜p-1v＋μ｜u｜a｜v｜β-2.＋λu in Rn To find nontrivial solutions, we first investigate autonomous systems. In this case, results of bifurcation from semi-trivial solutions are obtained by the implicit function theorem. Next, the existence of positive solutions of problem （0.1） is obtained by variational methods.

关键词： Elliptic system in RN positive solution bifurcation variational method