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MOMENT GENERATING FUNCTIONS OF RANDOM VARIABLES AND ASYMPTOTIC BEHAVIOUR FOR GENERALIZED FELLER OPERATORS

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Journal of Computational mathematics 2000年第2期18卷 173-182页

作者： Ji-hua Xu Jing-hui Zhao (department of mathematics, Hubei university, wuhan 430062, china) 湖北大学湖北武汉 430062

Describes the representation of moment generating function for the S-lambda type random variables. Higher order asymptotic formula for generalized Feller operators; Regular n-r order moment for the random variables.

关键词： generalized Feller operator moment generating function higher order asymptotic formula regular n-r order moment generalized Taylor formula

A Characterization for the Gevrey-Sobolev Wave Front Set

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Acta Mathematica Sinica,English Series 2001年第2期17卷 295-300页

作者： hua chen Institute of mathematics, wuhan university, wuhan 4.0072, P. R. china Institute of mathematics Wuhan University Wuhan 430072 P. R. China

In this note, we use the so-called microlocal energy method to give a characterization of the Gevrey-Sobolev wave front set WF(HT,σS （u）, which will be useful in the study of non-linear microlocal analysis in Gevre... 详细信息

关键词： Gevrey-Sobolev space Wave front set Microlocal energy method

GRAPH-DIRECTED STRUCTURES OFSELF-SIMILAR SETS WITH OVERLAPSGRAPH-DIRECTED STRUCTURES OFSELF-SIMILAR SETS WITH OVERLAPSS

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Chinese Annals of mathematics,Series B 2000年第4期21卷 403-412页

作者： huaSu RAOHUI departmentofmathematics TsinghuaUniversityBeijing100084China. departmentofmathematics WuhanUniversityWuhan430072China.

Some kinds of the self-similar sets with overlapping structures are studied by introducing the graph-directed constructions satisfying the open set condition that coincide with these sets. In this way, the dimensions ... 详细信息

关键词： Self-similar sets Graph-directed sets Overlapping Label Pisot number

SOLUTION PROPERTIES OF ANTITUMOR CARBOXYMETHYLATED DERIVATIVES OF α-(1→3)-D-GLUCAN FROM GANODERMA LUCIDUM

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Chinese Journal of Polymer Science 2001年第3期19卷 283-289页

作者： Li-na Zhang Mei Zhang Jing-hua chen Fan-bo Zeng department of Chemistry wuhan university, wuhan 4.0072, china Pharmacy College, Tongji Medical university, wuhan 4.0072, china wuhan Univ Dept Chem Wuhan 430072 Peoples R China Tongji Med Univ Coll Pharm Wuhan 430072 Peoples R China

Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38～0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or NaOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.

关键词： Solution properties Antitumor activity Carboxymethylated derivative α-D-glucan Ganoderma lucidum

Harmonic maps with potential from complete manifolds

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Chinese Science Bulletin 1998年第21期43卷 1780-1786页

作者： chen Qun mathematics department, Central china Normal university, wuhan 430079, china Institute of mathematics, Fudan university, Shanghai 200433, china mathematics department Central China Normal University Wuhan China Institute of mathematics Fudan University Shanghai China

Harmonic maps with potential from complete manifolds are considered. This is a new kind of maps more general than the usual harmonic maps relating to many interesting problems such as equilibrium system of ferromagnetic spin chain and Neumann motion. Aiming at the general properties, the author derives basic gradient estimates and then Liouville type results for these maps, which are interesting in constrast to those of the usual harmonic maps for the presence of potentials.

关键词： harmonic maps potential ferromagnetic chain gradient estimate.

ASYMPTOTIC BEHAVIOR OF HARMONIC MAPS FROM COMPLETE MANIFOLDS

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Chinese Annals of mathematics,Series B 1999年第2期20卷 247-254页

作者： chen QUN department of Matmematics Central China Normal UniversityWuhan 430079China. department ofmathematics Wuhan UniversityWuhan 430072China.

In this paper,the author considers a class of complete noncompact Riemannian manifoldswhich satisfy certain conditions on Ricci curvature and volume comparison. It is shown thatany harmonic map with finite energy from such a manifold M into a normal geodesic ball inanother manifold N must be asymptotically constant at the infinity of each large end of M. Arelated existence theorem for harmonic maps is established.

关键词： Ricci curvature VOlume comparison Fatou's property Harmonic map

Multiplicity of solutions for the semilinear subelliptic Dirichlet problem

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Science china mathematics 2024年第3期67卷 475-504页

作者： hua chen Hong-Ge chen Jin-Ning Li Xin Liao School of mathematics and Statistics Wuhan UniversityWuhan 430072China wuhan Institute of Physics and mathematics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China

In this paper,we study the semilinear subelliptic equation{−△Xu=f(x,u)+g(x,u)inΩ,u=0 on∂Ω,where△X=−∑m i=1 Xi∗Xi is the self-adjoint Hormander operator associated with the vector fields X=(X_(1),X_(2),...,X_(m))satisfying the Hormander's condition,f(x,u)∈C(Ω×R),g(x,u)is a Carathéodory function onΩ×R,andΩis an open bounded domain in R~n with smooth *** the perturbation from the symmetry method with the approaches involving the eigenvalue estimate and the Morse index in estimating the minimax values,we obtain two kinds of existence results for multiple weak solutions to the problem ***,we discuss the difference between the eigenvalue estimate approach and the Morse index approach in degenerate *** with the classical elliptic cases,both approaches here have their own strengths in the degenerate *** new phenomenon implies that the results in general degenerate cases would be quite different from the situations in classical elliptic cases.

关键词： degenerate elliptic equations Hormander operators perturbation method Morse index

Asymptotic Behaviour of the Phase in Non-Smooth Obstacle Scattering

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Acta Mathematica Sinica,English Series 1997年第1期13卷 81-89页

作者： chen hua (Institute of mathematics,wuhan university,wuhan 4.0072,china) Institute of mathematics Wuhan University 430072 Wuhan China

In this paper,we study the asymptotic behaviour of the scattering phase s（λ）of the Dirichlet Laplacian associated with obstacle,where Ω is a bounded open subset of IRn（n≥2） with non-smooth boundaryΩ and connected complement Ωe=IRn\.We can prove that if Ω satisfies a certain geometrical condition,then where φ（λ）=[（4π）n/2Γ(1+（n/2）]-1|Ω|nλn/2,dn>0 depending only on n,and |·|j（j=n-1,n）is a j-dimensional Lebesgue measure.

关键词： Scattering phase Counting function Dirichlet Laplacian Obstacle Exterior boundary problem Tessellation of domains

The Cyclicity of the Period Annulus Around the Quadratic Isochronous Center

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wuhan university Journal of Natural Sciences 2001年第4期6卷 754-758页

作者： chen Shi\|hua, Feng Jian\|wen, Zeng Xian\|wu School of mathematics and Statistics, wuhan university, wuhan 4.0072, china wuhan university School of Mathematics and Statistics Wuhan China (GRID:grid.49470.3e) (ISNI:***)

The number of the limit cycles bifurcating in small quadratic perturbations of quadratic systems with an ischronous center is studied, it turns out that the cyclicity of the period annulus around one kind of quadratic... 详细信息

关键词： cyclicity quadratic isochronous center perturbation