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91.
Hua-Shui Zhan 《Southeast Asian Bulletin of Mathematics》2000,24(2):341-343
The paper proves that every three-manifold with non-negative Ricci curvature and quadratic volume growth in strict sense must be contractible provided that its universal covering is finite.AMS Subject Classification (2000) 53C20 相似文献
92.
YEH Yeong-Nan 《中国科学A辑(英文版)》2006,49(10):1383-1391
Let G be a simple graph. Define R(G) to be the graph obtained from G by adding a new vertex e* corresponding to each edge e = (a,b) of G and by joining each new vertex e* to the end vertices a and b of the edge e corresponding to it. In this paper, we prove that the number of matchings of R(G) is completely determined by the degree sequence of vertices of G. 相似文献
93.
94.
Huashui ZHAN 《数学年刊B辑(英文版)》2012,33(5):767-782
Consider the following Cauchy problem:u_t = div(|▽u ~m |~ p-2▽u~m),(x,t) ∈ST=R~N ×(0,T),u(x,0) = μ,x ∈R~N,where 1
相似文献
95.
在Lω-空间中,借助于ω-连续的L值Zadeh型函数,给出ω-Tychonoff分离性的定义,并系统研究ω-Tychonoff分离性的特征性质。证明ω-Tychonoff分离性是可遗传的、任意可乘的、ω-弱同胚不变的。 相似文献
96.
Xingyu Mao Zhijian KeWeidong Zou Qiubao LinZhijie Qin Yan Wu 《Journal of magnetism and magnetic materials》2012,324(4):389-393
The dynamic magnetization processes of nanocrystalline Fe80Ge3Nb10B7 alloys after annealing at different temperatures are studied through the permeability spectroscopy. Three steps of crystallization are found when amorphous Fe80Ge3Nb10B7 alloys are heated from 300to 1200 K. The dominant magnetization process varies with different annealing temperatures. Domain wall bulging is the main magnetization mechanism under weak applied field. When the applied field exceeds pinning field Hp, the depinning-involved domain wall displacement occurs. Different annealing temperature results in different Hp. The lower value of μ′ and high relaxation frequency after heating at 923 and 973 K are due to the strengthened domain wall pinning and the increase of magnetocrystalline anisotropy. 相似文献
97.
S. Shen F. Liu V. Anh I. Turner J. Chen 《Journal of Applied Mathematics and Computing》2013,42(1-2):371-386
In this paper, we consider a variable-order fractional advection-diffusion equation with a nonlinear source term (VOFADE-NST) on a finite domain. Combining the characteristic method and the finite difference method, a characteristic finite difference method for solving the VOFADE-NST is presented. Its stability and convergence are analyzed. This new method is shown to be more efficient and superior to the standard finite difference method. Numerical experiments are carried out and the results demonstrate the effectiveness of theoretical analysis. 相似文献
98.
Luzhen Ye 《Linear and Multilinear Algebra》2013,61(6):645-650
The resistance distance is a novel distance function on a graph proposed by Klein and Randi? [D.J. Klein and M. Randi?, Resistance distance, J. Math. Chem. 12 (1993), pp. 81–85]. The Kirchhoff index of a graph G is defined as the sum of resistance distances between all pairs of vertices of G. In this article, based on the result by Gutman and Mohar [I. Gutman and B. Mohar, The quasi-Wiener and the Kirchhoff indices coincide, J. Chem. Inf. Comput. Sci. 36 (1996), pp. 982–985], we compute the Kirchhoff index of the square, 8.8.4, hexagonal and triangular lattices, respectively. 相似文献
99.
利用先验估计的方法讨论具非线性第二边界条件的快扩散方程解的存在性、唯一性、稳定性和渐近性.主要结果是:1)存在唯的整体广义解,解连续依赖于初值;2)存在T0,t<T0时解是无穷次可微的正则解;3)当t充分大时,解一致收敛到零. 相似文献
100.
WU Hong-Xia LIU Xiao-Jun ZENG Yun-Bo 《理论物理通讯》2009,51(2):193-199
We firstly propose two kinds of new multi-component BKP (mcBKP) hierarchy based on the eigenfunction symmetry reduction and nonstandard reduction, respectively. The first one contains two types of BKP equation with self-consistent sources whose Lax representations are presented. The two mcBKP hierarchies both admit reductions to the k-constrained BKP hierarchy and to integrable (1+1)-dimensional hierarchy with self-consistent sources, which include two types of SK equation with self-consistent sources and of hi-directional SK equations with self-consistent 相似文献