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1.
设G是一个简单图,(?)e∈E(G),定义e=uv在G中的度d(e)=d(u)+d(v),其中d(u)和d(v)分别为u和v的度数。若连通图G的每个桥都有一个端点度数为1,则称G是几乎无桥的图。本文的主要结果是:设G是p≥2阶几乎无桥的简单连通图,且G≠K1,p-1若对任何无公共顶点的两边e0及e1,d(e0)+d(e1)≥p+4,则G有一个D-闭迹,从而G的线图L(G)是哈密顿的。  相似文献   

2.
关于图Kn-H2n+i(i=1,2)的升分解   总被引:1,自引:0,他引:1       下载免费PDF全文
Yousef.Alavi等人在文献[1]中定义了一种新分解(Ascending Subgraph Decomposi- tion),即“升分解”,并且猜想:任意有正整数条边的图都可以升分解.本文证明了下面两个结 论: 1.Kn-H2n+1可以升分解,其中H2n+1为含有2n+1条边的Kn的子图; 2.Kn-H2n+2可以升分解,其中H2n+2为含有2n+  相似文献   

3.
设G是一个简单图,L=u1u2…ut是G中的一个路,定义L的度d(L)=∑ti=1d(ui),其中d(ui)为ui在G中的度数.本文证明了:若G是n≥3阶几乎无桥的简单连通图,GK1,n-1,且对G中任何两个无公共点的二长路L1,L2,有d(L1)+d(L2)≥2n-1,则G有一个D-闭迹,从而G的线图L(G)是Hamilton图.  相似文献   

4.
设G是无爪图.对x∈V(G),若G[N(x)]不连通,则存在yi∈V(G)-{x}(i-1,2),使|N(yi)∩Ki(x)|≥2,且|N(yi)∩N(Ki+1(x)){x}|≥2(i模2),那么称无爪图G是强2-阶邻域连通的,其中K1(x),K2(x)分别表示G[N(x)]的两个分支.本文证明了:连通且强2-阶邻域连通的无爪图是Hamilton图.  相似文献   

5.
一类泛圈图     
本文证明了如果 G 是 2 连通无爪图, G 不是圈,n= | V( G)|≥9, G 的每个导出子图 A都满足φ(a1,a2 ),且 G 中不含同构于 Z+2 的导出子图,则 G是泛圈图  相似文献   

6.
称有e条边的简单图G为调和图,若存在单射h:V(G)→Z,Z是模e的整数群,其导出映射h*:E(G)→Z;h*(vv)≡h(n)+h(v)(mode),n,v∈V(G)是一个双射,称h为G的一个调和标号三角形蛇图是一个其所有块都是三角形且其块-割点图为一条路的连通图。本文证明了具有t个块的三角形蛇图足调和的,当且仅当t≠2(mod4)。  相似文献   

7.
关于二部图K(m,n)-2的色唯一性   总被引:7,自引:0,他引:7  
设K(m,n)-2表示从完全二部图K(m,n)中删去任意2条边所得之图.本文证明了:1.若n≥m≥3,且n+m>((n-m)+8)1/2+1/2(n-m)+4,则K(m,n)-2是色唯一图;2.当m≥3时,K(m,m)-2,K(m,m+1)-2和K(m,m+2)-2均是色唯一图.  相似文献   

8.
本文讨论了积流形的P-形式上Laplace算子谱的唯一性问题,在紧Kachler流形乘积和紧Sasaki流形乘积的两类积流形中,CP×CP和S2n+1(1)×S2n+1(1)是P-形式上Laplacce算子谱特征。  相似文献   

9.
本文给出了一个关于长圈和长路的新的充分条件.主要结果是:设在3-连通图G中,任一对距离为2的顶点u,v,都满足max{d(u),d(v)}≥m/2,那么d(G)≥min{n-1,m-2}.  相似文献   

10.
对出现于公式Πn≥11/(1+dn/n!)=(1-t)e中的整数d给出了精确估计  相似文献   

11.
12.
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

13.
14.
正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with  相似文献   

15.
正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.  相似文献   

16.
A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].  相似文献   

17.
Résumé On décrit toutes les feuilles des laminations minimales dont un ensemble résiduel de feuilles ont 2 bouts.   相似文献   

18.
We develop a theory of downward sets for a class of normed ordered spaces. We study best approximation in a normed ordered space X by elements of downward sets, and give necessary and sufficient conditions for any element of best approximation by a closed downward subset of X. We also characterize strictly downward subsets of X, and prove that a downward subset of X is strictly downward if and only if each its boundary point is Chebyshev. The results obtained are used for examination of some Chebyshev pairs (W,x), where ∈ X and W is a closed downward subset of X  相似文献   

19.
In this paper, the author establishes the boundedness of multilinear operators on weighted Herz spaces and Herz-type Hardy spaces. The author also obtains their weak estimates on endpoints. As a special case, the conclusions may lead to the weighted estimates for multilinear Calderon-Zygmund operators.  相似文献   

20.
In this paper we present a generalized quantitative version of a result due to M. Revers concerning the exact convergence rate at zero of Lagrange interpolation polynomial to f(x) = |x|α with on equally spaced nodes in [-1, 1].  相似文献   

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