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1.
设v是图G=(V,E)的顶点,若存在顶点u∈V-{v},使子图G[N(v)∪{u}中任意一对顶点的距离不超过3,则称v是G的弱局部连通顶,点。设G是非平凡的连通无爪图,且它的任一顶点割均钫含一个弱局部连通顶点,则G包含Hamilton圈。  相似文献   

2.
假定G是顶点数的n的2-连通图,G中顶点数为4且包含爪K1.3的子图称为爪型子图。本文证明了对G的任一爪型图F,任何u,v属于V(F),由距离d(u,v)=2=│N(u)UN(v)│≥2n-1/3,则G是哈密顿图。  相似文献   

3.
本文主要证明了下面两个结论:(一)设G是3-连通无爪图,若存在顶点x∈v(G)使,则G是H-图。(二)设C是n阶尽连通无爪图(k≥2),则c的周长c(G)≥。  相似文献   

4.
设G是具有二分类(X,Y)的2连通等部偶图。如果对G中每一个顶点v,H是G中与v距离为2和3的所有顶点导出的子图,并且对于g中每一个与v距离为3的顶点u,u在H中的度数d_H(u)不小于距离v为2的顶点的数目减去(dG(v)-2),则G是Hamilton图。其中d_H(u)的下界不能改进。  相似文献   

5.
证明了下列结果:(1)设G是3连通无爪图,│V(G)│≥6且G的每个导出图A都满足φ(a1,a2)那么对任意u,v∈V(G),若2≤d(u,v)≤5,则对满足d(u,v)≤k≤5的整数k,G中存在(u,v)-k路(2)设G是3连通无爪图,│V(G)│≥6,且G的每个导出子图A都满足φ(a1,a2)而P=v1,v2,...v5(v1=u,v5=v)是G的(u,v)-4路G(V(P)=K│v(p)│则  相似文献   

6.
以γ(G)记图G的控制数,如果对v(G)中任何一对满足条件uvE(G)的顶点u,v,有γ(G+uv)<γ(G),则称G是控制临界的。γ(G)=k的控制临界图称为是k-控制临界的,得出以下两个结果:1)如果G是具有以(>>2k)个顶点的连通3-控制临界图,则G中度≤2k的顶点的个数至多为2k.2)每个连通3-控制临界图或者有一个独立3-控制集或者有一个完全3-控制集。  相似文献   

7.
以γ(G)记图G的控制数,如果对V(G)中任何一对满足条件uv不包于E(G)的顶点u,v,有γ(G+uv)<γ(G),则称G是控制临界的γ(G)=k的控制临图图称为是k-控制临界的,得出以下两个结果:1)如果G是具有n(>>2k)个顶点的连通3-控制临界图,则G中度≤2k的顶点的个数至多为2k,2)每个连通3-控制临界图或者有一个独立3-控制集或者有一个完全3-控制集。  相似文献   

8.
设G是n阶简单3-连通图,δ是G的最小度,uv是G的两个不相邻顶点,a(u,v)是G中包含u,v的最大独立数,本利用图G的任意两个距离为2的顶点u,v的独立数a(u,v),给出了图具有Hamilton性质的两个新的充分条件。  相似文献   

9.
设G是n阶3-连通无向简单图,α表示图的独立数.若对G的所有距离为2的顶点u,v,都有d(u)+d(v)≥n或|N(u)∩N(v)|≥α,则G是Hamilton连通的,除非G属于一个特殊图类.  相似文献   

10.
设G是连通图,X=V(G),G〔X〕是G的X生成子图,记σk(X)=min{Σi=1 k d(Vi);{v1,v2,…,vk}是G〔X〕的顶点独立集},得到如下结果,对于n阶的1-坚韧图(n≥3),X=V(G),且σ3(X)≥n+r≥n,3│X│-2n≥8t-6r-17,则存在一个圈C满足│C(X)│≥{C(X)│≥{│X│,│N(It)∩V(C)│},其中It是X中t个顶点的独立集。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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