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1.
设G是n阶k-连通图(K≥3),称G的独立集S为一个基本集,如果存在,得得dist(u,v)=2,本文证明了下述结论:如果对G的任-k-基本集S有mux,则G或者是Hamilton-连通的或者属于两类例外图之一。  相似文献   

2.
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   

3.
如果图G的每对不同顶点u和v之间都有哈密顿路相连,则称G是哈密顿连通的;而如果对于所有满足条件以d(u,v)≤q≤n-1的整数q,u和v之间有长为q路相连,则和G是泛连通的,其中以d(u,v)是u和v间的距离,而n是G的顶点数。本文证明了下述两个结果:(1)2k+1个顶点的k正则简单图是哈密顿连通的,(2)k连通国中任何两顶点之间存在k-1条长度不同的路;进而如果G的顶点数小于2k,则G是泛连通的。  相似文献   

4.
如果对a≤i≤b,图G的任一对顶点u、v都存在长为i-1的路Pi(u,v),则称G是[ab]-泛连通的.文中证明了关于图的泛连通性的下述结果:设G为n阶连通图,且对G中任一对距离为2的顶点u,v,有d(u)+d(v)≥n,则图G是[5n]-泛连通的当且仅当G是H连通的.此结果推广了Faudree和Schelp的一个结论.  相似文献   

5.
Hamilton连通图的一个充分条件   总被引:1,自引:0,他引:1  
设G是n阶3-连通图,若对任意不相邻二点{u,v}V(G)有d(u)+d(v)+2|N(u)∪N(v)|≥2n+1,则G是Hamiton连通的。  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   

7.
设G 是一个n 阶简单连通图,k≥2 是一个整数.G 的k 阶幂图记作Gk ,定义为:V( Gk) = V( G) 且对任意u ,v∈V( Gk) ( u≠v) ,( u ,v) ∈E( Gk) 当且仅当dG( u ,v) ≤k ,则对任意的k≥2 ,Gk 本原.令E(k,n) = { γ( Gk)| G 是n阶简单连通图} ,可以得到E(k ,n) =dk k+ 1 ≤d ≤n - 1 ,  若2 ≤k≤n - 2 ,{2} ,            若k≥n - 1 .  相似文献   

8.
设G是2-连通图,对G中任一对不相邻的顶点u,v,|N(u)∪N(v)|≥s.Faudree猜测,当G的顶点数 s为奇数时,G的最长路的顶点数 本文证明猜测当s>3时是真的.进而证明了除一类图外P(G)≥min{|v(G)|,2s+l}.  相似文献   

9.
A.Benhocine等人证明了当G为几乎无桥的阶≥3的连通图且对任意不相邻的两点u,v有deg(u)+deg*v)≥(2n+1)/3时,有D-闭迹存在。我们掖了这一结果,并得到:若G为连通的几乎无桥的阶n〉3的图且对任意三点独立集{x,y,z}有deg(x)+deg(y)+deg(z)〉n则G含D-闭迹。e  相似文献   

10.
利用领域域交给出了图G的每个S-厚大圈都是S-D-圈的一个充分条件,并给出了对任意{u,v}包含V(G),G的每条(u,v)-S-最大路都是S-D-路的一个充分条件。  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.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

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