首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
设G是一个图,G的部分平方图G^*满足V(G^*)=V(G),E(G^*)=E(G)∪{uv:uv∈E(G),且J(u,v)≠φ},这里J(u,v)={w∈N(u)∩N(v),N(w)(∈)N[u]∪N[v]}.本文利用插点方法,给出了关于k,或(k+1)-连通(k≥2)图G是哈密尔顿的,1-哈密尔顿的或哈密尔顿连通的统一证明.其充分条件是在图G中关于^k∑i=1|N(Yi)|+b|N(y0)|与n(Y)的不等式,这里Y是图G的部分平方图G^*的任一独立集,对于i∈{1,2,…,k},Yi={yi,yi-1,…,yi-(b-1)}(∈ )Y(yj的下标将取模k);b是一个整数,且0<b<k+1;n(Y)=|{v∈V(G),dist(v,Y)≤2}|.  相似文献   

2.
设G是简单图,f是从V(G)UE(G)到{1,2,…,k)的一个映射.对每个u∈y(G),令c(u)={f(u)}v∈V(G),uv∈ E(G)}.如果,是k-正常全染色,且对任意u,v∈V(G)(u≠v),有c(u)≠c(v),那么称f为图G的k-点可区别全染色(简记为k-VDTC).数χvt(G)=min{k|G-有k—VDTC}称为图G的点可区别全色数.通过应用概率方法,证明了对任意最大度A≥2的图G,χvt(G)≤32(△+1).  相似文献   

3.
设G是n阶简单图,G的零特征值的重数记作G的零度(记作η(G)).本文考虑n阶(n≥6)单圈图,刻画η(G)=n-6和η(G)=n-7的所有n阶单圈图.  相似文献   

4.
设G是,n阶简单图.G的特征值零的重数称为G的零度(记作η(G)).在此确定了所有n阶(n≥6)双圈图的零度集合是[0,n-4],并且刻画了n(G)=n-4的所有,n阶(n≥9)双圈图,以及η(G)=n-5的所有n阶(n≥10)双圈图.  相似文献   

5.
对于简单的连通图G,它的零阶广义Randic指数0Rα(G)定义为Σv∈V(G)[dG(v)]α,其中α是一个给定的实数,dG(v)是G中顶点v的度.简单连通图G的零阶广义Randic指数是化学图论中一个重要的拓扑指数,其在化学领域中有着广泛的研究及应用.基于此对于任意的α(≠0,1),它给出了顶点个数为n,悬挂点为k的所有三圈图的零阶广义Randic指数0Rα的一些紧的界.  相似文献   

6.
拟双星图的N-G型的代数连通度的界   总被引:1,自引:0,他引:1  
文章利用图G的代数连通度与其线图的邻接谱半径之间的关系,给出:任n阶拟双星图G ,s0-1相似文献   

7.
完全二部图K5,n的点可区别IE-全染色   总被引:2,自引:0,他引:2  
设G是简单图,图G的一个k-点可区别IE-全染色(简记为k-VDIET染色)f是指一个从V(G)∪E(G)到{1,2,…,k}的映射,且满足:A↓uv∈E(G),有f(u)≠f(v);A↓u,v∈V(G),u≠v,有C(u)≠C(v),其中C(u)={f(u)}∪{f(uv)|uv∈E(G)}。数min{k}G有一个k-VDIET染色}称为图G的点可区别IE-全色数,记为χut^ie(G)。本文给出了完全二部图K5,n(n≥6)的点可区别IE-全色数。  相似文献   

8.
设G是一个图,若删除G中任意n’个顶点的剩余子图依然是分数k-消去图,则称G为分数(k,n')-临界消去图.笔者证明了若k≥2,n,≥0,bind(G)≥^(n'+1)且6(G)≥k+n'+1,则G是分数(k,n')-临界消去图.  相似文献   

9.
设G=(V,E)是一个简单的连通图;用A(G),D(G),分别表示G的邻接矩阵和顶点的度对角矩阵,令L(G)=D(G)-A(G)表示G的拉普拉斯矩阵,设L(G)的特征值为μ1≤μ2≤ ... ≤μn,其最大特征值称为图G的谱半径,记作μ=μn.本文就循环图的拉普拉斯谱半径的下界给与讨论,我们得到了两个结论.  相似文献   

10.
对图G及正整数k,映射σ:VUE→{1,2,…,k}满足:(1)任意e1,e2∈VUE,如果e1,e2是相邻或相关联的,则有σ(e1)≠σ(e2);(2)对u,v,w∈V(G),uw,vw∈E(G),uv¢E(G)有σ(u)≠σ(v),则称σ为G的一个k-点强全染色,并且xτ^vs(G)={k|存在G的k点强全染色},称为G的点强全色数.研究了六色系统图G的点强全色数,得到△(G)+l≤xτ^vs;(G)≤△(G)+2,其中△(G),xτ^vs(G)分别表示G的最大度和点强全色数.  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号