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1.
文章证明了c≥2的正则c-部竞赛图D,V1,V2,…,Vc是D中的部集,如果|V1|=|V2|=…=|Vc|=r≥6,那么D包含一条阶为3c的有向路.进一步,如果r≥9,那么D包含一条来自每一部集至少两个顶点且阶为4c的有向路.更进一步,如果r≥3(n-1),这里n∈N+而且n≥3,那么D中包含一条来自每一部集至少两个顶点且阶为nc的有向路.  相似文献   

2.
研究了扩张竞赛图中的泛连通性点对的存在性问题。证明了如果传递的扩张竞赛图D不是竞赛图,那么D中不包含泛连通性点对。研究了扩张竞赛图中存在泛连通性点对的充分条件:证明了(a)设D1,D2,…,D1是连通但非强连通的扩张竞赛图D的一个强分支无圈序。若Di(i=1,2,…,f)有1一路一圈因子,则D中必存在泛连通性点对。午且找到泛连通性点对的时间复杂度为0(n^0.5).(b)设D是由连通但非强连通竞赛图r的强分支t(1y(t)1≥3)平衡扩张而成的,(当Iy(t)I=1时,Ti不变),则D中必存在泛连通性点对。  相似文献   

3.
给定一个竞赛图T=(V,A),与T相关联的偏序集P是一个偏序集P1=(V,≤),使得V.x,y∈V(T),x≤y当且仅当x=y或者d(x,y)≥3.证明了每一个竞赛图都与一个偏序集相关联,但存在偏序集不与任何竞赛图相关联.此外,还对与竞赛图相关联的偏序集的性质进行了讨论.  相似文献   

4.
2008年N.Lichiardopol在离散数学-竞赛图中经过给定0,1,2个公共顶点的圈.一文中提出以下公开问题:阶为2n+1的正则竞赛图T,对于任意的x∈V(T)是否存在n个有向三角形Ti使得V(Ti)∩V(Tj)=x(1≤i≤j≤n).文章证明了对于阶数为5,7,9的正则竞赛图,该问题答案是肯定的.  相似文献   

5.
设G=(X,Y;E)是连通二部图,│X│= │Y│=n,则(1)NC2=n≥4,则G是点泛圈偶图。(2)NC2≥n-1≥4,且6≥2,则G含有Hamilton圈,或者G的任何一点都含在G中长为2n-2的圈中,且这个圈为G的控制圈。  相似文献   

6.
设D是一个有向图,D中所有可能的两点x与y(x与y可以相同)的出度与 入度之差的绝对值的最大值叫做有向图D的非正则性,并记为i(D)。如果i(D)= 0,则称D为正则图;如果i(D)=1,则称D为几乎正则图。本文给出了几乎正则的n -部竞赛图的若干性质。  相似文献   

7.
圆可分解的局部竞赛图中的点外弧泛圈问题   总被引:1,自引:0,他引:1  
Yao Tianxing(Discrete Appl.Math.,2000,99:245-249)已经证明了每一个强连通竞赛图都包含点,它的每条外弧都是泛圈的.将此结论推广到强连通的圆可分解的严格局部竞赛图,并证明了每一个强连通的圆可分解的严格局部竞赛图D,它的圆分解是D=R[D1,D2,…,Da],其中Di,i=1,2,…,a是强连通竞赛图,那么D包含一个点v,它的每条外弧是(g 1)-泛圈的,g=max{l(Ca)|Ca是包含a的最长诱导圈,a∈V(R),l(Ca)是Ca的长度}。  相似文献   

8.
设G是一个n阶图,若对于每一个k (3≤k≤n),图G都含有k-圈,则称图G为泛圈图.泛圈图是圈理论研究中的重要课题.研究得到了Hamilton圈上两个不相邻的点在圈上的距离是3的泛圈性结果.  相似文献   

9.
讨论了部数为3和4的几乎正则多部竞赛图的Hamilton性质,证明了如下结论:(1)几乎正则非平衡4部竞赛图T,如果r≥8(其中r=max{|Vi‖i=1,2,3,4}),并且T有一个圈因子,则T是Hamilton的;(2)几乎正则平衡3部竞赛图T,如果r≥10,r≠11(其中r=max{|Vi‖i=1,2,3}),并且T有一个圈因子,则T是Hamilton的;(3)几乎正则非平衡3部竞赛图T,如果r≥18,r≠19,并且T有一个圈因子,则T是Hamilton的.  相似文献   

10.
设G是一个偶图,u是偶数且是G的阶,若对每个偶数t,4≤t≤v,G恰有一个长为t的圈,则称G是唯一偶泛圈图(简称UB-图)。作者证明恰有6个v 4条边的UB-图。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

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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