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1.
图的可圈性是哈密尔顿性的一个推广.设G是有向图,如果对G的每一个定向D,都存在S(D) V(G)使在D中改变所有恰与S(D)中一个顶点相关联的弧的方向后所得到的图为有向哈密尔顿图,则称G为可圈图.证明至少含5个顶点的连通图G的立方图是可圈图当且仅当G不同构于任何一条偶路.该结果改进了Klostermeyer的3个定理.  相似文献   

2.
本文从哈密尔顿回路的定义和图的邻接矩阵的定义入手,寻找到了一种图存在哈密尔顿回路时,它的邻接矩阵所表现出的一种特殊形式。  相似文献   

3.
Lenhard Ng(1997)给出k-可序(k-ordered)哈密尔顿图的定义,并证明了每一个(k 1)-Hamilton-连通图都是k-可序哈密尔顿图.Faudree J R(2000)将k-可序哈密尔顿图的定义改进为k-可序图.根据Lenhard Ng提出的开问题:是否存在3-正则4-可序哈密尔顿图的无限类,以及Faudree J R给出的可序图的定义.构造了3-正则4-可序图的无限类.  相似文献   

4.
树T中度为1的点称为叶子,叶子数目不超过k的树称为k-端点树.图中存在一个哈密尔顿路,说明图中存在恰好含有两个叶子的支撑树.自然就有了关于哈密尔顿路问题的一个推广:考虑图中至多有k个叶子的支撑树即支撑k-端点树的存在性问题.通过控制集参数,确定了连通无爪图中存在支撑k-端点树条件.  相似文献   

5.
图G的路图P_k(G)是依下述方法得出的图:以G中的有k个顶点的路P_k作为顶点,且两个顶点相邻当且仅当对应的P_k的并是G中的路P_(k-1)或圈C_k。本文给出了下列结论:1)不存在最大度大于3且具有哈密尔顿P_(3-)图的树;2)不存在最大度大于3且具有哈密尔顿P_(3-)图的单圈图;3)给出了最大度为4且有哈密尔顿P_(3-)图的单圈圉的特征,因而证明了由H.J.Broersma和C.Hoede提出的两个猜测。  相似文献   

6.
§1 有序定向竞赛图中的哈密尔顿回路令U_1,…,U为竞赛图T中的顶点。令d_(?)~ 为U_i的出度。如果每个U_i恰好指向U_(i 1),…,U_(i d~ ),(modn),其余的顶点指向U_i,则T被称为有序定向的。 Alspach等人曾在这类图中的回路计数问题上作了一些工作。本文将讨论的是这类图中哈密尔顿回路的计数问题。Thomassen曾提出这个问题:在同样的出度序列条件下,那一  相似文献   

7.
关于一个图是否为哈密尔顿图成立的充分条件,目前主要有两个研究方向,其一是参数的角度,主要有最小度、邻域、度和问题以及独立数等条件;另一个方向从图的结构上出发,在禁用某些特定子图的条件下描述.本文主要对各类哈密尔顿图成立的充分条件进行了概括总结,其中针对禁用子图,尤其是针对无爪图和半无爪图下哈密尔顿性成立的充分条件的概括...  相似文献   

8.
本文证明星形图的推广安置图并行结构是有哈密尔顿回路的,从而为今后在这种网络上设计算法打下了基础。文章还提出两种广义安置图结构,并初步讨论了它们的性质。  相似文献   

9.
图的谱半径和无符号拉普拉斯谱半径在研究图的结构和性质中发挥着重要作用。本文从边条件出发,通过计算得出度序列并刻画其对应的图形,进而对这些满足给定边条件的图是否为哈密尔顿图进行了研究,在此基础上把图的谱半径、无符号拉普拉斯谱半径与边条件联系在一起,对图的哈密尔顿性的充分条件进行了探讨。通过边条件和谱条件探讨图的哈密尔顿性是研究图哈密尔顿性的一种可行、有效的方法。  相似文献   

10.
本文研究的是简单图,它的邻接矩阵是表示顶点之间相邻关系的矩阵,它的最大特征值被定义为图的谱半径.如果图中有一条包含图中所有顶点的路,则称这条路为哈密尔顿路;如果一个图含有哈密顿路,则称该图是可迹图.设图具有最小度条件,本文主要研究了利用图的补图的谱半径给出图是可迹图的充分条件.  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.
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.
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   

20.
<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   

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