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1.
只含一个圈的简单连通图称为单圈图.郭继明给出了固定圈长的单圈图的Laplace谱半径并刻画了相应的极图.该文在此基础上确定了圈长为g的所有n=g+k(g≥5,k≥3)阶单圈图的Laplace谱半径从大到小的前[g/2]个图.  相似文献   

2.
研究一些偶单圈图按其Laplace谱半径排序的问题.利用扩圈变换对偶单圈图S1k的Laplace谱半径影响的证明方法,得出了顶点数为k+2,圈长为k(k≥10)的偶单圈图C(k+2,k)按其Laplace谱半径从大到小的顺序依次排在前三位和最后一位的单圈图.  相似文献   

3.
在郭曙光和刘颖等人确定了阶数固定的单圈图的第一到第九大 Laplace 谱半径的基础上,给出了阶数为 n(n≥11)的单圈图的 Laplace谱半径的第十大值到第十三大值, 并刻画达到这 4 个数值的 n 阶单圈图.  相似文献   

4.
设G为n阶的连通k(k≥3)圈图,λ1(G)是图G的laplacian矩阵的最大特征值.本文讨论了圈长为3的k圈图的最大特征值与其顶点数及各顶点的悬挂边个数之间的关系.  相似文献   

5.
按树的最大Laplace特征值对树进行排序   总被引:1,自引:1,他引:0  
通过对n阶树T的结构分析,得到了一些特殊的变换对树T的最大Laplace特征值的影响,然后利用这些结论,得出了按树T的最大Laplace特征值进行排序的一些结果.  相似文献   

6.
通过对n阶树T的结构分析,利用一些特殊变换对树T的最大Laplace特征值的影响,得出了按树T的最大Laplace特征值对树进行比较的新结果。  相似文献   

7.
主要研究最大匹配数为q的n阶单圈图谱半径的排序问题。采用移接变形的方法,在具有n个顶点和最大匹配数为q(q≥4)的单圈图中找出了谱半径为前三大的图。  相似文献   

8.
一个图G的邻接矩阵A(G)是n×n矩阵,如果v_i和v_j相邻,那么它的(i,j)位置为1,否则为0.图G的谱半径是邻接矩阵A(G)的最大特征值.本文确定了在所有的树和所有的二部单圈图、二部双圈图、二部三圈图、二部四圈图、二部五圈图以及二部拟树图中所对应的具有最大谱半径的图.  相似文献   

9.
单圈图依次小Q-特征值排序   总被引:1,自引:1,他引:0  
n阶图G叫做单圈图,如果G是连通的,并且G的边数也是n.图G的无符号拉普拉斯矩阵定义为Q(G)=D(G)+A(G),其中D(G)是以G所有顶点的度为对角元的对角阵,A(G)是图G的邻接矩阵.Q(G)是一个实对称的半正定矩阵,设它的特征值为q1(G)≥q2(G)≥…≥qn(G)≥0.图G的依次小Q-特征值为qn-1(G),简记为k(G).主要研究单圈图的k(G),记阶数为n的所有连通的单圈图的集合为U(n),给出了当阶数n≥25时,U(n)中依次小Q-特征值为前3大的图.  相似文献   

10.
讨论了双圈图的最大和最小特征值,给出了其最大特征值随圈上点的变化关系; 讨论了双圈图的最小特征值的下界; 当n≥18时双圈图中最小特征值达到最小的极图为Sn(3,3). 在此基础上给出了双圈图谱展的上界.  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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