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1.
整数距离图以全体整数作为顶点集,顶点u、υ相邻当且仅当|u-υ|∈D,其中D是一个正整数集.对于m〉3,令Dm=[1,m]/[1,3].本研究得到了G(Dm)的点荫度.  相似文献   

2.
整数距离图G(Dm,2)的点线性荫度   总被引:1,自引:1,他引:1  
整数距离图G(D)以全体整数为顶点集,顶点u,v相邻当且仅当|u-t|∈D,其中D是一个正整数集.对于m≥11,设Dm.2={1,2,…,m}\{2},得到了G(Dm,2)的点线性荫度的上界和下界并决定出了它在某些特殊的m上的确切值.  相似文献   

3.
整数距离图G(D)以全体整数为顶点集,顶点u,v相邻当且仅当|u-v|∈D,其中D是一个正整数集.对于m>3,设Dm,3={1,2,…m}\{3},得到了G(Dm,3)的点荫度的上界和下界并决定出了它在某些m上的确切值.  相似文献   

4.
整数距离图G(D)以全体整数为顶点集,顶点u,v相邻当且仅当|u—v|∈D,其中D是一个正整数集.对于m〉3,设Dm,3={1,2,…m}\{3},得到了G(Dm,3)的点荫度的上界和下界并决定出了它在某些m上的确切值.  相似文献   

5.
整数距离图G(D)以全体整数为顶点集,顶点u,v相邻当且仅当|u-v|∈D,其中D是一个正整数集。对于m≥4k,k≥3,设Dm,k,3={1,2,…,m}\{k,2k,3k},得到了G(Dm,k,3)的点荫度的上界和下界并决定了它在某些m上的确切值。  相似文献   

6.
关于距离图着色问题的一点结果   总被引:3,自引:0,他引:3  
整数距离图是这样一类图G(Z,D),其中V(G)=Z,两点u,v之间有一条边相连,当且仅当|u-v|∈D,这里D∈ N.本文确定了|D|≥4时某些距离图G(Z,D)的点色数χ(G),解决了|D|=3时某些距离图G(Z,D)的star extremal问题.  相似文献   

7.
图G的平方图G2是以V(G)作为它的点集,两个点在G2中相邻当且仅当它们在G中的距离至多为2.证明了:若G是一个最大度Δ6的外平面图,则G2的点荫度va(G2)=「Δ+12?;特别地,一棵树T的平方图T2的点荫度va(T2)=「Δ+12?.  相似文献   

8.
设图G=(V , E)是简单图,其中V是顶点集,E是边集.对G中任意顶点v∈V, dv表示点v的度数.图G的Randic指数也称为图G的连通性指数,定义为R=R(G)=∑uv∈E(1)/(dndv).关于连通图的Randic指数R与直径D有如下猜想:R-D≥2-(n+1)/(2)且(R)/(D)≥(1)/(2)+(2-1)/(n-1),两个等式都成立当且仅当G≌Pn.本文将简化该猜想,并进一步证明当D≤(2(n-1)(3)/(2))/(n-3+2 2)或D≤n-3时,猜想成立  相似文献   

9.
对于一个具有单位元的环R,R的单位图记为G(R).它的顶点是R中的元素,两个不同的顶点x和y相连当且仅当x+y是环R的单位.设G是一个图,V是G的顶点集,D是V的一个子集,若对于V\D的任一点,都存在D中至少一点与之相连,则称D是G的一个控制集,含有顶点数最少的控制集称为图G的一个γ-集,所含的顶点个数称为G的控制数.该文主要研究一类有限环的单位图的控制数,完全确定了当有限交换环R的直和分解恰好是3项时,环R的单位图的控制数.  相似文献   

10.
图G的平方图,记作G^2,是一个以原图的顶点集为顶点集,若原图中两点的距离不大于2则连以边所成的图.本文确定了圈的平方图的色数.对于外部平面图,得到以下结论:设G是一个最大度为△(G)的简单连通外部平面图,G≠C5.则x(G^2)≤△(G) 2.  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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