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1.
设G为简单图. G的全k-染色是指k种颜色对图G的全体顶点及边的一个分配.设c是图G的一个全k-染色,任意的x∈V(G),称w(x)=Σx∈ec(e)+Σy∈N(x)c(y)为点x的扩展和,其中N(x)={y∈V(G)|xy∈E(G)}.称图G的全k-染色c为邻点扩展和可区别(简记为NESD),如果w(x)≠w(y),其中xy∈E(G).图G的NESD全k-染色的最小值k被称为图G的邻点扩展和可区别全色数,简记为egndi∑(G).本文探讨了轮,扇,星和双星的邻点扩展和可区别全染色,并得到了它们的邻点扩展和可区别全色数.  相似文献   

2.
G是一个简单图,G的一个E-全染色f是指使相邻点着不同色且每条关联边与它的端点着以不同的色的全染色。设f为G的一个E-全染色。对任意点x∈V(G),用C(x)表示在f下点x的色以及与x关联的边的颜色所构成的集合。若u,v∈V(G),u≠v,有C(u)≠C(v),则f称为是图G的点可区别的E-全染色,简称为VDET染色。图G的VDET染色所用颜色数目的最小值称为图G的点可区别E-全色数或简称为VDET色数,记为χevt(G)。讨论并给出了完全二部图K3,n(n≥18)的点可区别E-全色数。  相似文献   

3.
设G是一个图,并设h是定义在图G的边集E(G)上的一个函数,使对任意的e∈E(G),有h(e)∈[0,1]。令dhG(x)= x瘕?h(e),则称dhG(x)是G中顶点x的分数度。若h满足对任意的x∈V(G),有g(x)≤dhG(x)≤f(x),则称h是G的一个分数(g,f)-因子。一个图称为分数(g,f)-2-覆盖图,如果对图G中的任何两条边e1和e2,G都有一个分数(g,f)-因子h满足h(e1)=1和h(e2)。本文给出了一个图是分数(g,f) 2 覆盖图的充分必要条件。  相似文献   

4.
设G是一个顶点集为V(G),最小度为δ(G),独立数为α(G)的图,k≥2是整数。图G的支撑子图F称作是图G的分数k-因子,如果对于每一个x∈V(F)都有dh G(x)=k。如果对于图G的每条边e,图G都有一个分数k-因子包含它而且同时有一个分数k-因子不包含它,则称图G为分数k一致图。证明了如果δ(G)≥k+2,且α(G)≤4k(δ-k-1)/(k+1)2,则图G是一个分数k一致图。  相似文献   

5.
对于非平凡连通图G,G的k集染色是指映射c:V(G)→Nk,对任意顶点v∈V(G),定义邻色集cN(v)={c(u)|u∈N(v)},若对uv∈E(G)有cN(u)≠cN(v),则称c为G的一个k集染色.满足上述条件的最小k值称为G的集色数,记为χs(G).为了更快更有效地给Halin图着色,采用集染色的着色方法,证明了当p≥4时,Halin图G(Cp,Tq)的集色数是3,并且还证明了对任意的Halin图G(Cp,Tq),有p+1≤q≤2p-2成立.  相似文献   

6.
一个n阶连通图G的Hamiltonian染色是从G的顶点集V(G)到正整数集N(称为颜色集)的一个映射c,使得对于G的任意2个不同的顶点u和v满足|c(u)-c(v)|+D(u,v)≥n-1,其中D(u,v)表示G中u到v的最长路径的长度。对一个Hamiltonian染色c,将max{c(u):u∈V(G)}称为c的值,记作hc(c)。将min{hc(c):c是G的任意Hamiltonian染色}称为G的Hamiltonian色数,记作hc(G)。本次研究得到了满足max{D(u,v)|u,v∈V(G),u≠v}≤n/2的d-重似星树和广义双星这两类树图的Hamiltonian色数的确切值。  相似文献   

7.
设G,H是阶至少为2的简单图。图G与H的强直积是指这样一个图G□×H,其顶点集合为V(G)×V(H),并且(x1,x2)(y1,y2)∈E(G□×H)当且仅当[x1y1∈E(G)且x2y2∈E(H)]或者[x1=y1且x2y2∈E(H)]或者[x2=y2且x1y1∈E(G)]。一个图G的使用了k种颜色的2-距离染色是指一个从V(G)到{1,2,…,k}的映射f,使得任意两个不同的距离最多是2的顶点染不同的颜色。对图G进行2-距离染色所需的最少的颜色数称为图G的2-距离色数,记为χ2(G)。文中将获得两个图的强直积的2-距离色数的可达到的上界和下界:Δ(G□×H)+1≤χ2(G□×H)≤χ2(G).χ2(H)。对一些特殊图,例如Pm□×Kn,Pm□×Wn,Pm□×Sn,Pm□×Fn,Pm□×Cn(n≡0(mod3)或者n=5),给出了它们的2-距离色数。  相似文献   

8.
设G是一个简单图,f为G的一个E-全染色.对任意点x∈V(G),用C(x)表示在f下点x的色以及与x关联边颜色所构成的集合.若u,v∈V(G),u≠v,有C(u)≠C(v),则f称为图G的点可区别E-全染色,简称VDET染色.图G的VDET染色所用颜色数目的最小值称为图G的点可区别E-全色数(简称为VDET色数),记为χevt(G).利用分析法和反证法,讨论并给出完全二部图K3,n(3≤n≤17)的点可区别E-全色数.  相似文献   

9.
将经典的Mobius反演公式在Gauss半群上作了进一步的推广.即如果对任何c∈G恒有g(c,x)=∑c∈GAaf(ac,x)则有Mobius反演公式∑h∈Uf(hc,x)=1/N∑b∈GBbg(bc,x)其中G为Gauss半群.  相似文献   

10.
令G是含n个点的边染色图,对G中任意顶点x,定义其色邻域CN(x)为集合{c(xy)|xy∈E(G),y∈V(G)}。如果G中任意相邻的两条边都染有不同的颜色,就称G是正常染色的。证明了如果边染色图G满足对V(G)中任意两点u,v有|CN(u)∪CN(v)|≥4n/3+8,则图G含有一个正常染色2-因子。  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 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   

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 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   

15.
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   

16.
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   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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