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1.
本文证明:设G为n阶2连通图,D(x)={y|y∈V(G),d(x,y)≤2},d_d~*(x)表示D(x)中所有的点的度排成的非减度序列:d_1~*,d_2~*,…,d_j~*,d_(j+1)~*,…,d_(|D(x)|)~*中当下标j=d(x)时的度。δ_0=min{d(x)|x∈V(G)},D(δ_(i-1))={x|x∈V(G),d(x)≥δ(i-1)}(i=1,2,…,k),δ_i=min{d_(d(x))~*|x∈D(δ(i-1))}(i=1,2,…,k)且δ_0<δ_1<δ_2<…<δ_(k-1)≤δ_k,则C(G)≥min{n,2δ_k}。此外也给出δ_k的算法。  相似文献   

2.
给一个图G,XV(G),G[X]为G的X生成子图,r为正整数。定义α(X)=max{|S|}S是G[X]的顶点独立集},αk(X)=min{∑ki=1d(vi)|{v1,v2,…,vk}是G[X]的顶点独立集},NCk(X)=min{|Uki=1N(vi)|{v1,…,vk是G[x]的独点独立集}(k≥2).我们得到结论;对—任意的n阶2-连通图G(n≥3),xG,且α3(X)≥n+r≥n+2,则存在一个包含X的顶点数为min{|X|,[X]+NC,+2+e(n+r)(X)-α(X)}的圈,ε(i)=3〔1-3i〕-1-3i.该结论推广了H.J.Broersma在文献[1]中的结果.  相似文献   

3.
运用 Diophantine 方程的相关知识,确定方程:a2(k 2,s(n))=2(k 1,s(n)) a2(k,s(n)):(1)对任意正整数r和6,设a(r,6)是b的前r住数字所组成的数,n,k∈N 的所有解.(2)对任意正整数r和b,设a(r,6)是b的后r位数字所组成的数的所有正整数解(n,k).  相似文献   

4.
一类正负相间方幂和中因子3的指数(英文)   总被引:2,自引:0,他引:2  
给出下面正负相间方幂和中因子 3的指数公式 : 2n - 1k =0 (- 1) k[x +dk]r,d =3s+1,d =3s+2 ,d =3s +3其中r ,n ,x是正整数 ,s是非负整数 ,n =3am ,3 m .  相似文献   

5.
对于任意正整数a,令σ(a)表示a的所有因子之和.设n是一个固定的正整数,称正整数x是n-完全数,如果它满足σ(x)+σ(nx)=2(n+1)x.运用σ(a)的一些性质讨论了2~r-完全数的存在性,其中r是固定的正整数,证明了x是2~r-完全数当且仅当x=2~s(2~(r+s)+2~s-1),其中s是正整数,2~(r+s)+2~s-1是一个奇素数.  相似文献   

6.
本文证明了:设 l、n、b、r 为正整数,方程 (b-2~rk)~l= (b+2~rk)~l 仅有正整数解 l=1,b=2~rn(n+1)和1=2,b=2~(r+1)n(n+1).  相似文献   

7.
设G是连通图,XV(G), G[X]是G的X生成子图.记α(X)=max{|S|:S是G[X]的顶点独立集}, ak(X)=MIN{k∑i=1d(vi):{v1,v2,...,vk}是G[X]的顶点独立集}, NCk(x)=min{|kUi=1N(vi)|:{v1,v2,...,vk}是G[X]的顶点独立集}(k≥2). 本文得到如下结果:对于n阶的1-坚韧图(n≥3), XV(G)且σ3(X)≥n+r≥n, r为正整数,则存在一个圈C满足|C(X)|≥min{|X|,|X|+NCr+5+ε(n+r)(X)-α(X)}, 其中ε(i)=3「1/3i」.-1/3i 此结果推广了H.J.Broersma等在文献[2]中的结果.  相似文献   

8.
方幂和中因子3的指数(英文)   总被引:6,自引:2,他引:4  
给出下面方幂和中因子 3的指数公式∑n - 1k =0 (x +kd) r,d =3s+ 1,3s+ 2 ,3s+ 3 ,其中x ,r ,n是正整数 ,s是非负整数 ,n =3am ,3 m  相似文献   

9.
对于图G的任意两个顶点x和y,如果G有一条(x,y)-生成迹,则称图G是迹连通的。给定一个整数s≥0,对于任意点子集X?V(G)并且|X|≤s,如果G-X是迹连通的,则称图G是s-迹连通。设k是一个正整数,图G的k次幂图记为G~k。设t(G)是t一个最大值s使得图G是s-迹连通但不是(s+1)-迹连通,设C_n是一个包含n个点的圈,k是一个正整数并且k≥2,将证明:t(C_n~k)={2k-3,如果n=2k+2 2k-2,如果n≥2k+3 n-3,如果n≤2k+1  相似文献   

10.
主要给出了图G恰好含有s个K3和k-s个K4的最小度条件即:设G是一个简单图,s,k是两个正整数且s k,其中G的顶点个数n≥3s+4(k-s)+3,如果G中任意两个不相邻顶点的最小度之和σ2(G)≥4n-3s-8/|2|或者最小度δ(G)≥3n+2k-s-2/4,则G包含k个顶点不相交的圈C1,C2…Ck,并且Ci=K3其中1≤i≤s,Cj=K4其中sj≤k.  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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