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1.
研究了如下一种场站设置问题:设S是欧空间Rm中由有限个点A1,A2,…,An组成的集合,d(Ai,Aj)表示点Ai和Aj之间的距离.令σ(s)=∑d(Ai,Aj),d(S)=min {d(Ai,Aj)},l≤i<j≤n 1≤i≠j≤nμ(m,n)=σ(S)/d(S)(S(∈) Rm,|...  相似文献   

2.
一种离散点集极值问题的几个结果   总被引:1,自引:0,他引:1  
平面凸n边形A1A2…An中记μn=∑1≤i≠j≤nd(Ai,Aj)min1≤i≠j≤nd(Ai,Aj)(d(Ai,Aj)表点Ai与点Aj之间距离),证明了μn的最小值只有当各边长等于min1≤i≠j≤nd(Ai,Aj)时才能取得,且μn的下确界为15+33,下确界取得仅当凸六边形退化为等边三角形。还证明了等边凸六边形当任一对角线长不小于边长时,μn的最大值为12+63。  相似文献   

3.
设G是一个图,对于任意U()V(G),令N(U)=Uu∈UN(u),d(U)=|N(U)|.我们给出了两个结果:设s和t是正整数,G是(2s 2t 1)-连通图,且阶为n;若对于任两个强不交独立集ST,|S|=s,|T|=t,有d(S) d(T)≥n 1,则G是哈密尔顿连通的或1-哈密尔顿.  相似文献   

4.
设S=(a_1,…,a_m;b_1,…,b_n),其中a_1,…,a_m和b_1,…,b_n是2个非增的非负整数序列.如果存在一个简单二部图G=(X∪Y,E),使得a_1,…,a_m和b_1,…,b_n分别是X和Y中顶点的度,则称S=(a_1,…,a_m;b_1,…,b_n)为一个二部可图对.设A是一个阿贝尔群(以"0"为单位元的加法群),定义σ(A,m,n)是最小的正整数k使得每一个二部可图对S=(a_1,…,a_m;b_1,…,b_n)满足a_m,b_n≥2且σ(S)=a_1+…+a_m≥k时都有一个A-连通实现,确定了当|A|=4且m≥n≥3时,σ(A,m,n)的下界和当|A|=6且m≥n≥2时,σ(A,m,n)的下界.  相似文献   

5.
给出了一类多线性振荡奇异积分算子TA1,A2,TA1,A2f(x)=p.v.∫RneiP(x,y) K(x,y)/|x-y|M-1 2Ⅱj-1Rmj(Aj;x,y)f(y)dy,n≥2的Lpωp(Rn)到Lrωr(Rn)有界性的判定准则.这里P(x,y)是Rn×Rn上非平凡的实多项式,K(x,y)为标准的Calderón-Zygmund核,DαA1(x)∈BMO(Rn),|α|=m1-1(m1≥2),DβA2(x)∈Lr0(Rn),|β|=m2,M=m1+m2,1相似文献   

6.
设A是非空集合,|A|=n.FA是A上的自由半群,γ是FA上的最小自由正则带同余.RA=FA/γ是集合FA上的自由正则带,|RA|表示RA中元素的个数.文章证明了(u,v)∈γ的充分必要条件为i(u)=i(v),f(u)=f(v),且| RA|=n∑k=1(nk)(k!)2.  相似文献   

7.
矩阵A的特征值的集合(含重数)记为σ(A),A的惯量是指三元有序数组i(A)=(i (A),i-(A),i0(A)),其中i (A),i-(A)和i0(A)分别表示具有正,负,零实部特征值的个数.n阶符号模式矩阵S=(sij)是指元素取自{1,-1,0}或者{ ,-,0}的矩阵,S的定性矩阵类是指集合Q(S)={A=(aij)∈Mn(R):对所有的i和j,sign(aij)=sij}.S的惯量是指集合i(S)={i(A):A∈Q(S)}.若对任意满足n1 n2 n3=n的非负三元数组(n1,n2,n3),都有(n1,n2,n3)∈i(S),则称符号模式S为惯量任意模式.考虑n阶符号模式Kn=(kij)n×n:当1≤j-i≤n-2或i=j=n时,kij=1;当1≤i-j≤n-2或i=j=1时,kij=-1;当|i-j|=n-1时,kij可以取任意固定值;其余情形时,kij=0.本文证明了Kn(n≥3)是惯量任意模式.  相似文献   

8.
设A是有限集,|A|=n,F(n,m)是从A到A的映射中满足fm(x)=f(x)的映射f的个数,在此给出了计数函数F(n,m)的一个表达式.  相似文献   

9.
一、引言和主要结果若f(z)=z+(sum(a_nz~n)from(n=2)=0 to ∞)∈S,即f(z)在|z|<1内正则、单叶,Bieberbach猜想:对f(z)∈S,|α_n|≤n对一切n=2,3,…成立,且等号仅限于Koebe函数k(z)=z/(1-ηz)~2,|η|=1。我们已经知道,n≤6时这猜想是成立的。另一方面,Hayman正则性定理说,对每个函数,等号仅限于上述Koebe函数成立。可见,对  相似文献   

10.
本文给出了有限域F_p上n阶一般线性群的指数公式为x=d(n)·[q-1,q~2-1,…,q~n-1]其中d(n)=min{P~u|P~u≥n},[q-1,q~2-1,…,q~n-1]为整数q-1,q~2-1,…,q~n-1的最小公倍数,这里q=|F_p|=P~r,p=CharF.F_p为特征数为P之有限域,|F_p|=p~r=q,G=GL(n,F_p)为F_p上n阶一般线性群,|GL(n,F_p)|=multiply from i=0 to n-1(q~n-q~i)对任意A∈GL(n,F_p), 使A~m=E之最小正整数m称为G上指数,本文对任意给定的n及F_p,给出了以n,q表示的G的指数公式.  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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