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1.
称半环S是强正则的,如果对任意的x∈S,都存在y∈S使得x=x2y.M2(S)是半环S上的矩阵半环.本文探究了含零元的加法交换半环S上的2×2阶矩阵半环M2(S)的强正则性.借助于矩阵的运算技巧,我们得到,如果加法交换半环〈S,+,·,0,1〉是antiring,则下列条件等价:(1)M2(S)是强正则的;(2)对任意的上三角矩阵A∈M2(S),方程A2X=A是可解的;(3)S是强正则的且〈S,+,·,0,1〉是一个布尔代数;(4)S是一个环且是一个Boolean idempotent orp-semiring.  相似文献   

2.
设2~X是X的非空子集全体所成之集合,E,F是Φ上的拓扑矢量空间(Φ是实数域R或复数域C),(·,·):F×E→Φ为双线性泛函,X是E的非空子集,S:X→2~E和M,T:X→2~F是集值映象和f:X×X→R.则广义双拟变分不等式问题(GBQVIP)是y∈X,使得y∈S(y)和inf Re(f—w,y—x)+f(y,x)≤0,x∈S(y)和f∈M(y).最近Shih-Tan在X为紧凸集和f≡0的情形下研究了上述GBQVIP解的存在性.本文讨论另一类双拟变分不等式问题,即找y∈X,使得y∈S(y)和(f—w,y—x)+f(y,x)≤0,x∈X和f∈M(y).得出了几个变分不等式和GBQVIP解的存在性定理.这些定理改进和推广了Ding-Tan的结果  相似文献   

3.
本文构造了Banach空间中多值广义非扩张映象对的不动点迭代逼近序列对,并证明此序列的聚点为映象对的公共不动点。它是文[1],[2]的推广和改进。设S,T:K→C(K)为多值映象,且(?)x,y∈K,满足: H(Sx,Ty)≤ad(x,y) b[d(x,Sx) d(y,Ty)] c[d(x,Ty) d(y,Sx)](*)其中a,b,c≥0,a 2b 2c≤1,则称S,T为广义非扩张映象对。  相似文献   

4.
~~的核 Sk( x,y)附加了对称性的要求 .本研究在文 [3]的基础上 ,利用最近 Y.S.Han在文 [2 ]给出的恒等逼近的改进定义给出了 Lipschitz函数类 Lipα的一个新刻画 ,是文 [3]结果的推广 ,其主要结果如下 .定理 设算子列 {Sk}k∈ z[2 ]是齐型空间 ( X,ρ,μ)上的恒等逼近 ,Dk=Sk- Sk-1,f是在任有界集上可积的函数 ,0 <α 相似文献   

5.
1.引言关于完备距离空间的局部压缩和局部集值压缩映射的不动点定理,及由此而导出的Banach空间紧星形子集上的局部非扩展集值映射的不动点定理,在[1,2]中已有研究。设X是一完备距离空间,M.Edelstein称X的自映射f是(ε—λ)局部压缩的,如果存在ε>o,o≤λ<1,使得对所有x,y■X,o相似文献   

6.
得到两个全局性隐函数定理:定理1设D_1是第一可数的拓扑空间E_1的开子集.D_2是Banach空间E_2的开子集.映象f:(?)_1×(?)_2→Y(?)E关于第一变元连续且满足条件:1°|f(x,y_1)-f(x,y_2)|≤L(x)|y_2-y_1|.Ax∈(?)_1.y_1.y_2∈D_2.其中Y=D_2或D_2=Y=E_2,L(x)<1.L:(?)_1→R~+连续.则方程f(x.y)=y有连续解y:(?)_1→Y,即f(x.y(x))=y(x).(?)x∈(?)_1.定理2 设f:(?)_1×(?)_2→C((?)_2)满足条件:1°d(f(x,y_1).f(x,y_2))≤k|y_2-y_1|.(?)x∈(?)_1.y_1.y_2∈(?)_2.其中k<1是常数.d(·,·)表示:对有界闭子集A_1,A_2(?)(?)_2d(A_l,A_2)=sup{|y_1-y_2||y_1∈A_1,y_2∈A_2}2°(?)y∈(?)_2,多值映象,f(·,y)弱下半连续.C((?)_2)为(?)_2的有界闭凸子集类.则包含方程y∈f(x,y)有连续单值解y;(?)_1→(?)_2即y(x)∈f(x,y(x)) (?)x∈(?)_1还给出了对随机映象不动点存在性的一个应用.  相似文献   

7.
拟二面体群的一个无限类1-正则4度Cayley图   总被引:1,自引:0,他引:1  
群G的一个Cayley图X=Cay(G,S)称为正规的,如果右乘变换群R(G)在Aut(X)中正规.得到了拟二面体群G=〈x,y|x2m=y2=1,xy=xm 1〉(其中m=2s,s为大于4的偶数)的一个无限类4度正规1-正则Cayley图 Cay(G,S),其中S={x,x-1,xs 1y,xs-1y},并且对2r阶拟二面体群的正规1-正则4度Cayley图进行了分类,其中r>3.证明了2r阶拟二面体群的任意4度正规1-正则Cayley图同构于Cay(G,{x,x-1,xs 1y,xs-1y}),其中s=2r-2.  相似文献   

8.
对于四阶两点常微分方程边值问题y( 4) =f ( x,y) ,y( a) =y( b) =y"( a) =y"( b) =0 ,其中 f ( x,y) :[a,b]× R→R连续 ,且满足 L ipschits条件 ,给出在 Banach压缩映象原理下的解的存在唯一性 ,并通过对 C[a,b]的范数的改造 ,给出最优结果 .  相似文献   

9.
首先给出了集合A={λ∈[0,1]:f(λE(x) (1-λ)E(y))≤max{f(x),f(y)},(A) E(x),E(y) ∈M}的稠密性证明,然后利用此引理并在E:Rn→Rn为线性映射,f:M(∈)Rn→R为上半连续的条件下,给出了拟半E-凸函数的一个新的充要条件,从而简化了对拟半E-凸函数的判别,为进一步认识和研究E-凸函数、半E-凸函数、拟半E-凸函数及其他广义凸函数提供了新的思路.  相似文献   

10.
设S是一个半群,a∈S.S的关于元素a的变量指的是S按运算 ∶x,y∈S, x y = xay做成的半群(S, ).本文给出了毕竟正则半群上变量的一些性质并刻画了毕竟正则半群的毕竟正则保持元,即使得(S, )是毕竟正则半群的元素a∈S.  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.
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 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   

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.
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   

18.
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   

19.
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   

20.
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   

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