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1.
作为Banach空间自反性判定定理的一个补充,给出了X是自反Banach空间的几个充要条件.  相似文献   

2.
给出平均一致凸Banach空间的定义,证明了一致凸Banach空间是平均一致凸Banach空间,平均一致凸Banach空间是自反和弱局部一致凸Banach空间,并且平均一致凸Banach空间X中任意元在X的闭凸子集存在唯一的最佳逼近元。  相似文献   

3.
作为Banach空间自反性判定定理的一个补充,给出了X是自反Banach空间的几个充要条件.  相似文献   

4.
将文献中在有限维Banach空间给出的集值上鞅存在Ries‘z分解的充要条件推广到无限维Banach空间,同时在条件相当弱的情形下,得到了一个近似于Ries’z分解形式的结论。  相似文献   

5.
关于平均一致凸Banach空间   总被引:6,自引:1,他引:6  
引入平均一致凸Banach空间的概念,证明了一致凸Banach空间是平均一致凸Banach空间,平均一致凸Banach空间是自反和弱局部一致凸Banach,并且平均一致凸Banach空间X中的任意元在X的闭凸子集中必存在唯一的最佳逼近元。  相似文献   

6.
将文献中在有限维Banach空间给出的集值上鞅存在Ries'z分解的充要条件推广到无限维Banach空间,同时在条件相当弱的情形下,得到了一个近似于Ries'z分解形式的结论.  相似文献   

7.
半范数的泛函表示及应用   总被引:1,自引:3,他引:1  
给出了局部凸空间上连续半范数,有界半范数和下半连续半范数等的泛函表示,应用这些表示定理,我们得到了Banach-Mackey空间的一个全局特征和囿空间的对偶特征,最后还给出了局部凸空间理论中一些重要定理的简化证明。设X是Hausdorff局部凸空间,X′为X上的连续线性泛函全体,X ̄b是X上的有界线性泛函全体,则有定理1(3)p:X→R是连续(下半连续)半范数当且仅当存在X′的等度连续(σ(X′,X)有界)子集B使得对任何x∈X都有定理4X是Banach-Mackey空间当且仅当X上每个下半连续半范数都是有界的。定理5X是囿空间当且仅当X ̄b中的β(X ̄b,X)有界集都是X′中的等度连续集。  相似文献   

8.
利用Tapia半内积(x,y)T=limt→0+[(x+ty2-x2)/(2t)],x,y∈X,研究了Banach空间X的自反和逼近性质,并在光滑的Banach空间X上利用由Tapia半内积定义的一类连续线性泛函T(X)={fx∈X*|〈fx,y〉=(x,y)T;x,y∈X}研究了Banach空间的严格凸、一致凸以及具有性质(H)的特征.  相似文献   

9.
研究无穷维控制系统,范数约束可达性,其中x∈X,1≤p≤∞,X,U是自反Banach空间.文中提出一致范数约束可达性概念,得到充分必要条件.  相似文献   

10.
利用Tapia半内积(x,y)τ=lim(‖x+ty‖^2-‖x‖^2/(2t),x,y∈X,研究Banach空间X的自反和逼近性质,并在光滑的Banach空间X上利用由Tapia半内积定义的一类性连续性泛函T(X)=(f,∈X│(fx,y)=(x,y)τ;x,y∈X)研究了Banach空间的严格凸,一致凸以及具有性质(H)的特征。  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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