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1.
Aluthge变换值域中的代数算子和平移性质   总被引:1,自引:0,他引:1  
研究了Aluthge变换值域中的代数算子、幂等算子和Aluthge变换的平移性质.证明了算子T的Aluthge变换△(T)是代数算子的充要条件是T为代数算子,并给出了△(T)是幂等算子的充要条件是T^3=T^2.当H形是有限维Hilbert空间时,证明了:如果算子T的Aluthge变换具有平移性质△(T+λ)=△(T)+λ(↓Aλ∈C),则T是正规算子.  相似文献   

2.
在本文,我们首先给出了T模算子的关联算子概念,并得到了一个定义在完备格L上的T模算子存在关联算子的充要条件。此外,还讨论了关联算子与下半格值连续函数的联系。并指出文「10」中的一个结果是错的。  相似文献   

3.
讨论了一类本性正常算子的(U K)-轨道的闭包:(U K)(T)↑-。具体地讲,如果T是一个具有正常加紧形式的三角算子,且它的本性谱是完备的,对角线以上部分是紧的,得出结论:A∈L(H),A∈(U K)(T)↑-的充要条件是:(1)A∈Nor(H) K(H);(2)σ(A)增包含σ(T),σ0(A)增包含于σ0(T),σe(A)=σe(T);(3)ind(λ-A)=ind(λ-T),A↓λ∈ρs-F(A)=ρs-F(A)=ρF(A);(4)nul(λ-A)≥nul(λ-T),A↓∈ρs-F(A);(5)如果λ∈σe(A)则rankE(λ;T)。除此之外,如果T是一个双三角的本性正常算子,它的谱σ(T)=σe(T)=σ是C的一个完备集,则A∈(U K)(T)↑当且仅当A满足:(1)A∈Nor(H) K(H);(2)σ(A)增包含σ(T)是完备的;(3)σe(A)=σe(A)=σe(T),且对任意的λ∈ρs-F(A),ind(λ-A)=0。  相似文献   

4.
针对正则蕴涵算子,从分析学的角度研究了其连续性,得到了正则蕴涵算子是连续函数的充要条件是当x≥y时,满足(x→y)→y=x;仅在(0,0)间断函数的充要条件是当x≥y,y≠0时,(x→y)→y=x,而对任意x∈(0,1),(x→0)→0≠x,同时研究了与这些蕴涵算子相伴随的三角模。  相似文献   

5.
设H2(Γ)表示Hardy空间,在Banach代数B(H2(Γ))上定义初等算子Sφψ,利用Toeplitz算子Tφ的性质得到算子Sφψ的一些性质,并给出算子Sφψ(T)为Fredholm算子的充要条件.  相似文献   

6.
利用半Fredholm算子的扰动不变性,研究有界线性算子与上三角算子矩阵的Weyl型定理。首先,给出有界线性算子同时满足Browder定理和(R1)性质,或者同时满足Weyl定理和(R)性质的充要条件;然后,讨论上三角算子矩阵同时满足Weyl定理和(R)性质的条件。  相似文献   

7.
文中定义了半格上的算子,给出了半格上算子的几个等价描述,得到如下定理:设(L,V)表示L是一并半格,F是L到自身的一个映射,则如下几条等价:(1)F是L上的闭包算子。(2)Vx,y∈L,xVF(F(x)VF(y))=F(xVy);3)F是L上的闭包算子,且满足F(F(x)VF(y))=F(xVy);(4)F满足,x≤F(x)且F(F(x)VF(y))=F(xVy)。另外,还给出拓扑内部算子的方程描  相似文献   

8.
一类4阶微分算子积的自伴性   总被引:2,自引:0,他引:2  
该文主要讨论了由正则和奇异的4阶对称微分算式生成的微分算子的积算子的自伴性,得到了Ⅰ(Ⅰ=[α,b]或[α, ∞)上的积算子L=L2L1是自伴算子,当且仅当AQ^-14(0)C^*=BQ^-14(0)D^*;Ⅰ上的幂算子L^21是自伴的充要条件是L^1是自伴的,并且给出了反例,说明2个自伴算子的积不一定是自伴算子,不同的非自伴算子的积可以是自伴算子。  相似文献   

9.
讨论了具有两同型部件的冷贮备可修复系统,首先证明系统算子可以生成正压缩C0半群T(t);接着证明了T(t)是拟紧算子,且0是对应系统的主算子及其共轭算子的几何重数与代数重数为1的特征值.由此推出:该系统的时间依赖解,当时间趋向于无穷时,以指数形式收敛于系统的稳态解.  相似文献   

10.
设H是复Hilbert空间,H上的有界线性算子T若满足对任意的x∈H有(Tx,x) 0,则称T是正算子,记为T 0;如果T是可逆的正算子,则称T是严格正算子,记为T>0.若A,B是严格正算子,我们知道A B蕴涵有logA logB,但反过来未必成立,见文献[1].设T是H上的有界线性算子且p 0,如果(T T)p (TT )p,则称T是p 亚正常算子,特别地当p=1及p=1/2时,p 亚正常算子分别称为亚正常算子和半亚正常算子.Lo¨wner Heinz不等式表明当0

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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