首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
目的 研究Hilbert空间中Bessel列的算子扰动.方法 运用算子理论.结果 对于Hilbert 空间H中的一个序列f={fi}∞i=1 及算子列{T(i)j}∞i,j=1(∩)B(H,K),给出使得{∑∞j=1T(i)jfj}∞ i=1成为K中的Bessel序列的一些充分条件;证明了如果{Ti}∞i=1(∩)B(H,K) 使得Ti=T(i>N0)且 f={fi}∞i=1是 H中的Bessel列, 则{Tifi}∞i=1 是 K中的Bessel列.结论 在一定的条件下,Hilbert空间中的Bessel列经过算子扰动,还可以是Bessel列.  相似文献   

2.
Hilbert空间中Bessel列的广义扰动   总被引:1,自引:1,他引:0  
运用算子理论方法,研究了Hilbert空间中Bessel列的广义扰动,对Hilbert空间H中的任一Bessel列f={fi}i∞=1,给出了序列g={gi}∞i=1={α1(1)f1,α1(2)f1,α2(2)f2,α1(3)f1,α2(3)f2,α3(3)f3,…},g={gi}∞i=1={α1(1)f1,α1(2)f2,α2(2)f2,α1(3)f3,α2(3)f3,α3(3)f3,…},g={gi}∞i=1={∑∞j=1αj(i)fj}∞i=1,成为Bessel列的充分条件。  相似文献   

3.
研究了Hilbert空间上框架的扰动问题.应用算子论的方法,给出了当f={fi}i∈Z是框架时,序列{λifi}i∈Z,{Tfi}i∈Z及{Tifi}i∈Z成为框架的条件;证明了当f为框架,g为Bessel列且T 满足一定条件时,g也是一个框架.f-g  相似文献   

4.
目的 研究Hilbert空间H上的Hilbert基、Bessel基、Riesz基三者间的关系,及其与Bessel列、小波Ricsz基的关系.方法 算子论方法 .结果 证明了对于Hilberr空间日的任一Schuder基{xn},序列{xn xn≠}是H的一个Besselian基且{xn xn≠}≥{xn},{xn xn≠}≥{xn≠}.结论 对于H的任一Schuder基{xn},定义U(xn xn≠):xn≠则{xn}是H的一个Besselian基当且仅当‖U‖<1.而且给出了彤eSZ基的5个等价刻画.  相似文献   

5.
引入了Hilbert空间H的Fredholm框架概念,它是一种介于普通框架与Riesz基之间的一类特殊框架.应用算子论方法,给出了Fredholm框架的重要性质及其等价刻画,证明了H上全体Fredholm框架构成了由H中全体Bessel列组成的Banach空间中的开集.研究了Fredholm框架在小扰动下和算子扰动下的稳定性,证明了框架与Riesz基的膨胀不变性.  相似文献   

6.
证明对于由{Xi,φi,fi}∞i=1生成的逆极限系统{X∞,f∞},如果每个fi具有逐点伪轨跟踪性,则诱导映射f∞也具有逐点伪轨跟踪性.举例证明,它的逆命题不成立.  相似文献   

7.
框架和基的研究是小波分析理论研究的重要内容之一。在预框架算子满足一定条件下,借助算子理论方法证明了两个Riesz基的直和是它们直和空间上的Riesz基,以及这两个Riesz基的直和构成了它们直和空间上的标准正交基的充分必要条件。并在一般框架扰动条件下,研究了一个Riesz基和一个Bessel序列的扰动性质。  相似文献   

8.
研究Riesz型乘积Pn=∏nj=1(1+awj+bwj+1),其中a,b是满足条件a+b1的实数,{wj}是等概率地取值于{-1,1}的独立随机变量.记dw为Cantor群Ω={-1,1}∞上的标准哈尔测度,{概率测度列Pndw/∫ΩPndw}在Ω上会弱收敛于唯一的一个连续测度,并且这个测度关于dw是奇异的.  相似文献   

9.
设 K是实 Banach空间 X中非空凸子集 ,T:K→K为 Lipschitzφ-半压缩算子 ,设 { an} ,{ bn} ,{ cn} ,{ a′n} ,{ b′n} ,{ c′n}为 [0 ,1 )中实数列且满足一定条件 ,{ μn}∞n=0 和 { νn}∞n=0 是 K中两任意有界序列 ,则带误差项的Ishikawa型迭代序列 { xn} ∞n=0 强收敛于 T的唯一不动点 ;一个相关结果处理含 φ-拟强增生算子的方程解的带误差项的 Ishikawa型迭代逼近 .  相似文献   

10.
从两方面讨论了Hilbert空间中框架和Riesz基的稳定性:在满足一定条件Bessel序列的扰动下,框架和Riesz基在Hilbert空间中的稳定性;把框架和Riesz基与小波结合起来,在母小波、采样序列的扰动下,小波框架和小波Riesz基在L^2(R)空间中的稳定性.对有关文献的相关结论进行了推广,目的在于可以根据框架的稳定性,设计或者选择一个更优的框架来精确地逼近信号.  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号