若尔当标准型的一个注记

指出了以下事实：任何矩阵都可以通过相似变换化为上三角形矩阵,矩阵对角线上的元素就是相应的特征值,且相同的特征值排在一起;进一步通过相似变换可以把矩阵化为分块矩阵,其中每一个子矩阵都只与一个确定的特征值相联系．从而任何矩阵可以通过相似变换化为若尔当标准形的直和．     

矩阵的若尔当标准形与有理标准形的关系探究

给出n级矩阵的若尔当标准形J与有理标准形B之间的关系,即存在可逆矩阵H,使得H^-1JH=B．     

矩阵的特征值与矩阵方程的关系

研究了矩阵A与A*的方程与A的特征值的关系.利用特征值的性质,得出了A的特征值λ应满足的条件.这个结果刻划了一些特殊矩阵的特征值的性质,并利用这个结果给出了广义投影算子的一个充要条件.     

域上矩阵的相似标准型

讨论相似矩阵的一些标准型，给出一般域F上矩阵的一种有理标准形式，提供它变到若尔当标准型的相似变换．     

若尔当标准形计算方法的注记与修正

结合一个实例指出了文献[8]中关于若尔当标准形计算方法的值得注意之处,并给出了相应的修正.为验证修正方法的有效性,本文列举了四个实际算例.修正方法的优点在于嵌入的条件方程解决了文献[8]中方法在确定根子空间循环基过程中因对应线性方程组基础解系的选择不当而无法得到循环基的共性问题,以达到最终顺利求得若尔当标准形所对应的可逆矩阵之目的.算例表明,以统一方式嵌入联系于循环基对应线性方程组中的条件方程有时会出现被约化掉的现象,从中揭示出产生循环基的基础解系具有选择上的任意性,反之则不然.     

诣零矩阵和拟阵

对于一个包含关系的关联矩阵,文献[1]构造了一个拟阵,并由关联矩阵定义了诣零矩阵(nil-矩阵),而且讨论了它的相关性质,进而提出具有N-特征的矩阵(即nil-矩阵)能否构造一个拟阵.本文在文献[2～5]的基础上,通过反例证明nil-矩阵不一定能构造拟阵,又给出了一个较强的能构造拟阵的nil-矩阵的条件,即对于关联矩阵A,若任意秩为的子矩阵皆为nil-矩阵,则(D,N(A))是一个拟阵,且其秩为,而且这个矩阵A的所有nil-矩阵都是拟阵(D,N(A))的独立集.     

用QQ-SVD解矩阵方程A=BXC

对于任意给定的矩阵C∈Cq×n,A∈Cm×n,B∈Cm×p,利用QQ-SVD分解给出了矩阵方程A=BXC的一个通解公式.利用这个通解公式,还给出了解集合中解的最大秩和最小秩.     

关于2×2分块矩阵的Drazin逆的一般表达式

1979年,Campbell和Meyer就提出:希望找到一个公式研究求解2×2分块矩阵M=(A B C D)的.Drazin逆这个问题,其中A和D必须是方阵.受Drangana S.Cvekovic-Ilic近期关于2×2分块矩阵的Drazin逆表示的启发,提出在特定条件下2×2分块矩阵的Drazin逆的一般表达式,继而给出一个例子以证明结论的正确性.     

关于矩阵展形的一些新上界

文献[1]提出了矩阵的展形,证明了矩阵展形的一个上界估计式,并且给出了这个不等式取等号的条件,即A是正规矩阵且A的特征值满足条件φ时等号成立。本文探讨矩阵展形的新的上界,证明了一个矩阵展形的上界估计式:s(A)≤2‖A‖2F-tr A2n()2-12‖[A,A*]‖2槡F{}12;然后,利用矩阵展形的估计式得到了一个奇异矩阵的谱半径的上界;最后,还给出了两个关于实展形、虚展形的上界的估计式:sRA()≤‖A‖2F-tr A2n()2-12‖[A,A*]‖2槡F+tr A2n+Re tr A2-2ntr B()2()12,sIA()≤‖A‖2F-tr A2n()2-12‖[A,A*]‖2槡F+tr A2n+Re tr A2-2ntr C()2()12.     

不确定离散系统的鲁棒H∞控制

系统的不确定性具有线性分式顶点凸多面体形式.引入一个一般变量Q(没有任何结构约束,例如对称),使Lyapunov函数矩阵P和系统矩阵A,C分离,得到一个关于此类离散系统H∞性能的线性矩阵不等式(LMI)性质.这个特性有助于通过依赖于参数的Lyapunov函数得到一个关于此类系统保守性更小的充分条件.在此基础上给出了H∞状态反馈控制器的设计.最后给出仿真例子检验结果.     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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