抽象矩阵的可逆性探讨

矩阵理论在高等代数中处于核心地位,较为基础的是求矩阵的逆矩阵。在n阶方阵求逆矩阵的方法基础上,介绍了抽象矩阵逆矩阵的不同求法。通过具体例题对抽象矩阵可逆性进行了归纳,得出一般抽象矩阵的逆矩阵判定。给出了利用矩阵的运算以及一元二次方程的求解公式来求几类抽象矩阵逆矩阵的方法,简化了类似抽象矩阵求逆问题的计算。     

双重Hermite矩阵的性质

通过对Hermite矩阵的研究,给出了次Hermite矩阵、反Hermite矩阵、Hermite矩阵、反次Hermite矩阵、双重Hermite矩阵、反双重Hermite矩阵的基本概念,得到了双重Hermite矩阵、反双重Hermite矩阵的线性运算的封闭性,判定次Hermite矩阵的充要条件,以及双重Hermite矩阵、反双重Hermite矩阵之积是双重Hermite矩阵的充要条件;还得出了反双重Hermite矩阵的主、次对角线元素的特征等。     

幂等Hermite矩阵性质探讨

给出了幂等Hermite矩阵的概念,研究了幂等Hermite矩阵的一些性质,取得了幂等Hermite矩阵与等幂矩阵、Hermite矩阵、正规矩阵、半正定矩阵的一些联系,讨论了幂等Hermite矩阵与正交投影算子和Moore-Penrose广义逆的关系.     

F-矩阵的性质与Hadamard不等式的注记

通过对正定矩阵、M-矩阵、逆M-矩阵的研究,使用Fisher不等式给出了F-矩阵的定义,并研究了F-矩阵及相关矩阵类的性质,得到的主要结果是:F-矩阵Schur补是F-矩阵;F-矩阵与逆F-矩阵Hadamard不等式等号成立的矩阵结构,以及F-矩阵与逆F-矩阵的一个组合性质.     

初等变换与矩阵的QR分解的关系

主要研究矩阵初等变换与矩阵的QR分解的关系.讨论了第一类,第二类矩阵的初等变换对矩阵的QR分解的影响,即初等变换后新矩阵的Q矩阵和R矩阵与母矩阵的Q矩阵和R矩阵之间的定量关系.并利用第三类初等变换给出了矩阵QR分解的新方法.     

工程计算中中心与反中心对称矩阵求逆的一个简便方法

首先研究了中心对称矩阵与反中心对称矩阵的结构与性质,然后得出了中心对称矩阵的逆是中心对称矩阵,反中心对称矩阵的逆是反中心对称矩阵等结论,最后在此结论的基础上得出了中心对称矩阵与反中心对称矩阵的一个求逆的简便方法。     

循环矩阵的性质及求逆方法

对于矩阵中一类重要的矩阵循环矩阵,从定义出发研究了它的各种性质,并利用矩阵对角化的方法给出了循环矩阵的逆矩阵和行列式的表达式。然后讨论了推广的循环矩阵,即准循环矩阵和广义循环矩阵,利用类似方法,也给出了它们的求逆阵和求行列式的方法。     

循环矩阵和分块循环矩阵的逆矩阵的简便求法

讨论了循环矩阵和分块循环矩阵的逆矩阵,给出了用初等变换求循环矩阵和分块循环矩阵的逆矩阵的简便方法.     

C-矩阵Kronecker积与Hadamard积的若干结论

利用C-矩阵定义的等价条件及不等式放缩技巧,研究了C-矩阵的Kronecker积、Hadamard积是否为C-矩阵.结果表明,C-矩阵的Kronecker积是C-矩阵,C-矩阵的Kronecker和不是C-矩阵.进一步给出了C-矩阵的Hadamard积为C-矩阵的几个充分条件,并用数值算例对所得结果进行了说明.     

中心对称矩阵的可逆性

研究了中心对称矩阵的定义、结构及分块矩阵表示方法,利用分块矩阵的方法分别表示出偶数阶和奇数阶中心对称矩阵,以此为基础讨论偶数阶和奇数阶中心对称矩阵可逆的充分必要条件。找到对角相似分块矩阵,利用相似矩阵的性质得到偶数阶中心对称矩阵可逆性的充分必要条件。分别考虑了a=0和a≠0两种情况,得到了奇数阶中心对称矩阵可逆性的充分必要条件。研究了中心对称矩阵的逆矩阵求法公式,获得了一些新的结论,并结合一个具体例子说明了将阶数较高的中心对称矩阵的可逆性问题转化为阶数较低的矩阵的可逆性问题的方法,使大矩阵的运算化成小矩阵的运算,达到简化计算的目的,由所得结果可知中心对称矩阵的逆矩阵仍然是中心对称矩阵。     

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.     

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     

Call for Papers

<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     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~