三维仿射非线性临界动态系统的局部解析镇定

针对三维仿射非线性解析动态系统在临界情形假设下局部渐近镇定性,假设三维系统在解析的情况下,给出了三维系统如何构造V函数（李雅普诺夫函数）,并确定V函数和反馈控制函数的一般方法,得出了判别的临界解析动态系统局部渐近镇定的充分条件。     

一类带控制项的模糊微分方程的一致渐近稳定性

考虑带控制项的模糊微分方程u'(t)=f(t,u(t),X(t)),利用李雅普诺夫函数的方法得到了方程平凡解一致渐近稳定的一个充分条件.     

一类非线性四阶方程李雅普诺夫函数之构造

<正> §1 在文([1]-[4])中已对方程(?)+a(?)+b(?)+c(?)+dx=0 (1)的七种等价系统构造了各种形式的李雅普诺夫函数,然后采用类比法解决了带有一个非线性函数的四阶方程的李雅普诺夫函数的构造,从而解决了零解的渐近稳定性或全局稳定性问题本文采用同样的办法,对方程(1)的多种其他等价系统构造了各种李雅普诺夫函数,再利用其中的某些函数采用类比方法解决一类特殊的带有多个非线性函数的四阶方程的李雅普诺夫函数,从而解决它零解的渐近稳定性或全局渐近稳定性问题。     

模糊微分方程的渐近稳定性

考虑了模糊微分方程u'=f(t,u),利用李雅普诺夫函数的方法得到了方程平凡解渐近稳定的一个充分条件.     

二阶差分系统Lyapunov函数的构造

本文给出了构造差分系统X(n 1)=AX(n)(1.1)的李雅普诺夫函数的公式.并给出了(1.1)的李雅普诺夫函数的几个具体形式.     

C-半群和李雅普诺夫方程

考虑线性控制系统x’(f)=Ax(f) Bu(t)(t>0),x(0)=x0,这里A是Hilbert空间X中指数稳定的C-半群T(t)的无穷小生成元,B是Hilbert空间Y到X的有界算子,且A的豫解集非空,R(C)在X中稠密时,获得了延拓控制映射LB是李雅普诺夫方程的唯一的自伴解.     

利用二次分解——集结法研究离散大系统的稳定性

本文分别用标量李雅普诺夫函数和向量李雅普诺夫函数利用二次分解——集结法,给出了由差分方程所描述的离散大系统的全局一致渐近稳定的三个充分条件,还用标量李雅普诺夫函数给出了大系统全局指数稳定的一个充分条件。     

一类差分方程的渐近性态

文章主要研究一类差分方程,其中aj>o,且ε是充分小的正常数,当1<∞∑J=0aj=a<2和∞∑J=0aJ=a=∞时,通过构造李雅普诺夫函数的方法,根据李雅普诺夫稳定性定理,给出此差分方程在不同情况下解的渐近稳定性的充分条件.     

一类三阶非线性系统的全局渐近稳定性

李雅普诺夫第二方法是研究非线性系统稳定性的基本方法之一,而Lyapunov函数的构造是解决问题的关键.本文运用"类比法"对非线性系统x g(x)x f(x,x)x h(x)=0,构造了较好的Lyapunov函数,得到其平凡解全局渐近稳定的条件,并且证明中脱离了对Lyapunov函数无穷大性质的约束,推广了旧有的结果.     

方程(x)+a(x)+f(x)+g(x)=0的全局渐进稳定性的一个新判据

在运用李雅普洛夫第二方法研究非线性系统稳定性的时候,能否做出合适的李雅普洛夫函数是问题的关键.较好的李雅普洛夫函数带来较好的结果.由于做出了较好的李雅普洛夫函数,本文得以提供关于方程(x)+a(x)+f(x)+g(x)=0的全局渐进稳定性的一个新判据.新判据推广了巴尔巴欣1952年和蒲利斯1955年的结果.     

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.     

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

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