非完整力学和Vaco动力学方程

本文对一些文献的论断提出不同意见，认为Ｖａｃｃｏ动力学方程无论从数学上还是物理上可能是解决一阶非完整系统力学问题的一种比较合理的方法，而建立在Ｈｏｌｄｅｒ原则和Четаев条件基础上的传统的非完整力学理论是值得怀疑的     

变质量二阶非чeтaeв型非完整系统的守恒律

利用Jourdain微分变分原理研究变质量二阶非Четаев型非完整系统的守恒律 ,引入Jourdain生成元 ,给出无限小变换下Jourdain原理的不变性条件 ,在一定条件下得到系统的守恒律。由于Четаев型非完整系统是非Четаев型非完整系统的特殊情形、常质量系统是变质量系统的特殊情形 ,因此 ,所得结果具有普遍意义。给出了应用例子。     

利用Jourdain原理研究二阶非完整系统的守恒律

目的研究具有二阶非完整约束的力学系统守恒律．方法利用Ｊｏｕｒｄａｉｎ变分原理∑Ｎｉ＝１（Ｆｉ－ｍｉｒ¨ｉ）·δ１ｒ．ｉ＝０,引入Ｊｏｕｒｄａｉｎ生成元（Δ１ｑｓ）．＝εＦｓ（ｔ,ｑ,ｑ．）,（Δ１ｔ）．＝εｆ（ｔ,ｑ,ｑ．）和推广的Четаев定义∑ｎｓ＝１φβｑ¨ｓδ１ｑ．ｓ＝０,得到无限小变换下列的不变性条件．结果当无限小生成元ｆ,Ｆｓ满足一定条件时可得到系统的守恒律．结论推广了完整系统和一阶非完整系统的相应结果,二阶非完整系统也存在守恒律．     

高阶非Четаев型非完整约束系统的广义守恒律

给出高阶非Четаев型约束加在m次速度空间中虚位移上的条件,研究m次速度空间中的非等时变分与无穷小变换,建立高阶非Четаев型非线性非完整非有势系统的广义Noether定理,并推广到变质量系统以及非惯性系中。     

关于非完整系统力学中三种变分的关系

0 引言 文[1]对非完整系统力学中d—δ运算交换关系的三种观点进行了有益的讨论。三种观点是:(1)Hlder观点。这一观点认为无论系统是否完整,d—δ运算都可交换;(2)以为代表的一方则认为,仅对与独立的广义速度相对应的广义坐标才成立d—δ交换性;(3)国内学者郭仲衡、高普云证明了对一阶非线性非完整系统,d—δ运算可交换性成立。文[1]指出,第三种观点本质上不同于第一种观点。本文对这三种变分所满足的条件作进一步的讨论,并揭示了它们相互之间的关系。     

非完整系统动力学的Lagrange理论框架

应用广义变分原理的理论, 论证了两个Lagrange经典关系既适用于完整系统又适用于非完整系统, 克服了长期以来对两个Lagrange经典关系应用于非完整系统的限制, 推导出一个类似于Lagrange经典关系的重要公式, 建议称之为推广的Lagrange经典关系. 从Vakonomic模型出发, 通过应用两个Lagrange经典关系和推广的Lagrange经典关系, 得到与Четаев模型一致的结果, 从而统一了Четаев和Vakonomic模型, 同时, 形成了非完整系统动力学的Lagrange理论框架. 最后, 应用非完整系统动力学的Lagrange理论框架, 研究了几个典型实例.     

对非完整系统力学中若干基本原理的质疑

我们从一则证明得出结论：人们用以得出一阶线性非完整系统广义坐标虚位移满足的关系的Ｈｏｌｄｅｒ原则不是普遍成立的，与此有关，我们作出了几点重要的推论，本文给出了取代Ｈｏｌｄｅｒ原则而获得的一阶线性非完整系统虚位移满足的关系，我们用物理的讲法推荐一种可处理具有任何一阶线性或非线性非完整约束的系统的方法。     

非完整系统的哈密顿方程

本文试图不使用乘子将哈密顿(Hamilton)方程推广到切塔耶夫(Четаев)型非线性非完整系统。首先概叙在非完整系统动力学中人们对拉格朗日(Lagrange)第二类方程和哈密顿方程的推广,其次推导方程并推出方程的非完整坐标形式,将方程应用于经典的阿佩尔(Appell)例(球坐标)。最后对不使用乘子的两种不同推导途径提出看法。     

相对论中变质量问题的Wittaker方程

研究相对论性非完整系统的广义能量积分在在的条件，给出用能量积分降阶相对论性非完整系统广义方程的方法，得到相对论性广义WHITTAKER方程，并变换到Nielsen形式的相对论性广义Whittaker方程。     

非完整系统基于El-Nabulsi分数阶模型的Noether对称性与摄动

El-Nabulsi针对非保守系统的建模提出了一类新的分数阶模型,即El-Nabulsi分数阶模型或类分数阶变分方法。文章研究该模型下线性非完整系统Noether对称性的摄动与绝热不变量问题,给出了该模型下线性非完整系统绝热不变量存在的条件及其形式。     

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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