黏性系数依赖于密度的一维可压Navier-Stokes方程的自模解

目的为研究黏性系数依赖于密度的一维可压Navier-Stokes方程自模解的非存在性问题。方法对能量函数进行定量分析。结果证明了黏性系数依赖于密度的一维可压Navier-Stokes方程不存在具有有限总能量的自模解。结论将研究常黏性系数Navier-Stokes方程的自模解的方法推广到黏性系数依赖于密度的情形。     

一维等熵Navier-Stokes方程的泛函分离变量解

研究了刻画一维空间中等熵可压流体运动规律的Navier-Stokes方程的泛函分离变量解.利用微分及分裂的方法把泛函微分方程简化为标准的双线性泛函方程并求解此泛函方程,建立了一维等熵Navier-Stokes方程的几类泛函分离变量解.     

一类三维非粘性可压流体力学方程解的有限传播速度及奇异性

研究了一类三维非粘性的可压流体力学方程局部光滑解的性质,证明了当方程的初值满足一定条件时,解在有限时间内会形成奇异.讨论了此方程具有有限传播速度,并利用有限传播速度讨论解的奇异性.解的有限传播速度对研究解的奇异性起非常重要的作用.     

黏性系数依赖于密度的一维可压等熵Navier-Stokes方程的全局经典解

目的研究黏性系数μ(ρ)=1+θρθ时一维可压熵Navier-Stokes方程在有界区域上的全局经典解。方法利用一个新熵不等式及一系列先验估计研究全局经典解。结果假设初始密度有正下界,首先得到该方程全局弱解的存在性的唯一性,然后通过提高初始数据的正则性及先验估计证明了此模型经典解的整体存在性。结论得到了模型经典解的唯一性与存在性。     

跳噪声扰动下人工压缩Navier-Stokes方程解的适定性

为了克服不可压约束条件数值计算困难，引入人工压缩方法，利用Lévy型伊藤公式、一致先验估计、局部单调性和弱收敛方法，由经典的Minty-Browder方法得到人工压缩Navier-Stokes方程强解的存在唯一性.     

Π-凝聚环上的同调方程A=Ext_R~n(X,R)

研究Π-凝聚环R上的同调方程A=ExtnR(X,R)的一类解的存在性,得到方程A=ExtnR(X,R)以有限生成半自反右R模为解的一个充要条件.     

Π-凝聚环上的同调方程A=ExtnR(X,R)

研究Π-凝聚环R上的同调方程A=ExtnR(X,R)的一类解的存在性,得到方程A=ExtnR(X,R)以有限生成半自反右R模为解的一个充要条件.     

∏—凝聚环上的同调方程A＝ExtR^n（X,R）

研究∏-凝聚环R上的同调方程A＝ExtR^n(X，R)的一类解的存在性，得到方程A＝ExtN^n(X，R)以有限生成半自反右R模为解的一个充要条件．     

可压Navier-Stokes-Korteweg方程组强稀疏波的稳定性

研究了一维可压Korteweg型流体模型强稀疏波的渐近稳定性问题.假设相应的可压Euler方程的黎曼问题存在稀疏波解(VR,UR,SR)(t,x),如果Navier-Stokes-Korteweg系统的初值是近似稀疏波的小扰动,利用能量方法,可以证明其柯西问题存在一个唯一的整体光滑解,并随着时间渐近趋于(VR,UR,SR)(t,x).     

无界区域上高维半导体流体动力学等熵模型的渐近性

主要研究无界区域中可压Navier-Stokes-Poisson方程的Cauchy问题.证明当给定初值是稳态解的小扰动时方程的整体光滑解的存在性和唯一性,进一步运用经典能量估计方法证明当时间t→+∞时整体光滑解以指数速率趋于稳态解.     

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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