一类具非局部边界条件的拟线性抛物方程解的整体存

考虑拟线性方程ut=f(u)(Δ u+a∫Ωu(y,t)d(y-u))在非局部边界条件u(x,t)=∫Ωk(x,y)u(y,t)dy(x∈Ω)下解的整体存在与爆破, 其中Ω是N中具光滑边界的有界区域. 通过对扩散系数f(s)和权函数k(x,y)加适当条件, 给出了解整体存在或爆破的充分条件, 并得到了一定条件下解的爆破速率估计.     

一类非线性退化抛物方程的解

在带权常指数索伯列夫空间中讨论一类非线性方程的解的适定性问题。方程u_t=div(a(x)|▽u|~(p-2)▽u)+f(u,x,t)中,a(x)在边界退化。在一定条件下,方程解的稳定性可不依赖于边界条件而完全由初值控制。     

一类超线性椭圆方程的非平凡解

应用环绕定理以及精确估计来讨论一类在零点有奇性的超线性椭圆方程:-Δu k(x)x 2u=u 2*-2u,u∈D1,0 2(Ω),其中k(x)满足一定的条件,2*=2N/(N-2)(N≥3),可以得到一个非平凡解的存在性.     

有圈二部图覆盖的一个结果

H.Wang猜想,对于任意整数k≥2,存在N(k)使得二部图G=(V1,V2,E)中,V1=V2=n≥N(k),且对于G中任意一对不相邻的顶点x∈V1,y∈V2,有d(x)+d(y)≥n+k,那么,对于G中任意k个独立边e1,e2,e3,…,ek,存在顶点不重的k个圈C1,C2,…,Ck,使得ei∈E(Ci),i∈{1,2,…,k}和V(C1∪C2∪…∪Ck)=V(G).H.Wang及J.A.Bondy对k=2,3时证明了猜想成立,本文对k=4证明了猜想的正确性.     

一类拟线性椭圆方程的多解性

考虑在满足一定条件下,下列拟线性方程解的存在性和多解性:-n∑i=1(e)/(e)xi(|(△)u|p-2(e)u/(e)xi |u|p-2=a(x)|u|q-2u g(x),x∈Rn,结合扰动与变分方法,证明了当g(x),a(x),p,q给定适当条件时,上述方程至少有两个非零解存在.     

Banach空间含导数项的二阶脉冲微分方程的解

讨论了抽象空间中非线性项含一阶导数的二阶脉冲微分方程边值问题{-u″(t)=f(t,u(t),u'(t)),t≠tk,t∈J=[0,1],-Δu'|_(t=t_k)=I_k(u(t_k),u'(t_k)),k=1,2,…,m,u(0)=θ,u(1)=θ解的存在性与唯一性,其中f∈C(J×E×E,E),I_k∈C(E×E,E),k=1,2,…,m.通过选取恰当的工作空间及等价范数,在非线性项f(t,x,y)及脉冲函数Ik满足较一般的非紧性测度条件下,结合新的非紧性测度估计技巧与凝聚映射的Sadovskii不动点定理,得到解及正解的存在性结果.此外,进一步讨论该问题唯一解的存在性.     

二阶脉冲微分方程解的等价性

本文研究的是二阶非齐次脉冲微分系统:{-u·(t)+ρ2u(t)=f(t,u(t)),t∈J,t≠tk(k=1,2,…,p)△u't=tk=-Ik(u(tk),u'(tk)),(k=1,2,…,p)u(0)=u(2π),u'(0)=u'(2π)=0,首先,利用常数变易法得到阶非齐次脉冲微分在连续情形下解的等价积分方程:u(t)=∫2x,0(t,s),(s,u(s))ds,t∈J其次,又利用还原的方法得到了二阶非齐次脉冲微分在一介导数带脉冲情形下解的等价积分方程:u(t)=∫2x,0 G(t,s)f(s,u(s))ds+∑p,k=1 G(t,tk)Ik(u(tk),u'(tk),u'(tk))     

具有一般非线性项的Cahn-Hilliard方程的整体吸引子

改变了Cahn Hilliard方程 : u t-△k(u) =0 ,　k(u) =-λ△u f(u) , u n =- △u n =0 ,u(x ,0 ) =u0 (x)的非线性项f(u) ,用较一般限制条件代替了“f(u)是首项系数为正的奇数多项式”这一条件 ,并证明了该方程存在紧连通整体吸引子 .     

拟线性抛物型方程和方程组的blow-up

设Ω■R~n是有界区域,u是u_t=▽(k(u)▽u) f(u),在Ω×(0,T),k(u)(?)u/(?)v u=g(u),在(?)Ω×(0,T)上,u(x,0)=u_0(x)的古典解,此处▽n是维梯度算子,k(u)≥k_0>0,(?)u/(?)v表示u在(?)Ω的外法导数。利用凸性方法,证明了当函数f(),g(u),k(u)和u_0(x)满足以下条件:(d_1)u_0(x)>0,f(u)>0,g(u)>0;(d_2)k'(u_0)u_0~2xi k(u_0)u_(0xixi) f(u_0)>0,(?)k(u)/(?)v 1-g'(u)>0;(d_4)存在一个K,0相似文献   

具有非线性源项的非线性热传导方程解的渐近性质

在本文中。研究了下面始值边值问题:γ,β是非负正数u(x,o)=i_0(x)解的渐近性质,此地M_,N为非线性二阶椭圆算子证明了在k,f的一定限制条件下,(A)的解的渐近性质类似于相应(A)的某个半线性方程解的渐近性质。此方程是(A)中用某个常数代替k(u)所得的方程。     

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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