三阶三点奇异半正边值问题的正解

利用锥拉伸锥压缩不动点定理 ,研究了三阶三点奇异半正边值问题x (t) - f(t,x) =0 ,　　　　t∈ (0 ,1 ) ,x(0 ) =x′(η) =x″(1 ) =0。正解的存在性。其中 12 <η<1 ,f(t,x)在t=0和t=1处有奇异 ,在某些t和x处 f(t,x)可能为负值     

一类脉冲微分方程边值问题的求解

给出了一类脉冲微分方程边值问题的求解方法 :先求出 Lx =g( t)R1( x) =y1,R2 ( x) =y2的解 x( t) ,再求出Ly =0 ,t≠ ti,i=1 ,2 ,… ,mΔy| t=ti =Ii( y( ti) + x( ti) ) ,Δy′| t=ti =Ii( y( ti) + x( ti) ) ,i =1 ,2 ,… ,mR1( y) =0 ,R2 ( y) =0的解y( t) ,则 x( t) + y( t)即为此类脉冲边值问题的解。     

一类时滞双曲型微分方程解的振动性

利用广义Riccati变换 ,建立了下列时滞双曲型微分方程 2 t2 u(x ,t) =a(t)Δu(x ,t) + sk =1ak(t)Δu(x ,t- ρk) - mj =1qj(x,t)u(x,t-σj)解的振动的若干充分条件 ,其中 (x ,t)∈Ω× [0 ,∞ )≡G ,Ω是RN中具有逐片光滑边界 Ω的有界区域 ,Δu(x ,t) = Nr=1 2 u(x ,t) x2r.     

二阶拟线性退缩抛物方程的第三边值问题

本文在Q_Υ={(x,t),-1相似文献   

脉冲 Sturm-Liouville 方程边值问题的多重正解

利用不动点指数理论,讨论了含无数个间断点的脉冲Sturm-Liouville方程边值问题(p(t)x′(t))′ f(t,x(t))=0,t∈[0,1],t≠tk;-Δx′|t=tk=Ik(x(tk)),k=1,2,…,α1x(0)-β1p(0)x′(0)=0;α2x(1) β2p(1)x′(1)=0的正解的存在性.     

具有粘性阻尼的波动方程的可控性

利用郑权的扰动定理 ,对粘性阻尼是连续有界函数的一维波动方程 , 2 u(x,t) t2 - 2 u(x,t) x2 b(x) u(x,t) t =0 ,　 0 0 ,u(x,0 ) =u1 (x) ,　 ut(x,0 ) =u2 (x) ,提出了一个实用的控制方法。     

一类奇异边值问题正解存在的充分必要条件

设 0 <α 1,β<0 ,p(t) ,q(t)∈C((0 ,1) ,(0 ,+∞ ) ) ,则边值问题x″+ p(t)xα+ q(t) (x′) β =0 ,0 相似文献   

一类具时滞的Lotka-Volterra系统的持久性和稳定性

一类具时滞的Lotka Volterra系统的持久性和稳定性(涪陵师范学院数学系,重庆涪陵408003)1　引言生态系统的持久性与全局渐进稳定性是受到学术界重视的问题[1～4].本文研究如下一类Lotka Volterra时滞系统: x1(t)=x1(t)[b1(t)-a1(t)x1(t)-d2(t)x2(t)-d3(t)x3(t)], x2(t)=x2(t)[-b2(t)+k2(t)∫0-τ1μ1(θ)x1(t+θ)dθ-a2(t)x2(t)-a3(t)x3(t)],(1) x3(t)=x3(t)[-b3(t)+k3(t)∫0-τ2μ2(θ)x1(t+θ)dθ-e2(t)x2(t)-a3(t)x3(t)].这里bi(t),ai(t),(i=1,2,3),di(t),ei(t),ki(t)(i=2,3)是连续函数,且有正的下界和上界.μi(s)(i=1,2)是[-τi,0]上…     

一类脉冲微分方程边值问题的求解

给出了一类脉冲微分方程边值问题的求解方法：先求出｛Lx=g(t)R1(x)=y1,R2(x)=y2的解x(t),再求出｛Ly=0,t≠ti,i=1,2,…，m△y|t=ti=Ii(y(ti) x(ti)),△y′|t=ti=Ii(y(ti) x(ti)),i=1,2,…,的解R1(y)=0,R2(y)=0y(t),则（x(t) y(t)即为此类脉冲边值问题的解。     

拟线性抛物型偏微分方程组解的振动性

利用Green定理和微分不等式,研究一类拟线性抛物型偏微分方程组 ((e)ui(x,t))/((e)t)=ai(t)Δui(x,t)+∑sk=1aik(t)Δui(x,ρk(t))-pi(x,t)ui(x,t)-∑mj=1fij[t,x,uj(x,σ(t))],i=1,2,...,m解的振动性,获得该类方程组在两类不同边值条件((e)ui(x,t))/((e)N)+gi(x,t)ui(x,t)=0,(x,t)∈(e)Ω×R+,i=1,2,...,m和ui(x,t)=0,(x,t)∈(e)Ω×R+,i=1,2,...,m所有解振动的若干充分条件 limt→∞ inf∫tσ(t)q(s)exp∫sσ(s)p(r)drds>(1)/(e).     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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