二阶非线性差分方程的振动性与渐近性质

借助于不动点定理，研究了非线性差分方程△(rng(△xn)) f(n,xn)=0 的渐近性质与振动性质，给出了当∑n=n0^∞g^-1(1/rn)=∞时上述方 程存在非振动解的充要条件，同时还给出了该方程振动的充要条件。     

方程—Δu—μu／x^2＝u^2—1＋σf（x）极小正解的存在性

考虑了半线性椭圆型方程。这里，0∈Ω，ΩN是一个光滑有界区域，σ＞0是一个参数,μ＜μ－＝（N－2）^2／4，f(x)是L∞（Ω）中一个给定的函数，并且f(x)大于等于0，f(x)不等于0，利用隐函数定量及上下解方法，我们得到了一定条件下，方程极小正解的存在性。     

一类二阶拟线性差分方程的非振动性定理

研究了二阶拟线性差分方程Δ（Pnφ（Δxn)) f(n,xn)=0的渐进性，并给出了当任给k≠0，∑∞n=n0|φ^-1(k/pn)|=∞时此方程存在A∞^c,Ac^0型非振动解的充要条件以及存在A∞^0型非振动解的充分条件。     

非线性hammerstein型积分方程的多重解及其应用

在讨论非线性Hammerstein型积分方程(*)φ(x)=integral from n=G to k(x,y)f(y,φ(y))dy,0相似文献   

二阶变系数线性齐次微分方程的求解定理

在文[1]的启示下,对微分方程y″ a(x)y′ b(x)y=0的求解方法作了探讨,给出只与方程系数a(x),b(x)相关的求解定理,应用求解定理解有关方程,其过程十分简捷。     

一类四阶非线性方程边值问题的正解

讨论方程ц^(4)(x)=?(x，ц（x），ц″（x）在边界条件ц（0）=ц(1)=ц″(0)=ц″(1)=0下正解的存在性，给出了该问题至少存在一个正解的存在性定理。     

边坡极限平衡面的求解与应用

边坡极限平衡面确定是边坡稳定性分析的关键,以极限平衡理论为基础,设边坡的边界面为已知函数f(x0),通过微分和积分中值定理来确定边坡极限平衡面的方程f(x),并通过算例进行了验证,为不同类型边坡极限平衡面的确定提供了确切的方程或近似的方程.     

对方程f(x)=0根的题型分析

对方程f(x)=0根的存在性证明、唯一性证明及方程根的个数讨论等三个方面提出浅见.     

一个反问题的存在唯一性定理

按初值问题的解，讨论确定了抛物方程ut-Δu qu=0的系数q(x,t)，给出了此问题的解存在唯一性定理。     

三阶差分方程边值问题三正解存在的条件

利用代数知识结合Guo-Krasnosel'skii不动点定理研究三阶非线性差分方程边值问题△3u(t-1)+f(t,u(t-1),u(t),u(t+1))=0,t∈Z(1,N),u(0)=0,u(1)=0,u(N+2)=0三个正解存在的条件.     

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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