一类非线性多时滞中立型差分方程的振动性

讨论了非线性多时滞中立型差分方程　　　　Δ(x(n) - p(n)x(n-τ) ) +q(n) ∏mi =1(x(n -σi) ) αisgnx(n-σi) =0的振动性 .其中 :p(n) ≥ 0 ,q(n)≥ 0且不恒等于 0 ;τ ,σi是非负整数 ,i=1,2 ,… ,m ;αi >0 ,∑mi=1αi=1;Δ是前差分算子 ,Δx(n) =x(n+1) -x(n) .采用离散的Riccati变换和某些函数变换 ,利用反证法 ,得出了此方程所有解的若干振动准则 .     

一阶中立型差分方程的振动性

考虑一阶中立型差分方程Δ[x(n)-px(n-τ)] qx(n-σ)=0,　n≥n0.其中:Δ为前差分算子,即Δxn=xn 1-xn;p,q,τ,σ为正常数.利用求函数极值的方法,建立了新的振动准则.     

一类三阶非线性中立型时滞差分方程的振动性和渐近性

本文研究了一类三阶非线性中立型时滞差分方程Δ3(a(n)x(n)-b(n)x(n-τ)) q(n)f(x(n-σ))=0的振动性,得到了该方程振动的一个充分条件及其有界的非振动解趋于零的判据.     

具正负系数的多滞量中立型差分方程的振动性

讨论了具正负系数的多滞量中立型差分方程Δ[x(n)-m∑l=1Rl(n)x(n-rl)] w∑i=1Pi(n)x(n-τi)-k∑j=1Qj(n)x(n-σj)=0的振动性.其中:w≥k;Rl,Pi,Qj∈([n0,∞),R );rl,τi,σj都是非负整数,并且关于l,i,j都是单调减的,τi≥σi.在新的条件下得到了该方程振动的充分条件.     

二阶非线性中立型时滞差分方程的振动性

本文研究了一类二阶非线性中立型时滞差分方程Δ2(x(n) m∑i=1pi(n)x(n-ki)) q(n)f(x(n-σ))=0的最终正解的存在性,并得出了其解振动的充分条件.     

一类非线性中立型时滞差分方程的振动性

讨论了一类高阶中立型多时滞差分方程△＇（x（n）-p（n）x（n-k）＋q（n）^mП（j=1）｜x（n-σi）｜a^Sgnx（n-σ1）=0，n=0,1,…的振动性，获得了方程在[^m∑（j=1）]αi=1条件下振动的一个充分条件，同时又给出该方程非振动解趋于零的判据。     

二阶非线性中立型差分方程的始终正解

研究了二阶非线性中立型差分方程Δ(a(n)Δ(x(n) p(n)x(n-τ))) f(n,x(σ(n)))=0的非振动性.利用Banach压缩映射原理,得到了这个方程具有某种极限性质的始终正解的存在性定理.     

二阶中立型差分方程非振动解的不存在性和渐近性

讨论了二阶中立型差分方程Δ(a(n)(x(n) p(n)x(n-l)) q(n)f(x(n-k))=0,n≥n0的非振动解的不存在性与渐近性,获得了该方程非振动解的不存在与渐近的几个充分条件。     

奇数阶非线性中立型时滞差分方程的振动性

研究了一类奇数阶非线性中立型时滞差分方程Δd(a(n)x(n)-p(n)x(n-τ))+q(n)f(x(n-σ))=0的振动性,得到了该方程振动的若干充分条件,推广并改进了现有文献中的结果.     

三阶中立型时滞差分方程的振动性和渐近性

研究了一类三阶中立型时滞差分方程△’（α（n）x（n）-b（n）x（n-τ））＋Σmj=1qj（n）fj（x（n-σj））=0的振动性,得到了该方程振动的充分条件及其有界的非振动解趋于零的判据．     

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.     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~