高阶非线性中立型方程的振动定理

研究了一类具有连续分布滞量的高阶非线性中立型方程a(t)ψ(x(t))[x(t) ∑mi=1ci(t)x(τi(t))](n-1)′ ∫baf(t,ξ,x(g(t,ξ)))dσ(ξ)=0解的振动性,运用数学分析方法和技巧及方程各阶导数的符号关系,在2种不同情形下得到了该类方程新的振动准则.     

高阶中立型方程的振动定理

研究一类具连续分布滞量的高阶中立型方程{a(t)Ψ(x(t))[x(t)+∑mi=1ci(t)x(τi(t))](n-1)}′+∫baq(t,ξ)x(g(t,ξ))dσ(ξ)=0的振动性,利用Riccati变换并运用分析方法和技巧,得到了该类方程新的振动准则,所得结论推广和改进了已知文献的部分结果。     

高阶非线性中立型方程的振动定理

研究了一类具连续分布滞量的高阶非线性中立型方程{a(t)[x(t) m∑i=1 ci(t)x(τi(t))](n-1)}' ∫baq(t,ξ)f(x(g(t,ξ)))dσ(ξ)=0的振动性,利用一般的Riccati变换和完全平方技术,通过引进参数函数H(t,s),并在减弱H(t,s)的条件下,获得了方程更一般性的振动准则,所得结论改进并推广了已知文献中的部分结果.     

二阶非线性中立型动力方程的振动定理

借助时间尺度的有关理论,利用广义Riccati变换和加权平均不等式,讨论时标上二阶非线性中立型动力方程(r(t)[(x(t)+a(t)x(τ(t)))Δ]α)Δ+∫dcF(t,ξ,x(δ(t,ξ)))Δξ+∑ni=1∫dcFi(t,ξ,x(δ(t,ξ)))Δξ=0,t∈Τ的振动性,其中,α是奇整数之商.获得了动力方程振动的充分条件.该文结论推广和改进了已有文献的有关结果,并给出了应用实例.     

随机和的局部精细大偏差

利用风险理论讨论了随机和S(t)=sum from i=1 tp N(t)(ξi),t≥0中心化的局部精细大偏差问题,得到了对x∈[I(t)+J(t),∞)一致地有P(ξ1+ξ2+…+ξN(t)-ES(t)∈x+Δ)~nF(x+Δ),其中{N(t):t≥0}是一个与{ξi:i≥1}独立的泊松过程.     

迭代微分方程x〃(t)=∑ai(t)fi(x(t))解的存在性

首先通过构造一个连续函数集合上的连续自映射的方法,利用Schuder不动点定理,证明了一类二阶自迭代泛函微分方程x＇(t)=∑ai(t)fi(x相似文献   

关于一阶具分布型偏差变元滞后型微分方程的振动性

本文讨论了滞后型方程x‘(t) ∫^bap(t,ξ）X[g(t,ξ)]dσ（ξ）＝0，b＞a的振动性，改进了文[1]的结果。     

一类二阶广义Sturm—Liouville边界条件多点边值问题的可解性

应用Leray-Schauder延拓定理,得到了二阶常微分方程多点边值问题x″(t)=f(t,x(t),x′(t)) e(t), t∈(0,1)αx(0)-βx′(0)=∑m-2i=1aix(ξi), γx(1) δx′(1)=∑n-2j=1bjx(τj)解的存在性,其中f:[0,1]×R2R满足Caratheodory条件,e(·)∈L1(0,1),ai,bj∈R,ξi,τj∈(0,1),i=1,2,…,m-2,j=1,2,…,n-2,0＜ξ1＜ξ2＜…＜ξm-2＜1,0＜τ1＜τ2＜…＜τn-2＜1.     

二阶无穷多点半正边值问题正解的存在性问题

研究二阶无穷多点半正边值问题:x″(t)+λf(t,x(t))=0,0ξ1>ξ2>…>ξn>…>0,0<η1<η2<…<ηn<…<1,αi,βi∈(0,∞),0<∑∞i=1αi(1-ξi)<1,0<∑∞i=1βiηi<1且ρ∞=∑∞i=1αiξi1-∑∞i=1(β)i+1-∑∞i=1(βiη)i1-∑∞i=1α()i>0.给正参数λ和函数f(t,x(t))赋予一定的条件,使得上述问题至少存在一个正解.该文应用锥上不动点定理证明了主要定理.     

高阶非线性中立型方程的振动性

研究了一类具有连续分布滞量的高阶非线性中立型方程{α（t)Ψ（x(t))[x(t) m↑∑↑i=1ci(t)x(τi(t))]^(n-1)}′ ∫α^bq(t,ζ）f(x(g(t,ζ）））dσ（ζ）=0的振动性,利用Riccati变换并运用数学分析方法和技巧,得到了该类方程新的振动准则。     

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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