2阶齐次微分方程的次正规解

研究了周期系数的2阶齐次微分方程f”+[P1(ez)+Q1(e1)]f'+[P2(ez)+Q2(e-z)]f=0的次正规解的存在性及表示形式.当Qj(j=1,2)的次数不同时,所得方程的次正规解的表示形式将会不同,完善了已有的结果.     

关于微分方程f″+(e~(-z)/e~z+1)f'+Q(z)f=0解的增长性

主要研究了二阶微分方程f″+e-z/ez+1f'+Q(z)f=0解的增长性,其中Q(z)是有限级超越整函数,得到了当Q(z)满足一定条件时,该方程的任意非平凡解为无穷级。     

单位圆内高阶非齐次线性微分方程解与小函数的关系

对高阶非齐次线性微分方程f(k)+Ak-1f(k-1)+Ak-2(f(k-2)+…+A1f’(z)+A0f=F的复振荡进行了研究,其中A0(z),A1(z),…,Ak-1(z),F(z)≠0是单位圆Δ内的有限级解析函数.讨论了系数是单位圆内的解析函数的高阶非齐次线性微分方程解及一次导数和二次导数与其小函数之间的关系,并获得了它们之间的精确估计.     

一类非齐次微分方程解的级与零点

在方程系数A0的型起控制作用的条件下,研究了高阶非齐次线性微分方程f(k)+Ak-1(z)f(k-1)+…+A0(z)f=F(z)解的增长性,得到了上述微分方程解的增长级和零点的一些精确估计.     

高阶常系数微分方程解的进一步探讨

高阶常系数非齐次线性微分方程y(n)+an-1y(n-1)+…+a1y(1)+a0y=f(x),(a0,a1,…,a n+1∈R),文章将讨论一种将此高阶方程化为a个一阶非齐次线性微分方程组的解法来简化解题过程,并介绍了一种求一类高阶常系数线性微分方程特解的比较简单的方法.     

单位圆内高阶齐次线性微分方程解的复振荡

对高阶齐次线性微分方程f(k)(z)+Ak-1(z)f(k-1)(z)+Ak-2(z)f(k-2)(z)+…+A1(z)f'(z)+A0(z)f(z)=0的解进行了研究,其中Aj(z)(j=0,1,2,…,k-1)为单位圆△={z:|z|<1}内的解析函数,给出了高阶齐次线性微分方程解的增长性与系数增长性之间的关系,并证明了高阶齐次线性微分方程的亚纯可允许解在单位圆内的充满圆序列的存在性.     

周期系数高阶线性微分方程的次正规解

考虑周期系数高阶线性微分方程f~((n))+∑j=1 n[P_(n-j)(e~z)+Q_(n-j)(e~(-z))]f~((n-j))=R_1(e~z)+R_2(e~(-z)),其中n≥2,P_j(z),Q_j(z)(j=0,1,2,…,n-1),R_1(z)和R_2(z)均是关于z的多项式,且Pj(z),Qj(z)(j=0,1,2,…,n-1)不全为常数.在条件degPjdegP0(j=1,2,…,n-1)下,获得方程的次正规解的表示.     

一类高阶齐次线性微分方程解的增长性

研究了高阶齐次线性微分方程f(k)+Ak-1(z)epk-1(z)f(k-1)+Ak-2(z)epk-2(z)f(k-2)+…+A0(z)ep0(z)f=0和f(k)+(Ak-1(z)epk-1(z)+Dk-1(z))f(k-1)+…+(A0(z)ep0(z)+D0(z))f=0解的增长性问题,其中,pj(z)=ajzn+bj,1zn-1+…+bj,n,Aj(z)和Dj(z)是有限级整函数.针对pj(z)中aj(j=0,1,…,k-1)的幅角主值相等的情形,得到了σ2(f)=n.     

一类非齐次微分方程解的增长性

研究一类非齐次线性微分方程f(k)+ak-1f(k-1)+…+a1f'-(eQ(z)-h0)f=1(k≥1)解的增长性,其中aj(j=1,2,…,k-1)为常数,Q(z)为非常数多项式,h0为超越慢增长整函数.利用所得结果,还可以给出有关亚纯函数唯一性的结果.     

一类高阶线性微分方程解的超级估计

利用Nevanlinna的值分布理论和分类讨论的思想方法,研究了一类高阶齐次线性微分方程f(k)+Hk-1f(k-1)+…+H1f'+H0f=0解的增长性,得到了一些有意义的结果:当Hj(z)(j=0,1,…,k-1)是整函数时,根据线性微分方程的一般理论,上述方程的每个解都是整函数.当方程系数满足:Hj(z)=hj(z)ePj(z)(j=0,1,…,k-1),Pj(z)是首项系数为aj的n(n≥1)次多项式,hj(z)为整函数,σ(hj(z))n,aj是复数,存在as和al,使得ls,as=dseiφ,al=-dleiφ,ds0,dl0.对j≠s,l,aj=djeiφ(dj≥0)或aj=-djeiφ,max{dj;j≠s,l}=dmin{ds,dl},hshl0,给出了该微分方程的每个超越解的超级的精确估计.结果可以推广到亚纯函数系数的微分方程.     

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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