一类微分方程周期边值问题的单调失代方法

研究二阶非线性积分微分方程的周期边值问题：－ｘ″＝ｆ（ｔ，ｘ′，Ｔｘ），ｘ（０）＝ｘ′（０）＝ｘ′（１）解的存在性及唯一性，并说明所得主要结果在高阶微分方程混合问题上的应用。     

一个三阶边值问题解的存在唯一性定理

考虑三阶边值问题ｘ′′′＝ｆ（ｔ，ｘ，ｘ′，ｘ″），ｘ（０）＝ｘ（１）＝ｘ′（０）＝０。用基于度理论的不动点定理，建立了一系列存在唯一性定理。     

中立型时滞微分方程的一个正解存在定理

本文利用上，下解单调迭代方法，得到了当０≤Ｃ（ｔ）≤１时中立型时滞微分方程［ｘ（ｔ）－Ｃ（ｔ）ｘ（ｔ－ｒ）］′＋ｐ（ｔ）ｘ（ｔ－τ）＝０（１）的正解存在条件．     

守恒双曲型方程式初边值问题的隐式解及一维情形下激波稀疏波的确定

１　一维守恒双曲型标量方程的初边值问题解法讨论一维标量守恒双曲型方程　ｕｔ＋ｆ（ｕ）ｘ＝０（１）的纯初值问题　ｕ（ｘ,０）＝φ１（ｘ）（－∞＜ｘ＜∞）（２）及初边值问题　ｕ（ｘ,０）＝φ１（ｘ）,（０≤ｘ＜∞）　ｕ（０,ｔ）＝φ２（ｔ）（０≤ｔ＜∞）（３）并得到如下结果：１）问题（１）,（２）当１＋ｆ″φ１′ｔ≠０时的隐式解为　ｕ（ｘ,ｔ）＝φ１（ｘ－ｆ′（ｕ（ｘ,ｔ））ｔ）（４）２）问题（１）,（３）当１＋φ′１ｆ″ｔ≠０,１－φ２′ｘｆ″／（ｆ′）２≠０时的解为　ｕ（ｘ,ｔ）＝φ１（ｘ－ｆ′…     

二阶三点共振边值问题的多重解

该文研究二阶三点共振边值问题ｘ″＋ ｆ（ｔ，ｘ，ｘ′） ＝ ｓ，ｘ（０） ＝ ｘ（η） ，ｘ′（１） ＝ ０（０ ＜ η＜ １） 的多重解的存在性，这里ｓ 是参数。所使用的方法是ＬｅｒａｙＳｃｈａｕｄｅｒ 连续定理以及上下解方法。     

关于高阶泛函数值问题的一个比较定理

考虑泛函边值问题：ｘ＾（ｎ）－ｎ／∑／ｉ＝１Ａｉ（ｔ，，ｘ，ｘ′，…，ｘ＾（ｎ－１））ｘ＾（ｉ－１）＝ｆ（ｔ，ｘ，ｘ′，…，ｘ＾（ｎ－１）（０≤ｔ≤１），Ｂ（ｘ，ｘ′，…，ｘ＾（ｎ－１）＝ξ。在适当条件下，利用Ｂｏｒｓｕｋ定理主明了上述问题的可解性蕴含于边值问题：ｘ＾（ｎ）－ｎ／∑／Ｐｉ（ｔ）ｘ＾（ｉ－１）＝０，Ｂ（ｘ，ｘ′，…，ｘ＾（ｎ－１）＝ξ”解的唯一性。     

非线性项有非线性增长的三阶边值问题

考虑三阶三点边值问题ｘ＝ｆ（ｔ，ｘ，ｘ′，ｘ″），ｘ（０）＝ｘ（ξ）＝ｘ（１）＝０，其中ξ∈（０，１）．对于ｆ有非线性增长的情况，利用基于度理论的不动点定理，建立了某些存在唯一性定理．     

关于函数极值的几个定理

在函数极值的一般理论的基础上，得出了形如ｆ′（ｘ）＝ｇ（ｘ）φ（ｘ）的一类可导函数ｆ（ｘ）有极值的充分条件：设函数ｆ（ｘ）在ｘ０点的某邻域二阶可导，且ｆ′（ｘ）＝ｇ（ｘ）φ（ｘ），ｆ′（ｘ０）＝０．（１）若φ（ｘ０）＞０，则当ｇ′（ｘ０）＞０时，ｆ（ｘ０）为ｆ（ｘ）的极小值；当ｇ′（ｘ０）＜０时，ｆ（ｘ０）为ｆ（ｘ）的极大值．（２）若φ（ｘ０）＜０，则当ｇ′（ｘ０）＞０时，ｆ（ｘ０）为ｆ（ｘ）的极大值；当ｇ′（ｘ０）＜０时，ｆ（ｘ０）为ｆ（ｘ）的极小值．     

混合型方程在矩形域上的非局部边值问题

给出了混合型二阶线性偏微分方程Ｌｕ≡ｈ（ｙ）ｕ＿（ｙｙ）＋ｕ＿（ｘｘ）＋ａ（ｘ，ｙ）ｕ＿ｙ＋ｂ（ｘ，ｙ）ｕ＿ｘ＋ｃ（ｘ，ｙ）＝ｆ（ｘ，ｙ）在非局部边界条件ｕ（ｘ，１）一ａｕ（ｘ，０）＝０，ｕ＿ｙ（ｘ，１）一ａｕ（ｘ，０）＝０，ｕ（１．ｙ）一βｕ（０，ｙ）＝０，ｕ＿ｘ（１，ｙ）－βｕ＿ｘ（０，ｙ）＝０下，在Ｓｏｂｏｌｅｖ空间中解存在及唯一的充分条件。     

一类高阶非线性摄动微分方程的振荡定理

对一类高阶非线性摄协微分方程（α（ｔ）φ（ｘ＾（ｎ）（ｔ）ｘ′（ｔ））′－ｍ（ｔ）φ１／２（ｘ＾（ｎ）（ｔ）ｘ′（ｔ）＋Ｑ（ｔ,ｘ,ｘ′）＝０（ｎ＝０,１,…）在满足一定的条件下,建立了若干使该方程解振荡的充分条件,该结果推广了原有结论,扩大了应用范围。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has