二阶半线性微分各分方程的奇摄运边值问题

本文研究微分积分方程奇摄动边值问题εｄ＾２ｙ／ｄｔ＾２＝ｇ（ｔ，ｙ，ｊ，ε），ｙ（０，ε）＝ｙ（１，ε）＝０，０〈ε《１，其中Ｊ＝ψ（ｔ，ε）＋∫＾α０Ｋ（ｔ，ｓｙ（ｓ，ε），ε）ｄｓ，ａ＝１或ｔ。首先利用边界层函数法构造了这个问题解关于√ε的形成渐近展开，然后证明该问题解的局部存在唯一性以及所构造渐近级数的一致有效性。     

某类双参数非线性系统初值问题的双重边界层现象

研究奇摄动双参数非线性系统初值问题εｙ＂＝Ｆ（ｔ,ｙ,／μｙ＇）,ｙ（０,ε,μ）＝Ａ（ε,μ）,ｙ＇（０,ε,μ）＝Ｂ（ε,μ）当ε＝０（μ＾ｋ）,ｋ≥３时的双重边界层现象,通过引进不同量级的伸长变量,得到解的一致有效的渐近展形式。     

定常奇异摄动系统的概周期解

本文考虑定常的奇异摄动系统（１．１）ｄｘ／ｄｔ＝ｆ（ｘ，ｙ，ε），εｄｙ／ｄｔ＝ｇ（ｘ，ｙ，ε）及其退化 系统（１．２）ｄｘ／ｄｔ＝ｆ（ｘ，ｙ，０），０＝ｇ（ｘ，ｙ，０）．假设系统（１．２）有一个非常数的概周期解（１．３） ｘ＝ｕ（ｔ），ｕ＝Ｖ（ｔ）．当系统（１．２）关于（１．３）的第一变分方程系恰具有一个广义零特征指 数时，我们在适当的条件下证明了对充分小的ε，系统（１．１）有唯一的概周期解ｘ＝ｘ（ｔ，ε）， ｙ＝ｙ（ｔ，ε）使得当ε→ｏ时，对一切ｔ有｜｜ｘ（ｔ，ε）－ｕ（ｔ）｜｜＋｜｜ｙ（ｔ，ε）－ｖ（ｔ）｜｜→０。 在证明中，我们首先推广了法坐标变换，进而建立指数型二分法，然后把问题化为非定常系统的 相应问题，从而利用Ｋ．Ｗ．Ｃｈａｎｇ［５］的结果加以解决．     

Banach空间微分方程初值问题弱解的一个存在性定理

在弱耗散型条件ｌｉｍ／ｈ→０＾－１／ｈ［｜ψ（ｘ－ｙ＋ｈ（ｆ（ｔ，ｘ）－ｆ（ｔ，ｙ）））｜－ψ（ｘ－ｙ）｜］≤ｇ（ｔ，｜ψ（ｘ－ｙ）｜）下给出了Ｂａｎａｃｈ空间常微分方程初值问题弱解的一个存在性定理。     

一个变系数热方程的初值问题的局部解的不存在性

本文在空间Ｃ（「ε０,Ｔ」,Ｌ＾ｐ）∩Ｃ＾１（ε０,Ｔ「,Ｌ＾内考虑边值问题 ｛δｕ／δｔ－１／ｔ＾αｕ＝│ｕ│＾ｒ－１ｕ ｔ〉ε０〉０ （１） ｌｉｍｕ ｔ ↓ε０（ｔ,ｘ）＝ψ（ｘ） ｘ∈Ｒ＾ｎ（２）其中γ〉１,ｐ≥１,ε０是一个固定的正数。在Ｌ＾ｐ内ψ（ｘ）≥０且不恒为零,α〉０,我们给出了问题（１）（２）有正解的一个必要条件,并研究了正解的不存在性。     

一类非线性ROBIN问题解的边界层现象

本文讨论了非线性Ｒｏｂｉｎ问题εｙ″＝ｆ（ｔ,ｙ,ｙ′）,ａ〈ｔ〈ｂ,ｙ（ａ,ε）－ｐ１ｙ′（ａ,ε）＝Ａ,ｙ（ｂ,ε）＋ｐ２ｙ′（ｂ,ε）＝Ｂ在ｆｙ′ｙ′≠０的情形下解的边界层现象。     

一类奇摄动三阶时滞微分方程边值问题

在本文中,我们利用微分不等式理论研究下列奇摄动三阶ＲＦＤＥ：εｙ′″（ｔ）＝ｆ（ｔ,ｙ（ｔ）,ｙ（ｔ－τ）,ｙ′（ｔ－τ）,ｙ″（ｔ）,ε）,ｔ∈（０,１）ｙ（ｔ）＝θ（ｔ）,ｔ∈［－τ,０］,ｙ′（０）＝θ′（０）,ｙ′（１）＝Ａ｛的边值问题,证明了解的存在性,并给出了解的有效估计式．     

含两参数的三阶半线性常微分方程边值问题的奇摄动(Ⅰ)

研究含两参数的三阶半线性常微分方程奇摄动边值问题εｙ＋ μｆ（ｘ）ｙ″＋ ｇ（ｘ）ｙ′＝ ｈ（ｘ,ｙ,ε,μ）,ｙ（０） ＝ Ａ（ε,μ） , ｙ′（０） ＝ Ｂ（ε,μ）, ｙ′（１） ＝ Ｃ（ε,μ） ．采用两阶段展开的方法,对（ε／ μ２） →０ （μ→０）的情况构造出形式渐近解,并利用微分不等式理论,证明了解的存在惟一性,同时给出余项的一致有效的估计．     

一类变系数半线性热方程初值问题解的blow—up问题

本文讨论了初值问题｛δｕ／δｔ－１／ｔΔｕ＝ｕ＾ｒ ｔ〉ε０〉０ ｘ≤Ｒ＾ｎ（０．１） ｕ（ε０，ｘ）＝（ｘ） ｘ∈Ｒ＾ｎ（０．２）其中γ≥１，ψ（ｘ）连续有界，且ψ（ｘ）≥０但不恒为零。我们证明了当１／γ－１≥ｎ／２时，初值问题（０．１）（０．２）的非负解必在有限时间ｂｌｏｗ－ｕｐ。即问题（０．１）（０．２）在１／γ－１≥ｎ／２时没有非负的整体解。     

二阶非线性抛物型偏微分方程初边值问题的奇摄动

本文讨论一类二阶非线性抛物型偏微分方程初边值问题的奇摄动解法，设Ｌεｕ＝δｕ／δｔ－〔εΣ↑ｎ↓ｉｊ＝１δｉｊ（ｘ，ｔ）δ＾２ｕ／δｘｉδｘｊ＋Σ↑ｎ↓ｉ＝１ｂｉ（ｘ，ｔ）δｕ／δｘｉ＋Ｃ（ｘ，ｔ，ｕ）〕＝０ ｕ（ｘ，ｔ，ε）│ｔ＝０＝ｕ（ｘ，０，ｔ）＝μ（ｘ，ε），ｘ∈Ｂ↑－ ｕ（ｘ，ｔ，ε）│ｓ＝ｈ（ｘ，ｔ，ε）│ｓ（ｘ，ｔ）∈Ｓ其中ε〉０是小参数，给出了上述问题的解的渐近展开式。利用比较定理     

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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