一类非线性中立型泛函微分方程振动的充要条件

给出非线性中立型泛函数微分方程ｄ／ｄｔ「ａ（ｔ）ｘ（ｔ）－∑ｂ（ｔ）ｘ（ｔ－ｒｉ）」＋∑ｆｊ（ｔ，ｘ（ｔ），ｘ（ｔ－τｉ（ｔ））＝０振动的充要条件是，微发不等式ｄ／ｄｔ「ａ（ｔ）ｘ（ｔ）－∑ｂｉ（ｔ）ｘ（ｔ－ｒｉ）」≤－∑ｆｊ（ｔ，ｘ（ｔ），ｘ（ｔ－τｊ（ｔ））无最终正解。     

具有可变时滞的随机系统的指数稳定性

研究了具有可变时滞的随机系统ｄｘ（ｔ）＝（ｆ（ｔ，ｘ（ｔ），ｘ（ｔ－δ１））＋△ｆ（ｔ，ｘ（ｔ），ｘ（ｔ－δ２（ｔ）））ｄｔ＋ｇ（ｔ，ｘ（ｔ），ｘ（ｔ－δ３（ｔ））ｄｗ（ｔ）的ｐ阶均值指数稳定性与几乎必须指数稳定性，引入对应的随机系统，（无时滞与扰动）ｄｘ（ｔ）＝ｆ（ｔ，ｘ（ｔ），ｘ（ｔ）ｄｔ＋ｇ（ｔ，ｘ（ｔ），ｘ（ｔ）ｄｗ（ｔ）并假设它是指数稳定的，应用Ｒａｚｕｍｉｋｈｉｎ技巧证明了当时滞δｉ（     

一维奇异非稳态问题全离散解的误差估计

研究如下奇异非稳态问题｛ｕｔ（ｘ，ｔ）－ｐ＾－１（ｘ）（ｐ（ｘ）ｕ＇（ｘ，ｔ））＇＋ｑ（ｘ）ｕ（ｘ，ｔ）＝Ｈ（ｘ，ｔ）ｔ〉０ ｘ∈Ｉ≡（０，１） ｕ＇（０，ｔ）＝ｕ（１，ｔ）＝０ ｔ〉０ ｕ（ｘ，０）＝ψ（ｘ）的有限元方法。分别使用Ｅｕｌｅｒ－Ｇａｌｅｒｋｉｎ方法和Ｃｒａｎｋ－Ｎｉｃｏｌｓｏｎ－Ｇａｌｅｒｋｉｎ方法，给出全离散解的加权Ｌ２模误差估计。     

一类非线性时滞微分方程的振动性

讨论了非线性时滞微分方程ｄ／ｄｔＨ（ｔ，ｘ（ｔ），ｘ（ｔ－ｒ）＋ｆ（ｔ，ｘ（ｔ－τ））－ｇ（ｘ（ｔ－σ））＝０的振动性，推广了有关文献的部分结果。     

无穷时滞中立型系统零解的稳定性

考虑了一类非线性中立型微分方程ｘ（ｔ）＝ｇ（ｔ，ｘ（ｔ））＋ｆ（ｔ，ｘ（ｔ）），ｘ（ｔ－△（ｔ）），ｘ（ｔ－△（ｔ）），其中△ｔ是非负无界函数，满足（ｔ－△（ｔ））→＋∞（ｔ→＋∞），得到了零解在Ｃ（１）空间中渐近稳定的简单的判别准则     

高阶中立型时滞微分方程正解的存在性

研究ｎ阶中立型时滞微分方程ｄｎｄｔｎ［ｘ（ｔ）＋ｐ（ｔ）ｘ（ｔ－τ）］＋ｆ［ｔ，ｘ（ｔ－τ１（ｔ）），…，ｘ（ｔ－τｋ（ｔ））］＝０，ｔ≥ｔ０，其中ｎ≥１是奇数，在对ｆ较弱限制及对ｐ（ｔ）适当限制下，获得该方程正解存在的充分条件     

具有时滞的Lurie型控制系统的绝对稳定性

利用Ｌｉａｐｕｎｏｖ泛函讨论了系统方程分别为ｘ（ｔ）＝Ａｘ（ｔ）＋Ｂｘ９ｔ－τ）＋ｂｆ（σ（ｔ）），ｘ（ｔ）＝Ａｘ（ｔ）＝Ｂｘ（ｔ－τ）＋ｂｆ（σ（ｔ－τ））的Ｌｕｒｉｅ型直接控制系统和间接控制系统的绝对稳定性，得到了一些比较实用的代数判据。     

关于高阶泛函边值问题的一个比较定理

考虑泛函边值问题：ｘ（ｎ）－ｎｉ＝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定理证明了上述问题的可解性蕴含于边值问题“ｘ（ｎ）－ｎｉ＝１Ｐｉ（ｔ）ｘ（ｉ－１）＝０，Ｂ（ｘ，ｘ，…，ｘ（ｎ－１））＝ξ”解的唯一性．     

滞后中立型高维周期系统周期解的存在性

对滞后中立型高维周期系统ｘ’（ｔ）＝Ａ（ｔ，ｘ（ｔ））ｘ（ｔ）＋ｆ（ｔ，ｘ（ｔ－ｒ１））＋Ｂ（ｔ）ｘ‘（ｔ－ｒ２），利用不动点方法，建立了保证其周期解的存在性充分条件。     

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．     

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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