中立型线性微分—差分方程的稳定性

应用Ｌｉａｐｕｎｏｖ泛函法研究了［ｘ（ｔ）－Σｋｉ＝１Ａｉｘ（ｔ－τｉ）］′＝－Ｂ０ｘ（ｔ）－Σｋｉ＝１Ｂｉｘ（ｔ－τｉ）中立型微分－差分方程的稳定性，其中ｘ∈Ｒｎ，Ｂ０，Ａｉ，Ｂｉ（ｉ＝１，２，…，ｋ）皆为ｎ×ｎ阶实常阵，τｉ∈（０，＋∞）（ｉ＝１，２，…，ｋ）．得到了该方程平衡态稳定性的几个充分判据     

红血球补充模型的全局吸引性

研究了动物体内红血球补充模型Ｎ（ｔ） ＝ ｒ（ｔ） － Ｎ（ｔ） ＋ Ｐｅｘｐ － ∑ｎｉ＝ １γｉＮ（ｔ－ τｉ） ,ｔ≥０,其中ｒ（ｔ） ∈Ｃ（［０, ＋ ∞）,（０, ＋ ∞））,Ｐ＞ ０,γｉ,τｉ ∈（０, ＋ ∞）。获得了保证其每一正解Ｎ（ｔ）趋于一常数的若干充分条件,改进了已有结果。     

衰减激励条件下确定性系统多新息辨识的收敛性分析

在衰减激励条件下,分析了确定性系统多新息辨识算法的收敛性。得到了如下结果：１）当信息向量φ（ｔ）有界时：（ｉ）衰减指数ε＞１２时,估计误差θ（ｔ）有界,即‖θ（ｔ）‖＝Ｏ（１）或‖θ（ｔ）‖≤Ｍ＜∞;（ｉ）ε＝１２时,θ（ｔ）以１ｔｃ（ｃ＞０）速度收敛于零,即‖θ（ｔ）‖＝Ｏ１ｔｃ;（ｉｉ）０＜ε＜１２时,θ（ｔ）以指数ｅｘｐ（－ｃｔ１－２ε）（ｃ＞０）速度收敛于零,即‖θ（ｔ）‖＝Ｏ（ｅｘｐ（－ｃｔ１－２ε））。２）当φ（ｔ）以ｔμ速度增加（μ＞０）,即φ（ｔ）＝Ｏ（ｔμ）或‖φ（ｔ）‖≤ｃｔμ,ｃ＞０,（ｉ）μ＋ε＞１２时,θ（ｔ）＝Ｏ（１）;（ｉ）μ＋ε＝１２时,θ（ｔ）＝Ｏ１ｔｃ,ｃ＞０;（ｉｉ）μ＋ε＜１２时,θ（ｔ）＝Ｏ（ｅｘｐ（－ｃｔ１－２（μ＋ε）））,ｃ＞０。     

一类中立型微分差分方程解的振动性与渐近性

研究了微分差分方程ｘ（ｋ）－∑Ｃｋｘ（６－τｋ）＋∑Ｐｉ（ｔ）ｘ（ｔ－ｒ）＝０的振动性渐近性，其中０〈τ〈τ２〈…〈τｍ，０〈ｒ１〈ｒ２〈…〈ｒｎ，Ｃｋ≥０均为常数（ｋ＝１，２，…），Ｐｉ（ｔ）≥０连续（ｉ＝１，２，…ｍ），改进并推广了已知的一些结果。     

多滞量具有正负系数的一阶中立型时滞微分方程的稳定性

本文考虑一阶中立型时滞微分方程（１）：［ｘ（ｔ）＋Σ＾ｎ１ｉ＝１ｃｉ（ｔ）ｘ（ｔ－ｒｉ）］＾１＋Σ＾ｎ２ｋ＝１ｐｋ（ｔ）ｘ（ｔ－τｋ）－Σ＾ｎ３ｊ＝１ｑｉ（ｔ）ｘ（ｔ－σｊ）＝０的稳定性。这里ｐｋ（ｔ），ｑｉ（ｔ）∈Ｃ（［ｔ０，＋∞），Ｒ），γｉ，τｋ，σｊ均为非负实数，我们建立了此方程的一个稳定性结果，较文献［６］讨论得更广泛，所得结论更深刻。     

一类非线性时滞微分方程解的存在性

给出了非线性时滞微分方程ｄｘ／ｄｔ＝Σ↑ｍ↓ｉ＝１Ｈｉ（ｔ，ｘ（ｔ－τｉ（ｔ）））在某个半无限区间〔ｔ０，＋∞）上解存在的充分条件。     

延时微分方程组的隐式Runge Kutta方法的P_mL稳定性

介绍了延时微分方程组的Ｐｍ Ｌ稳定性⒚用隐式ＲｕｎｇｅＫｕｔｔａ 方法去解如下形式的含有ｍ 个延时量的线性试验方程组：ｙ′（ｔ） ＝ ａｙ（ｔ） ＋ ｍｊ＝ １ｄｊｙ ｔ－ τｊ , ｔ≥０ｙ（ｔ） ＝ φ（ｔ） , 　　　　　　　　ｔ≤０其中ａ,ｂｊ（ｊ ＝ １,２,…,ｍ ） ∈Ｃ,τｍ ≥τｍ － １ ≥…≥τ１ ＞ ０⒀φ（ｔ） 是已知函数⒚当ｍ ＝ ２ 时,证明隐式ＲｕｎｇｅＫｕｔｔａ 方法是Ｐ２Ｌ稳定的充要条件是它为Ｌ稳定的⒚当ｍ ＞ ２ 时,此结论也成立⒚     

一类二阶Volterra-hammerstein型积分微分方程非线性边值问题

本文利用上下解方法研究了一类Ｖｏｌｔｅｒｒａ－ｈａｍｍｅｒｓｔｅｉｎ型积分微分方程非线性边值问题（｜ｕ｜ｐ－２ｕ）＝ｆ（ｔ，ｕ，Ｔ１ｕ，Ｔ２ｕ，ｕ）（ｐ＞１）Ｌ（ｕ（０），ｕ（０））＝０Ｒ（ｕ（１），ｕ（１））＝０｛［Ｔｉｕ］（ｔ）＝φｉ（ｔ）＋∫ｔｏＫｉ（ｔ，ｓ）ｕ（ｓ）ｄｓ（ｉ＝１，２）给出了解的存在性定理．     

一类连续分布时滞模型的稳定性

运用Ｌｙａｐｕｎｏｖ泛函方法，研究一类具有连续分布时滞模型ｘ′ｉ（ｔ）＝－ｂｉｘｉ（ｔ）＋∑ｎｊ＝１ａｉｊｆｊ（μｊ∫ｔ－∞ｋｉｊ（ｔ－ｓ）ｘｊ（ｓ）ｄｓ）＋Ｆｉ（ｔ），τｉｊ∈［０，∞），ｉ，ｊ＝１，２，…，ｎ其平衡点的全局渐近稳定性，获得了一些新的充分条件．     

一类泛函微分方程解的全局吸引性

本文研究了非线性时滞微分方程ｘ（ｔ）＝－μｘ（ｔ）＋∑ｉ＝１＾ｎｂｉｆ（ｘ（ｔ－σｉ））＝ｇ（ｔ,ｘ（ｔ－τ１）,．．．,ｘ（ｔ－τｍ））的全局吸引性,并得出相关结论。     

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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