非自治与随机动力系统的吸引子

介绍了无穷维单值非自治动力系统的一致吸引子、一致指数吸引子、拉回吸引子、拉回指数吸引子及多值非自治系统的拉回轨道吸引子与随机系统的随机吸引子的一些最新研究成果.     

运动电荷间的电磁力与吸斥力

本文就两个运动的点电荷之间的相互作用电磁力存在于吸斥相互作用中，以及电磁力式表示成吸斥力式，主要从三方面讨论：①电场力、磁场力分别与吸引或排斥的相互作用；②电磁力与吸斥的相互作用；③电磁力与准吸斥的相互作用。     

周期边界条件下推广的B-BBM方程的整体吸引子

证明了周期边界条件下推广的B BBM方程整体吸引子的存在性.     

基于共存吸引子的图像加密算法

为了探究自激吸引子和隐藏吸引子共存系统的动力学特性,分析了其相图、分岔图、Lyapunov指数谱与谱熵复杂度.研究发现,该系统具有较大的复杂度值且其混沌状态分布在较大的参数范围内,说明由该系统迭代产生的混沌序列具有强的随机性,进而更适合应用于图像加密中.为此,设计了一种基于共存吸引子的图像加密算法.采用改进的Zigzag算法置乱明文图像的像素点位置,然后利用混沌系统迭代产生的混沌序列,通过加取模运算对置乱后图像的像素值进行扩散处理,得到加密图像.通过密钥空间、密钥敏感性、直方图、相邻像素间相关性、信息熵以及差分攻击等分析了加密算法的安全性能.实验结果表明,所设计的加密算法不仅能够有效地加密图像而且具有较高的安全性能.     

Chemotaxis-Growth系统的整体吸引子

研究了具有Dirichlet边界条件的Chemotaxis-Growth系统解的长时间行为.证明了Chemotaxis-Growth系统的解在L2(Ω)×L2(Ω)和H01(Ω)×H01(Ω)上的整体有界性,得到系统在L2(Ω)×L2(Ω)中整体吸引子的存在性.     

一类半群极小闭全局吸引子存在的充分条件

给出ξ（Ａξ）类算子半群存在极小的闭不变全局吸引子的若干充分条件，证明了如果ξ类算子半群｛Ｖｔ｝有有限的全局吸收庥Ｂ０，则｛Ｖｔ｝有极小的紧不变全局吸引子ξ＝μ＝ω（Ｂ０），并且μ与有限全局吸收集Ｂ０的选取无关。     

弱耗散耦合系统强全局吸引子的存在性

利用半群方法,证明了由两个双曲型方程耦合组成的Timoshenko梁系统在强拓扑空间中紧吸引子的存在性.     

溶胶-凝胶法制备的纳米材料吸波特性的研究

利用溶液—凝胶自蔓延合成法制备了稀土镧掺杂的钡铁氧体及锂铁气体，利用功率比法测试了这两种材料的吸波性能，并取得了一些有益的结论．     

GD121P卷接机组吸丝成形关键技术的CFD仿真分析

采用计算流体力学数值仿真方法,对以GD121P卷接机组为原型的吸丝成形关键技术进行了研究.给出了问题的仿真方法,建立了仿真模型,并根据实验对比建立了吸丝带多孔介质模型.仿真获得了吸丝带附近压强场关键特征,结果表明:在烟丝平整器前端,吸丝带上下压差较大,有利于形成较紧密的烟丝层,降低回丝量;仿真结果符合工程实际.     

蒲绒纤维的吸油性能

利用蒲绒纤维作为吸油材料吸附机油和植物油.结果表明:由蒲绒纤维制得的吸油材料吸油效果良好,1g纤维分别能吸收24.7g纯机油和27.8g纯植物油;在油:纯净水混比1:4条件下,1g纤维分别能吸收17～22g机油和18～24g植物油.香蒲绒纤维经2.5kPa压强机械挤压重复5次,1g蒲绒纤维分别吸收11g机油和9g植物油.蒲绒纤维独特的结构和表面蜡质是决定其吸油能力的重要因素.     

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

正~~