光通信系统中相干暗孤子间的相互作用

利用最小作用量原理导出非线性Schrodinger方程两个相干暗孤子之间的相互作用，它作为孤子间距△和初位相差θ的函数，随△的增大而指数地衰减，当两个孤子之间初位相差θ＜π/2时相互排斥，θ＝π/2时几科不存在相互作用。θ＞π/2时相互吸引，本也研究了高阶色散效应对相互作用的影响。     

光纤暗孤子的相互作用

利用最小作用量原理，从非线性Ｓｃｈｒｄｉｎｇｅｒ方程，导出两个暗孤子之间的相互作用．它作为孤子间距△和初位相差θ的函数，随△的增大而指数地减小，当两个孤子之间初位相差θ＜π／２时相互排斥，θ＝π／２时几乎不存在相互作用     

两组分玻色-爱因斯坦凝聚体中亮-亮孤子的碰撞

基于准一维异核两组分玻色-爱因斯坦凝聚体的Gross-Pitaevskii方程模型,在调制不稳定条件下,通过调节相互作用强度参数,研究了亮-亮孤子解的产生及其碰撞问题。若不存在外部势阱,相对相位是π的情况下亮-亮孤子产生了完全弹性碰撞,相对相位是π/2时亮-亮孤子碰撞产生了能量的转移;若存在外部势阱,相对相位为π时亮-亮孤子产生了周期性碰撞,而相对相位是π/2时两孤子碰撞合并成一个孤子,并伴随有能量逃逸。     

两组分玻色-爱因斯坦凝聚体中矢量孤子的动力学性质

通过数值求解异种两组分玻色爱因斯坦凝聚体在弱囚禁势中的运动方程来讨论其矢量孤子解的动力学性质.研究表明,种内和种间相互作用强度满足不同的条件时,会形成亮亮孤子、亮暗孤子和暗暗孤子等不同的矢量孤子解.其中亮亮孤子和亮暗孤子是稳定的,而暗暗孤子很不稳定.适当改变种间相互作用强度,亮、暗孤子之间能够相互转换.     

二阶孤子相互作用的研究

本文用等效势的观点,对非线性单模光纤中的二阶孤子间的相互作用进行了理论分析,得出了其相互作用表现为引力,并且引力的大小随孤子间隔的增大而减小的结论。本文还用数值计算法模拟了在不同注入条件下的两个二阶孤子在光纤中的传输情况。结果表明:非等幅注入可以使二阶孤子相互作用减弱。     

光纤通信系统中非相干暗孤子间的相互作用

利用变分法，通过非线性Schroedinger方程，导出光通信系统中非相干暗孤子间的相互作用，即通过非线性强度叠加产生的相互作用。结果表明：在两个非相干暗孤子之间存在排斥力，并且高阶色散效应减弱了非相干暗孤子的相互作用。这与相干暗孤子之间的相互作用结果一致。     

矢量暗孤子两偏振分量的相互作用特性

利用变分法研究双折射光纤中矢量暗孤子两偏振分量的相互作用,导出矢量暗孤子两分量间相互作用能和相互作用力的表达式,由此详细讨论了两分量孤子的相互作用特性.     

一维BEC中暗孤子在抛物势阱中的动力学

给出一维BEC中暗孤子在抛物势阱中的运动方程,并由此讨论暗孤子在抛物势阱中的动力学演化.结果表明:暗孤子在抛物势阱中呈周期运动.同时,通过数值模拟研究在Thomas-Ferm i近似下暗孤子在BEC中的演化情况,数值结果与理论预测非常一致.另外,我们还讨论暗孤子在抛物势阱中的相互作用,结果表明:暗孤子在抛物势阱中的相互作用呈周期性的弹性碰撞,并且随着孤子间隔的减小,周期碰撞的振幅越来越小,直到两个暗孤子合而为一;同时,随着孤子间隔的减小碰撞周期也随之减小.这与光学传输过程中的孤子相互作用是不同的.     

光纤通信系统中孤子的相互作用

光孤子因其独特优点成为光纤通信系统中最理想的信息载体．借鉴前人研究成果,简述了光孤子通信中孤子间相互作用的机理,展望了光孤子通信的应用前景。     

基于对称分步傅里叶法的光孤子传输特性研究

详细讨论了一种形式的对称分步傅里叶法,用Matlab软件对光孤子的传输进行仿真,模拟了基态、三阶孤子的传输,研究了一阶、二阶孤子对间的相互作用,分析了傅里叶正、逆变换选取时应注意的问题.结果表明这种形式的对称分步傅里叶法能适用于对光孤子传输的仿真.     

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