复合势中的玻色一爱因斯坦凝聚孤子的操控

提出了一种处理在光晶格势和抛物势共同作用下的玻色-爱因斯坦凝聚孤子动力学的拓展变分法．利用拓展变分方法给出了玻色．爱因斯坦凝聚孤子的解析处理,并和基于分步傅立叶变换的直接数值方法进行比较,发现这种拓展变分方法能够充分揭示上述外势场中的玻色．爱因斯坦凝聚孤子的动力学行为．同时,给出了能支持多稳定晶格囚禁玻色一爱因斯坦凝聚孤子的多晶格稳定势槽,并通过调控光晶格势实现了玻色一爱因斯坦凝聚孤子从某一稳定晶格势槽为初始位置到任意位置的操控．这为玻色一爱因斯坦凝聚的实验和应用研究提供了一定的理论依据．     

反抛物势与双光晶格势中的三维玻色-爱因斯坦凝聚涡旋孤子

提出了一种处理囚禁于反抛物势和双光晶格复合势中玻色-爱因斯坦凝聚涡旋孤子动力学的能量密度泛函和直接数值仿真相结合的方法.利用静态Gross-Pitaevskii方程和柱对称玻色-爱因斯坦凝聚涡旋孤子试探波函数,给出了玻色-爱因斯坦凝聚静态涡旋孤子能量密度泛函的解析式,再运用数值模拟含时Gross-Pi-taevskii方程的方法,得到了稳定演化的涡旋孤子;并且通过调控双光晶格势,实现了玻色-爱因斯坦凝聚涡旋孤子从某一晶格势槽为初始位置到任意位置的操控,为玻色-爱因斯坦凝聚的实验和应用研究提供了一定的理论依据.值得指出的是,双涡旋孤子的稳定演化与操控是最重要的发现.     

复合势下三维旋量玻色-爱因斯坦凝聚暗孤子及其自旋纹理

为了充分揭示复合势下三维旋量玻色-爱因斯坦凝聚暗孤子的动力学性质及自旋纹理结构,运用能量泛函方法和直接数值仿真耦合Gross-Pitaevskii方程组,在三维抛物势和二维高斯势组成的复合势下构造了多种带有不同拓扑结构因子稳定的自旋为1的三维铁磁态旋量玻色-爱因斯坦凝聚暗孤子,并分析了它们的动力学特性.选择其中一种暗孤子作为例子,分析了其在关键参量空间中的稳定性,得到了稳定性区域.然后通过计算暗孤子的自旋密度矢量,得到了指向自旋消失圆的三维环形自旋纹理结构和自旋密度矢量大小随空间变化的分布.这为更好地理解玻色-爱因斯坦凝聚的磁性性质提供了帮助,也为实验上实现三维旋量玻色-爱因斯坦凝聚暗孤子提供了理论依据.     

玻色-爱因斯坦凝聚简介

近年来，有关玻色一爱因斯坦凝聚Bose—Einstein condensation（BEC）实验研究取得了一系列重要成果。本文简述了玻色一爱因斯坦凝聚的由来、研究进展和相关实验实现，并对BEC的应用做了概括性介绍。     

凝聚体隙孤子的动力控制

发展了研究光晶格中波色-爱因斯坦凝聚体线性与非线性激发动力学性质的系统控制方法,得到了周期势下波色-爱因斯坦凝聚体孤子解析解和典型色散关系.通过对孤子解析解的分析,发现原子相互作用强度对波色-爱因斯坦凝聚体孤子的动力学性质有重要影响.     

一类具非线性阻尼项的Schr?dinger方程的达布变换

考虑一类具非线性阻尼项的Gross-Pitaevskii方程,该方程出现在玻色-爱因斯坦凝聚中.首先运用AKNS方法构造方程的Lax对,并推导出相应的达布变换公式,最后应用此公式得到该方程的孤子解.     

三维复合势下的玻色-爱因斯坦凝聚暗孤子结构及操控

基于二维抛物势、一维光晶格势和二维高斯势所组成的复合势,讨论了一个具有层状结构并带有增益的三维玻色-爱因斯坦凝聚暗孤子结构.应用能量泛函和直接数值仿真,得到了暗孤子结构在关键参量空间中的稳定性区域,并分析了暗孤子结构的动力学性质.结果发现:在线性增益的作用下,暗孤子结构的振幅和脉宽实现了同步变化,这为通过增益调制来控制物质波孤子的动力学行为提供了一种思路.而且,对不同原子数比例下的暗孤子结构的中心位置进行了成功操控,这将对量子信息的存储和处理起到一定的理论指导作用.     

玻色-爱因斯坦凝聚体中孤子正碰及相移的研究

采用推广的PLK(Poincare-Lighthill-Kuo)方法研究二维盘状玻色-爱因斯坦凝聚体(BEC)中孤子的正碰,得到了2个描述暗孤子及其传播的KdV方程和孤子正碰引起的相移.与准一维柱状BEC中孤子正碰的相移结果进行比较发现:当波数取1时,二维平面上孤子正碰后发生的相移与一维柱线上孤子正碰后发生的相移近似相等.     

一维倾斜光晶格势阱中两组分玻色-爱因斯坦凝聚体的矢量孤子解及其稳定性

用变分方法研究了在一维倾斜光晶格势阱中的两组分玻色-爱因斯坦凝聚体,分别得到了对称不分离、对称分离和不对称不分离三种不同类型的矢量孤子,并与数值模拟得到的结果进行比较,两者吻合得很好。进一步通过引入强扰动,研究了凝聚体中孤子的稳定性问题。     

改变命运的明信片

萨特延德拉·纳特·玻色(Satyendra Nath Bose)是有史以来印度本土诞生的最伟大的科学家之一。以他的名字命名的物理学概念包括玻色子(Boson)、玻色气体(Bose gas)、玻色-爱因斯坦统计(Bose-Einstein statistics)和玻色-爱因斯坦凝聚(Bose-Einstein condensate)。从一名职位难保的大学讲师一跃而成为世界级的大物理学家,玻色的命运转变始于一张小小的明信片。1921年,27岁的玻色在新成立不久的印度达卡大学获得了高级讲师的职位,一边教学一边从事科研。1923年,恰逢玻色的第一批学生刚毕业,他被告知一年以后将无法得到校方的续聘。迫于养家糊口的压力,玻色不得不就续聘问题卷入和校方漫长的抗     

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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