自洽玻恩近似下串联双量子点的量子输运研究

结合自洽玻恩近似,用量子输运主方程理论研究了串联双量子点在任意电压下的输运问题.结果表明,对于无多体相互作用情况,用修正后的主方程理论计算得到的稳态电流-电压特性关系,与用波函数方法获得的结果符合得很好,但单粒子波函数方法不便描述有多体相互作用的量子输运问题,说明自洽玻恩近似下的主方程理论是一个有效的理论方法.给出有库仑阻塞情况下的电流电压关系,得到通常情况下量子主方程不能得到的库仑台阶的量子展宽效应.     

自洽玻思近似下串联双量子点的量子输运研究

结合自洽玻恩近似,用量子输运主方程理论研究了串联双量子点在任意电压下的输运问题．结果表明,对于无多体相互作用情况,用修正后的主方程理论计算得到的稳态电流一电压特性关系,与用波函数方法获得的结果符合得很好。但单粒子波函数方法不便描述有多体相互作用的量子输运问题,说明白洽玻恩近似下的主方程理论是一个有效的理论方法．给出有库仑阻塞情况下的电流电压关系,得到通常情况下量子主方程不能得到的库仑台阶的量子展宽效应．     

介观二能级体系的量子输运特性研究

利用电子数分辨的量子主方程,推导了介观输运体系中的电流和散粒噪声计算方法,研究了二能级体系的量子输运特性。在非对称隧穿耦合强度下,电流输运出现了快慢通道的输运机制,导致了动态库伦阻塞,以及新颖的负微分电导现象和超泊松散粒噪声。这些研究结果对量子器件的实现、优化和控制具有一定的实际意义。     

胶子的量子输运理论

本文推导出了胶子的一般性量子输运方程和限制方程,并讨论了理论的半经典和经典极限情况。     

夸克的量子输运理论

在本文,我们推导出了夸克的一般性量子输运方程和限制方程,并讨论了理论的半经典和经典极限情况。     

量子阱中自旋电流与电荷流

由薛定谔方程和密度矩阵推导出量子阱中电子输运的几率方程,并由此得出了量子阱中自旋流与电荷流的表达式.结果发现随着自旋退相干时间的增加左边的自旋电流增加,而右边的自旋电流减小.这些结论对量子自旋器件的研究有重要的意义.     

点内库仑相互作用对三量子点系统输运性质的影响

本文利用非平衡格林函数运动方程方法,研究了与两个电极耦合在一起的三耦合量子点系统中,点内部的库仑关联或阻塞与点间的耦合强度对体系输运性质,即对系统微分电导和系统态密度的影响.通过理论计算发现,由于量子点上的局域态密度的不同从而导致系统微分电导或隧穿性质的不同,会开启新的Kondo输运通道,也会增强一些原有的输运通道.     

分形子-电子相互作用导致的电阻率

利用推广的Hnsch-Mahan量子输运方程,求解了分形子-电子相互作用系统的电阻率.克服了电阻率的低温发散困难,给出了电阻率反常处的温度.     

磁性多层膜巨磁电阻效应理论

简要概述了磁性多层膜结构巨磁电阻效应的现有主要理论。对唯像理论、Boltzmann输运方程理论和量子理论的相关工作进行了总结评述。     

交换耦合双能级量子点的全计数统计

基于粒子数分辨的量子主方程,研究了自旋交换耦合双能级量子点中的电子全计数统计,给出了平均电流、散粒噪声和偏斜度.库仑排斥和交换作用导致了平均电流中的小平台;散粒噪声和铁磁电极的极化率以及量子点与电极的不对称耦合密切相关.极化率和量子点电极不对称耦合越大,超泊松散粒噪声越容易出现.当两个自旋单态通道能级参与输运时散粒噪声会大大降低,而当两个自旋三重态通道能级同时参与输运时散粒噪声则会明显增大.     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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~~