Persistent spin current in a quantum wire with weak Dresselhaus spin——orbit coupling

The spin current in a parabolically confined semiconductor heterojunction quantum wire with Dresselhaus spin--orbit coupling is theoretically studied by using the perturbation method. The formulae of the elements for linear and angular spin current densities are derived by using the recent definition for spin current based on spin continuity equation. It is found that the spin current in this Dresselhaus spin--orbit coupling quantum wire is antisymmetrical, which is different from that in Rashba model due to the difference in symmetry between these two models. Some numerical examples for the result are also demonstrated and discussed.     

Scheme for entanglement concentration of unknown W class states via linear optics

This paper proposes a scheme for entanglement concentration of unknown triparticle W class states with a certain probability. This protocol is mainly based on the coincidences of single-photon detectors and requires single-photon detectors and linear optical elements. The scheme is feasible within current technology.     

Construction of the elliptic Gaudin system based on Lie algebra

Gaudin model is a very important integrable model in both quantum field theory and condensed matter physics. The integrability of Gaudin models is related to classical r-matrices of simple Lie algebras and semi-simple Lie algebra. Since most of the constructions of Gaudin models works concerned mainly on rational and trigonometric Gaudin algebras or just in a particular Lie algebra as an alternative to the matrix entry calculations often presented, in this paper we give our calculations in terms of a basis of the typical Lie algebra, A _n , B _n , C _n , D _n , and we calculate a classical r-matrix for the elliptic Gaudin system with spin.      

射流温度场与拟序结构间相互作用的大涡模拟

本文分别对常温空气和高温空气的平面自由射流进行了大涡模拟,采用分步投影法求解动量方程,亚格子项采用标准Ｓｍａｇｏｒｉｎｓｋｙ亚格子模式模拟,并同时求解了标志物输运方程以实现数值流场显示。模拟结果给出了湍流的瞬态发展过程以及流动中拟序结构的发展演变过程,通过对常温射流和高温射流瞬态流场的比较揭示了射流中温度场与拟序结构间相互作用的细节过程。     

A boundary only procedure for time-dependent diffusion equations

In the recent literature, the boundary element method (BEM) is extensively used to solve time-dependent partial differential equations. However, most of these formulations yield algorithms where one has to include all interior points in the computation process if finite difference procedures are used to approximate the temporal derivative. This obviously restricts the advantages of the BEM, which is mainly considered to be a boundary only algorithm for time-independent problems. A new algorithm is demonstrated here, which extends the boundary only nature of the method to time-dependent partial differential equations. Using this procedure, one can reduce the finite difference time integration algorithm, generated in a standard manner, to a boundary only process. The proposed method is demonstrated with considerable success for diffusion problems. Results obtained in these applications are presented comparatively with analytical and other boundary element time integration procedures. The algorithm proposed may utilize several coordinate functions in the secondary reduction phase of the formulation. A summary of such functions is described here and performances of these functions are tested and compared in three applications. It is shown that some coordinate functions perform better than others under certain conditions. Using these results, we propose a general coordinate function, which may be used with satisfactory results in all parabolic partial differential equation applications.     

纳米晶复合永磁材料的交换耦合相互作用和磁性能

本介绍了纳米磁性材料晶粒交换耦合相互作用的有关理论。采用不同模型讨论了晶粒交换耦合相互作用对纳米单相软磁材料、永磁材料及双相复合永磁材料磁性能的影响。简述了用δM（H）曲线和不可逆磁导率的变化研究晶粒交换耦合相互作用及反磁化过程的方法。讨论了合金分配比、添加元素、制备及热处理工艺对磁体硬磁性能的影响。从理论和实验两方面分析、研究了纳米复合永磁材料的反磁化过程和矫顽力机制。     

拉曼光谱对新石器时期白石斧的研究

本文采用显微拉曼光谱技术 ,对云南省永仁县菜园子出土的新石器时期白石斧的表面和截面进行了测试研究 ,结合矿物拉曼谱确定了石斧白色和黑色物质的成分。通过对白石斧截面拉曼谱的分析 ,得出了石斧拉曼主峰 (46 2cm- 1 )的强度随深度变化情况的散点图 ,实验结果发现 ,石斧表面的腐蚀层厚约为 40 0 μm。石斧截面拉曼谱给出了与石斧埋葬年代和周围环境有关的信息     

具有三个公共值的亚纯函数(Ⅱ)

本文研究了具有三个公共值的亚纯函数的唯一性问题，改进了Ueda，H．,叶寿桢和仪洪勋的有关定理，并且纠正了Gross和Yang的一个结果．     

Mo2C膜表面粗糙化规律的计算机模拟

引入晶粒边界修正,改进了Ｍｏ２Ｃ膜表面粗糙化物理模型,将ＤＴ２模型推广到包括有温度的情况对Ｍｏ２Ｃ膜表面形态进行计算机模拟并统计模拟图的高度分布,确定表面粗糙度随沉积时间和基底温度的变化规律,结果表明：引入晶粒边界修正大大促进了理论与实验结果的一致,Ｍｏ２Ｃ膜表面粗糙化属快速粗造化,粗造度随基底温度升高在而非线性地增大。