Topological aspect of Chern--Simons p-branes

By generalizing the topological current of Abelian Chern--Simons (CS) vortices, we present a topological tensor current of CS p-branes based on the \phi -mapping topological current theory. It is revealed that CS p-branes are located at the isolated zeros of the vector field \phi(x), and the topological structure of CS p-branes is characterized by the winding number of the \phi-mappings. Furthermore, the Nambu--Goto action and the equation of motion for multi CS p-branes are obtained.     

Multi-types of Skyrmions in SU(N) Quantum Hall System

The skyrmions in SU(N) quantum Hall (QH) system are discussed. By analyzing the gauge field structure and the topological properties of this QH system it is pointed out that in the SU( N) QH system there can exist ( N - 1)types of skyrmion structures, instead of only one type of skyrmions. In this paper, by means of the Abelian projections according to the (N - 1) Cartan subalgebra local bases, we obtain the (N - 1) U(1) electromagnetic field tensors in the SU(N) gauge field of the QH system, and then derive (N - 1) types of skyrmion structures from these U(1) sub-field tensors. Furthermore, in light of the φ-mapping topological current method, the topological charges and the motion of these skyrmions are also discussed.     

Topological Aspects of Liquid Crystals

Using -mapping method and topological current theory, the properties and behaviors of disclination points in three-dimensional liquid crystals are studied. By introducing the strength density and the topological current of many disclination points, the total disclination strength is topologically quantized by the Hopf indices and Brouwer degrees at the singularities of the general director field when the Jacobian determinant of the general director field does not vanish. When the Jacobian determinant vanishes, the origin, annihilation, and bifurcation of disclination points are detailed in the neighborhoods of the limit point and bifurcation point, respectively. The branch solutions at the limit point and the different directions of all branch curves at the first- and second-order degenerated points are calculated. It is pointed out that a disclination point with a higher strength is unstable and will evolve to the lower strength state through the bifurcation process. An original disclination point can split into at most four disclination points at one time.     

Generalized Dirichlet Normal Ordering in Open Bosonic Strings

Generally, open string boundary conditions play a nontrivial role in string theory. For example, in the presence of an antisymmetric tensor background field, they will lead the spacetime coordinates noncommutative. In this paper, we mainly discuss how to build up a generalized Dirichlet normal ordered product of open bosonic string embedding operators that satisfies both the equations of motion and the generalized Dirichlet boundary conditions at the quantum level in the presence of an antisymmetric background field, as the generalized Neumann case has already been discussed in the literature. Further, we also give a brief check of the consistency of the theory under the newly introduced normal ordering.     

A New Route to the Interpretation of Hopf Invariant

We discuss an object from algebraic topology, Hopf invariant, and reinterpret it in terms of the Ф-mapping topological current theory. The main purpose of this paper is to present a new theoretical framework, which can directly give the relationship between Hopf invariant and the linking numbers of the higher dimensional submanifolds of Euclidean space R^2n-1. For the sake of this purpose we introduce a topological tensor current, which can naturally deduce the （n- 1）-dimensional topological defect in R^2n-1 space. If these （n- 1）-dimensional topological defects are closed oriented submanifolds of R^2n-1, they are just the （n - 1）-dimensional knots. The linking number of these knots is well defined. Using the inner structure of the topological tensor current, the relationship between Hopf invariant and the linking numbers of the higher-dimensional knots can be constructed.     

菌紫质中视黄醛超快异构化反应的动态光谱分析

利用飞秒时间分辨吸收光谱方法研究了菌紫质(BR)光循环中视黄醛超快异构化反应过程. 发展了结合全局拟合的奇异值分解(SVD)分析方法, 建立了超快异构化反应动力学模型, 解析了几个重要的中间态I460, J625和K590的物种相关差异光谱(SADS)和布居动力学, 确定了光致异构化反应过程. 同时明确了700 nm附近存在的受激荧光来自于弗兰克-康登跃迁态(H中间态)的贡献, 其衰减寿命为0.04 ps. 这些结果对深入认识H态在超快异构化反应过程中的作用具有参考价值.     

Topological Aspects of Superconductors at Dual Point

We study the properties of the Ginzburg-Landau model at the dual point for the superconductors. By making use of the U（1） gauge potential decomposition and the φ-mapping theory, we investigate the topological inner structure of the Bogomol＇nyi equations and deduce a modified decoupled Bogomol＇nyi equation with a nontrivial topological term, which is ignored in conventional model. We find that the nontrivial topological term is closely related to the N-vortex, which arises from the zero points of the complex scalar field, Furthermore, we establish a relationship between Ginzburg Landau free energy and the winding number.     

四甲基吡啶卟啉与核酸相互作用的稳态和时间分辨光谱

采用稳态吸收和荧光光谱、圆二色谱和皮秒时间分辨荧光光谱手段, 研究了5,10,15,20-四[4-(N-甲基吡啶)]卟啉(TMPyP4)与腺嘌呤(A)、鸟嘌呤(G)、胸腺嘧啶(T)和胞嘧啶(C)等4种碱基, 以及相应的核苷、核苷酸和单链DNA的结合能力和光谱学性质. 研究结果发现, 嘌呤与TMPyP4的结合能力比嘧啶的强. 对于某一碱基系列, 结合能力强弱顺序依次为: 碱基~核苷<核苷酸<单链DNA. 时间分辨荧光谱研究发现, 除鸟嘌呤外, 核酸和TMPyP4复合物的荧光动力学均含有快(1~2 ns)和慢(约10 ns)两个衰减过程, 它们分别是由激基复合体和环境极性对激发态TMPyP4分子的影响所致. 单链DNA能诱导TMPyP4产生诱导圆二色信号, 而单分子(碱基、核苷、核苷酸)则无此功能.     

Finite element technique to solve the elastic strain for Leonov fluid flow

The finite element method is used to find the elastic strain (and thus the stress) for given velocity fields of the Leonov model fluid. With a simple linearization technique and the Galerkin formulation, the quasi-linear coupled first-order hyperbolic differential equations together with a non-linear equality constraint are solved over the entire domain based on a weighted residual scheme. The proposed numerical scheme has yielded efficient and accurate convective integrations for both the planar channel and the diverging radial flows for the Leonov model fluid. Only the strain in the inflow plane is required to be prescribed as the boundary conditions. In application, it can be conveniently incorporated in an existing finite element algorithm to simulate the Leonov viscoelastic fluid flow with more complex geometry in which the velocity field is not known a priori and an iterative procedure is needed.     

SU(2)规范理论与N个磁单极运动体系的电动力学

本文扼要地阐明了关于规范势B_μ可分解和具有内部结构的基本观点,指出B_μ可分解为b_μ和Γ_μ两部分,b_μ满足伴随交换,它对应于某种具有质量的矢量粒子,Γ_μ满足规范势的变换,它可由更基本的场组成,在SU(2)规范理论中,这种基本场是Higgs场φ(x),由此导出了N个磁单极运动体系存在时的电动力学的基本方程,由于这一理论自身包含了磁单极的拓朴守恒流,由此给出磁荷量子化条件,并证明了φ(x)的零点的世界线对应磁单极的运动轨迹,磁单极的电动力学由φ(x)零点的电动力学描述,文中还得到了对应于N个磁单极运动体系的SU(2)规范场方程的无源解,并将吴-杨势推广到N个磁单极的运动体系。