Effects of Nonlinear Time-Delay on a Stochastic Asymmetric System

We numerically investigate the effects of nonlinear time-delay on the stochastic system. With the delay time increasing, it is found that the peak of probability distribution in low steady states is decreased, and the peak of probability distribution in high steady states is increased. The mean of state variable, the normalized variance, and the normalized autocorrelation function which quantifies the concentrated degree are slowly varied for small delay time. However, the mean of state variable is rapidly increased, and the normalized variance and the normalized autocorrelation function is rapidly decreased for large delay time.

Electronic Structure and Optical Properties of Semiconducting Orthorhombic BaSi2

Full potential linearized augmented plane wave （FPLAPW） method calculations are carried out for semiconducting orthorhombic BaSi2. The optical properties and the origin of the different optical transitions are investigated. Our calculated band gap of 1.0918eV is indirect, which is in good agreement with the experimental result. The bonds between Ba and Si are considered to be electrovalent bond. The anlsotropy in the imaginary part ε2（w） and real part εl（w） of the optical dielectric tensor are analysed. The contributions of various transition peaks are explained from the imagnary part of the dielectric function.

Collision Statistics of Driven Polydisperse Granular Gases

我们在场二维的 polydisperse 的一个动态模型有分数维的尺寸分发，磁盘在服从于无弹性的相互的碰撞的小粒的气体并且由标准白噪音开车。磁盘尺寸分发的不同类能被分数维的尺寸 d f 。由蒙特卡罗模拟，我们主要在一样的无弹力案例中在系统的统计性质上调查了不同类的效果。一些新奇结果被发现系统的平均精力与最后完成稳定的 asymptotic 价值，和系统的一个趋势指数地腐烂，这到达一非平衡在一长进化时间以后的稳定的状态。而且，不同类在不变的统计性质上有大影响。随分数维的尺寸 d f , 在碰撞之间的路径长度和空闲的时间的分布为有弹性的范围从期望的理论形式更显然背离并且有短距离和时间箱的人中过剩。有 d f , 而是它独立于时间。同时，速度分发从 Gaussian 那更强烈背离，但是不表明任何明显的通用行为。

First-principles study on the electronic structure and optical properties of T12Cd2（SO4）3 and Rb2Cd2（SO4）3

With the help of ab initio full-potential linearized augmented plane wave （FPLAPW） method, calculating the electronic structure and linear optical properties is carried out for XCd2（SO4）3 （X =Tl, Rb）. The results show that Tl2Cd2（SO4）3 （TlCdS） has a larger band gap than Rb2Cd2（SO4）3 （RbCdS） and the energy bands for RbCdS are more dispersive than those of TlCdS. From their partial densities of states （PDOS）, we have observed that the hybridization between S ionic 2p and O atomic 2p orbitals forms SO4 ionic groups. The remarkable difference between RbCdS and TlCdS is, however, the degree of hybridization between cation （Tl and Rb） and its surrounding oxygen atoms. In the view of quantum chemistry, the strong p-d hybridization indicates the existence of their cation ionic bonds （Cd-O, Rb-O, and Tl-O）. The calculations of TlCdS and RbCdS show their optical properties to be less anisotropic. Their anisotropies in the optical properties mainly occur in a low photon energy region of 5-16 eV.

Effects of Fractal Size Distributions on Velocity Distributions and Correlations of a Polydisperse Granular Gas

By the Monte Carlo method, the effect of dispersion of disc size distribution on the velocity distributions and correlations of a polydisperse granular gas with fractal size distribution is investigated in the same inelasticity. The dispersion can be described by a fractal dimension D, and the smooth hard discs are engaged in a two- dimensional horizontal rectangular box, colliding inelastically with each other and driven by a homogeneous heat bath. In the steady state, the tails of the velocity distribution functions rise more significantly above a Gaussian as D increases, but the non-Gaussian velocity distribution functions do not demonstrate any apparent universal form for any value of D. The spatial velocity correlations are apparently stronger with the increase of D. The perpendicular correlations are about half the parallel correlations, and the two correlations are a power-law decay function of dimensionless distance and are of a long range. Moreover, the parallel velocity correlations of postcollisional state at contact are more than twice as large as the precollisional correlations, and both of them show almost linear behaviour of the fractal dimension D.

Optical Properties of Filled Skutterudite ThFe_4P_(12)

加计算为 ThFe 4 在充满的 skutterudite 的 P 12 以便调查光性质并且显示出不同光转变的起源。乐队差距为 ThFe 4 P 12 。然后，不同转变山峰的贡献从绝缘的功能的想象的部分被分析。与最近的试验性的期望相对照，我们的计算在对试验性的思考系列和 ∈ 1(ω) 光谱的好同意。

Spatial Soliton Solutions in a Harmonic Potential

The F-expansion technique and the homogeneous nonlinear balance principle have been applied for solving a general （19-1）-dimensional nonlinear Schrodinger equation （NLSE） with varying coetficients and a harmonic potential. A family of （1＋1）D spatial solitons has been obtained. The evolution features of exact solutions have been investigated.

Exact Soliton Solutions to a Generalized Nonlinear Schrodinger Equation

The (1+1)-dimensional F-expansion technique and the homogeneous nonlinear balance principle havebeen generalized and applied for solving exact solutions to a general (3+1)-dimensional nonlinear Schrodinger equation(NLSE) with varying coefficients and a harmonica potential. We found that there exist two kinds of soliton solutions.The evolution features of exact solutions have been numerically studied. The (3+1)D soliton solutions may help us tounderstand the nonlinear wave propagation in the nonlinear media such as classical optical waves and the matter wavesof the Bose-Einstein condensates.

Non-Gaussian and Clustering Behavior in One-Dimensional Polydisperse Granular Gas System

<正> We present a one-dimensional dynamic model of polydisperse granular mixture with the fractal characteristicof the particle size distribution,in which the particles are subject to inelastic mutual collisions and are driven byGaussian white noise.The inhomogeneity of the particle size distribution is described by a fractal dimension D.Thestationary state that the mixture reaches is the result of the balance between energy dissipation and energy injection.Bymolecular dynamics simulations,we have mainly studied how the inhomogeneity of the particle size distribution and theinelasticity of collisions influence the velocity distribution and distribution of interparticle spacing in the steady-state.The simulation results indicate that,in the inelasticity case,the velocity distribution strongly deviates from the Gaussianone and the system has a strong spatial clustering.Thus the inhomogeneity and the inelasticity have great effacts on thevelocity distribution and distribution of interparticle spacing.The quantitative information of the non-Gaussian velocitydistribution and that of clustering are respectively represented.