局部各向异性的薄壳收缩变形

基于位置动力学提出局部各向异性的薄壳收缩变形方法.首先针对基于位置动力学变形模拟方法的材质局限性的不足,提出薄壳收缩变形的弹性变形能,实现了多材质的弹性收缩变形.其次,针对薄壳收缩变形过程中的抖动问题,给出适当的弯曲能系数,实现了稳定的收缩变形.第三,针对薄壳局部类球面结构收缩变形缓慢且细微的不足,定义了局部各向异性ARAP变形能等,实现了薄壳局部类球结构的快速、显著、稳定的收缩变形.最后以轴向平行包围盒与非渗透滤波器作为碰撞检测的预处理,剔除不可能发生碰撞的图元对,提高了收缩变形过程中的碰撞检测效率.相关实验结果表明,提出的薄壳收缩变形算法适用于多种材质模型以及多种各向异性能量,且有效地解决了抖动及局部类球结构收缩变形缓慢且不显著等问题.

Dispersion Energy in a Molecule Composed of Two Anisotropic Vibrating Dipoles

For the first time, we derive the dispersion energy for a molecule which involves the anisotropic dipole interaction by virtue of the invariant eigen-operator method, which greatly simplifies the usual calculation if one uses the Schroedinger equation.

Anisotropic Bianchi Type-I Magnetized String Cosmological Models with Decaying Vacuum Energy Density A(t)

The present study deals with a spatially homogeneous and anisotropic Bianehi-I cosmological models representing massive strings with magnetic field and decaying vacuum energy density A. The energy-momentum tensor, as formulated by Letelier （1983）, has been used to construct massive string cosmological models for which we assume the expansion scalar in the models is proportional to one of the components of shear tensor. The Einstein＇s field equations have been solved by applying a variation law for generalized Hubble＇s parameter in Bianchi-I space-time. The variation law for Hubble＇s parameter generates two types of solutions for the average scale factor, one is of power-law type and other is of the exponential form. Using these two forms, Einstein＇s field equations are solved separately that correspond to expanding singular and non-singular models of the universe respectively. We have made a comparative study of accelerating and decelerating models in the presence of string scenario. The study reveals that massive strings dominate in the decelerating universe whereas strings dominate in the accelerating universe. The strings eventually disappear from the universe for sufficiently large times, which is in agreement with current astronomical observations. The cosmological constant A is found to be a positive decreasing function of time which is corroborated by results from recent supernovae Ia observations. The physical and geometric properties of the models have been also discussed in detail.

Polarization of plane wave propagating inside elastic hexagonal system solids

Based on the reported physical parameters for hexagonal system solids,we have calculated the effects of anisotropy on polarization of plane P-wave propagation.Herein we report the results of calculations and the newly observed physical phenomena.It is found that,for a given propagation,if the polarization is parallel to the wave vector,so also to the Poynting vector.In such a case,the phase velocity is identical to the energy velocity;the quasi P-wave degenerates to a pure P-wave along the propagation.It is also noted that if the polarization is parallel to the Poynting vector but not to the wave vector,the propagating wave cannot be a pure P-wave.Furthermore,the polarization in a quasi P-wave may deviate from the wave vector for more than 45°,but the deviation from the Poynting vector is always less than 45°.The energy velocity of a quasi SV-wave can be larger than that of the quasi P-wave in some propagation directions,even though the phase velocity of a quasi SV-wave may never be larger than either the phase velocity or energy velocity of the quasi P-wave.Finally,in case of parameters ε=0 and δ*≠0,the polarization of a quasi P-wave has an observed symmetry at a 45°phase angle.The anisotropy of a hexagonal system solid determines if a pure P-wave can be created and what the propagation direction is for a plane wave propagating inside such a hexagonal system solid.

Effects of Anisotropy on Scalar Field Ghost Dark Energy and the Non-Equilibrium Thermodynamics in Fractal Cosmology

Since the fractal cosmology has been created in early universe, therefore their models were mostly isotropic. The majority of previous studies had been based on FRW universe, while in the early universe, the best model for describing fractal cosmology is actually the anisotropic universe. Therefore in this work, by assuming the anisotropic universe, the cosmological implications of ghost and generalized ghost dark energy models with dark matter in fractal cosmology has been discussed. Moreover, the different kinds of dark energy models such as quintessence and tachyon field, with the generalized ghost dark energy in fractal universe has been investigated. In addition, we have reconstructed the Hubble parameter, H, the energy density, p, the deceleration parameter, q, the equations of state parameter, wD, for both ghost and generalized ghost dark energy models. This correspondence allows us to reconstruct the potential and the dynamics of a fractal canonical scalar field according to the evolution of generalized ghost dark energy density. Eventually, thermodynamics of the cosmological apparent horizon in fractal cosmology was investigated and the validity of the Generalized second law of thermodynamics （GSLT） have been examined in an anisotropic universe. The results show the influence of the anisotropy on the OSLT of thermodynamics in a fractal cosmology.

Anisotropic lithium-ion migration and electro-chemo-mechanical coupling in Sb_(2)Se_(3) single crystals

Harvesting the promising high energy density of advanced electrode materials in lithium-ion batteries is critically dependent on a mechanistic understanding on how the materials function and degrade along with the battery cycling.Here,we tracked phase transformations during(de)lithiation of Sb_(2)Se_(3) single crystals using in situ high-resolution transmission electron microscopy(HRTEM)technique,and revealed electro-chemo-mechanical evolution at the reaction interface.The effect of this electro-chemo-mechanical coupling has a complicated interplay on the lithiation kinetics and causes various types of defects at the reaction front,including dislocation dipoles,antiphase boundaries,and cracks.In return,the formed cracks and related defects build a path for fast diffusion of lithium ions and trigger a highly anisotropic lithiation at the twisted reaction front,giving rise to the formation of presumably "dead" Sb_(2)Se_(3) nanodomains in amorphous Li_(x)Sb_(2)Se_(3).The detailed mechanistic understanding may facilitate the rational design of high-capacity electrode materials for battery applications.

Gravitational Wave in Lorentz Violating Gravity

By making use of the weak gravitational field approximation, we obtain a linearized solution of the gravitational vacuum field equation in an anisotropic spacetime. The plane-wave solution and dispersion relation of gravitationaJ wave is presented explicitly. There is possibility that the speed of gravitational wave is larger than the speed of light and the easuality still holds. We show that the energy-momentum of gravitational wave in the ansiotropic spacetime is still well defined and conserved.

Dark Energy Models and Cosmic Acceleration with Anisotropic Universe in f(T) Gravity

This paper is devoted to studing the accelerated expansion of the universe in context of f（T） theory of gravity. For this purpose, we construct different f（T） models and investigate their cosmological behavior through equation of state parameter by using holographic, new agegraphic and their power-law entropy corrected dark energy models. We discuss the graphical behavior of this parameter versus redshif~ for particular values of constant parameters in Bianchi type I universe model. It is shown that the universe lies in different forms of dark energy, namely quintessence, phantom, and quintom corresponding to the chosen scale factors, which depend upon the constant parameters of the models.