可形变自驱动粒子在不对称周期管中的定向输运

粒子的随机运动被整流为定向运动是非平衡统计物理的重要研究内容.尽管如此,在活性粒子整流的研究中,粒子通常被视为刚性的.然而,在软物质中,粒子通常具有可变形的性质.本文重点探讨了可形变自驱动粒子在非对称周期通道中的定向运输行为.由于这些粒子具有可变形的特性,它们可以通过比自身小的通道.本文通过数值计算发现,可形变自驱动粒子能够打破热力学平衡,在空间不对称的条件下产生定向运动.粒子的集体运动方向完全由通道的不对称性决定.本文还发现,增加自驱动速度和粒子软化都能促进粒子的整流,而增大密度和旋转扩散则会阻碍粒子的定向运动.本文的研究成果有助于理解可形变粒子在受限结构中的定向运动行为,并为相关软物质马达的实验研究提供理论支持.

水性涂料中的几何效应

颜料体积浓度、边缘效应和聚合物粒子的几何形变关系到水性涂料成膜过程和涂料的最终性能,但是对这些几何效应的认识还不十分深入。本文在分析有关文献和实验基础上,分析探讨了这几类几何效应。通过定量的数学计算和理论分析,得到了聚合物粒子几何形变的部分参数,并应用该分析解释了一些实际问题。

Using LBG quantization for particle-based collision detection algorithm

Most collision detection algorithms can be efficiently used only with solid and rigid objects, for instance, Hierarchical methods which must have their bounding representation recalculated every time deformation occurs. An alternative algorithm using particle-based method is then proposed which can detect the collision among non-rigid deformable polygonal models. However, the original particle-based collision detection algorithm might not be sufficient enough in some situations due to the improper particle dispersion. Therefore, this research presents an improved algorithm which provides a particle to detect in each separated area so that particles always covered all over the object. The surface partitioning can be efficiently performed by using LBG quantization since it can classify object vertices into several groups base on a number of factors as required. A particle is then assigned to move between vertices in a group by the attractive forces received from other particles on neighbouring objects. Collision is detected when the distance between a pair of corresponding particles becomes very small. Lastly, the proposed algo- rithm has been implemented to show that collision detection can be conducted in real-time.

Numerical Simulation of Shaped Charge Jet Using Multi-Phase SPH Method

Since the jets and detonation gaseous products are separated by sharp interfaces, the traditional smoothed particle hydrodynamics (SPH) method is difficult to avoid the computational instability at interfaces. The multi-phase SPH (MSPH) method was applied to improving the stabil-ity, which smoothes the particle density and makes pressure continuous at interfaces. Numericalexamples of jet forming process were used to test capability of the MSPH method. The results show that the method remains algorithm stability for large density gradient between the jets and gaseous products and has potential application to both the explosion and the jet problems. The effect of initiation ways of the shaped charge was discussed as well.

A novel particle swarm optimizer without velocity:Simplex-PSO

A simplex particle swarm optimization(simplex-PSO) derived from the Nelder-Mead simplex method was proposed to optimize the high dimensionality functions.In simplex-PSO,the velocity term was abandoned and its reference objectives were the best particle and the centroid of all particles except the best particle.The convergence theorems of linear time-varying discrete system proved that simplex-PSO is of consistent asymptotic convergence.In order to reduce the probability of trapping into a local optimal value,an extremum mutation was introduced into simplex-PSO and simplex-PSO-t(simplex-PSO with turbulence) was devised.Several experiments were carried out to verify the validity of simplex-PSO and simplex-PSO-t,and the experimental results confirmed the conclusions:(1) simplex-PSO-t can optimize high-dimension functions with 200-dimensionality;(2) compared PSO with chaos PSO(CPSO),the best optimum index increases by a factor of 1×102-1×104.

Continuous Spectrum of Trigonometric Rosen-Morse and Eckart Potentials from Free Particle Spectrum

The shape invariant symmetry of the Trigonometric Rosen-Morse and Eckart potentials has been studied through realization of so（3） and so（2, 1） Lie algebras respectively. In this work, by using the free particle eigenfunction, we obtain continuous spectrum of these potentials by means of their shape invariance symmetry in an algebraic method.

Stereo particle image velocimetry measurement of 3D soil deformation around laterally loaded pile in sand

A developed stereo particle image velocimetry(stereo-PIV) system was proposed to measure three-dimensional(3D) soil deformation around a laterally loaded pile in sand.The stereo-PIV technique extended 2D measurement to 3D based on a binocular vision model,where two cameras with a well geometrical setting were utilized to image the same object simultaneously.This system utilized two open software packages and some simple programs in MATLAB,which can easily be adjusted to meet user needs at a low cost.The failure planes form an angle with the horizontal line,which are measured at 27°-29°,approximately three-fourths of the frictional angle of soil.The edge of the strain wedge formed in front of the pile is an arc,which is slightly different from the straight line reported in the literature.The active and passive influence zones are about twice and six times of the diameter of the pile,respectively.The test demonstrates the good performance and feasibility of this stereo-PIV system for more advanced geotechnical testing.

Formation Mechanism of Triaxial Superdeformed Nucleus ^(160)Yb

By using Total Routhian Surface （TRS） method the deformation of the nucleus ^160Yb is studied. The result shows that the triaxial superdeformed state exists with deformation parameters ε2 = 0.38 and γ = 21°, where proton shell correction energy plays a key role, and the sum of two quasi-proton particle energies gives an additional driving effect. The rotational energy also has an additional role in the formation of triaxial superdeformed.

Hawking Tunneling Radiation of Black Holes in Deformed Horava-Lifshitz Gravity

Tunneling of scalar particles and Dirac particles from a black hole in the deformed Horava-Lifshitz gravity is discussed in this paper. We consider the case that the dynamical coupling constant λ= 1, when it reduces to Einstein＇s General Relativity at large scales and the black hole behaves like the Reissner-Nordstr6m black hole. The result shows that though the black hole entropy bears logarithmic correction, the tunneling probability is still related to its differences for the scalar particles and Dirac particles.

TRACKING DEFORMABLE AND OCCLUDED OBJECTS USING PARTICLE FILTERING AND GVF-SNAKE

An adaptive object tracking algorithm based on particle filtering and a modified Gradient Vector Flow (GVF) Snake is proposed for tracking moving and deforming objects. The original contours of objects are obtained by using the background differencing method,and the true contours of objects can be converged by means of the powerful searching ability of a modified GVF-Snake. Finally,an Energetic Particle Filtering (EPF) algorithm is obtained by combining particle filtering and a modified GVF-Snake,and by using K-means and the EPF algorithm,multiple objects can be tracked. The proposed tracking tactic for partially occluded objects can effectively improve its anti-occlusion ability. Experiments show that this algorithm can obtain better tracking effect even though the tracked object is occluded.

Number-Conserving Coherent State in Rindler Space

We introduce a kind of number-conserving coherent state in Rindler space which can describe the quantum state of thermal particles observed in Rindler space. This is based on the Unruh effect that the thermal particles seen by an accelerating observer in fiat space can be seen by an inertial observer in curved space under a conformal transformation.

Rotational Property of^(249)Cm in Particle-Triaxial-Rotor Model

We study the particle-triaxial-rotor model rotational energy spectrum and with variable moment of inertia deformation feature of very heavy nucleus 249Cm in the band structure and high spin states and locating very near the we determine the configurations and quadrupole and triaxial calculated results indicate that the high spin band of 249Cm is Such a nucleus is the unique one involving both multisuperheavy region. By calculating the energy spectrum, deformation parameters β and γ of the nucleus. The built upon the v[620]1/2＋ configuration with deformation 1- configuration respectively parameters β= 0.296 and γ = 7.5° and the bands based on the v[622]3/2＋,v[613]7/2＋, v[750]1/2- are also the ones with quite large axial deformation but small triaxial deformation.

g factors of nuclear low-lying states:A covariant description

The g factors and spectroscopic quadrupole moments of low-lying excited states 2+1,…,81+ in 24Mg are studied in a covariant density functional theory.The wave functions are constructed by configuration mixing of axially deformed mean-field states projected on good angular momentum.The mean-field states are obtained from the constraint relativistic point-coupling model plus BCS calculations using the PC-F1 parametrization for the particle-hole channel and a density-independent delta-force for the particle-particle channel.The available experimental g factor and spectroscopic quadrupole moment of 21+ state are reproduced quite well.The angular momentum dependence of g factors and spectroscopic quadrupole moments,as well as the effects of pairing correlations are investigated.

Microemulsion synthesis and photocatalytic activity of visible light-active BiVO_4 nanoparticles

A water-in-oil microemulsion made up of a cyclohexane/n-hexyl alcohol/Polyethylene glycol tertoctylphenyl/aqueous solution including Bi3+ and VO+3 ions yields the spherical BiVO4 precursors with the size from 5 to 300 nm. Well-crystallized monoclinic scheelite BiVO4 particles with nanometer or micrometer size are fabricated in control by heating microemulsion precursors under various temperatures. The corresponding nucleation and growth process of as-prepared samples has also been investigated via TEM,which demonstrates the detailed morphological evolution of nuclei inside the precursors. As-prepared BiVO4 photocatalysts exhibit enhanced photocatalytic activity under visible-light irradiation in comparison with the bulk BiVO4 prepared by solid-state reaction. The highest RB degrading efficiency of 98% in 180 min under visible-light irradiation is observed for the sample calcined at 600 °C.

Relativistic Treatment of Spinless Particles Subject to a q-Deformed Morse Potential

The approximate analytical solutions of the Klein-Gordon equation with equal scalar and vector q-deformed Morse potential are presented for arbitrary e-states by using Laplace integral transform. The energy eigenvalues and corresponding wave functions are obtained for n and e values. In this study, in the non-relativistic limit c →∞, it has been also provided that the energy eigenfunetions for Klein-Gordon system turn into those for Schrodinger one.

Current Reversals of an Underdamped Brownian Particle in an Asymmetric Deformable Potential

Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force,respectively.From numerical simulations,we obtain the current average velocity.The current reversals and the absolute negative mobility are presented.The increasing of the deformation of the potential can cause the absolute negative mobility to be suppressed and even disappear.When the static force is small,the increase of the potential deformation suppresses the absolute negative mobility.When the force is large,the absolute negative mobility disappears.In particular,when the potential deformation is equal to0.015,the two current reversals present with the increasing of the force.Remarkably,when the potential deformation is small,there are three current reversals with the increasing of the friction coefficient and the average velocity presents a oscillation behavior.