多介质流体力学两步欧拉方法的模型封闭性方法

描述多介质流体力学两步欧拉方法拉氏步中方程的不封闭问题.分析已存在的模型封闭性方法的优缺点,给出根据声速特征的自适应的模型封闭性方法.数值例子表明方法合理可靠,并说明压力弛豫过程在数值计算中的作用.     

Dynamics of the Photoinduced Rotation of a Spherical Particle in a Constant Electric Field

Technical Physics - The rotation of a spherical particle in a constant electric field (an effect found earlier) has been analyzed. The particle is illuminated to induce the electric dipole moment...     

Semimicroscopic Description of High-Energy Charge-Exchange Spin-Monopole Excitations in Medium-Heavy Spherical Nuclei

Physics of Atomic Nuclei - The semimicroscopic particle–hole dispersive optical model developed recently is applied to describing main properties of the Gamow–Teller and charge-exchange...     

Dynamics of damped rotating solids of revolution through an Eulerian modal approach

This article presents a technique for modelling the dynamic response of rotating flexible solids with internal modal damping. The method is applicable to solids with geometry of revolution that rotate around their main axis at constant spinning velocity. The model makes use of an Eulerian modal coordinate system which adopts the vibration modes in a non-rotating frame as basis functions. Due to the coordinate system, the technique is particularly suitable for studying the dynamic interaction between rotating solids and non-rotating structures and permits to obtain Frequency Response Functions. The current investigation presents the development of the proposed technique from a previous Lagrangian model, and consequently the mathematical relationships between the two coordinate sets are found. The approach has been adopted to study the dynamics of a simply supported cylinder including damping in order to obtain the receptance function and the modal properties of the rotating solid.     

Replicator Dynamics and Mathematical Description of Multi-Agent Interaction in Complex Systems

Abstract

We consider the general properties of the replicator dynamical system from the standpoint of its evolution and stability. Vector field analysis as well as spectral properties of such system has been studied. A Lyaponuv function for the investigation of the evolution of the system has been proposed. The generalization of replicator dynamics to the case of multi-agent systems is introduced. We propose a new mathematical model to describe the multi-agent interaction in complex system.     

Limiting Dynamics for Spherical Models of Spin Glasses at High Temperature

We analyze the coupled non-linear integro-differential equations whose solution is the thermodynamical limit of the empirical correlation and response functions in the Langevin dynamics for spherical p-spin disordered mean-field models. We provide a mathematically rigorous derivation of their FDT solution (for the high temperature regime) and of certain key properties of this solution, which are in agreement with earlier derivations based on physical grounds. AMS (2000) Subject Classification: Primary: 82C44 Secondary: 82C31, 60H10, 60F15, 60K35     

Limiting Dynamics for Spherical Models of Spin Glasses at High Temperature

We analyze the coupled non-linear integro-differential equations whose solution is the thermodynamical limit of the empirical correlation and response functions in the Langevin dynamics for spherical p−spin disordered mean-field models. We provide a mathematically rigorous derivation of their FDT solution (for the high temperature regime) and of certain key properties of this solution, which are in agreement with earlier derivations based on physical grounds. AMS (2000) Subject Classification: Primary: 82C44, Secondery: 82C31, 60H10, 60F15, 60K35     

The Eisenhart Geometry as an Alternative Description of Dynamics in Terms of Geodesics

We show the advantages of representing the dynamics of simple mechanical systems, described by a natural Lagrangian, in terms of geodesics of a Riemannian (or pseudo-Riemannian) space with an additional dimension. We demonstrate how trajectories of simple mechanical systems can be put into one-to-one correspondence with the geodesics of a suitable manifold. Two different ways in which geometry of the configuration space can be obtained from a higher dimensional model are presented and compared: First, by a straightforward projection, and second, as a space geometry of a quotient space obtained by the action of the timelike Killing vector generating a stationary symmetry of a background space geometry with an additional dimension. The second model is more informative and coincides with the so-called optical model of the line of sight geometry. On the base of this model we study the behaviour of nearby geodesics to detect their sensitive dependence on initial conditions—the key ingredient of deterministic chaos. The advantage of such a formulation is its invariant character.     

Classical Description of Intense Field Stabilization Dynamics of 1D Model Atom

Abstract In this paper classical nonlinear dynamics approaches are used to study the intense field stabilization (IFS) for ID model atom according to differential equation (DE) and map approximation (MA). The exact stability boundary and region of I-period fixed points in the parameter space of field strength and frequency are obtained, and the results of MA are in excellent agreement with those of DE. The electrons dynamical behavior in phase space is investigated and the IFS mainly occurring in high frequency regime is confirmed. The stabilization phenomenon connected with the stable fixed points is also examined. In particular it is shown that this phenomenon depends on tightly the KAM tori. It can be predicted that the stabilization probability is just the fraction of initial electrons confined by the KAM tori.     

Spherical Model in a Random Field

We investigate the properties of the Gibbs states and thermodynamic observables of the spherical model in a random field. We show that on the low-temperature critical line the magnetization of the model is not a self-averaging observable, but it self-averages conditionally. We also show that an arbitrarily weak homogeneous boundary field dominates over fluctuations of the random field once the model transits into a ferromagnetic phase. As a result, a homogeneous boundary field restores the conventional self-averaging of thermodynamic observables, like the magnetization and the susceptibility. We also investigate the effective field created at the sites of the lattice by the random field, and show that at the critical temperature of the spherical model the effective field undergoes a transition into a phase with long-range correlations ∼r ^4−d .     

Spherical solitons in a Kerr medium

Solutions of the complete system of the Maxwell equations for a Kerr medium are found numerically in the form of spherical surface waves—spherical solitons.     

Spatiotemporal Dynamics of the Concentration Response of Spherical Particles in the Field of Interfering Laser Waves

A theory of the spatiotemporal dynamics of the concentration response of transparent spherical particles in a liquid in a confined region under the action of a gradient force in the field of interfering laser waves is developed in the Rayleigh-Gans approximation. For the case of a relatively small variation in the concentration of particles, an analytical solution of the Smoluchowski equation is obtained, on the basis of which the kinetics of the formation of spatial concentration structures induced by the gradient force is investigated. The process of the concentration response relaxation is studied.     

Spherical striations in a glow discharge

The stratification of a volume glow discharge is observed experimentally. Spherically symmetric stationary striations are detected. Pis’ma Zh. éksp. Teor. Fiz. 66, No. 11, 679–682 (10 December 1997)