共查询到20条相似文献,搜索用时 109 毫秒
1.
D. A. Sidorenko P. S. Utkin 《Russian Journal of Physical Chemistry B, Focus on Physics》2018,12(5):869-874
A two-dimensional numerical parametric study is made of the interaction of a shock wave with a system of cylinders modeling a bed of a granular medium. The mathematical model is based on the Euler equations. The integration of the defining system of equations in a multiply connected domain is taken using an original computational algorithm of the Cartesian grid method. Computational experiments are carried out with various values for bed permeability and length, the diameter of the cylinder, and channel width. The formulation of the problem imitates natural experiments. The results of all the computational experiments in terms of overpressure behind the reflected and transmitted waves are generalized using a dimensionless criterion. The calculated results are compared with the data from the natural experiments. 相似文献
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Static packing structures of two-dimensional granular chains are investigated experimentally. It is shown that the packing density approximates the saturation with the exponential law as the length of chain increases. The packing structures are globally disordered, while the local square crystallization is found by using the radial distribution function. This characteristic phase of chain packing is similar to a Hquid crystal state, and has properties between a conventional liquid and solid crystal. 相似文献
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We study experimentally the jamming phenomenon of granular flow of monodisperse disks of D = 5 mm diameter in a two-dimensional hopper with opening R. The jamming probability J(d) is measured where d identical withR/D. We found that J(d) decreases from 1 to zero when d increases from 2 to 5. From observing the disk configurations of the arch in the jamming events, the jamming probability can be explained quantitatively by treating the arch as the trajectory of a restricted random walker. 相似文献
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LI Rui ZHANG Duan-Ming HUANG Ming-Tao SU Xiang-Ying CHEN Zhi-Yuan ZHU Hong-Ying ZHANG Lin 《理论物理通讯》2007,48(2):343-347
We propose a two-dimensional model of polydisperse granular mixtures with a power-law size distribution in the presence of stochastic driving. A fractal dimension D is introduced as a measurement of the inhomogeneity of the size distribution of particles. We define the global and partial granular temperatures of the multi-component mixture. By direct simulation Monte Carlo, we investigate how the inhomogeneity of the size distribution influences the dynamic properties of the mixture, focusing on the granular temperature, dissipated energy, velocity distribution, spatial clusterization, and collision time. We get the following results: a single granular temperature does not characterize a multi-component mixture and each species attains its own "granular temperature"; The velocity deviation from Gaussian distribution becomes more and more pronounced and the partial density of the assembly is more inhomogeneous with the increasing value of the fractal dimension D; The global granular temperature decreases and average dissipated energy per particle increases as the value olD augments. 相似文献
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LI Rui ZHANG Duan-Ming HUANG Ming-Tao SU Xiang-Ying CHEN Zhi-Yuan ZHU Hong-Ying ZHANG Lin 《理论物理通讯》2007,48(8):343-347
We propose a two-dimensional model of polydisperse granular mixtures with a power-law size distribution in the presence of stochastic driving. A fractal dimension D is introduced as a measurement of the inhomogeneity of the size distribution of particles. We define the global and partial granular temperatures of the multi-component mixture. By direct simulation Monte Carlo, we investigate how the inhomogeneity of the size distribution influences the dynamic properties of the mixture, focusing on the granular temperature, dissipated energy, velocity distribution, spatial clusterization, and collision time. We get the following results: a single granular temperature does not characterize a multi-component mixture and each species attains its own "granular temperature"; The velocity deviation from Gaussian distribution becomes more and more pronounced and the partial density of the assembly is more inhomogeneous with the increasing value of the fractal dimension D; The global granular temperature decreases and average dissipated energy per particle increases as the value of D augments. 相似文献
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The collection efficiency of aerosols in the low Knudsen number region was studied using a system of multiple spheres. Kuwabara's free vorticity model was expanded to include the effects of gas slip at the collector surface, with the collection efficiency due to diffusion obtained analytically and compared with existing experimental results. The results showed that the diffusional collection efficiency increases as the Knudsen number increases due to gas slippage at the collector surface. The obtained analytical solution converged to the existing collection efficiency of a solid sphere system with a Knudsen number of zero, and that of a bubble with an infinite Knudsen number. The comparison of the experimental results with analytic solution in this study shows that the trends agree well. Therefore, this study is a subsequent expansion of the collection efficiency in the finite Knudsen number region, and can be used for a broad range of collector sizes, pressures and temperatures. 相似文献
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The creep motion in a two-dimensional fully frustrated square lattice Coulomb gas model with disorders is studied by using the Monte Carlo technique. The dependence of charge current density J on electric field E is investigated at low temperature T and at low E. The results show that the creep obeys the Arrhenius law J - C(T) exp[-U(E)/T]. The prefactor C(T) increases with the temperature in a power law relation with an exponent about 3.0. The energy barrier U ( E) increases logarithmically with Ec,/ E as U ( E) - Uo ln( Ec/ E) with Ec being the critical field at zero temperature. 相似文献
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R.S. Chakrawarthy P. von Brentano J. Gableske A. Dewald R. Wirowski S. Albers M. Schimmer 《The European Physical Journal A - Hadrons and Nuclei》1998,2(4):323-324
Abstact: The level structure of 113Sn has been investigated. The data were obtained by in-beam γ-ray spectroscopy using the reaction 100Mo(18O,5n)113Sn at 70 MeV performed at the OSIRIS gamma array in the Institut für Kernphysik FN Tandem accelerator. We report in this short
note the observation of two intruder type rotational bands in this nucleus.
Received: 28 April 1998 相似文献
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Particle aspects of two-dimensional conformal field theories are investigated, using methods from algebraic quantum field
theory. The results include asymptotic completeness in terms of (counterparts of) Wigner particles in any vacuum representation
and the existence of (counterparts of) infraparticles in any charged irreducible product representation of a given chiral
conformal field theory. Moreover, an interesting interplay between the infraparticle’s direction of motion and the superselection
structure is demonstrated in a large class of examples. This phenomenon resembles the electron’s momentum superselection expected
in quantum electrodynamics. 相似文献
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N. S. Simonović 《Few-Body Systems》2006,38(2-4):139-145
In agreement with the Kohn theorem the relative motion (rel) of three electrons in a two-dimensional parabolic trap separates
from the centre-of-mass (CM) motion. By introducing new coordinates the Hamiltonian for relative motion in the approximation
of non-interacting electrons can be taken to the normal form. The eigenstates of the normalized Hamiltonian are products of
the Fock-Darwin states for normal modes. The energy levels for relative motion are obtained by diagonalizing the exact Hamiltonian
in the eigenbasis for the non-interacting case. In this basis the interaction matrix elements can be obtained in the analytical
form. Since the rank of the Hamiltonian matrix is significantly reduced, the calculations are faster and more accurate than
those for the full (CM + rel) motion. This advantage is especially important for the calculations of excited states and the
analysis of energy spectra. 相似文献
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G. Lhersonneau J.C. Wang S. Hankonen P. Dendooven P. Jones R. Julin J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》1998,2(1):25-27
The decays of 112Rh
g
and 112Rh
m
obtained as on-line mass separated fission products have been investigated by standard β and γ spectroscopic techniques and
γ-γ angular correlations. Low-lying 0+ and 2+ states are identified in the daughter nucleus 112Pd. Systematics suggests the existence of an intruder band which is the lowest in 110Pd, i.e. two neutrons before the midshell.
Received:13 March 1998 相似文献
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The integrability character of nonlinear equations of motion of two-dimensional gravity with dynamical torsion and bosonic string coupling is studied in this paper. The space-like and time-like first integrals of equations of motion are also found. 相似文献
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Integrability of Nonlinear Equations of Motion on Two-Dimensional World Sheet Space-Time 总被引:1,自引:0,他引:1
The integrability character of nonlinear equations of motion of two-dimensional gravity with dynamical torsion and bosonic string coupling is studied in this paper. The space-like and time-like first integrals of equations of motion are also found. 相似文献
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The wave motion on the charged surface of a viscous Newtonian liquid is solved as an initial-value problem. Both the leaky dielectric and perfect dielectric cases are considered. The amplitude of wave is assumed to be small. The electric field induced by surface charge is shown to have a generally destabilizing effect on surface wave. The neutral stability curve is drawn in the (G, N~) plane (G: the gravitational bond number; N~: the electrical Bond number). The Ohnesorge number, Taylor-Melcher number and permittivity ratio have little influence on the neutral stability curve. It is testified that the classical normal mode method cannot predict wave behaviour at small times. 相似文献
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In this article, we study the long-time behavior of solutions of the two-dimensional fluid-rigid disk problem. The motion of the fluid is modeled by the two-dimensional Navier–Stokes equations, and the disk moves under the influence of the forces exerted by the viscous fluid. We first derive L p ?L q decay estimates for the linearized equations and compute the first term in the asymptotic expansion of the solutions of the linearized equations. We then apply these computations to derive time-decay estimates for the solutions to the full Navier–Stokes fluid-rigid disk system. 相似文献