Showing 21 - 30 of 54
The equation of motion for the reduced density matrix of a system weakly coupled to a bath is obtained using projection operator techniques. The exact equation of motion reduces to a generalized master equation when the bath relaxation is faster than the relaxation of the system induced by the...
Persistent link: https://www.econbiz.de/10010586883
Within the context of a general mode-coupling theory previously developed for the description of equilibrium fluctuations in simple classical fluids, we derive an expression for the effective longitudinal viscosity includings couplings to currents so that certain key assumptions inherent in...
Persistent link: https://www.econbiz.de/10010586936
A general mode-mode coupling theory is developed for the microscopic mass, energy and momentum densities of a simple classical fluid. A projection operator method is employed to derive a generalized Langevin equation that contains nonlinearities of all orders with both convective and dissipative...
Persistent link: https://www.econbiz.de/10010587307
Under the assumption that structural relaxation is dominated by the decay of clusters of particles, we develop a microscopic theory for transport in a strongly supercooled liquid. By introducing a local order parameter that describes the geometry of particle aggregates in addition to the number...
Persistent link: https://www.econbiz.de/10010587502
In this paper a mode coupling theory for equilibrium tagged particle correlation functions in simple fluids is developed from molecular considerations. The mode coupling formalism developed in a previous paper [Physica A 181 (1992) 89] to describe equilibrium fluctuations in simple liquids is...
Persistent link: https://www.econbiz.de/10010587624
The Fokker–Planck equation for the translational modes of an inelastic system of Brownian particles in a non-equilibrium bath of light particles is derived from first principles of statistical mechanics. The bath and internal modes relax on a time scale that is much shorter than that of the...
Persistent link: https://www.econbiz.de/10010599471
The time-convolutionless mode-coupling theory (TMCT) equation for the intermediate scattering function fα(q,t) derived recently by the present author is analyzed mathematically and numerically, where α=c stands for a collective case and α=s for a self case. All the mathematical formulations...
Persistent link: https://www.econbiz.de/10011264568
A new viewpoint on the kinetics of Ostwald ripening is presented by studying the kinetic equation recently derived for the late stage of phase separation. It is shown that the average droplet radius grows as t13 and the number density of droplets decays as t-1. An important effect of a soft...
Persistent link: https://www.econbiz.de/10010872825
We investigate the dynamics of phase separations in quenched binary mixtures, such as binary alloys and polymer blends with low mobilities, at higher volume fractions. Computer simulations are performed using simple model equations in the presence of encounters of droplets. Four characteristics...
Persistent link: https://www.econbiz.de/10010874635
Extensive molecular-dynamics simulations on two different glass-forming systems are performed to test the prediction proposed recently by the mean-field theory (MFT) of glass transition that a fragile system can be mimicked by a simpler one near their glass transitions. One is a simulation for a...
Persistent link: https://www.econbiz.de/10011057179