We analyse and compare the properties of the integrals of motion of two types of quantum systems: pure systems which can be described in terms of the wave functions obeying the Schrödinger equation and mixed systems described in terms of density matrix. The model equation for the Wigner...

Diffusion in simple classical liquids is analyzed in terms of the test-particle phase-space density, with emphasis upon its long-time behavior. The Green's function of the generalized Fokker-Planck equation is used to define auxiliary quantities, in particular the transport mean path that enters...

With a spectrophone vibrational relaxation times in CH4 and in mixtures of CH4 with rare gases were measured. Both the amplitude and the phase method were used. The two infrared active modes of CH4 (ν4 and ν3) were investigated separately. The relaxation times, at one atmosphere, after...

A comparison has been made between the deterministic and stochastic (master equation) formulation of nonlinear chemical rate processes with multiple stationary states. We have shown, via two specific examples of chemical reaction schemes, that the master equations have quasi-stationary state...

In this paper the problem of the mean power transmission for one-dimensional wave propagation in a random medium is studied. We use a cumulant technique valid for small αk0Lc where α measures the size of the fluctuations, Lc is the correlation length of the random wave number, and k0 is the...

Two three-dimensional models exhibiting coexistence of superconductivity and lattice distortion are discussed. One of the models, studied in detail by Rusinov, Do Chan Kat and Kopayev, takes into account the superconductivity inter- and intra-band pairing phenomenologically. The other has been...

The concept of the Ginzburg-Landau parameter, κ, and of its extension to the case of non-pure materials is discussed in the framework of the BCS formulation and of the boson formulation. The data derived from several experiments performed on different samples containing various concentrations...

Starting from a N-particle diffusion equation for a system of N interacting spherical Brownian particles, a non-linear transport equation for concentration fluctuations δc(r, t) of the particles is derived. This dynamic equation is transformed into a hierarchy of equations for retarded...

The theory of subdynamics is formulated assuming the existence of a spectral representation of the collision operator. This approach avoids perturbation schemes; however the presentation is formal. It may be used to develop further the theory as well as a starting point for a rigorous...

It is shown that within the Percus-Yevick approximation the radial distribution function for sticky (i.e. with a surface adhesion) hard spheres satisfies a linear differential equation with retarded right-hand side. Using the theory of distributions and the Green's function technique the...