Table of contents

The modern point of view on the physics of the spin-glass state is considered. The physical meaning of the phenomenon known as the "replica symmetry breaking" is discussed.

A systematic presentation is given of the current state of experimental and theoretical studies of elementary processes involved in chemi-ionization by collision between atoms and molecules at thermal energies. General conclusions are presented about the rates of these processes, their importance in practical applications, and their effect on the macroscopic properties of the medium in which they take place. The review is intended for research workers and for postgraduate and graduate students specializing in plasma physics, atom-molecule collisions, and the interaction between radiation and matter.

This paper is a review of methods of generating molecular beams. Conventional effusion and gasdynamic sources are examined in detail and a comparative analysis is made of them. Methods of producing high-energy beams

( > 1 eV),

an area of present intense development, are discussed at length. Particular attention is focused on fast molecular beams that contain atomic oxygen and are used for the study of physicochemical processes on solid surfaces (erosion, chemoluminescence).

A generalization of the force-free equation describing steady-state axially symmetric flows in the vicinity of a Kerr black hole is carried out to the case of ideal magnetohydrodynamics. It is shown how this equation changes from an elliptic to a hyperbolic type in the vicinity of the horizon. The limits of applicability of the approach under discussion are examined for different astrophysical sources. It is shown that a high photon density strongly restricts the limits of applicability of the MHD approach.