Table of contents

The results of experimental and theoretical studies of chemical reactions in nonequilibrium plasmas are reviewed. Special attention is given to processes stimulated by vibrational excitation of the ground electronic state of the reacting molecules in the plasma. General patterns in the kinetics of these reactions are discussed, and the optimum discharge parameters for maximum energy efficiency are noted. Specific plasma-chemical processes—the dissociation of CO₂ and H₂O and the synthesis of nitrogen oxides—are described. Experimental results are presented for hf, microwave, glow, plasma-beam, and non-self-sustained discharges, for plasma radiolysis, etc.

A review is given of the information on the processes resulting in the formation and loss of population inversion in the most widely encountered types of chemical laser. This information is used to determine the optimal conditions for the excitation of chemical lasers under cw and pulsed conditions.

We review the theoretical and experimental studies on the helically twisted supemolecular structure of cholesteric liquid crystals (CLCs). We discuss the problem of the nature of the forces responsible for the helical twist, generalize the results of studying the orientational order in CLCs, and treat the features of the supermolecuiar structure of CLCs in the region of pretransition phenomena. We pay special attention to the temperature- and concentration-dependences of the pitch of the helix in different cholesteric systems. We analyze critically the theoretical models that have been proposed to describe these dependences. We examine in detail the approach based on averaging the angle of twist in the mean-molecular-field approximation for various types of angular dependence of the intermolecular interaction energy (modified Keating-Böttcher theory). We undertake an attempt to treat from a unitary standpoint the types of cholesteric systems known up to now (cholesterics proper, chiral nematics, nematic-cholesteric mixtures, and systems of a nematic with an optically active additive) and other types of mesophases that possess helical twist (chiral smectics-C, cholesteric polymers, and lyotropic CLCs). We discuss the features of the supermolecuiar structure and of the intermolecular interaction in the stated systems. We treat in detail the nematic-cholesteric mixtures and cholesteric systems having nonmesogenic components, which are important in application.

Fundamental research on the physics of amorphous magnetic materials is reviewed. The atomic and magnetic structure and the magnetic properties are discussed. Theoretical results on the nature of the magnetic ordering and the spectrum of elementary excitations are reported. Applications are discussed.