Table of contents

Data on order–disorder phase transformations in strongly nonstoichiometric carbides and nitrides MX_y (X=C, N) of Group IV and V transition metals at temperatures below 1300–1400 K are reviewed. The order-parameter functional method as applied to atomic and vacancy ordering in strongly nonstoichiometric MX_y compounds and to phase equilibrium calculations for M–X systems is discussed. Phase diagram calculations for the Ti–C, Zr–C, Hf–C, V–C, Nb–C, Ta–C, Ti–N, and Ti–B–C systems (with the inclusion of the ordering of nonstoichiometric carbides and nitrides) and those for pseudobinary carbide M⁽¹⁾C–M⁽²⁾C systems are presented. Heat capacity, electrical resistivity and magnetic susceptibility changes at reversible order–disorder phase transformations in nonstoichiometric carbides are considered.

The surface active properties of the vapor of volatile, inert fluorocarbon compounds such as C₆F₁₄, C₈F₁₈, and C₁₀F₁₈ have been discovered. In a newly observed phenomenon of capillary instability, permanent oscillatory and rotary motions occur in many fluids, due to a 10–30% reduction in the surface tension of a fluid when in contact with fluorocarbon vapors at room temperature. The features and possible uses of the effect and prospects for finding new types of volatile surfactants are discussed.

The structural analysis of genomic DNA sequences is discussed in the framework of the spectral approach, which is sufficiently universal due to the reciprocal correspondence and mutual complementarity of Fourier transform length scales. The spectral characteristics of random sequences of the same nucleotide composition possess the property of self-averaging for relatively short sequences of length M≥100–300. Comparison with the characteristics of random sequences determines the statistical significance of the structural features observed. Apart from traditional applications to the search for hidden periodicities, spectral methods are also efficient in studying mutual correlations in DNA sequences. By combining spectra for structure factors and correlation functions, not only integral correlations can be estimated but also their origin identified. Using the structural spectral entropy approach, the regularity of a sequence can be quantitatively assessed. A brief introduction to the problem is also presented and other major methods of DNA sequence analysis described.

The emission of phonons produced under the absorption or emission of a γ quantum (or the scattering of an electron or a neutron) by an atomic nucleus in a crystal lattice is a Poisson process from the probability point of view. This approach enables, in particular, an expression for the Mössbauer effect probability to be derived in a simple and transparent manner without the cumbersome mathematical (quantum-mechanical) computations being involved.

The history of the theoretical prediction and experimental discovery of the Rayleigh line fine structure (which belongs to one of the most important phenomena in optics and physics of condensed matter) is discussed along with the history of first publications concerning this topic.