Table of contents

A review of the current status of theoretical and experimental investigations of the magnetism of actinides and their compounds is given. The electron structure of actinides is considered and information is given on the magnetism of actinide metals. The problem of the actinide valence in compounds (specifically, the phenomenon of mixed valence) is analyzed. A review is given of the models which allow for the collectivization of the 5f electrons and for their hybridization with other groups of electrons in actinide compounds. Variation of the magnetic properties with the degree of collectivization is studied. Descriptions are given of the characteristics of the critical behavior and of magnetic excitations in actinide compounds. Data are provided on the magnetic anisotropy and on magnetoelastic interaction in actinide compounds.

The concepts listed in the title are introduced and clarified. The relations among them are pointed out. It is shown that the corresponding optical phenomena are definitely of a quantum nature. The basic quantities which are measured in correlation optical experiments are discussed. Manifestations of photon antibunching and of sub-Poisson photon statistics in the recording of delayed coincidences, in the distribution of photon counts, and in intensity fluctuation spectra are analyzed. (More precisely, what is involved is the spectrum of fluctuations in the photocurrent; all the results of the theoretical analysis in this review are expressed in terms of directly measurable quantities.) A diagram technique for calculating the correlation characteristics of the radiation from a polyatomic system is outlined. Photon correlations in nonlinear resonance fluorescence are analyzed. There is a discussion of approaches to the development of macroscopic sources of radiation with sub-Poisson photon statistics: the production of a squeezed state of a field in phase-sensitive parametric effects in nonlinear optics and the introduction of repulsive statistics in luminescence excitation events and in the pumping of a laser. Experiments in these directions which had been reported through April 1986 are discussed. The practical importance of reducing the quantum noise in radiation for extremely precise measurements and for optical data transmission is pointed out.

The current status and prospects are examined of the rapidly developing field that studies the structure and properties of lyotropic nematic liquid crystals. Typical amphiphiles are presented, and systems based on them. Typical textures and their optical properties are examined. The physical properties of nematics are described in detail: diamagnetic, dielectric, and viscoelastic. A special section is devoted to biaxial nematics, which have no analogs among the thermotropic nematic liquid crystals. The features of their order parameter and elastic properties are examined. Textures and optical properties are described. Further, molecular ordering (from NMR data) and features of phase transitions are discussed. In closing, lyotropic cholesterics are discussed, both those based on individual chemical compounds and those induced by chiral additives.

A brief review is given of recent work on the application of laser radiation in nuclear physics, including the laser spectroscopy of unstable nuclei, laser detection of very rare nuclei, laser orientation and separation of nuclei, mixed nuclear-optical γ-transitions, and other topics.