Table of contents

A review is given of the phenomenon of backbending which is observed in the rotational spectra of deformed nuclei. The phenomenon is interpreted in terms of superconducting-type pairing correlations. This model was previously successful in the description of the low-lying rotational states. Analysis of high-spin rotational states in the backbending region has established a similarity between pairing correlations in nuclei and in superconductors of small linear dimensions. In view of this, low-lying quasiparticle terms of the subshell with high angular momentum j on the Fermi surface assume particular importance (through the dependence of quasiparticle energy on the nuclear rotational frequency). The importance of quasiparticle terms in the analysis of the structure of deformed nuclei is noted. The review covers the period up to the beginning of 1980.

The review deals with new results in the theory of electron localization in disordered systems and with experiments which have been stimulated by these results. An elementary scaling theory of localization and its consequences are discussed. Attention is concentrated on the phenomenon of localization in two-dimensional systems. The main experiments on the conductivity of thin metal wires and films, demonstrating qualitatively new behavior associated with localization, are discussed. The review concludes with a brief look at the problems of deriving a self-consistent scaling theory of critical behavior at a mobility edge.

This review presents a systematic kinetic theory of nonequilibrium phenomena in superconductors with excess quasiparticles created by electromagnetic or tunnel injection. The energy distributions of excess quasiparticles and of nonequilibrium phonons, dependence of the order parameter on the power and frequency (or intensity) of the electromagnetic field, magnetic properties of nonequilibrium superconductors, I-V curves of superconductor-insulator-superconductor junctions, and other properties are described in detail. The stability of superconducting states far from thermodynamic equilibrium is investigated and it is shown that characteristic instabilities leading to the formation of nonuniform states of a new type or phase transitions of the first kind are inherent to superconductors with excess quasiparticles. The results are compared with experimental data.

Areas of nuclear physics which have seen important developments recently are reviewed: (1) the discovery and study of new unstable isotopes, (2) rapidly rotating nuclei, (3) heavy-ion collisions and the distinctive features of reactions induced by heavy ions, (4) giant multipole resonances, and (5) the nature of nuclear forces and the effective interactions between particles within a nucleus. Many examples are cited to illustrate the progress in these areas.

Contrary to a wide-spread impression, the possibility of measuring an energy in a finite time without changing its initial value (E' =E₀) is not in contradiction with the principles of quantum mechanics. The relation Δ(E'-E₀)Δt≥ holds only in the case when the energy of interaction between the quantum system in question and the apparatus is a function of a coordinate of the system. The condition for a nonperturbing energy measurement is that the interaction energy H₁, of the system and the apparatus depend on the energy operator Ê and that the operators Ĥ and Ê commute. It is also possible to have a nonperturbing measurement in which the error in measuring the energy is so small that ΔE /Δt. Measurement of the energy of a given system is accompanied by an increase in the uncertainty Δ_ε of the energy of the apparatus. The error ΔE in the measurement of the system's energy and the perturbation Δεof the energy of the apparatus are connected by the relations (ΔE + Δε) · Δt≥ and ΔE · Δε≥(/2Δt)².