Table of contents

A review of the theoretical studies on wide-band microwave sources employing the stimulated Cherenkov radiation of relativistic electron beams in a plasma waveguide is presented. The motivation for such studies lies in recent experiments on microwave plasma noise sources using intense relativistic electron beams. Although only theoretical problems are discussed, all the necessary estimates are obtained using parameter values taken from actual General Physics Institute experiments, in part already published. A very incomplete preliminary comparison of theoretical and experimental results is given.

New experimental and theoretical results on the electronic structure and spectral properties of quasiparticles in copper oxides are reviewed. It is shown that the electronic structure transforms from antiferromagnetic insulators to optimally doped high-temperature superconductors as the doping level is varied. The experimental methods considered are primarily angular resolved photoelectron spectroscopy (ARPES), neutron scattering, and NMR. Two types of electronic structure calculations for data interpretation purposes are considered, namely, exact numerical methods for finite clusters (exact diagonalization and the quantum Monte Carlo method) and approximate schemes for an infinite lattice. As a result, a coherent unified picture emerges, in which magnetic polarons (which are carriers in a weakly doped antiferromagnetic lattice) transform into a system of Fermi quasiparticles dressed in short-range antiferromagnetic-type spin fluctuations. In the region of weakly doped metallic compositions, deviations from Fermi-liquid properties are seen, such as the failure of Luttinger's theorem, shadowy photoemission bands, and the spin pseudogap effect in spectral and thermodynamic measurements. The situation in the neighborhood of the insulator–metal concentration transition is noted to be least understood.

Self-excited spinodal decomposition oscillations are obtained in a binary, liquid, stratified mixture deep in the labile region. An opto-thermodynamic method is presented for locating the binodal and the spinodal in the temperature-concentration plane for stratified solutions with a lower critical point. It is shown that light-induced barodiffusion serves as an effective mechanism for quenching a stratified solution into the metastable region.

Entropy is fundamental to describing open systems. It makes possible the distinction between non-equilibrium and equilibrium processes. The influx of negentropy is a measure of all physical and chemical processes occurring in a system. The entropy balance equation is a useful tool for the comprehensive description of an open system, as its application to planets and ecosystems illustrates. The entropy-information relationship established by the theory of information is applicable to self-organising systems provided their special features, particularly the presence or absence of memory, are taken into account.

Local non-equilibrium models of heat and mass transport processes are considered and shown to form a hierarchy of parabolic and hyperbolic equations whose order increases with deviation from local equilibrium. The basic features of these models, in particular their relationship to generalized irreversible thermodynamics, are discussed.

Field-representing force line pictures for a number of simple moving-charge radiation problems are discussed.

A method for determining the Earth's magnetic field components on a moving object having its own magnetic field is presented. A simplified scheme is considered to illustrate the method of problem solution. Equations yielding a correct solution for both the simplified scheme and a real moving ferromagnetic object are derived. Technological problems are listed that can be solved by measuring the Earth's and other magnetic fields onboard a moving object with an arbitrary magnetic field of its own.

Earlier [1], a historical review of the Russian Federal Nuclear Centre (Sarov, Nizhnii Novgorod region) work on explosive laboratory devices for dynamic compressibility measurements was given, but most of the devices described were mainly applied to substances with the normal initial density. In the present work, another Sarov explosive devices of the late 50's are described with which the dynamic compressibility of porous metals and porous ionic compounds were determined [2-4].

A scientific session of the Division of General Physics and Astronomy of the Russian Academy of Sciences was held on May 14, 1997 at the P L Kapitza Institute for Physical Problems, RAS. The following reports were presented at the session: (1) Mineev V P, Vavilov M G (Landau Institute of Theoretical Physics, RAS, Chernogolovka, Moscow Region) ''De Haas—van Alphen effect in superconductors''; (2) Volkov V A, Takhtamirov E E (Institute of Radio-Engineering and Electronics, RAS, Moscow) ''Dynamics of an electron with space-dependent mass and the effective-mass method for semiconductor heterostructures''; (3) Sukhorukov A P (M V Lomonosov Moscow State University, Moscow) ''New avenue of investigation in the physics of solitons: parametrically-coupled solitons in a quadratically-nonlinear medium''; (4) Bogatov A P (P N Lebedev Physics Institute, RAS, Moscow) ''Optics of semiconductor lasers''; (5) Korovin S D (Institute of High-Power Electronics, Tomsk) ''Generation of high-power microwave radiation on the base of high-current nanosecond electron beams''; (6) Ardelyan N V, Bisnovatyi-Kogan G S, Moiseenko S G (M V Lomonosov Moscow State University, Moscow; Institute of Space Research, Moscow) ''Explosion mechanisms of supernovae: the magnetorotational model''; (7) Slysh V I (Astrocosmic Centre of the P N Lebedev Physics Institute, RAS, Moscow) ''Stars, planets, and cosmic masers''. Summaries of four (1, 2, 6, 7) of the reports are given below.