[en] The paper presents review of techniques and results of experimental studies of structural transitions in solids under shock-wave loading. The developed explosion-proof containers allow to save studied samples after explosive loading up to pressures exceeding 100 GPa. The authors present results obtained by studies of solid structures of various types (metals, chemical compounds, etc.) after compression of them by shock waves. The studies were carried out with use of the methods for metallographic, X-ray structural, and electron-microscopic analyses. It is shown that in majority of the considered cases the phase transitions of solids in shock waves occur in accordance with the martensite type. For determination of the fact of melting at shock-wave compression, the method for loading of composite sample is suggested. The composite sample consists of studied sample and more fusible one that is a melting indicator capable to form solid solutions or intermetallic compounds with material under study. Results of study of Bi, Sn, Pb, Cd, Zn with the help of this method are presented

[en] Complete text of publication follows. New experimental results on thermodynamics and electrical conductivity of shock and isoentropically compressed hydrogen and deuterium are presented. Strongly coupled plasmas at pressures achieved 18 Mbar, Coulomb coupling parameter exceeded 450, electron degeneracy parameter came up to 290 were obtained with semi-spherical explosive-driven generators. Theoretical models for description of thermodynamics of strongly coupled hydrogen are discussed, comparison of the experimental and theoretical data for strongly non-ideal hydrogen plasmas under high energy density are presented. Experimental and theoretical problems in studying of warm dense hydrogen are discussed. Problems of accurate description of weakly coupled solar plasma on basis of astrophysical observations are discussed as well.

[en] The low-frequency electrical conductivity of strongly nonideal hydrogen, helium, and xenon plasmas was measured in the megabar range of pressures. The plasmas in question were generated by the method of multiple shock compression in planar and cylindrical geometries, whereby it was possible to reduce effects of irreversible heating and to implement a quasi-isentropic regime. As a result, plasma states at pressures in the megabar range were realized, where the electron concentration could be as high as n_e ≅ 2 x 10²³ cm^-3, which may correspond to either a degenerate or a Boltzmann plasma characterized by a strong Coulomb (Γ_D = 1-10) and a strong interatomic (Γ_a = r_an_a^1sol3 ∼ 1) interaction. A sharp increase (by three to five orders of magnitude) in the electrical conductivity of a strongly nonideal plasma due to pressure-produced ionization was recorded, and theoretical models were invoked to describe this increase. Experimental data available in this region and theoretical models proposed by various authors are analyzed. The possibility of a first-order 'phase transition' in a strongly nonideal plasma is indicated