[en] A brief review of physical properties of a new class of materials - rare earth semiconductors - is made. Special attention is paid to the so-called classical rare earth semiconductors: monochalcogenides of europium, samarium and thulium and compounds of the type Ln²X³, Ln³X⁴ (X=S, Se, Te). Development perspectives and possible practical applications of rare earth semiconductors are discussed

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[en] A structure and tuning procedure of a small-size two-resonator accelerating system operating at a wavelength of 10 cm with total energy of 1.5 MeV and electron beam current of 500 mA/pulse are described. The flight distance of each resonator equals 32 mm and the drift distance between them is 29 mm. Waveguides with dimensions of 72x34x3 mm excite the pair resonators. The bridge for the resonator supply is made using standard copper rectangular waveguides iith damensions of 72x34x5 mm. The total length of the high-frequency track from the resonator coupling windows to magnetron flanges constitutes 2.4 m. Experimental characteristics of the accelerated beam are given. The acceleration rate achieved amounts to 10-13 MeV/m depending on the choosen mode of the device operation

[en] Considered in detail is the up-to-date state of experimental investigations and the theory of the isostructural semiconductor-metal phase transformation of the first type at hydrostatic compression of Psub(k) >= 6.5 kbar (300 K) in samarium monosulfide. As experimental data illustrating the given transformation, considered are dependences of volume change, electric resistance, the Hall constant, concentration of electrons and their mobility, reflection coefficient and magnetic susceptibility on the value of hydrostatic pressure. The brief data on the band structure of semiconductor and metallic modification of SmS are given. Studies on the semiconductor-metal phase transformation in solid solutions on the basis of SmS-Smsub(1-x)Lnsub(x)sup(+3)S, where Ln is rare earth metal are briefly outlined

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[en] Short note. 1 ref

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[en] The problems of the efficiency of nuclear heat-and-plants (NHPP) in the heat-andpower energetics of the USSR are discussed. Most attention is centered on an NHPP of heat-condensation type equipped with constant steam flow turbines of the TK-450/500-60 and K-500-60 types and WWER-1000 reactors. According to the specially developed procedure, the problem of selecting the profile of a TK-type turbine, NHPP composition and applications are subjected to the technico-economic analysis. The distance to the urban area from a central heat-and-power plant utilizing organic and atomic fuel is adopted to be the same and equal to 5, 10 and 15 km, and the thermal load is variable between 500 and 7000 Gcal/hour (the share of hot water supply load in the total thermal load being 0.2). The heat supply system is open-circuited, the hot/return water temperatures being 150/70 deg C. The optimum calculated heat production factor for the NHPP does not exceed 0.7, and the optimum heat production values from controlled turbine outputs are within 500-600 Gcal/hour. The mininum thermal load, for which the NHPP with TK turbines is more effective than an organic fuel heat-and-power station, is about 1000-1500 Gcal/hour if cooling towers are used in the technical water supply system, and if it is possible to construct a water reservoir-cooler for the NHPP, this range is reduced to a thermal load level, at which the combined system becomes more effective than the separate power generation systems, i.e. to 500-600 Gcal/hour