The structure and strength properties of two-component copper-based Cu-Co, Cu-Mo and Cu-Ta vacuum condensates are investigated. It is shown that cobalt, molybdenum and tantalum disperse the grain structure of the copper matrix to submicron and nanometer dimension, form supersaturated solid solutions in the copper fcc lattice and heterophase structures. A decrease in grain size of condensates is explained by the formation of adsorption layers by the atoms of doping elements on the surface of the copper matrix metal growing grains. The Hall-Petch dependences for the yield strength are built. The dependences for Cu-Mo and Cu-Ta condensates have greater slope than a similar function for the single-component copper. The observed effect is explained by the influence of monolayer grain boundary segregation of molybdenum and tantalum atoms and multilayer segregation of Co atoms.
Selected composition of structural heat-insulating ash tuff concrete class B15-20 on tuff rubble and ash using plasticizer D5, determined the calculated heat transfer resistance of the two-layer structure, the dependencies of the density and strength of the mixture from cement consumption for 1 m3.
The results of a study of the emission spectra of thin nanocrystalline films of Cu(In1-xGax)(SySe1-y)2 (CIGSSe) direct-band-gap solid solutions in the structure of solar cells at ~ 0.5 W/cm2 continuous wave and nanosecond pulsed laser excitation in the range of excitation power density 0.1 - 53 kW/cm2 and temperatures of 10-300 K are presented. It was found that stimulated emission (SE) occurs in thin CIGSSe films in the temperature range from 10 K to 90 K in the spectral region h = 1.062 - 1.081 eV with a minimum threshold pump level of about 1 kW/cm2. It was shown, that, with increasing intensity of the exciting emission, the spontaneous emission bands shift toward higher energies. It was found that the photoluminescence bands at low excitation levels and the SE bands shift with increasing temperature toward higher energies, and the PL bands at high excitation levels shift toward low energies. Possible causes and mechanisms of the influence of temperature and excitation intensity on the spectral positions of spontaneous and SE of the films of solid solutions are discussed.
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