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Abstract: Calculated and experimental mass spectra of gaseous tungstates of alkaline earth metals MgWO4(g), CaWO4(g), SrWO4(g), and BaWO4(g)in the temperature range from 1600 to 2000 K are presented. The partial vapor pressures are determined and equations are derived for the temperature dependences of the partial pressures of gaseous molecules of alkaline earth metal tungstates for liquids in the following form (P, atm): \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\log P\left( {{\text{MgW}}{{{\text{O}}}_{4}}_{{\left( {\text{L}} \right)}}} \right) = - 28\,737{\text{/}}T + 7.95{\text{ for the range from }}1600{\text{ to }}1900{\text{ K}};$$\end{document}\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\log P\left( {{\text{CaW}}{{{\text{O}}}_{4}}_{{\left( {\text{L}} \right)}}} \right) = - 25\,265{\text{/}}T + 6.913{\text{ for the range from }}1850{\text{ to 20}}00{\text{ K}};$$\end{document}\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\log P\left( {{\text{SrW}}{{{\text{O}}}_{4}}_{{\left( {\text{L}} \right)}}} \right) = - 25\,052{\text{/}}T + 7.13{\text{ for the range from }}1800{\text{ to 19}}00{\text{ K}};$$\end{document}\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\log P\left( {{\text{BaW}}{{{\text{O}}}_{4}}_{{\left( {\text{L}} \right)}}} \right) = - 20570{\text{/}}T + 4.58{\text{ for the range from }}1770{\text{ to 19}}00{\text{ K}}{\text{.}}$$\end{document}On the basis of experimental data on vapor pressure, the enthalpies of evaporation (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Delta H_{{s,0}}^{0}$$\end{document}), formation (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ - \Delta H_{{f,0}}^{0}$$\end{document}), and atomization (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Delta H_{{{\text{at}},0}}^{0}$$\end{document}) of gaseous tungstates of alkaline earth metals are calculated, which, respectively, amount to (ΔH0, kJ/mol) 652, 890, and 2855 for MgWO4; 644, 974, and 2968 for CaWO4; 615, 1045, and 3056 for SrWO4; and 548, 1045, and 3095 for BaWO4. It is determined that the enthalpy of sublimation of alkaline earth metal tungstates decreases from magnesium to barium.

Abstract: Separation of titanium and silicon oxides in the melt of quartz–leucoxene concentrate of the Yarega deposit under diffuse arc heating was investigated. Melting was carried out in argon at atmospheric pressure at direct current in a graphite crucible with an arc power of ≈25 kW. The crucible with the material was the anode of the arc. The arc heating was dispersed by applying an axial magnetic field. At the same time, a diffuse anode spot with a current density of 8 A/cm2was formed on the surface of the material. The current–voltage parameters of the diffuse arc were investigated. As a result of melting, an oxide ingot consisting of two phases was obtained, one of which is enriched in titanium oxide, and the other in silicon oxide. However, the separation of these oxides did not occur completely because of the high cooling rate of the melt. Despite the low current density in the heating spot, the melt evaporated intensely. Evaporation occurred congruently. Owing to the high temperature of the bath mirror, no volatile titanium oxide evaporated along with the volatile silicon oxide. Condensation of the evaporated material occurred selectively. A condensate consisting almost entirely of SiO2was formed in the form of powder on the cooled surfaces near the crucible. The specific surface area of the powder was 120 m2/g. The evaporated TiO2was removed with the exhaust gas.

Abstract: Calculated and experimental mass spectra of gaseous alkali metal molybdates Li2MoO4, Na2MoO4, K2MoO4, Rb2MoO4, and Cs2MoO4at temperatures of 1050–1800 K are presented. On the basis of the experimental data, the vapor pressures are determined and the enthalpies of evaporation, formation, and atomization of gaseous alkali metal molybdates are calculated.

Abstract: The effect of small additions of cerium-group rare-earth metals such as samarium (Sm), neodymium (Nd), and lanthanum (La) on the properties of a light high-strength structural magnesium IMV7-1 type alloy of the Mg–Y–Gd–Zr system, where yttrium (Y) and gadolinium (Gd) are yttrium-group rare-earth metals, has been studied. It is established that the presence of small quantities of samarium in the IMV7-1 alloy contributes to an increase in its strength properties upon heat treatment (aging) and makes it possible to reduce the time to reach the maximum strengthening. In the case where two other cerium-group rare-earth metals, neodymium and lanthanum, are present in the IMV7-1 type alloy, the strengthening upon heat treatment (aging) is also observed, but to a much lesser extent. It has also been established that, as the contents of the main alloying elements (yttrium and gadolinium) are simultaneously increased and samarium is added, the maximum strengthening of the alloys under study gradually increases, and the time to its achievement decreases. The fact that the alloying with samarium results in substantially higher strengthening of the IMV7‑1 type alloy than that provided by neodymium and lanthanum is explained by a much higher solubility of samarium compared to that of neodymium and lanthanum in solid magnesium.

Abstract: Sorption conditions of ions and colloidal particles of silver by a zeolite (clinoptilolite) and clays, and specific features of distribution of absorbed silver in clinoptilolite grains were studied. Temperature dependences of the intensity of heterogeneous chemiluminescence from samples of natural clinoptilolite and its modified forms were obtained. The activation energies of the luminescence-active chemisorption of oxygen on electron-donor centers of the zeolite surface and relative amount of centers were determined.

The autonomic-hormonal and psychophysiological status of 94 13- to 17-year-old urban and rural schoolchildren was studied. It was shown that, during sexual development, differing socioecological conditions determine the formation of specific endocrine and psychoautonomic regulatory mechanisms in adolescents.

By means of a complex of cost-effective, rapid, and, whenever possible, computerized screening procedures, a systematic two-week study period of the functional states of subjects in a small group of healthy adults was performed. The daily variations of 125 parameters and periodic changes in 51 parameters of somatic and mental health were investigated at increasing doses of an adaptive drug. In the initial state of the subjects, various deviations of the somatic parameters from the normal level were found, presumably of a nutritional origin. The adaptive drug was found to normalize the changed parameters of somatic health within a week due to a strain in the regulatory systems and a decline in the functional reserves of adaptation. At the end of the examination, excessive doses of the adaptive drug returned the majority of the somatic parameters to the initial levels. At the same time, the work capacity of the subjects decreased and the strain on the autonomic nervous system and the level of stress increased. Discomfort and fatigue developed, which restricted the abilities of the examined subjects to choose behavioral tactics.