The results of calculations of the electron structure for Ag2S and Ag2Se crystals from first-principle in the framework of density functional theory (DFT) are presented in this work. The origin of the bands from [Formula: see text] and [Formula: see text] electron states of Ag, S and Se atoms are investigated. It was established that the orthorhombic Ag2Se crystal shows semiconductor properties in P2221 and P212121 space groups and semimetallic properties in Im-3m space groups with cubic crystal system. Monoclinic crystal type of Ag2S shows semiconductor properties in P21/c space group. However, semimetallic properties manifested itself in monoclinic Ag2S in P21 and cubic Ag2S structure in Im-3m phases.

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This paper presents the results of selective purification of oil distillates with a viscosity of 7.5 mm2/s and 18 mm2/s at [Formula: see text]C, as well as a mixture of these oil distillates obtained by compounding at various ratios using an ionic liquid based on diethylamine and formic acid as an extractant acid. The conditions for the ionic liquid dearomatization of the indicated oil distillates were determined by studying the influence of various factors on the selective purification process. Many parameters are set for the objects of research. The values of physicochemical parameters determined under various conditions are presented in the tables.

This work is devoted to study the extraction dearomatization of the kerosene fraction using ionic liquids synthesized on the basis of formic acid and morpholine, as well as acetic acid and diethylamine as a selective solvent. The influence of various factors on the selective purification process has been investigated and the conditions for dearomatization of kerosene have been determined. The group hydrocarbon composition of the dearomatized kerosene raffinate samples by ion-liquid extraction was determined by IR and UV spectral analysis.