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The dispersed fractions of industrial high-calcium fly ash (HCFA), selectively collected in the form of fractions 1-4 (Fr1-Fr4) on fields 1-4 of the electrostatic precipitators of the ash collecting unit at the Krasnoyarsk TPP-2, are systematically characterized. The fluidity parameters of ash mortars prepared from 100 % of each of the fractions at a ratio of water/binder = 0.5 were determined. It has been established that the value of fluidity decreases with an increase in the specific surface area of the fractions from Fr1 to Fr4. The parameters of cement-ash mortars with the replacement of cement by 50 and 20 % of each of the four fractions were determined. It has been established that at a 20 % HCFA content, the fluidity of cement-ash mortars of all fractions meets the requirements of GOST 1581-2019 for oil well cements. The samples based on finely dispersed fractions Fr3 and Fr4 meet the requirements for compressive strength on the second day of hardening. The specimens of ash-cement composites with high strength, more than 50 MPa for the 28th day of hardening, were prepared on the basis of the Fr4 fraction. In particular, high compressive strength (62-90 MPa) has been achieved for composite cements containing 80 and 90 % of the Fr4 fraction of HCFA in the presence of the superplasticizer Melflux 5581 F, which promotes efficient dispersion of finely dispersed HCFA in the liquid phase, faster and more complete interaction of active components with the formation of hardening hydrated phases. The addition of 5 % microsilica, which promotes the formation of an additional amount of calcium hydrosilicates, made it possible to achieve an increase in strength up to 108 MPa. The results obtained show that finely dispersed HCFA can be used as the components of oil well cements to improve the flowability of cement-ash slurries and improve the strength properties of highly filled ash-cement composite materials.

It is shown that the yield of humic acids increases by 20-30 % during the mechanical treatment of coals with a complex of oxidative-alkaline reagents. Upon the mechanochemical oxidation of the organic matter of brown coals, the molecular weight of humic acids and the percentage of aliphatic fragments in their structure decrease, while the content of phenolic and carboxyl groups increases. Ion exchange processes during the mechanical treatment of coals with mineral salts are accompanied by a decrease in the content of Na⁺ cations and an increase in Ca²⁺, Mg²⁺ cations in the composition of water-soluble humic substances. The concentration of SO₄^2- ions increases in samples of humic substances obtained from coals after mechanical treatment with ammonium sulphate.

The urgent problems of decarbonization in the power-generating sector are analyzed, along with the potential routes to solve ecological problems connected with CO₂ evolution from the combustion of coal - one of the major kinds of fuel for power generating facilities in the world, and especially in Russia and in Kazakhstan. The technology and equipment of the technological line for low-temperature (not higher than 75 °C) hydroconversion of power-generating coal into high calorific (heat of combustion 45 MJ/kg), ecologically safe (purified from ash) liquid hydrogenated coal fuel (HCF) with low carbon content (less than 45 %) are described. The methods for processing coal fuel in the form of water-coal suspension are considered. The routes to conserve the coal industry are discussed, relying on the production of hydrogenized coal fuel with low prime cost from power-generating coal, which will ensure technologically efficient and ecologically safe transition to low-carbon power engineering with zero greenhouse gas emission.

The history of processes for obtaining synthetic fuels by liquefying coals is described. Coal processing technologies are analyzed since the time of F. Bergius up to the present day. Modern hydrogenation processes are described. The basics of single-stage coal liquefaction technologies are described: Kohleoel (Ruhrkohle, Germany), NEDOL (NEDO, Japan), H-Coal (HRI, USA), Exxon Donor Solvent (ExxonMobil, USA), and Solvent Refined Coal (SRC-I and SRC-II, Gulf Oil, USA), as well as two-stage technologies for producing synthetic liquid hydrocarbons from coal: Brown Coal Liquefaction (NEDO, Japan), Catalytic Two-stage Liquefaction (DOE, HTI, USA), Integrated Two-stage liquefaction (Lummus, USA) , Liquid Solvent Extraction (British Coal Corporation, UK), Supercritical Gas Extraction (British Coal Corporation, UK). The scientific foundations of the processes for obtaining biochars from different kinds of biomass by means of hydrothermal carbonization are described. The existing technologies based on this process are indicated. The possibility to upgrade modern coal chemistry in line with “green chemistry” by integrating biomass and the products based on it into coal chemical processes is shown.

The chromatographic behavior of a number of human blood plasma metabolites in HPLC-MS/MS analysis using a monolithic chromatographic column with a 1-vinyl-1,2,4-triazole-based sorbent was studied. Acetonitrile and a buffer based on ammonium carbonate and ammonia (pH 9.8) were used as the mobile phase. The experiment was carried out in two chromatographic modes: reversed-phase and hydrophilic. The metabolites selected for analysis allow for an unambiguous demonstration of the behaviour of both polar molecules and hydrophobic or amphiphilic lipid molecules in both of the chromatographic modes used. It was discovered that the change of chromatographic regime was accompanied by an inversion of the order of elution of metabolite groups having differences in chemical structure and hydrophilicity. It was shown that this 1-vinyl-1,2,4-triazole-based monolithic column can be used to screen metabolites in both reverse-phase and hydrophilic chromatography modes, and the use of two chromatography modes in metabolome screening using this column is mutually complementary and can help to increase the coverage of metabolites from different metabolic pathways.

In view of the 2^nd type diabetes mellitus "epidemic" developing over the world, and the absence of any efficient and safe drug therapy, the search for new hypoglycemic agents is a highly relevant task. Usnic acid produced by lichens, in addition to its diverse biological effects, also exhibits hypoglycemic action, though only in high doses. To decrease the effective hypoglycemic dose and reduce the risk of side effects, in the present work usnic acid was modified through reactions with the amino acid β-alanine and its derivatives. The hypoglycemic effect of the synthesized enamine derivatives of usnic acid was investigated in mice with alloxan-induced diabetes mellitus. It was determined that the derivative containing the amide fragment in the substituent exhibited a clearly pronounced hypoglycemic effect at the dose of 50 mg/kg. Neither of the studied compounds exhibited activity in the oral glucose-tolerance test in mice without any carbohydrate metabolism disorders.

Results of the multidisciplinary investigation of unique cult objects of the Ob Ugrians are reported. These objects were discovered during field work in the Berezovsky district of Khanty-Mansi Autonomous Territory - Yugra. The first item is a head scarf, which is a sacrificial gift to the Mansi deity Mis-Ne (Forest Woman); the second is a fragment of clothing of an ittarma figure (the Khanty family spirit). The third item (a head scarf) had no embroidery, but part of it was made of handmade fabric. The artefacts were used in the ritual practice of the northern groups of the Ob Ugrians and were probably imported, since the art of embroidery and the skills of hand-weaving existed in the 18^th-19^th centuries only among the southern groups of the Khanty and Mansi. The analysis of fibres and identification of embroidery dyes for hand-woven products of the turn of the 18^th-19^th centuries were carried out. The samples were studied by IR spectroscopy, scanning electron microscopy, and high-performance liquid chromatography with diode array detection. As a result, the plant structure of the fabric of products (presumably nettle fabric) and the composition of decoration dyes and pigments were determined.

The applicability of N,N -substituted bispidines as ligands of metal complex catalysts for the ethynylation reaction was demonstrated on the addition of phenylacetylene to 4-fluorobenzaldehyde. It was shown that the N,N -myrtenyl-substituted bispidinone led to a slight enantioselectivity in the formation of the corresponding propargyl alcohols.

The paper presents the generalizing results of a long-term study (1994-2020) of the behaviour of persistent organic pollutants (POPs) in the unique Baikal-Selenga lake-river ecosystem in Russia and Mongolia. The research started in 1993 on the initiative of V. A. Koptyug by the staff of the Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS and the Baikal Institute of Nature Management SB RAS within the framework of Russian and international field work missions. As a result of the analysis of the data obtained by means of gas chromatography-mass spectrometry, some regularities of the entry, distribution and accumulation of POPs in various regions of the Baikal-Selenga aquatic ecosystem, which is the largest lake-river system in Inner Asia, were revealed. Detailed data on the content, distribution and profiles of organochlorine pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons in surface waters, bottom sediments and biota have been obtained. The studies were carried out over the entire territory of the Baikal-Selenga ecosystem: Lake Baikal, the Selenga River delta, the Selenga River basin at the territories of Russia and Mongolia, including industrial areas and specially protected natural areas. The data obtained are an assessment of the current ecological state of the Baikal-Selenga region and can serve as a basis for identifying anthropogenic impact on the environment and public health with an assessment of environmental risk. These data can be used to develop approaches for environmental quality management and rational use of natural resources, conservation of unique biodiversity and sustainable development of the Baikal region territory and can be considered as an element of the implementation of the Stockholm Convention on POPs.