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The content and distribution of fluorine in two soil catenas located in the basins of the Burla and Kulunda rivers on the territory of the Kulunda Plain was studied. The use of the catenas method made it possible to compare the content of fluorine in soils of different geochemical relief positions, in zonal and intrazonal soils. It is not just the presence of fluorine in soils that matters, but its concentration, which underlies the dual nature of his biological role - positive or negative, which requires the introduction of sanitary and hygienic standards for his content. In the studied soils, the total content of fluorine varies from 13.9 to 711.03 mg/kg, the water-soluble form varies from 0 to 34.65 mg/kg. It was found that in saline solonetzes developing in superaquatic landscapes, the content of total and water-soluble fluorine have, respectively, ecologically critical and unacceptable concentrations, therefore, the use of these soils in agricultural production is associated with the risk of accumulation of excess amounts of fluorine in the body of animals and humans.

A geobotanical analysis of 160 steppe and ecotone plant communities with the participation of cereals in the north of the Lower Volga region (within the Saratov region) was carried out. The species diversity of apomictic cereals is significantly inferior to the diversity of their amphymictic relatives in the flora of the region and in the studied phytocenoses (24 apomictic and 109 amphymictic species in the flora; 17 and 34 species in the phytocenoses, respectively). At the same time, the dominants of the studied communities are equally represented by both amphymictic (14 species) and apomictic cereals (9 species). It was established that cereals with amphymictic mode of reproduction dominate in 64 phytocenoses, apomictic cereals dominate in 48 ones. The number of phytocenoses in which apomicts are codominants significantly exceeds the number of plant communities with amphymicts codominance (46 and 22, respectively). The studied plant communities are similar in species richness and evenness. The obtained data indicate successful competition between apomictic cereals and amphymicts and their significant contribution to the composition of steppe and ecotone phytocenoses in the northern Lower Volga region.

The problem of differences in the rates of evolution among different species of animals and plants has been discussed very intensively in recent years, and, in connection with this, the question of whether the so-called molecular clock hypothesis is valid is acutely raised. We conducted a search for scientific papers providing median networks that include mitochondrial gene haplotypes for closely related boreal and Arctic (or dispersed through the Arctic) fish species. In all seven cases analyzed by us, in Arctic taxa or taxa that passed through the Arctic during their phylogeny, the rate of nucleotide substitutions was higher, and this difference, as it turned out, is statistically significant. Thus, the formation of new fish taxa in polar latitudes is accompanied by rapid evolution of mitochondrial DNA, which, apparently, is the manifestation of their adaptation to a new habitat. In addition, speciation in fish in the Arctic is usually accompanied by multiple chromosome fusions. Thus, both our and the literature data give new strong reasons to doubt the validity of the molecular clock hypothesis.

A fuel processor for autothermal reforming of diesel fuel into synthesis gas is developed and tested. The developed reactor is demonstrated to possess a fast start-up and high efficiency. During the tests, complete conversion of diesel fuel and the composition of reaction products close to equilibrium values were achieved. The thermal circuit of a power plant based on a solid oxide fuel cell (SOFC) with the electrical power of 1 kW was optimized. The results obtained are the basis for the further development of a real prototype of a power plant based on planar SOFC with an integrated diesel fuel processor, opening up the prospects in the area of making low-power electrochemical generators.

The binary systems of deep eutectic solvents (DESs) have been synthesised and investigated: tetraxydroxy alcohol - a salt of a quaternary ammonium base (DES₁), tetrahydroxy alcohol - carbamide (DES₂), a salt of a quaternary ammonium base - carbamide (DES₃), and the ternary system tetrahydroxy alcohol - a salt of a quaternary ammonium base - carbamide (DES₄). Eutectic compositions of binary systems DES₁, DES₂ and DES₃ are characterised by significantly lower pour/melting points than those of the initial components. The lowest pour point among the binary mixtures is that of eutectic composition DES₃. The ternary system is characterised by an even lower melting point (-14 °C), which is associated with the formation of intermolecular donor-acceptor hydrogen bonds within the system. An aqueous solution of DES₄ with the concentration of 26 wt% was prepared, and its pH value was determined depending on temperature during preparation. At room temperature, pH of three-component DES is 6.6-7.1, but after thermostating for 6 h at 150 °C pH increases to 9.2 due to carbamide hydrolysis. It is assumed that further on, using DES₄ as the basis for an alkaline oil-displacing composition directly in the reservoir, under the influence of the temperature of injected heat carrier, CO₂ is formed, along with the ammonia buffer system with the maximal buffer capacity within the pH range 9-10. Resulting carbon dioxide, dissolving predominantly in oil, will cause a decrease in its viscosity, on the one hand, while the formed alkaline medium, being most favourable for surfactant performance due to a decrease in interfacial tension, liquefaction of high-viscosity layers or films at the oil-water-rock boundaries, on the other hand, will ensure efficient use of this system for oil displacement. In addition, the oil-displacing composition based on DES₄ will be low-solidifying, which opens the possibility of its transportation and use in the northern regions and the Arctic zone.

Samples of primary low-sulphide gold-quartz ore and oxidised host rock containing up to 10 wt% sulphides and 5 wt% their oxidation products were investigated to reveal the relationship between the migration of elements during the hypergenic transformation of ores and rocks and their mineral composition. Mineralogical studies employed optical and electron microscopy to identify the shapes and sizes of mineral individuals and aggregates and to determine their chemical composition. It is determined for major element content that the oxidised host rocks contain significantly more iron, sulphur, aluminium, potassium and phosphorus than primary low-sulphide quartz gold ores, while silicon and calcium content is lower. This is due to the removal of sulphur and iron into the near-vein rocks with the formation of primarily pyrite and arsenopyrite, and the presence of aluminosilicates (feldspars and layered silicates) in them. The same applies to arsenic and antimony, as their concentrations are higher in the host rocks than in the ores. The rates of lithophile elements recovery from primary gold-quartz ores are much higher than those from oxidised host rocks. Сhalcophile elements, on the contrary, are more intensively transferred to the solution from host rocks. Thus, the complex of elements extracted from ore suspensions is directly determined by their mineral composition. The main carrier of gold is native gold and its tellurides. Silver is associated with low-grade gold, copper and silver sulphosalts, and also tellurides.

The milestones of the development of X-ray diffraction and crystal chemical studies in the Laboratory of Crystal Chemistry of the Nikolaev Institute of Inorganic Chemistry SB RAS for 1958-2024 are highlighted.

The targeted screening of 11 phenolic toxicants (phenol, chlorophenols, 2,4-dichlorophenoxyacetic acid, octylphenol, nonylphenol, bisphenol A) has been carried out over river water and bottom sediments (BS) in the middle reaches of the Don river within the boundaries of the Voronezh Region. Three sampling points were selected for quantitative chemical analysis: in the zone affected by the discharge of sewage treatment plants of a large city (Voronezh), in the district centre (the city of Liski), and in an area with insignificant anthropogenic influence. The concentrations of phenolic compounds were determined using gas chromatography - mass spectrometry (GC-MS), the analytes were preconcentrated on a magnetic sorbent functionalised with aminated hypercrosslinked polystyrene. Sampling was carried out four times a year, taking into account seasonal climatic fluctuations and precipitation. The maximum concentrations were established in the spring for 2,4-dichlorophenoxyacetic acid (1022 ng/L) and 2,4-dichlorophenol (557 ng/L). In bottom sediments, the highest concentrations are achieved for alkylphenols: 1.99 and 7.84 μg/g for octylphenol and nonylphenol, respectively. Bisphenol A has not been found in detectable amounts in waters, however, a significant concentration of this compound has been found in bottom sediments: 3.18 μg/kg. The bottom sediments were also determined to contain 2,4,5-trichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol. The maximum concentrations of phenolic pollutants in river water are usually observed in spring during high water and after heavy rainfall. Phenol concentrations in bottom sediments are less susceptible to seasonal fluctuations. The hydrophobicity of substances and an increase in their stability against degradation significantly affect their accumulation in BS.

In order to develop a catalytic technology for processing coal mine methane into hydrogen-containing gas, thermodynamic analysis of methane tri-reforming (TRM) was carried out, and the influence of temperature (600-850 °C), contact time (0.04-0.15 s), linear feed rate (80-240 cm/min) and composition (CH₄ / CO₂ / H₂O / O₂ / He = 1: (0.3-0.5) : (0.2-0.5) : (0.1-0.3) : (2.9-3.2)) of the reaction mixture on the conversion of the initial reagents and target products in the TRM process in the presence of a supported Ni catalyst was studied. It has been shown that with an increase in the temperature of the TRM reaction from 600 to 800 °C the process performance improves (methane conversion: 36 → 94 %, carbon dioxide conversion: 57 → 97 %, hydrogen yield: 37→ 91 %, carbon monoxide yield: 44→ 94 %, molar ratio H₂/CO: 1.5 → 1.7), and at a reaction temperature of 850 °C the process indicators are close to equilibrium values. It has been established that varying the O/C value and the composition of oxidants makes it possible to regulate the performance of TRM process. The optimal conditions for the TRM process were identified to achieve maximum efficiency of the catalytic processing of coal mine methane into hydrogen-containing gas: temperature - in the range of 800-850 °C, contact time - 0.15 s, linear feed rate - 160 cm/min and molar ratio of reagents in the initial feed - CH₄ / CO₂ / H₂O / O₂ = 1: 0.5 : 0.2 : 0.25.

A mathematical model of the flow of hydrogen from gas mixtures through the walls of capillary tubes made of metallic nickel has been developed, taking into account the inhomogeneity of the partial pressure of hydrogen along a long tube, as well as temperature nonuniformity in different regions of the tube. Using the model and relying on experimental data, the kinetic parameters of hydrogen transport were calculated within the temperature range of 600-850 ºС and the hydrogen partial pressure range of 0.3-0.8 atm. The model can be used in the design of membrane modules for hydrogen separation from gas mixtures to calculate the length of individual membranes, their number, and the optimal flow rate of the hydrogen-containing gas mixture through the membrane.