Home – Home – Jornals – Avtometriya 2026 number 1

The article presents the results of geochronological, geochemical and isotopic studies of intrusive complexes in the central and southern parts of Rudny Altai, which until recently have been practically uncharacterized using modern research methods. The results of U-Pb dating of zircon grains from igneous rocks (26 determinations) made it possible to establish 4 stages of endogenous activity: 1) Late Devonian (~ 370–360 Ma); 2) the end of the Early Carboniferous (~ 330–320 Ma); 3) Middle–Late Carboniferous (~ 315–305 Ma); 4) Early Permian (300–286 Ma). During each stage, both mafic and granitoid magmatism was manifested, which indicates the active development of mantle-crust interaction processes. An examination of the geochemical characteristics of the studied rocks allowed us to draw conclusions about the sources of magmas and the conditions of their melting, while comparison with geological and geochronological data from neighboring regions allowed us to determine the most likely geodynamic regimes for the manifestation of intrusive magmatism in the region. In the Late Devonian, magmatism occurred in a subduction setting on the active margin of the Siberian continent. At the end of the Early Carboniferous, magmatism was associated with the onset of orogenic processes during the formation of the Zaisan folded system orogenic structure. In the Middle to Late Carboniferous, magmatic activity reflects the onset of post-orogenic extension. Early Permian magmatism is due to a combination of post-orogenic extension and the activity of the Tarim large igneous province, formed as a result of the impact of the mantle plume of the same name on the lithosphere. Special attention is given to metallogenic aspects, and suggestions are made regarding the absence of ore deposits associated with intrusive magmatism in the region..

An automatic method is proposed for counting maize seedlings under conditions of substantial weed infestation and partial occlusion using ultra-high-resolution (<0.5 cm/pixel) RGB imagery acquired from an unmanned aerial vehicle. The method is based on a combination of computer vision and machine learning algorithms. Experimental results demonstrate that the accuracy of estimating the number of maize seedlings at early growth stages averaged 97%.

A histogram scene-based algorithm is developed to compensate for gain and bias non-uniformity in infrared focal-plane arrays. The statistical scene-based calibration method is proposed. Experimental results illustrating the effectiveness of the method are presented.

Issues related to the variational approach to the problem of non-parametric a priori uncertainty are disclosed is a method of converting a system of a priori stochastic differential equations, which enables to reduce the initial problem of nonlinear filtering of a multidimensional Markov process to a problem of filtering a new Markov process, characterised by a zero drift vector. The main provisions of the method of independent first integrals are given, allowing to provide the required transformation of linear systems of a priori stochastic differential equations. Filtering algorithms were constructed, in which the method of transforming multidimensional densities is used to restore the initial a priori and a posteriori densities of the probability distribution. An example of filtering the phase of a narrowband random process using the proposed conversion method is given. It has been shown that the proposed method of transformation using numerical integration reduces the requirements for the selection of parameters of the posterior density of the probability distribution of the vector of filtered parameters

The article discusses algorithms and neural network models for semantic segmentation of the Amur River water surface areas obtained using aerial photography. A dataset has been prepared for training a neural network based on aerial photography materials of the Amur River water area. The article presents the results of research on the accuracy of prediction of the most popular models in the field of semantic segmentation, such as UNet++, DeepLabV++, FPNet, and SAM. The experiments used the IoU (Jaccard similarity measure) and Boundure IoU (object boundary segmentation accuracy assessment) metrics. Computational experiments were conducted to measure the accuracy of the trained models in order to select the optimal parameters. As a result, it was found that the UNet++ model has an advantage in terms of segmentation accuracy, with an average Boundure IoU score of > 0.9. The developed algorithms and trained neural network models can be used in river water surface monitoring systems based on orthophoto images to determine the boundaries of the coastal zone.

The superior efficiency of the piecewise linear approximation method based on Delaunay triangulation has been demonstrated. This method completely eliminates negative concentration values on the resulting surface and exhibits the most favorable gradient distribution, with only 3.33% of gradients exceeding 75 ppm across the entire point cloud surface. The significance of the obtained results lies in the confirmed ability of this approximation method to generate highly reliable and physically accurate regime maps. These maps are essential for predicting critical emission levels, such as carbon monoxide (CO) and nitrogen oxides (NOx), during liquid hydrocarbon fuel combustion, enabling the development of effective burner optimization strategies to minimize environmental impact and maximize combustion efficiency in practical power installations.

Modern trends in underwater robotics development are focused on creating fully autonomous unmanned underwater vehicles (UUVs) equipped with multi-link manipulators (MLMs) and capable of performing complex research, manipulation, and technological operations in dynamic and uncertain underwater environments without direct operator involvement. The key challenge in UUV implementation is the generation and adaptive real-time adjustment of control programs based on data about the current environmental conditions obtained from the UUV's onboard sensors and MLM sensors. This paper presents a comprehensive set of tools for an intelligent UUV mission planner, including its information and software components, as well as development methodology. The proposed planner provides decomposition of strategic tasks into elementary operations with dynamic selection of their execution sequence and parameters depending on actual data and external conditions. The architecture of the developed software is based on principles of modularity and scalability, allowing the system to be adapted for various classes of UUVs and mission types. The presented solution contributes to the advancement of autonomous UUV control methods and can be used in designing advanced robotic systems for marine research, monitoring, and underwater technological operations.

This work is devoted to the study of acoustic phonon scattering in aluminum nitride (AlN) thin films grown by magnetron sputtering with an emphasis on their potential application as piezoactive layers for microwave resonators. The main objective of the work is to establish a correlation between the data obtained by various analytical methods, including Mandelstam-Brillouin scattering (MBS), Raman scattering (RS), infrared (IR) and terahertz (THz) spectroscopy, as well as X-ray diffraction (XRD), to assess the quality and homogeneity of AlN films. The data analysis confirmed the high stability of the MBS peaks in the studied films. It was found that the stability of the MBS phonon peak reaches 87.6 ± 0.5 GHz, which corresponds to the literature data, and confirms the homogeneity of the films with an error of less than 1 %. The presence of a specific peak in the XRD patterns and the minimum width of the phonon peak obtained by Raman and FTIR spectroscopy confirm the possibility of using these methods to characterize such micron-thick films. Considering that the peak frequency of the phonon resonance did not change for films with a thickness of 4.5 μm, it is assumed that the analysis of the phonon line width may be sufficient to evaluate the grown films. The Raman method seems to be especially promising, which in the future can allow in situ analysis during the growth of AlN films. Thin AlN films with a thickness of less than 7 μm have the quality sufficient for the development of acoustic microwave resonators, which opens the way for the experimental creation of multilayer structures with different acoustic impedances based on the obtained data.

The effect of a gas curtain, formed by the destruction products of thermal protection elements in the combustion chambers of solid-propellant gas generators, on the material degradation of critical-section liners is investigated. Experimental data from two series of fire tests conducted on test benches are analyzed: one series performed by the authors and another reported in the literature. Both test series yield relatively low linear material loss rates, measuring 2.5 and 6 times lower, respectively, than those calculated using methods for large-scale solid-propellant rocket motors. A mathematical model is proposed based on the coupled solution to integral momentum and energy equations for the boundary layer and on the determination of the thermal state and failure of materials. This model allows for the introduction of additional admixtures of a cold gas, which is chemically inert with respect to carbon, into the fuel combustion product flow. The applicability of the model is validated by comparing simulation results with experimental data, with discrepancies not exceeding 5%.

The kinetic physical-mathematical theory of metal creep, which accounts for thermally activated dislocation glide, is applied to describe the creep process under uniaxial tension for the EI696 steel and the EI826 nickel alloy under non-stationary thermomechanical loading conditions. The new results obtained in this work demonstrate the potential of this theory for applications in aircraft design.

The fabrication of Al-metallic glass (Fe₆₆Cr₁₀Nb₅B₁₉) composites with low residual porosity and varying component concentrations is presented. During sintering, no interfacial interactions between the composite components are observed. The hardness and thermal conductivity of the Al-metallic glass composites are experimentally determined. The experimental data are compared with values calculated using the rule of mixtures. The measured thermal conductivity of composites containing 20 and 80 vol.% metallic glass closely matches values predicted by models for parallel and series phase connectivity, respectively. The hardness values for these composites are consistent with those calculated using the Reuss and Voigt models.

An experimental setup for free circular rotation of blunt bodies about their longitudinal axis is described. A procedure for determining the roll moment in wind tunnel tests is presented. A method for determining the equivalent aerodynamic roll damping coefficient is developed, based on the fact that the viscous friction moment component in rolling bearings is independent of the axial load. For a segmental-conical body, the experimental value of the coefficient is shown to be close to the value calculated by numerical integration of the continuum equations in a quasi-stationary approximation. The proposed method can be used to determine the roll damping moment of reentry vehicles, which is necessary for solving flight dynamics problems.

Results of a combined computational and experimental study of the vortex structure in the reattachment region of a separated flow at a freestream Mach number M_∞ = 6 are presented. Three compression corner configurations are examined: a compression corner formed by two flat surfaces, the same compression corner with sidewalls, and an axisymmetric model. The compression angle is identical in all cases, equal to 30°. The model geometry is found to significantly affect the structure and parameters of the vortex flow in the reattachment region. This specifically pertains to the presence or absence of longitudinal Görtler-type wall vortices, their geometric dimensions, and the magnitude of the force and thermal parameters in this region.

The distributed receptivity of a swept-wing laminar boundary layer to unsteady freestream vortices with a longitudinally oriented vorticity vector in the presence of uniform spanwise surface undulations is experimentally investigated. Experiments are performed on a 25° swept-wing model under fully controlled disturbance conditions. Unsteady longitudinal freestream vortices are found to induce highly efficient distributed (in the streamwise direction) excitation of unsteady cross-flow instability modes at combination spanwise wavenumbers. This excitation results from vortex scattering by surface inhomogeneities. Part 1 of this study (published in the previous issue of the journal) describes the experimental approach and its theoretical justification; the experimental setup; the mean flow structure; the method of disturbance generation; the characteristics of freestream and surface disturbances; experimental evidence for the high efficiency of the investigated receptivity mechanism; the important role of longitudinal wavenumber resonance in exciting the most amplified cross-flow instability modes. Part 2 of this study (the present paper) presents the experimental determination of the amplitudes and phases of the distributed vortex-roughness receptivity coefficients as functions of disturbance frequency and spanwise wavenumber. Receptivity coefficients responsible for cross-flow wave excitation on a smooth surface are also obtained, and the relative efficiencies of the distributed vortex receptivity and vortex-roughness receptivity mechanisms are compared. The results are further compared with those previously reported for distributed vortex receptivity on a smooth surface.

The feasibility of controlling turbulent incompressible flow over an asymmetric Clark Z airfoil is investigated using two passive techniques. Firstly, air bypass through perforated surface regions from a high-pressure to a low-pressure area. Secondly, an external pressure flow introduced through the leading edge of a wing and subsequently diverted to its lower surface. The study is conducted over a chord within a Reynolds number range Re_c = (0.40-1.28) × 10⁶ and angles of attack from -6° to 6°. The examined control method exhibits an ambiguous effect, which depends significantly on the length and chordwise position of the mass-transfer region, the angle of attack, and the Reynolds number. Under certain conditions, however, a reduction in airfoil drag of 4-5% and an increase in lift are achieved, leading to an improvement in aerodynamic efficiency.

Results of the first combined computational and theoretical study of the effect of flow-aligned rectangular depressions (slots) on the surface of a flat plate on boundary-layer stability at a freestream Mach number M_∞ = 2 are presented. Slots of various depths (Reynolds number 0 ≤ Re_h ≤ 5400) and small width relative to the instability wavelength are considered. The mean flow is obtained using the FlowVision computational fluid dynamics package. Linear stability theory calculations reveal that increasing slot depth shifts the frequency range of boundary-layer instability toward higher frequencies. The spatial growth rates of the disturbances become lower than those for a boundary layer over a smooth surface, indicating flow stabilization.

The mechanism of longitudinal vortex formation in a supersonic jet issuing from an axisymmetric radial nozzle is investigated. Numerical simulations of the gas flow reveal that these vortices arise when gas flows from the prechamber into the inlet channel through a series of holes in a direction perpendicular to the axis of symmetry of the radial nozzle. The resulting vortices are then transported by the gas flow from the inlet channel into the radial nozzle and subsequently into the supersonic jet emanating from the nozzle. The numerical results are in satisfactory agreement with experimental data.

An original method for constructing a model porous medium is proposed. The approach is based on a well-known and widely used capillary model that accounts for pore-size distribution. The porous medium model is constructed by dividing the medium into thin layers perpendicular to the assumed flow direction, with capillary segments whose characteristics are determined using standard core analysis methods. The layers are probabilistically interconnected, forming parallel capillaries with variable cross sections. Within the inertialess flow approximation, the effective diameter of the capillaries is calculated. A pair of connected capillaries of different diameters is then replaced by a new capillary with this effective diameter. After repeating this operation iteratively, the original porous medium is represented by a bundle of parallel capillaries of uniform diameter. The theoretical aspects of the method are described, the adopted assumptions are substantiated, and the limitations of the model's applicability are identified. Results of absolute permeability calculations for two rock samples are presented and compared with those obtained using the classical capillary model. The proposed model is shown to provide a more accurate match between calculated and experimental data.

A method for controlling aerosol dispersion by applying ultrasonic vibrations of varying intensity is theoretically substantiated. Depending on the frequency and intensity of the ultrasonic field, either particle coarsening or fragmentation can be induced in the gas-dispersed system. A mathematical model for the coagulation and fragmentation of aerosol droplets in an ultrasonic field is developed. For the first time, a coagulation-fragmentation criterion ( t_CF ), defined as the ratio of the characteristic times of these two processes, is proposed. An expression for the critical particle diameter at which the characteristic times are equal ( t_CF = 1) is derived.

The distributions of velocity fluctuations in a Hagen-Poiseuille flow are obtained experimentally for various Reynolds numbers and pipe diameters. The longitudinal velocity fluctuation distribution is found to peak on the axis and to be independent of the Reynolds number. As the Reynolds number increases, the turbulence intensity in the tube decreases, while the root-mean-square value of the fluctuations increases. Velocity fluctuations (less than 2%) in the Hagen-Poiseuille flow are shown to have virtually no effect on the jet outflow from long pipes.

Full Navier-Stokes equations are applied to identify two branches of viscous flow regimes in the form of steady traveling waves between two smooth surfaces. The existence domain of the new solutions is determined on the parameter plane (wavelength and Reynolds number), and the flow regimes corresponding to one of the branches are shown to be unstable. Stable regimes exist over a wide range of Reynolds numbers, starting from values significantly lower than the Reynolds number at which the linear stability of the base steady-state solution is lost. The main wave characteristics of the new-type solutions are calculated. Achieving these solutions requires a pressure drop substantially greater than that needed for the base steady-state solution, while also resulting in enhanced heat transfer from the walls.

A numerical study of the effect of a perturbation generated by a vortex-generator fin on the local flow structure and turbulence of a bubbly flow in a planar channel behind a backward-facing step is performed. An Eulerian approach is employed to describe the flow dynamics and heat and mass transfer in both the carrier gas and dispersed phases. The problem is solved using the Reynolds-averaged Navier-Stokes equations, modified to account for the presence of bubbles. The influence of air bubble concentration, initial bubble diameter, and vortex generator height on the turbulent flow structure and the length of the separation region is investigated. The presence of the vortex-generator fin induces a significant (twofold) increase in the turbulence level in both single-phase and two-phase bubbly separated flows. The fin is found to exert a substantial effect on turbulence in the separated flow, with the turbulence level increasing by up to 60%. The addition of bubbles reduces the recirculation zone length (by 60% for ∆/H = 1/3).

A model for coupled axial-torsional oscillations of a drill string in a borehole of arbitrary profile is proposed. A numerical solution scheme is developed. A comparative analysis of the simulation results and field test data is performed. The main factors influencing the onset of stick-slip oscillations are identified as the intrinsic specific energy of rock destruction and the rotor speed. Comparison of the calculated results with field measurements demonstrates the adequacy of the model, with an accuracy acceptable for practical applications.

Results of an experimental study on the acoustoelasticity arising from the propagation of ultrasonic Rayleigh surface waves in a field of static bending stresses are presented. For a St. 20 steel specimen, the acoustoelastic effect is shown to differ under compression and tension. A calibration curve is constructed for Rayleigh surface waves, enabling their use for monitoring bending stresses-a capability not possible with bulk wave probing.

A gravity-based hydrodynamic flow loop capable of generating both steady and unsteady flow conditions is presented. The setup achieves velocities up to 16 cm/s and pressure fluctuations in a range of 60-130 mmHg within the measurement zone, enabling hemodynamic studies of virtually any segment of the cardiovascular system. For the first time, flow rate control is achieved by varying the angle at the junction of the systolic and diastolic flow circuits of the loop. Independent control of the minimum and maximum pressure in the unsteady flow is also implemented.

Nekrasov matrices, as a subclass of H-matrices, exhibit unique functionalities and hold significant importance in diverse fields. These matrices are characterized by their distinctive structure, which endows them with numerous remarkable properties. This paper extends the study of Nekrasov matrices by introducing a new subclass of H-matrices, termed DN-matrices, and explores their properties, particularly focusing on the Schur complement.

In this paper, we consider two-dimensional multi-term time-space fractional diffusion-wave equations. We develop an alternating direction implicit (ADI) spectral method based on Legendre spectral approximation in space and finite difference discretization in time. We also prove the numerical stability and convergence of the developed scheme and that the error is O(τ²+N^γ-r), where Ν,τ,γ,r are the polynomial degree, time step size, Riesz derivative order and the regularity of the exact solution, respectively.

A continuous-discrete stochastic model describing the dynamics of a spatially heterogeneous population is presented. The individuals of the population are located in a system consisting of two interconnected compartments. The individuals move between the compartments along unidirectional pipes. The duration of individual motion along the pipes is specified by constants or functions depending on time. The individuals located in the second compartment can contact one of the reproduction centers located in this compartment. As a result of contact with a reproduction center, an individual begins the process of fission. The reproduction of the individuals arising due to fission occurs until the number of descendants exceeds a threshold level, otherwise the reproduction of individuals ends. The population formed after the completion of fission contains descendant individuals that are not subject to fission and leave the system over time. The assumptions of the model are formulated, a probabilistic formalization of the model and an algorithm of numerical modeling based on the Monte Carlo method are given. The results of a computational experiment to simulate the dynamics of the population depending on the parameters of the model are presented.

For an isotropic random field a simple computer-efficient grid model is developed which provides sufficiently high accuracy of solutions to stochastic transport problems for small correlation lengths. Results of test estimation of the time asymptotics of mean particle flux in a random multiplying medium are presented.

In this paper, we explore a double-step method for solving nonlinear equations containing a differentiable and non-differentiable operator. Our approach is built upon a combination of three different methods. We have analyzed the local convergence of the suggested method, considering both Lipschitz and L-average conditions & established the superquadratic (≈ 2.414) order of convergence. Finally we have pictured numerical results in comparison with several existing methods.

The paper considers an algorithm for numerical solving of a one-dimensional inverse magnetotelluric sounding problem. The algorithm is based on a special type of algebraic equation which is called a pseudo-quadratic equation. The inverse problem is considered in three variants: 1) for media with fixed geometry; 2) for media with fixed geoelectrical properties; 3) general case. Additionally, an algorithm is proposed for input data processing which provides the existence of a solution to the inverse problem. Numerical experiments realized on test media with different sets of parameters are carried out to study and illustrate the efficiency of the proposed algorithms.

The paper is devoted to modeling the propagation of seismic waves in a chemically inert elastically deformable rock. Only changes in stress and pore pressure are considered, and the chemistry of the saturating pore fluid does not directly affect the deformation of the rock. Chemical effects are taken into account by changing pore pressure and rock deformation in the transport equations. In the numerical solution of the problem under consideration, an algorithm is used to combine a Laguerre integral transform method and a finite difference method. The paper presents results of modeling of the transport of a dissolved substance through a semi-permeable clay shale.

The North Crimean Canal (NCC) is an irrigation and water supply canal built in 1961-1971 to provide water to low-water and arid areas of Crimea. The canal waters are used for economic purposes, so investigation of the processes that were formed after the destruction of the Kakhovka Reservoir in 2023 and currently occur in the watercourse is urgent. In this work, we determined the concentrations of hydrocarbons (with safety assessment), features of the distribution of n-alkanes, potential sources of their income in the water and bottom sediments of the canal and adjacent water areas. The total concentrations of hydrocarbons and separately n-alkanes were determined by gas chromatography. Exceedance of the maximum permissible concentrations of hydrocarbons in water (0.05 mg/L) was detected in 50 % of samples in 2024, independently of sampling territory and time. The hygienic standard of hydrocarbon content (0.1 mg/L) was not exceeded in any sample, which makes the water suitable for drinking water supply. In all the bottom sediment samples collected in the canal in 2024, the standard level of HC content (50 mg/kg) was exceeded. Conditionally clean bottom sediments were detected only in the Biyuk-Karasu River bed. The genesis of hydrocarbons in 2024 in the waters of the canal and adjacent areas was mixed, mainly biogenic. The molecular composition of n-alkanes in the bottom sediments of the canal corresponded to the mixed origin of hydrocarbons with the predominance of allochthonous components.

In the studies of various kinds of biological activity of sulphur-containing monoterpenoids, we previously revealed a practically promising leading compound, the product of the reaction of limonene-(+)-1,2-oxide with methylmercaptoacetate. In the present work, investigation of the antioxidant and membrane-protecting activity of this leading compound is presented in comparison with the starting structures for its synthesis: limonene and limonene-1,2-oxide. For the studies of antioxidant activity, erythrocytes from the blood of laboratory animals were used as a cell test system, and a heterogeneous substrate based on the brain homogenate of laboratory animals was the non-cellular test system. Membrane-protective activity was studied under the conditions of Н₂О₂-induced hemolysis and with oxidative stress induction by 2,2'-azobis-(2-amidinopropane)dihydrochloride. It is shown that all the three compounds exhibit statistically significant antioxidant and membrane-protective activity in both test systems. The most active compound is the leading one, thioterpenoid with the methylmercaptoacetate fragment. In order to expand the synthesis possibilities of monoterpenes of menthane series in thiating reactions, and develop the approach to the synthesis of new potentially bioactive thioterpenoids, the pharmacophoric methylmercaptoacetate fragment was introduced into the structure of limonene dioxide and carvone. The reaction of limonene with methylmercaptoacetate in a basic medium resulted in obtaining a bicyclic product of intramolecular cyclisation participated by the OH group at isopropenyl fragment. The reaction of carvone with methylmercaptoacetate under acid catalysis occurred regioselectively, with the formation of terpene sulphide at the endo-cyclic double bond. The crystal structures of the two latter terpene sulphides were studied by X-ray diffraction. Both thioterpenoids in the crystals under investigation are represented by only one enantiomer.

The chemical composition of volatile organic compounds emitted by tropical and subtropical plants representing four families Begoniaceae, Liliaceae, Myrtаceae, Moraceae used in indoor landscaping are investigated. Seven species and one interspecific hybrid are studied. The sampling procedure has been developed to provide concentrating the organic substances from air onto a specially treated sorbent placed in sampling tubes. The composition of volatile organic compounds was determined by high performance liquid chromatography. The compounds were identified using the spectrophotometric mode and witness method. The compounds detected in the volatile emissions of plants included carbonyls (aldehydes and ketones), carboxylic acids, as well as normal and branched hydrocarbons. The composition of emitted compounds and their ratios were determined to depend on the phases of plant development. The data on the composition of volatile organics were compared with the data on the seasonal variations of antibacterial and antifungal activity of these plants against test microorganisms Escherichia coli, Staphylococcus epidermidis and Candida albicans. Among exometabolites, the compounds that can enhance the phytoncide action have been detected. Thus, an increase in the activity of gaseous emissions of plants against E. coli was determined to be accompanied by the appearance or a sharp increase in the concentration of furfural derivatives, in particular 5-methylfurfural, 5-hydroxymethylfurfural, while an increase in the activity against C. albicans coincided with the appearance of o-methoxybenzaldehyde in volatile exometabolites. The possibility to use the studied species of decorative plants to improve the indoor air quality was assessed.

The content of total ash, ascorbic acid, tannins was determined in the leaves and flowers of Hemerocallis species: H. citrina, H. fulva, H. lilio-asphodelus, H. middendorffii, H. minor, cultivated under the conditions of the forest-steppe zone of the Novosibirsk Region. Biochemical parameters were determined during the flowering period in 2022. It has been found that the concentration of tannins, ascorbic acid, total ash in the leaves is 1.3-1.5 times higher than in the flowers. The leaves are distinguished by the highest content of ascorbic acid (11.43-16.35 mg/100 g). The specificity of the content of these substances in plants depending on the species, vegetative and generative organs during the flowering period is noted.

The paper presents the results of creating a new oil-displacing composition based on the ternary system of deep eutectic solvents (DES) “pentaerythritol - urea - choline chloride” with surfactants, and the results of laboratory tests of its effect on the filtration characteristics of the heterogeneous formation of the Usinskoye field with heavy and high-viscosity oil. As a result of studying the physicochemical characteristics and phase equilibrium of the ternary DES system, a new oil-displacing composition of prolonged action was created, based on the ternary DES system “pentaerythritol - urea - choline chloride” and surfactant, applicable for various geological and physical conditions of fields, in particular in the Arctic zone of the Russian Federation. The effectiveness of the composition was assessed for sections of the field at the early and late stages of development. It has been established that the use of the composition based on DES and surfactants leads to the equalisation of filtration flows with an increase in formation coverage, restoration of the initial permeability and, as a consequence, to a significant increase in the oil displacement coefficient at both low and high temperatures.

Maintaining a stable content of phenylpropanoids (rosavins: rosavin, rosarin, rosin, and cinnamic alcohol) and phenylethanoids (salidroside and tyrosol) in line with pharmacopoeial standards remains a critical challenge for scaling up the cultivation of Rhodiola rosea L. to meet global demand. One possible cause of low compound levels is the inadequacy of current standardisation methods for raw materials and preparations of Rhodiola rosea. This study aimed to identify the optimal drying temperature for raw materials from even-aged clonal plants of Rhodiola rosea cv. ‘Mattmark’. Results showed that higher drying temperatures reduced phenylethanoid levels, with room-temperature drying is optimal. In contrast, the maximal concentrations of rosavins, mainly rosavin, were detected at increased temperature (80 °C). Analysis of the relative distribution of phenylpropanoids revealed that higher drying temperature causes an increase in the proportion of rosavin and a decrease in cinnamic alcohol content, while rosarin and rosin levels remained stable. It has been shown that rosavin is the dominant phenylpropanoid independently of temperature. Thus, drying rhizomes at 80 °C enhanced rosavin content by 20 % but significantly (by a factor of 1.5-2) reduced total phenylethanoids. Therefore, drying at room temperature is recommended to maximise the total phenylethanoid and phenylpropanoid content in the raw material.

The elements of D. I. Mendeleev’s Periodic System (Mendeleev’s Table) have the relative atomic weight calculated as the average value of the atomic weights of several isotopes. The number of these isotopes is quite large; however, there is a lack of convenient and accessible systematisation for practical work. This article proposes a method and a device for such systematisation.

Antimicrobial resistance (AMR) constitutes one of the foremost threats to global public health in the XXI century: according to the data of the World Health Organization for 2025, one of the six laboratory-confirmed bacterial infections exhibits resistance to standard antibiotic therapy, with annual resistance rates increasing by 5-15 % across more than 40 % of pathogen-antibiotic combinations. Amid the declining efficacy of single-target antibiotics, the development of multitarget hybrid antibacterial agents - single molecules incorporating two or more pharmacophoric moieties capable of simultaneously engaging distinct bacterial targets - has gained critical relevance. This review systematically outlines the principal strategies for designing such hybrids: linked, fused, and merged pharmacophores. It also addresses key pharmacokinetic and toxicological considerations, limitations inherent to conventional combination therapy, and the advantages conferred by hybrid molecules, including a unified pharmacokinetic profile, elimination of chemical incompatibilities between components, and simplified dosing regimens. Particular emphasis is placed on the mechanisms of action of hybrid compounds. Several reviewed hybrids demonstrate low minimum inhibitory concentrations, reduced frequencies of spontaneous resistance emergence, and favourable fractional inhibitory concentration indices (FIC ≤ 0.5), underscoring the therapeutic potential of this approach. Some examples of compounds are highlighted for their potent activity against diverse resistant bacterial strains and biofilms. A number of hybrid compounds have successfully advanced through clinical trials (TNP-2092, TNP-2198, cefilavancin, DNV-3837).