Home – Home – Jornals – Scientific journal “Vestnik NSUEM” 2024 number 3

The efficiency of the taxation system largely influences the economic development of any state. This article examines the problem of reforming the modern taxation system in the Russian Federation in view of the problems and shortcomings it has. The authors, based on an analysis of statistical data and materials from consulting agencies, has established that the tax burden on the economy in the Russian Federation exceeds the world average, as well as the indicators of most of the closest economic partner countries that are members of the Eurasian Economic Union. In addition, the modern taxation system in the Russian Federation imposes a significant tax burden on business, which hinders its progressive development in the medium and long term. Also, the modernization of the Russian taxation system is also necessary due to the construction of a digital economy, which requires automation of tax withholdings and effective control over tax accruals. It is concluded that the current Russian taxation system requires its optimization by reducing individual taxes and introducing a single tax on turnover and consumption, which will reduce individual taxes and replace them with a single tax that could be effectively used as part of the development of the digital economy.

This study examines the issue of the impact of digitalization on the intellectual property management system. The authors note that intellectual property, digital economy, and international cooperation will become key factors determining the socio-economic growth of economic entities and the country as a whole. The results of the study are divided into three key sections, providing theoretical and practical aspects. The first section examines the essence of intellectual property management. Authors presented the main approaches to defining the categories of “intellectual property” and “intellectual property management”. This section also includes a chart that represents level of funding of innovation activities by country, as innovation is a fundamental aspect of intellectual property. In the second section, the authors paid special attention to the issues of digitalizing the intellectual property management system. This section presents an analysis of official global statistical data, as well as data from the Russian Federation, which helped to identify the reasons for the heterogeneous contribution of innovation development to global progress. In the third section, the authors examined the risks associated with intellectual property management. They illustrated and described the main risk areas in the intellectual property system. The conclusion highlights that effective intellectual property management will enable organizations to adapt to the evolving relationships emerged due to the growth of the digital economy.

The article examines the concept of social responsibility of business structures in the service sector as a component of social sustainability. The article reveals the content, the main parameters, and a set of measures, the nature of which is determined by the level of development of the organization in the context of large and small businesses. An approach to understanding social responsibility in the service sector is argued, including the specifics of consumer cooperation activities, the main categories and directions of the social component.

In the context of digitalization, it is becoming relevant to search for approaches to the choice of management strategies for business structures of regional importance. The purpose of the study is to analyze the implementation of approaches to managing entrepreneurial ecosystems in the regions of Russia using the example of a sample of 200 ecosystems and to determine the choice of management strategies in the implementation of the digital transition. As a result, we propose criteria for identifying applied strategies in ecosystems, which determine the specific features of their implementation, in 16 areas. The share of ecosystems implementing digital platforms and technologies ranges from 7 to 37 % in groups of various sizes. We have found that most ecosystems in the context of digitalization choose a strategy to create a favorable environment for the development of projects and enterprises in combination with other strategies. We have identified the features of the digital transition for small ecosystems (the use of consulting and cooperation in the field of communications); for medium-sized ecosystems - the use of digital modules in value chains and full-fledged cooperation with manufacturers of digital products; In large ecosystems, there is a need for exclusive digital products aimed at maintaining the functioning of the entire ecosystem as a whole.

The demographic factor plays a crucial role in the economic development of countries, largely determining the pace of economic growth and the level of well-being of the population. The experience of Southeast Asian countries (India, China), Brazil and other countries shows that population growth is a powerful factor in economic growth. At the same time, excessively rapid population growth can increase poverty and lead to a decrease in the quality of life of the population. The purpose of the presented study is to analyze the influence of the demographic factor on socio-economic dynamics. The authors have established the features of demographic processes in the modern world. Global demographic trends have been identified, the main of which are an increase in the demographic burden on the economy as a result of population aging; uneven gender structure of the population; accelerating urbanization; active migration processes. The main theoretical approaches to the relationship between population size and socio-economic dynamics, set out in fundamental works devoted to the study of economic growth factors, are analyzed. It is concluded that population growth will have a positive impact on socio-economic development, provided that it is accompanied by a competent state economic policy to involve the growing population in the production process.

Digital transformation is a tool for strategic management and is designed to rebuild an enterprise from its product line to entire production and supply chain modernization in order to maintain and increase its competitiveness in a constantly changing business environment. At the same time, effective approaches, management methods and determination of digital transformation effectiveness have not been developed. In this article, an attempt was made to propose a method, as well as to select and adapt a mathematical apparatus for accounting the business environment influences on product line effectiveness, and therefore on digital transformation effectiveness of commercial enterprises in general. The scientific novelty of the proposed method lies in the application of new principles for taking into account factors of changes in the business environment and their mutual influence, as well as in approaches to calculating the forecast of their condition and development. The practical value of the proposed method is that it allows a commercial enterprise to quickly obtain an assessment of the factors, forecast their changes, and forecast the effectiveness of the product line (and therefore the overall effectiveness of the commercial company).

The article provides explicit formulas for the parameters of an effective stock portfolio obtained based on Markowitz’s theory, including for the Tobin’s Model. An empirical test was performed and confirmed the correctness of the obtained formulas. They can be useful in theoretical studies related to effective securities portfolios, as well as in the development of computer programs for analysing investments and the stock market.

Reproductive behavior is the primary basis of negative trends associated with a decrease in fertility in the world. The study of this phenomenon will allow us to find ways to regulate the current situation. However, the main problem lies in the complexity of statistical research of this phenomenon due to its specificity. In this article, an attempt was made to solve this problem by determining the location of Russian regions in the boundaries of reproductive behavior using the McKinsey matrix portfolio analysis method.

This article proposes an algorithm for calculating the vector of the stationary probability distribution for the Markov chain. Markov chains are effective for modeling complex systems in dynamics, including socio-economic processes, since instead of deterministic equations and dependencies, various scenarios are taken into account. At the same time, with an increase in the number of options, the complexity of solving the problem of finding a stationary probability distribution increases sharply. The idea of the algorithm is to replace the problem of solving the characteristic equation of the n-th degree for the matrix of probability transitions with the problem of linear programming. The mathematical formulation of the problem is formulated, including the definition of independent variables, finding the type of objective function, restrictions in the form of equalities. To perform calculations, a program was created in the algorithmic language Python. In order to verify and prove its effectiveness, calculations were carried out both for typical tasks of a general nature and for specific socio-economic cases. The obtained results completely coincided with the test ones and showed that the complexity of the algorithm is O(n). The developed technique allows wider application of Markov in the study of socio-economic processes and obtain more reliable results due to an increase in the number of probabilistic states of the system.

In modern conditions, the concept of sustainable economic development is effectively implemented through the processes of introducing ESG principles into the activities of enterprises in various industries. The hospitality industry is currently poorly engaged in the ESG transformation process. This is evidenced by the absence of companies from the hotel and restaurant business in ESG ratings. Modern realities require hospitality industry enterprises to reorient their activities in accordance with the principles of ESG transformation. ESG principles can be actively introduced into the cycle of use of fixed assets: from capital investment objects to liquidation objects. Fixed assets play a key role in the operations of hospitality businesses. Consumer demand for the company’s services depends on their volume, technical condition, as well as appearance. Corporate culture and the ESG agenda in modern conditions have a huge impact both on the entire resort and recreational industry of the country, and on the use of fixed assets within the industry. The purpose of this work is to assess the impact of corporate culture and the ESG agenda on the business activity of hospitality enterprises and the use of fixed assets. The ESG transformation of resort and recreational enterprises can be aimed at protecting the hospitality industry as a whole, as well as in the state economy, from risks that may arise due to conditions of uncertainty. The implementation of ESG transformation will contribute to the formation of a positive image, increasing the operating efficiency and competitiveness of entities in the hospitality sector.

This paper presents a critical review of experimental results and theoretical models for the effect of mechanical activation on the ignition of powder mixtures in gasless and filtration combustion and the ignition of thermite compositions. It is shown that all available data clearly indicate an increase in the sensitivity of powder compositions for thermal initiation, but in the case of shock initiation, the sensitivity does not always increase. The change in the sensitivity is due to the combined effect of two factors: an improvement in the contact between reactants and a decrease in the activation energy of the chemical reaction. It is proposed to use the mechanical activation factor taking into account the change in contact area and activation energy to describe the sensitivity of activated compositions.

The effect of preliminary mechanical activation of powder compositions on the combustion rate and maximum temperature is considered. The burning rate can increase, decrease or pass through an extremum with increasing activation time. It is argued that this complex behavior is most fully described by a microheterogeneous combustion model; homogeneous and convective-conductive models are also considered. The questions of whether additional energy is accumulated in powder mixtures under mechanical treatment and why superadiabatic combustion temperatures are not observed in activated compositions are discussed.

Numerical data on chemically equilibrium parameters of detonation of a stoichiometric hydrogen-air mixture and the same mixture with partly dissociated components are reported. It is found that the dissociated components (hydrogen, oxygen, and nitrogen atoms) produce a significant effect on the system parameters, especially on reduction of the critical energy of detonation initiation. As the fraction of atomic nitrogen in the hydrogen-air system increases, its explosion hazard also increases, and the initiation energy becomes even smaller than the critical energy of detonation initiation in the hydrogen-oxygen mixture. The system parameters for heated air are analyzed.

An experimental study was performed to investigate flame propagation above a liquid fuel film on the surface of the solid phase under conditions where the vapor pressure of the liquid is below the lean limit and the solid phase consists of granules of a porous medium. The flame propagated at a speed of the order of the normal speed of a homogeneous stoichiometric mixture. The effects of the characteristic element size of the porous medium and the oxygen concentration in the gas phase on the flame speed in porous media wetted with n-butanol were experimentally investigated.

The study of ignition and thermal decomposition of solid waste of the oil industry was conducted using different methods of thermogravimetric analysis. The experiments were carried out on pre-dried, crushed and fractionated (from 40 to 100 m m) samples. Ignition was carried out in a vertical tubular furnace. The effect of mechanical activation on the processes of ignition and decomposition is shown. The results of analysis by different methods correlate with each other. The kinetic parameters of the thermal decomposition process are determined depending on the particle size and the degree of decomposition of the coke residue.

The oxidation of amorphous boron powders modified with vanadium pentoxide were studied by thermogravimetry, differential scanning calorimetry, X-ray phase analysis, and electron microscopy. The modification was carried out by mixing powders with vanadium-containing gels: V₂O₅ × nH₂O hydrogel and V(OCH₂)₂ × n(HOCH₂)₂ oleogel. It was found that adding 2 wt.% V₂O₅ to the amorphous boron powder led to a decrease of 200 °C in the temperature at the onset of its intense oxidation and to a 25% increase in the specific heat release during interaction under heating in air at a rate of 10 °C/min. The reaction of boron with vanadium pentoxide is considered within the framework of a boron thermal process model.

Combustion of cylindrical Hf + 0.5 C samples pressed from hafnium powder mixtures with soot in nitrogen is investigated. Non-activated mixtures and compositions that had undergone preliminary mechanical activation in a planetary mill were studied. The nitrogen pressure in the experiments was 0.2-4 MPa. It was found that the combustion mode of samples from the non-activated mixture depends on the nitrogen pressure. At a pressure below 2 MPa, the front propagates in a self-oscillating mode, and at high pressures - in a stationary mode. The combustion of samples from the mechanically activated mixture proceeds in a stationary manner over the entire range of studied pressures, while the combustion rate is 50-100 times higher than the combustion rate of samples from the non-activated mixture. This is due to the difference in the microstructures of these mixtures and, accordingly, to different reaction mechanisms. During mechanical activation of the mixture, composite particles are formed, the contact area of carbon and hafnium in which is orders of magnitude greater than the contact area between them in the case of a non-activated mixture. As a result, the leading role in the combustion of samples from mechanically activated mixtures is played by the interaction of hafnium with carbon, which leads to an improvement in the gas permeability of the sample and subsequent nitriding. In samples from a nonactivated mixture, the leading role is played by the nitriding of hafnium, which occurs at a low rate due to filtration difficulties.

The combustion of powder and granulated mixtures (1 - X)(Ti + C) + X (5Ti + 3Si), 0≤X≤1 was studied. The experimental values of the combustion rate of powder mixtures depended on the fraction X of the binary mixture 5Ti + 3Si, on the characteristic size of titanium particles d(Ti) in the charge and on the value of the free volume above the charge in the reactor. The convective-conductive combustion model was used to explain the results. It was shown that the nature of the change in the combustion rate of powder mixtures with increasing X is associated with the fulfillment or nonfulfillment of the conditions for heating the charge particles and desorption of impurity gas in front of the combustion front. A large amount of liquid phase at 0.4<X<0.6 prevents equalization of gas pressure in front of and behind the melt layer, which ensures maximum combustion rates of the ternary mixture at d(Ti) = 120 μm (or minimum at d(Ti) = 20 μm according to other authors). Based on the experimental combustion rates of mixtures with granules measuring 0.6-1.7 mm, the combustion transfer time between granules and the combustion rate of the substance inside the granules were calculated, i.e., the combustion rate of powder mixtures with the effect of gas evolution leveled out. The dependence of the combustion rate of the granule substance on X is close to linear. For the 5Ti + 3Si composition, it is shown that, in contrast to the Ti + C mixture, due to the release of impurity gases behind the melt layer, the combustion front velocity in the powder mixture exceeds the combustion velocity of granulated mixtures and the combustion velocity of the substance inside the granules.

Model experiments on shock-wave synthesis in mechanocomposites of the composition 64% Ti + 36% Al were carried out in the developed flow-type pulse reactor. Composites after 3,5 and 7 min of mechanical activation, separated into four fractions, were subjected to extreme thermal action. A planetary ball mill “Activator-2SL” was used to activate the mixture. It was experimentally established that different times of mechanical activation action and different granulometry of powders do not affect the qualitative phase composition of the synthesis products. The reaction products include amorphized Al, underreacted Ti, intermetallic compounds TiAl, TiAl₃ and Ti₃Al, as well as nuclei of metastable phases or solid solutions based on Ti, which are in a nonequilibrium weakly ordered state. It was revealed that varying the time of mechanical activation and granulometric composition changes the quantitative content of the phase composition of the final synthesis products. The microstructures of the obtained samples confirm the formation of a multiphase product with a partially ordered structure, having amorphous and crystalline components.

The process of detonation propagation in semi-annular charges made of plasticized TATB with a steel shell inside during initiation of normal detonation along a line on the outer surface of the charge was studied using the X-ray method. In the experiments, the shape of the detonation wave front was determined using the X-ray method at different moments in time. The experiments recorded the effect of a layer of plastic explosive based on hexogen located on the surface of the main charge and having a detonation velocity ≈10% higher than that of TATB on the shape of the detonation front. The experimental position and shape of the detonation wave front in a cylindrical TATB charge are not described by the laws of geometric optics (Huygens principle) due to the peculiarities of detonation initiation in the initial section and the presence of a steel shell. Numerical modeling of the experiments was carried out using the LEGAK technique using macroscopic detonation kinetics. A similar to the experimental picture of the initiation and propagation of detonation in the TATB charge was obtained. A theoretical analysis of the features of the propagation of the detonation wave was carried out.

Detonation velocity was measured for an emulsion explosive with the addition of PAP-2 and ASD-4 aluminum powders in charges of different thicknesses with different initial densities. Adding PAP-2 aluminum powder was found to reduce the critical thickness of the emulsion explosive. At large charge thicknesses and densities of the aluminized emulsion explosive of more 1.0 g/cm³, the effects of PAP-2 and ASD-4 powders on the detonation velocity are equivalent. Replacing aluminum powder with talc powder markedly deteriorates the detonation characteristics of the emulsion explosive. The results of the work suggest that PAP-2 and ASD-4 aluminum powders in the emulsion explosive with a density of more than 1.0 g/cm³ react completely during detonation to the Chapman-Jouguet surface.

The case of an impact on a thin annular layer of incompressible viscoplastic material with a cavity filled with gas is considered. The layer is placed in a rigid assembly such as a press mold and is compressed by a piston at a constant speed. The solution of the corresponding strength problem is performed by a semi-inverse method with the specification of the rod type of medium flow and the governing equations of the viscoplastic substance. The obtained data on the accelerated motion of the cavity walls are considered as an example of focusing (energy accumulation) in a converging flow. Information on the temperature distribution under a load on the layer is used to calculate the parameters of explosion initiation by an impact on a ring charge of a solid explosive. The possibility of thermal ignition of reactive substances without the participation of self-heating and only due to dissipative heating due to the energy of mechanical action is discussed.

Emulsion explosives exhibit a strong nonideal detonation behavior. Their blast performance is commonly enhanced by inserting additives, such as aluminum powders. To investigate the nonideal detonation properties of aluminized emulsion explosives, a series of tests are conducted for emulsion explosives with 5% of an aluminum powder additive using mortar confinement. The velocity of detonation and the profile of the detonation front for charges of different diameters are measured. Then, the ignition and growth (I and G) model is employed to numerically investigate the detonation properties of aluminized emulsion explosives based on experimental results. A procedure combining the optimization LS-OPT code with the LS-DYNA hydrocode is first developed to calibrate the parameters of the I and G model. Then, the detonation pressure and temperature of charges of different diameters are predicted using the calibrated parameters. The results are in line with the existing literature data.

High-entropy alloys show noticeably better mechanical and physical properties than traditional alloys and have found widespread application prospects in the fields of national defense equipment, aerospace, high-pressure physics, and so forth. The preparation of high-entropy alloys largely involves the arc melting method, which displays defects like element segregation and low production efficiency in the preparation process. In this study, based on the mechanical alloying of a mixed refractory metal powder, the explosive sintering technology is adopted to prepare refractory high-entropy alloys (RHEAs). Through numerical calculations, the formation conditions of the solid dissolution phase of RHEAs and the minimum detonation pressure needed for explosive sintering are derived, and an explosive sintering test is performed with the explosive-powder tube ratio as a test variable. A dense bulk material containing the Mo-Nb-Re-Ta-W type of RHEAs is prepared through explosive sintering. The explosively sintered alloy products are characterized by X-ray diffraction analysis, scanning electron microscopy, energy dispersive spectroscopy, etc. The results show that the alloy products only contain the BCC phase and some Re elements that are not yet miscible, distributions of various elements are not completely homogeneous, and RHEAs are developed only in some parts of the product, implying the feasibility of the method for RHEA preparation.

The impact sensitivity of propellants is a significant concern during production, application, and storage. To study the impact sensitivity and reaction behavior of 3,3-bis(azidomethyl) oxetane and tetrahydrofuran copolymer (PBT propellants) subjected to a low-velocity impact, 20 sets of Susan tests are performed, and a simulation model is developed. The results show that the reaction is initiated by the impact and extrusion pyrolysis of PBT propellants. For impact velocities ranging from 120 to 300 m/s, the relative released energy of the Susan tests is greater than 20%, increases with the impact velocity, and reaches the maximum value of 57.67%. PBT propellants exhibit severe reactions under a low-velocity impact and are sensitive to crushing impact conditions. According to the simulation results, extruded PBT propellants dominate the reaction behavior of PBT propellants in a projectile of Susan tests under a low-velocity impact, and the reaction behavior of extruded PBT propellants is primarily dominated by coupling of both the impact velocity and confinement. The simulation results are in good agreement with the experimental results. The initiation impact velocity of partial detonation is about 260 m/s, based on experimental and simulation results.

The results of a study of the biology of the development of vegetative and seed progeny of rare forms of the Siberian stone pine ( Pinus sibirica Du Tour), created under new testing conditions in the experimental forestry “Pogorelsky Bor” in the Krasnoyarsk forest-steppe, are presented. Mother trees of vegetative offspring grow in optimal conditions in the low mountains of the Western Sayan, and seed trees in the foothills of Khamar-Daban and the Lake Baikal basin. Rare forms of the Siberian stone pine trees are characterized, in addition to the two-year seeding period, by the development of megastrobiles in the year of flowering, a year earlier than in typical forms. According to the results of the study, it was revealed that the vegetative offspring of the Siberian stone pine inherits the annual and mixed type of seed production of the mother tree (808) of the Sayan population; The seed offspring of the Baikal population are distinguished by growth indicators (increased number of cotyledons, long needles, number of lateral shoots, height, growth), which are also characteristic of mother trees. All identified signs of vegetative and seed progeny of the Siberian stone pine rare forms created in the Krasnoyarsk forest-steppe are characteristic of hybrid plants, manifested as growth heterosis.

The results of 23-year study of the species composition, vertical and horizontal structure, and ecological characteristics of old-growth high-mountain Siberian stone pine ( Pinus sibirica Du Tour) forests survived in the valley of the Aktru River (North-Chuysky Range, Republic of Altai) at altitudes of 2160-2300 m above sea level and not exposed to human impact and fires throughout their existence are presented. The studies were carried out on ecological profiles laid on the northern, western and eastern slopes of the Aktru River valley. For the ecological assessment of habitats, the method of standard ecological scales by L. G. Ramensky - I. A. Tsatsenkin, implemented in the IBIS software were used. In total, eight variants of old-growth P. sibirica forests were identified on the territory of the Aktru mountain-glacial basin, characterized by significant differences in the composition and structure of the shrub layer and ground cover: three variants in the periglacial zone on the northern slope, two variants on the eastern slope and three variants on the western one. The richest species composition of vascular plants, mosses and lichens, is characteristic of the periglacial P. sibirica forests on the northern slope: 46 species of vascular plants, nine species of mosses and five species of ground lichens occur here; in the western slope forests, 32 species of vascular plants, six species of mosses and three species of lichens were found; on the eastern slope, 26 species of vascular plants and 8 species of mosses were discovered. In total, 104 species of vascular plants were identified in the composition of old-growth P. sibirica forests. The main generation of the trees of P. sibirica is over 400 years old. Despite being confined to different types of soils (cryozems, thin podburs, soddy podburs), forests are characterized by a narrow range of moisture (4 grades) and active soil richness (2 grades). The studied forests are of high scientific importance for understanding the formation and functioning of high-mountain forests. The necessity to preserve these forests is due to their rarity, undisturbed and significant age of the trees.

The ongoing climate changes in the boreal zone affect carbon sequestration capacity of forest ecosystems. Thus, the environmental conditions and taxonomic diversity of the plant cover of ecosystems determine the relevance of studying the fractional composition of their phytomass and pigment complex in the stability and regulation of the activity of the photosynthetic apparatus. Living ground cover is typically underestimated or excluded when estimating forest phytomass due to the lack of standard equations. In this study, we assessed the stock of aboveground phytomass and developed a set of allometric equations for widespread species of living ground cover growing in the mixed forest of the middle taiga: Vaccinium vitis-idaea L., Ledum palustre L., Vaccinium uliginosum L., Vaccinium myrtillus L., Linnaea borealis L. The highest percentage of occurrence in the forest ecosystems (60 %) is characterized by the species V. vitis-idaea . The dominant species is V. myrtillus , the reserve of which is 21.2 ± 52.8 g/m². The ratio of the average supply of leaf phytomass to wood phytomass ranged from 0.08 ± 0.17 for V. myrtillus to 0.73 ± 1.04 for V. vitis-idaea . Leaf area index and photosynthetic pigments for the study objects were also determined. The index varied from от 0.027 ± 0.062 м² м^-2 for V. myrtillus to 0.097 ± 0.077 м² м^-2 for L. palustre . In the mixed forest of the middle taiga zone, the largest amount of chlorophylls and carotenoids was found in the leaves of V. uliginosum , and the smallest - in V. vitis-idaea . The photosynthetic apparatus of the studied species is characterized by a fairly stable accumulation of photosynthetic pigments belonging to the light-harvesting complex.

Monitoring the distribution of tree and shrub vegetation at the upper forest limit in mountainous regions is one of the simplest and most effective methods for obtaining evidence of the effects of climate change on vegetation. One of the largest and most widespread shrub species on the Putorana plateau is the shrub alder ( Duschekia fruticosa (Rupr.) Pouzar). The study presents an analysis of the age and morphological structure of shrub alder thickets, which grow at different altitudes (200-600 m above sea level) within the forest - tundra ecotone in forest stands of different density on slopes with different exposures of the Putorana plateau. It has been established that the intensive expansion of shrub alder into mountain tundras, sparse and open forests on the slopes of all exposures of the Sukhie Gory massif occurred in the 20^th century, mainly in its second half. The influence of Gmelin larch ( Larix gmelinii (Rupr.) Kuzen) stands on the distribution and morphological structure of shrub alder cenopopulations was revealed. The colonization and spread of shrub alder occurs in conjunction with larch stands. We established relationships between snow depth and the sum of projections of shrub crowns ( R² = 0.582). Shrub alder cannot survive in the absence of snow cover. There are significant differences in the distribution of shrub alder depending on the slope exposure. The distribution of shrub alder is higher on the slopes of southern and eastern exposures. The largest number of shrubs grow mainly in the lower part of the ecotone, where snow masses accumulate in greater quantities. The most likely explanation for the increase in density and advance to the mountains of alder shrub may be a general change in climatic conditions in the study area.

Long-term data on variations in snow cover parameters in the subtaiga and mountain-taiga group of forests in the protected area of the National Park Krasnoyarsk Stolby are presented. A significant reduction in the period of occurrence of stable snow cover (~ 20 days) was revealed due to later snow formation and earlier melting. To evaluate the water storage in snow, we use the thickness of the snow cover ( r = 0.74-0.96; p < 0.001) in specific conditions for period 2018-2023. According of our estimation the territory with snow depths in the intervals of 50-70 cm ( V , % < 50) is identified as a most stable areas (from 52 to 71 % of all protected area) in different years, except for 2021 yrs. (only 28 % of the territory) with the critically low amount of the snow. The total amount of the water storage in snow at the beginning of snowmelt, depending on the weather conditions of a different years, varied from 46.6 to 89.7 · 10⁶ m³ with an average weighted water storage per unit area from 98.8 to 190.1 mm. The presented data are comparable with those previously published for other territories of the Krasnoyarsk region (Burenina et al., 2013) and Siberia (Report..., 2019-2023), which makes it possible to further in-depth analysis of the relationship between evaluated data on water storage in snow and climatic parameters of the environment in longer time scale.

The patented method for introducing in vitro culture and obtaining regenerates from young shoots of Korean poplar ( Populus koreana Rehder) plus tree of the male genotype are discussed in the article. Modified MS and ½ MS media supplemented with an antibiotic and hormones were used for cultivation. To activate the axillary meristem, a combination of hormones was used in the following concentrations: 0.2 mg/l BA; 0.05-0.1 mg/l TDZ; 0.01 mg/l NAA. The shoots were multiplied on the same media using hormones: 0.4-0.6 mg/l BA and 0.1 mg/l IBA. Shoot growth was performed using the hormone 0.1 mg/l kinetin, and shoot rhizogenesis in the presence of 0.25-0.5 mg/l IBA and 0.1 mg/l kinetin.The sterile substrate consisting of equal parts of sand, vermiculite and forest soil was used for plants rooted. Poplar regenerants are differed in growth rate, but no morphological changes among them were observed. Some of the plants are characterized by rapid growth in height, while other plants developed very slowly. The tallest plant specimens in clones 1/1, 1/8 and 1/14 were observed, and their height varied from 18 to 30 cm. We believe that the appearance of plants with different growth rates is the result of the manifestation of somaclonal variability poplar during its cultivation in vitro . However, this phenomenon requires further confirmation. The plants obtained by this method do not have fungal, bacterial or viral infections and are able to reproduce by cuttings. The proposed technology enables for their further reproduction poplar for practical purposes.

Given the importance of Scots pine ( Pinus sylvestris L.) for forestry in the European part of Russia, it is necessary to have tools that allow one to make informed decisions on managing the forest growing process and planning forest use. The aim of the study is to develop a dynamic model of the growth and productivity of pine forest stands in the European part of Russia using data from repeated observations on permanent sample plots. The data used in the study are represented by 99 permanent sample plots in natural pine stands in the European part of Russia, observations of which were carried out from 1862 to 2023. The growth and productivity model of stands consists of separate equations for the dependence of the average height, average diameter and number of growing trees on the initial and final ages and initial values of the corresponding stand indicators and the dependence of the average form height on the average height of the stand. The model developed in the study provides forecasting of stand indicators within the accuracy established by the Forest measurement instructions, providing a confident forecast for an average period of 9 years. The average absolute percentage of error for average heights, diameters and form heights does not exceed 5 %, and for the number of trees, the stand basal areas and stand volume does not exceed 15 %. The developed model can serve as an alternative to traditional course growth tables in the design and justification of forestry activities, in the inventory of forests using the updating method, as well as for making management decisions when managing pine forests. In combination with additional equations, it can be used to predict the carbon sequestration potential of pine stands.

The results of studies of physiological processes (root respiration, intensity of photosynthesis and transpiration, pigment content, growth of needles and shoots) of Scots pine ( Pinus sylvestris L.) trees of different groups of subordination of a 230-year-old drained same-aged shift-sphagnum pine forest and the influence of selective (mine) felling. The position of the pine tree in the tree stand was consistent with the physiological state of the tree. The highest intensity of physiological and growth processes was noted in dominant trees (according to G. Kraft, trees of class II) - 1.5-2 times higher than in other groups of trees (co-dominant, oppressed). The lowest activity of physiological and growth processes was observed in oppressed trees. After selective felling, the illumination under the canopy of the tree stand increased by 3.2 times compared to the control without felling (up to 47.9 % of the illumination of the open area) and became favorable even for the growth of undergrowth. In pine trees left for cultivation, root respiration increased by 1.5 times, the intensity of photosynthesis and transpiration increased by 1.2-1.5 times, the content of chlorophylls decreased by 15-42 %, carotenoid pigments - by 5-32 % compared to control. The highest physiological and growth response to the selective cutting was shown by dominant trees of Kraft’s class II, and the lowest - by deppressed trees of class IVa. Mine cuttings did not change the structural differentiation of trees in the canopy, but increased their physiological activity, the growth of needles and shoots.

Bioecological characteristics (allometry, viability, morphometry) of the pyramidal shape of pedunculate oak ( Quercus robur L. var. pyramidalis ) under conditions of anthropogenic pollution of the city of Donetsk in the south of the East European Plain (Donetsk Ridge) were studied. The higher viability of control group of trees (1 point, healthy trees) compared with the experimental group (1.5 ± 0.5 points, healthy trees, rarely weakened) growing in anthropogenically polluted areas. The diameter of the trunks of the experimental group is on average 34 % higher than the diameter in control pedunculate oak stands. The volume of the stem and phytomass of various fractions of pyramidal pedunculate oak trees growing under conditions of anthropogenic load are ~ 50-70 % greater than for the control area. Moreover, the allometric dependencies in the two territories have the same patterns and are subject to power-law regression. The allometric ratio of the diameter to the length of the trunk ( d : l ) for both the control and experimental groups had a high value and amounted to 0.04-0.05. Deformations of the stems were not observed due to the high mechanical stability. The crown architecture underwent transformation in the presence of skeletal branches with a diameter to length ratio d : l < 0.01. In the course of studies of crown architectonics, irreversible deformations of skeletal branches of various orders (mostly small ones) were revealed in two territories equally, but no breaks or changes in crown closure were observed, the degree of plant accidents was at a low level (no breakages after removal of loads). Pedunculate oak trees are recommended for use in the formation of long-term plantings in industrial cities, because they retain high viability, mechanical stability and stable allometric indexes on which the stability of the entire plant depends.

Throughout its life cycle a plant receives nutrients from the soil and fertilizers that are introduced into it and then absorbed by the roots. Higher plants have an additional ability to absorb nutrients when their leaves are sprayed with a solution of a certain concentration. The amount of fertilizers applied to the soil must be determined in accordance with the analysis of its composition. However, it’s not obligatory when we apply foliar fertilization method, since the properties of the leaves depend not only on the type of plant, but also on the conditions in which it grew. This study for the first time introduces a method for determining optimal concentrations of foliar fertilization based on the structure and optical properties of the plant leaf. In 2023, Kuraginskoe production farm was chosen as a site of a field experience aimed at studying foliar fertilization of Novosibirskaya 31 spring soft wheat ( Triticum L.). The experiment was conducted in 4 ways: 1) control; 2) one-time foliar fertilizing in the tillering phase; 3) two times foliar fertilizing: in tillering and shooting phase; 4) triple fertilizing: in tillering phase, the shooting, and the beginning of earing. We used electron microscopy pictures to assess the standard deviation of thylakoids size as a degree of ordering. Based on models of one-dimensional photonic crystals, graphs of the density of photonic states were calculated. From the analysis of the obtained fluorescent spectra of the flag leaves, changes in the intensity and width of the spectrum lines are visible. Comparison of contours of the peak corresponding to photosystem (PS) II shows a difference in half-widths, which indicates a more active pumping of energy in a plant treated with triple fertilizing. The methods used in the study let us calculate a correlation coefficient equal almost to 1, which means strong link of these parameters. The study has shown that the main mechanism for increasing crop yield when applying foliar fertilizing is a more efficient transfer of energy from PS II to PS I.

This article discusses the results of retrospective verification of the strength prediction model for saturated rocks of southern Yakutia. The model was developed for the geotechnical conditions of the city of Neryungri. The input data for the model consisted of the decay rate coefficients of the harmonic field of a vertical magnetic dipole measured at a 1.125 MHz frequency using the geometric electromagnetic induction sounding method. The error of model predictions was close to the allowable error of ±20 % for average laboratory estimates of rock sample strength and ranged from ±16.8 to ±33.5 % for different site conditions with a probability of about 70 %. The total error of the model at this probability is 27.2 % with maximum outliers overestimating the laboratory strength of weak rocks by 120.5 % or underestimating the strength of strong rocks by 86.8 %. The model predictions were more accurate (errors of 22.8 and 21.9 %) for the rock masses composed predominantly of moderately strong (15-50 MPa) and strong (50-120 MPa) rocks. The statistical results indicate that the model is regionally representative and can be applied in the areas of warm and cold permafrost sedimentary rocks of southern Yakutia for rapid, cost-effective terrain evaluation by rock strength.

The purpose of this work was to specify the hydrogeological conditions in the poorly studied northeastern part of the Lena-Amga interfluve. We analyzed archival (1965-1995) and published data on subpermafrost waters and permafrost thickness in the Churapcha and Tattinsky districts of the Republic of Sakha (Yakutia), including new field studies (2009-2022). The research was based on the data from 19 groundwater exploration wells, 450 to 650 m in depth. It is shown that the Jurassic and Middle Cambrian aquifer complexes differ in piezometric pressures and chemical composition. Based on the new information, it is suggested that the boundary between these two aquifer complexes should be shifted northward by 50-80 km. A zone with distinct specific hydrogeological conditions confined to the Tatta-Tompo fault was identified. Presumably, the fault was formed under conditions of horizontal compression, which resulted in the compaction of the rocks and their reduced permeability along the fault, as well as in the increased freezing intensity in the strata with a low water content during periods of decreased global temperatures.

Natural gas hydrates exist in porous media under high pressure and low temperature conditions, including permafrost. The development of methods for calculating the phase equilibria in hydrate-bearing soils and sediments is of great interest. This includes the equilibrium content of nonclathrated water, as pore water in equilibrium with pore hydrate and under given thermobaric conditions. Nonclathrated water is similar to unfrozen water in frozen soil. The current study focuses on thermodynamic relationships for calculating nonclathrated water content in soil under certain thermobaric conditions based on experimental data of pore water activity and soil water content. It has been shown that at a constant temperature the nonclathrated water content decreases sharply according to a power law as gas pressure increases. The results of thermodynamic calculations are in agreement with direct measurements of nonclathrated water in soil systems using the contact method. Thus, at temperatures below 0°C, the nonclathrated water content decreases by more than two times in kaolinite clay and in sandy clayey soils with an increase in methane pressure from 2.3 to 11 MPa. The obtained relationships allow us to recalculate the nonclathrated water content after transition from one hydrate-forming gas to another, as well as calculate nonclathrated water content using the unfrozen water content curve at different temperatures. Developed thermodynamic approach can be applied to various hydrate-forming gases and their mixtures.

Climate change affects the parameters of snow cover, including the distribution of snow storage on plain territories under forests and in fields. A comparison of the average long-term maximum snow storage in forests and fields for different climatic periods is carried out. The average value of snow storage on fields for the current climatic period (1991-2020) increased by 4 % compared to the period 1966-1990; in forests, it decreased by 6 %. Average snow storage in forests and fields in 2001-2010 amounted to 127 and 123 mm; in 2011-2020, it decreased to 121 and 120 mm, respectively. The ratio of snow storage in forests to its value in fields - the snow accumulation coefficient - for 1966-1990, 1981-2010, and 1991-2020 has been constantly decreasing and amounted to 1.16, 1.08 and 1.05, respectively. Maps of the distribution of snow storage and the coefficient of snow accumulation within plain territories of Russia for different climatic periods have been constructed. The tendency of leveling the maximum snow storage in forests and fields under the modern climate (1991-2020) has been confirmed.

The main stages in the development of geocryology in the XX-XXI centuries are highlighted. The major research achievements are presented in the fields of permafrost science, permafrost engineering, historical geocryology and regional geocryology. The most important results of research at the Melnikov Permafrost Institute of the Siberian Branch of the Russian Academy of Sciences are described.