Nauka Yuga Rossii

The present paper is dedicated to studying the stability of nonlinearly elastic sandwich plates, which are common structural elements. The bifurcation of equilibrium is considered for a three-layer circular plate under radial compression and a three-layer rectangular plate under biaxial tension and compression. It is assumed that the middle layer of plates (core) is made of a highly porous material, while the top and bottom layers (coatings) are homogeneous, prestrained and contain internal stresses. An original approach is taken when modeling them in this study: to describe the behavior of the porous core, the governing equations of a nonlinear micropolar body are used, and the behavior of the coatings is studied within the framework of the classical elasticity. This allowed us to take into account in detail the effect of material microstructure on buckling. Using representations of constitutive relations for different reference configurations, in the case of a physically linear material model, linearized equilibrium equations were derived that describe the behavior of sandwich plates with a highly porous core and prestressed uniform coatings in a perturbed state. Using special substitutions, the stability analysis of three-layer circular and rectangular plates was reduced to solving linear homogeneous boundary value problems for systems of ordinary differential equations. As a result of the numerical analysis for plates with a core of dense polyurethane foam and polycarbonate coatings, it was determined that preliminary tension of the coatings stabilizes the considered deformations of the plates as a whole, while the effect of preliminary compression of the coatings is negative.

The article is devoted to the assessment of the Aral region of the Republic of Kazakhstan for the presence of lithium hydromineral raw materials (LHMRM) on the basis of criteria and features established by analyzing literature data on regions with large LHMRM resources. The Aral region is a tectonic depression occupied at various times by the waters of the Aral Sea. For the first time, attention is drawn to the manifestation of a giant thermal anomaly that captures the entire depression, as a reflection of ascending endogenous flows of energy and matter. These flows could bring lithium and other valuable elements into the sedimentation pool, which accumulated in halogen deposits during evaporation. It is shown that the Upper Pliocene and Holocene layers are of interest in relation to LHMRM. In the first, up to a depth of 500 m, promising salt strata with a total capacity of 85 m are noted on LHMRM. The Holocene stage of development of the Aral Sea is characterized by sharp fluctuations in its level and salinity. In regressive epochs, coinciding with hot arid conditions and, most likely, with the activation of heat flow, the level of the Aral Sea fell sharply. The sea was shallow and broke into separate lakes filled with highly mineralized waters. The composition of regressive sediments is mainly sandy-siltstone chemogenic (gypsum, mirabilite, etc.). Chemogenic deposits accumulated in the Small Sea, and saline landscapes existed on the coasts. Calculations of possible concentrations of dissolved forms of lithium in seawater of the order of 15 mg/l as of 1967 (before the beginning of modern shallowing of the Aral Sea) are given. The sea level has dropped by more than 16 m since then. At the same time, millions of tons of salts of various metals, including lithium, accumulated on the exposed bottom of the sea. All these salts, penetrating into the pore and groundwater, could enrich them, forming a brine containing high concentrations of salts of rare metals, including lithium, in the area of the bottom of the former sea.

The work investigated the effect of modification of the 1Н/2Н isotopic composition of the medium on the growth of biomass and respiratory activity of the bacterial culture Shewanella oneidensis MR-1. An experimental study of the theory of isotope resonance by R.A. Zubarev was carried out. The growth of cultures in the incubation medium was assessed by measuring optical density using a Thermo Scientific Multiskan FC multiplate photometer. To determine the optical density, a Multiscan FC photometer for ELISA studies in microplates was used. The determination of the deuterium concentration in the resulting medium was carried out using a JEOL JNM-ECA 400MHz pulsed NMR spectrometer. It was found that groups with 2H contents of 150, 350 and 370 ppm demonstrated positive trends in both biomass growth and CO2 emissions (p < 0.05). At a 2H level of 200 ppm throughout the experiment, CO2 emissions were slightly less than in all control groups, with the exception of measurements after 14 hours. It has been established that a change in the natural ratio of isotopes in some structural components of living systems is accompanied by a modification of some mechanisms of biochemical reactions in biological objects, which is due to, for example, compartmentalization and, in general, this can lead to faster adaptation under the influence of various stress factors. The obtained results can be explained by the presence of a phenomenon known as “isotope shock” which can be realized through the formation of an isotope gradient that stimulates the work of the nonspecific defense system, leading to the accumulation of biologically active protective factors in the body.

In September 2023, during phytopathological surveys in Mariupol, Donetsk and Berdyansk, foci of quarantine pest the brown marmorated stink bug Halyomorpha halys (Stål, 1855) (Hemiptera: Pentatomidae) were registered for the first time. Despite long-term monitoring research, which we began in 2017 and covering both natural and anthropogenically transformed ecosystems of the region, the pest was found exceptionally in urban plantings, which indicates the leading role of unintentional introduction in its spread. The high density of populations suggests that the species entered the region 2–3 years ago. Detection of naturalized populations of the pest in Donetsk People’s Republic and Zaporozhye region indicates the completion of the process of H. halys expansion in Azov-Black Sea region and the continuing outspread of its range in the northern direction. Findings of older instar larvae and young uncolored imagoes in the second decade of September confirm the development of at least two generations of the bug during the vegetation period in the Northern Azov region. The largest aggregations of larvae and imagoes were registered in urban plantings of Mariupol on southern catalpa Catalpa bignonioides Walter. The appearance and naturalization in the region of a new polyphytophagous pest, capable of feeding on more than 300 plant species from 75 families, requires organizing monitoring of the state of its population and a detailed study of biology in order to develop effective methods of its control. An important area of work at the current stage of pest invasion is conducting an information campaign among agricultural producers.

The article provides data on the new wintering site of the greylag goose Anser anser (Linnaeus, 1758), nesting in Western Manych (Veselovskу water storage reservoir: 47°06′N, 40°54′E), registered in Crimea in 2023. Recording the position of geese during wintering outside the breeding area was confirmed by marking the geese with metal rings, colored collars (yellow, numbers RXXX) and GPS-GSM transmitters (ECOTONE). Greylag geese wintered from 2015 to 2022 only in Ciscaucasia reservoirs: Krasnodar, Varnavinskoe, Kryukovskoe water storage reservoirs, Kuban and Primorsko-Akhtarsk floodplains, 240‒300 km from the breeding area. For the first time, the wintering of 2022/2023 of the “Veselovskaya” population of greylag geese was registered on the inland waters of the Kerch Peninsula (Crimea) 475 km from the place of “birth” based on the localization of the goose marked with a transmitter. A hypothesis has been put forward that the emergence of a new wintering area is associated with an increase in hunting pressure on the gray goose in the Ciscaucasia. In 2021, the greylag goose was included in the Red Book of the Russian Federation (29 administrative regions, including the Republic of Crimea). The exception was the south of European Russia, including the Krasnodar Region, where the greylag goose from the Western Manych population winters. Hunting for greylag goose has shifted from other regions to the south of European Russia. Almost simultaneously with the inclusion of the greylag goose in the Red Book of the Russian Federation, the terms of the autumn hunt, which ended on December 31 in previous years, were extended until January 20, which increased the impact on the wintering group. About a third of the tagged greylag geese returned were taken in the Krasnodar Region in January. Thus, the movement of part of the wintering greylag goose group to the Kerch Peninsula into a “protected zone” will allow it to survive in conditions of increasing hunting pressure. Probably, the creation of a protected area in the Eastern Azov region will help preserve the greylag goose in Russia.