Nauka Yuga Rossii

This paper investigates the excitation of acoustic waves on the surface of a ferroelectric heterostructure consisting of a 1000 nm thick industrial-cut lithium niobate wafer deposited through a fused silica interlayer onto an (001) cut а-sapphire substrate. Horizontally polarized shear waves are considered as the object of study. The electromechanical coupling coefficient is used as a parameter characterizing the efficiency of surface acoustic wave excitation. Lithium niobate wafers of various cuts were used to study the efficiency of surface wave excitation in the ferroelectric heterostructure. The optimal orientations of lithium niobate plate cuts for excitation of shear waves with the maximum electromechanical coupling coefficient, as well as the geometric parameters of the heterostructure elements, were determined. With a decrease in the thickness of the piezoactive layer, the presence of a fused silica interlayer leads to an increase in the electromechanical coupling coefficient.

The materials based on BiCoxFe1 − xO3 and BiCuxFe1 − xO3 solid solutions at concentrations of x = 0.00–0.15 were fabricated using common ceramic technology. X-ray diffraction, microstructural, and spectral studies of their structure, grain composition, and properties were carried out. X-ray diffraction analysis revealed that copper and cobalt substitutions have different effects on structure formation. In ceramics with Co substitution, sillenite Bi25FeO40 acts as an impurity phase, while in ceramics with Cu substitution, mullite Bi2Fe4O9 acts as an impurity phase, with its amount exceeding the perovskite phase at x = 0.15. Microstructural analysis revealed that cleavages for all samples occurred predominantly along grain boundaries, and the grains themselves had a prismatic shape. Based on the analysis of the cleavage surfaces of the studied solid solution systems, it can be assumed that the kinetics of their grain formation processes also differ. The cleavage surface of BiCu0.15Fe0.85O3 is the most heterogeneous, presumably with traces of secondary recrystallization. Based on the statistical analysis of the grain sizes, it can be concluded that an increase in the cobalt concentration leads to monotonic grain growth, and the ceramics, unlike BiCuxFe1 − xO3 solid solutions, are homogeneous. Studies of the Raman spectra at room temperature and the dielectric characteristics at T = −190... 200 °C confirmed the results of X-ray phase analysis. Due to local changes in the crystal structure of BFO with the introduction of Co and Cu ions up to 15 mol.%, the Raman spectra are significantly transformed in the spectral range of 250–900 cm−1, new modes appear, and the ratios of their intensities change (relative to pure BFO). The temperature dependences of ε(T) and tgδ(T) show a decrease in the permittivity and dielectric loss tangent. With increasing Co concentration, both the threshold temperature for the sharp increase in ε(T) and the maxima of tanδ(T) shift toward higher temperatures. The introduction of Cu ions leads to the emergence of additional anomalies (humps or maxima).

At numerically modeling processes, it becomes necessary to solve systems of linear algebraic equations (SLAE) of large dimension. The operational solution of large-scale SLAE requires significant computing performance, for which multiprocessor computing systems are used. The features of the design of computing systems with traditional architecture are such that performance growth slows down significantly and may even decrease after reaching a critical number of processors. This is due to the fact that the organization of parallel calculations requires more time than the actual calculations. Various iterative methods are used to accelerate the SLAE solution. However, the following feature is typical for all of them - the calculation of the k-th approximation of the vector of unknowns is based on the values obtained in the previous iteration. An alternative approach to accelerate calculations is to use more advanced fast computing algorithms that can significantly speed up calculations by recursively splitting the input sequence into two equal parts. For iterative methods in general and for the Jacobi method in particular, the bisection method has not been used before, since the programming of computing systems with traditional architecture uses a procedural computing paradigm, which implies a consistent description of the operations of the performed algorithm. At the structural approach to the organization of calculations, it becomes possible to implement the entire information graph of the task, which makes it possible to optimize the algorithm. The paper covers the possibility of using bisection to modify the information graph of the Jacobi method. For the one-dimensional case of the fast Jacobi method estimates of computational and time costs are given. The approach for extending the bisection method for two-dimensional and three-dimensional problems is also described. The use of bisection in combination with a structural approach to computing organization makes it possible to achieve a significant increase in the performance of computing systems when solving SLAE using the Jacobi method, as well as to obtain an acceleration of 3.5 times compared to the classical method.

In recent decades, the water supply problem for the Volga, the Caspian Sea, and the Don River has increased dramatically. The Volga runoff in 2021-2023 amounted to only 211.1-218.8 km3, with a longterm average of 250 km3, and the Caspian Sea level dropped to -29 m, with an average of -27.5 m. The causes of water shortages are natural, climatic, and are also determined by solar activity. Economic activity has a significant impact: regulation of river flow, withdrawal of water resources for irrigation of agricultural land, industrial and municipal needs, etc. The main factors affecting the sea level are the amount of river runoff and the volume of evaporation from its surface. Unfavorable hydrological conditions have led to a deterioration in the basin’s ecological status and are hindering the development of economic sectors and the creation of a North-South logistics corridor. In the Volga and Don rivers, there is a shortage of high-quality water supplies, and conditions for aquatic life and navigation have worsened. The sea’s ecosystem is disrupted, the salinity regime changes, fish nurseries and food sources are reduced. Shallow waters prevent ships from entering ports and disrupt the operations of coastal businesses. During low-water periods of 20-35 years, the only measure to replenish the water deficit of the Volga and the Don and maintain the level of the Caspian Sea is the donor transfer of 50-60 km3 of the northern rivers’ flow into the Volga with the diversion of 5-6 km3 to the Don. Based on an analysis of data from long-term monitoring studies, the causes of ongoing environmental changes in the Caspian basin are presented and the ways to improve the hydrological regime of the Volga are considered. Instead of the previously rejected project, it is proposed to search for new options for water transfer by taking water from the pre-estuary sections of rivers using modern technologies, without creating reservoirs. This will address a range of issues related to improving the basin's ecology and developing the region’s economy, as well as reducing the flow of northern rivers into the seas, which flood their coastlines. An analysis of other measures has shown that they do not fully address the water shortage problem. At the same time, it is necessary to implement water-saving technologies in agriculture and industry and implement the government’s “Volga Recovery” program.

The problem of drinking water quality occurs both in economically highly developed countries, as well as in developing countries and in countries with economies in transition. Unlike centralized water supply systems, insufficient attention is paid to assessing the water quality of decentralized sources.The purpose of the work is the hydroecological assessment of water quality from decentralized household and drinking water supply sources and health risks for the population of the Lipetsk Region caused by drinking water from these sources.From April 2025 to February 2026, 119 samples of water from decentralized water sources (springs, wells, individual wells, columns) were collected during field studies. Five organoleptic parameters (odor, taste, color, transparency, presence of sediment) and 12 indicators characterizing the chemical composition were determined, including 6 indicators that are of priority for Lipetsk water (ammonium and nitrate nitrogen, boron, iron, manganese, and total hardness).The results of the chemical analysis revealed that the majority of water samples did not meet hygienic standards for nitrates (20.17%), hardness salts (17.64%), ammonium nitrogen (13.45%), boron (12.6%), and iron (8.4%). Taking into account the dose approach, it is shown that when drinking water from decentralized sources, the health risk of the population living in a number of separate rural territories (about 3.21 thousand people) is classified as alarming by two indicators - nitrates and total hardness.Based on the results of the study, recommendations are given to increase the level of safety of drinking water from decentralized sources in the Lipetsk Region.

The article presents the results of a comprehensive study of the Ancient and New Azov deposits of the Sea of Azov using diatom, malacological, and pollen analysis methods. Samples for studying different stratigraphic groups (diatoms, mollusks, pollen, and spores) were synchronously selected from the same horizons of column K-59.19 and supplemented with the results of radiocarbon dating. According to the results of the diatom analysis, the boundary between the Ancient and New Azov layers can be traced at the turn of 3.4-3.2 thousand BP. The key species of the Ancient Azov complex of diatoms, consisting of marine genera and species (Coscinodiscus, Chaetoceros, Thalassiosira eccentrica, Paralia sulcata, etc.), are described. For the New Azov deposits, an alternation of layers is noted, in which Actinocyclus octonarius var. ralfsii, Actinoptychus senarius, Thalassiosira decipiens and spores of Chaetoceros alternately dominate.Two taxa (Actinocyclus octonarius var. tonsura and A. pseudopodolicus) are considered as markers for the New Azov deposits. According to the results of the malacological analysis, the boundary between the Ancient and New Azov layers is marked later (at the turn of about 3.1—2.8 thousand years BP). The complex of leading species in the Ancient Azov layers is represented by marine mollusks Abra prismatica, Bittium reticulatum and numerous Rissoidae. In the New Azov layers, the role of euryhaline Hydrobia acuta and Cerastoderma glaucum increases in the malacocenosis, indicating a decrease in salinity and a decrease in hydrodynamic activity at this time. The periods of the driest conditions identified according to the data of the pollen analysis coincide with the phases of regressions (Phanagoria and Korsun), which can be traced by the materials of the diatom and malacological analyses. The results presented in the article show that column K-59.19 can be considered as one of the reference columns for comparing stratigraphic materials from other cores sampled in the Sea of Azov.

An introduction experiment to study the biology (from seed to seed) of Allium makleanii J.G. Baker was conducted in the Botanical Garden-Institute (Ufa, Republic of Bashkortostan) during 2018-2024. Allium makleanii is endemic to the Pamir-Alai region. The seeds were sown in the ground before winter in 2017. The pre-generative period lasted 5-6 years. According to phenological indicators, A. makleanii belongs to the group of ephemeroid plants with a short growing season: it grows in the first half of April, blooms in late May-mid-June, and the seeds ripen in July. It blooms for 11 days on average. Its vegetation period lasts 95 days on average. In young generative plants, the average height is 74.04 ± 9.29 cm, the inflorescence diameter is 6.44 ± 0.71 cm. This species at a young generative age is characterized by stable satisfactory real seed productivity: flowers 108.50 ± 28.17 pcs., fruits 82.33 ± 6.25 pcs., real seed productivity 341.52 ± 102.69 pcs., potential seed productivity 1084.97 ± 281.66 pcs. (real seed productivity is 3.2 times lower than potential), seeds in fruit 4.05 ± 0.19 pcs. The seed productivity realization coefficient is 30.6%. Reproduction is by seed,the weight of 1000 seeds is 3.8 g. Biochemical composition of leaves: ascorbic acid 210.4 mg%, carotene 12 mg/kg, dry matter 19.2%, sugar 3.2%, fat 0.31%, nitrogen 0.17%, potassium 0.25%, phosphorus 0.14%, calcium 0.04%, zinc 1 mg/kg, manganese 0.27 mg/kg, copper 0.36 mg/kg, cobalt 0.004 mg/kg (in raw matter). Allium makleanii characterized itself as a promising plant (total introduction success points 17).

The results of the expeditionary research conducted on the territory of the Donetsk People’s Republic, Lugansk People’s Republic and Zaporozhye Region are presented. Seventy four old-age trees have been identified, representing potentially valuable objects of the natural heritage of Novorossiya and Donbass. These unique specimens require special protection and urgently need to be included in the system of environmental protection measures of the Russian Federation. Among the surveyed forest ecosystems, only 7% are outstanding century - old oaks between 151 and 200 years old, and only 5 % are trees over 200 years old. As of 2025, the age limit for Quercus robur L. has been set in various locations: in Donetsk - 140-145 years (Putilovskiy forest); in the DPR - 313 years (Gornyatskiy Oak) and 182 years (Velikoanadolskiy Forest); in the LPR - 150-200 years (Kondrashevskiy Nature Reserve); in the Zaporozhye Region - 350-400 years (Melitopol District, village of Mayskoe and Melitopol, Railway Workers’ Park) and 150 years (Staroberdyanskoe Forestry). The viability of all the old-age trees studied was estimated at an average of 2 points, which corresponds to a good condition. At the same time, a number of damages have been identified that reduce the viability of plants. These damages are classified into two groups: those caused by military operations and those caused by environmental factors. Old-growth trees, despite their high mechanical stability, are at risk of trunk and branch breakage in the following situations: precipitation and ice formation, simultaneous exposure to dynamic factors (reducing critical load by 20 %), temperature fluctuations (have a critical effect on the modulus of elasticity of wood), increasing the risk of irreversible deformations of plant organs, with the significant development of putrefactive processes (especially core stem rot), damage to the root system or damage caused by fragments of explosive devices.

The conservation and reproduction of valuable and endangered fish species, in particular sturgeon, is an important task of modern fish farming. Sterlet Acipenser ruthenus Linnaeus, 1758 populations in Russia are on the verge of extinction, despite compensatory measures for artificial reproduction. When producing offspring in fish farms, it is very important to maintain genetic diversity by eliminating inbreeding. For this purpose, it is advisable to use samples of seminal fluid from a cryobank. The purpose of the research was to obtain viable sterlet fry using cryopreserved sperm and to evaluate its size and weight characteristics in comparison with offspring obtained by the traditional method. Native eggs, native and cryopreserved milt (stored in a cryobank in 2015) of sterlet were used for the research. During the embryonic and postembryonic periods of development, no deviations or anomalies were detected in the control and experimental groups. The yield of fingerlings from eggs laid for incubation was 45% in the control group and 40% in the experiment. During the early stages of larval rearing, mass accumulation and linear growth occurred equally, but after 15 days, faster growth was observed in the offspring obtained from cryopreserved sperm. It has been established that cryopreserved offspring have a higher growth rate and mass accumulation. The average daily growth rate of sterlet fry is 0.19 g in the control and 0.25 g in the experiment. This allows us to recommend fertilization of sterlet eggs with defrosted milt for artificial reproduction in conditions of deficit and untimely maturation of breeders in fish farms.

In 2024-2025, the fate of 147 nests of 7 bird species was traced in the Voronezh Nature Reserve using automatic camera traps: 68 nests of the song thrush Turdus philomelos, 35 nests of the common blackbird T merula, 21 nests of the Eurasian chaffinch Fringilla coelebs, 20 nests of the Eurasian blackcap Sylvia atricapilla, one nest each of the garden warbler S. borin, the hawfinch Coccothraustes coccothraustes and the common chiffchaff Phylloscopus collybita. Predators destroyed the 85 nests (57.8%), in 48 cases (56.5%) they were identified, these were 10 species of mammals and birds: the forest dormouse Dryomys nitedula, the European pine marten Martes martes, the bank vole Myodes glareolus, the red squirrel Sciurus vulgaris, the cat Felis catus, the hooded crow Corvus cornix, the tawny owl Strix aluco, the European honey buzzard Pernis apivorus, the Eurasian jay Garrulus glandarius, the great spotted woodpecker Dendrocopos major. The European honey buzzard destroyed 12% of the nests: two nests each for the common blackbird and the Eurasian chaffinch, and one nest each for the Eurasian blackcap and the hawfinch. It mainly attacked nests with nestlings, eating them on the spot or carrying them away. The nests were destroyed between May 14 and June 1, when the European honey buzzard is just beginning to breed, and most passerine birds are already feeding their nestlings. All the reported cases of predation were committed by males. The European honey buzzard actively searches for bird nests, just as it finds the nests of hymenopteran insects.