bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Hydrodynamics of Swirling Flows in Direct-Flow Cyclones
Authors: Toptalov V. S. , Chesnokov Yu. G. , Flisyuk O. M. , Martsulevich N. A. , Likhachev I. G.
Published: April 2024

A mathematical model is presented that describes the movement of gas in a direct-flow cyclone. The equations of motion of the gas phase were solved and profiles for the tangential and axial components of gas velocity were derived based on them. The results obtained are compared with the results of numerical simulation. The latter was carried out in the FlowVision software using the SST turbulence model. Via numerical calculations the change in the tangential and axial components of the gas velocity was determined at distances of 110, 150, 200, and 250 mm from the plate turbulator, or cyclone swirler.
Impact of the Chelate Complex of Nitrilotris(methylenephosphonic Acid) with Copper on the Corrosion-Electrochemical Behavior of Carbon Steel in an Aqueous Medium
Authors: Zhilin I. A. , Chausov F. F. , Lomova N. V. , Kazantseva I. S. , Isupov N. Yu. , Averkiev I. K.
Published: April 2024

The effect of the Na4[CuN(CH2PO3)3]·13H2O complex compound with a chelate structure on the corrosion-electrochemical behavior of 20# steel in a borate buffer solution at pH 7.4 and natural aeration was studied using the potentiodynamic method and methods of X-ray photoelectron spectroscopy and surface scanning electron microscopy with microanalysis. It was established that in the concentration range of 0.2–1.0 mM the complex under study inhibits the anodic dissolution of the metal and drives it at higher concentrations. In terms of its effect on the corrosion-electrochemical behavior of steel, the Na4[CuN(CH2PO3)3]·13H2O complex differs significantly from the previously studied complexes Na4[ZnN(CH2PO3)3]·13H2O and Na4[Cd(H2O)N(CH2PO3)3]·7H2O. In the potential range –0.66…–0.05 V relative to the Ag,AgCl|KCl-electrode (SSCE) a layer of metallic copper is generated on the surface in the form of nano-sized crystals, shielding the surface of the steel. In the potential range of 0.05–0.13 V (SSCE), metallic copper is oxidized, and with a further increase in the potential, a layer of mixed iron and copper oxides is formed.
Intermolecular Interactions of Cefotaxime with Sodium Alginate Biopolymer in Aqueous Solutions
Authors: Mirgaleev G. M. , Shilova S. V. , Barabanov V. P.
Published: April 2024

The complexation of cefotaxime with an anionic polysaccharide, sodium alginate, in aqueous solutions with different pH values was studied by conductometry and by UV and IR spectroscopy. The compositions and stability constants of the complexes were determined. At pH 2.0, 5.6, and 7.2, the composition of the complex of cefotaxime with alginate corresponds to the [cefotaxime] : [alginate] molar ratio of 4.0 : 1.0, 2.3 : 1.0, and 1.0 : 1.0, respectively. The cefotaxime–alginate complex is most stable in strongly acidic media.
Preparation of a Structural Polyimide Foam Plastic Based on a Bulk Copolymer of Acrylonitrile and Methacrylic Acid
Authors: Safonov A. N. , Kornienko P. V. , Shirshin K. V.
Published: April 2024

Foaming of particles of acrylonitrile–methacrylic acid copolymer in the temperature interval 160–220°С was studied. As shown by IR spectroscopy, the final polymer matrix of the foam plastics consists of glutarimide fragments. Thermogravimetric analysis shows that the products start to degrade at a high temperature (about 350°С). The effect of the prolonged heat treatment at 150–190°С on the physicomechanical characteristics of the foamed plastics was examined.
Effect of Silica Nanofiller on Thermal-Oxidative Degradation of Epoxy Composites Synthesized by the Sol-Gel Method
Authors: Mogila T. N. , Mikhal'chuk V. M. , Lyga R. I. , Glazunova V. A.
Published: April 2024

Using the sol-gel method, amine-curing polymer silica composites based on cycloaliphatic epoxy resin were obtained. The content of SiO2 filler in the composites was 0.5–10 wt %. The formed mass fractal of silica nanoparticles during the synthesis of composites has a reinforcing effect on the epoxy polymer matrix. The patterns of non-isothermal destruction of polymers and composites in the presence of atmospheric oxygen have been established. At 5 wt % SiO2, the effective activation energy of the main stage of destruction of composites increases from 165 to 254 kJ mol–1. As a result, the rate of weight loss of the samples decreases (the temperature corresponding to 50% weight loss shifts towards higher values by 30°C). The mechanism of high-temperature oxidation of pure polymer and composite with oxygen has been studied. It has been established that the introduction of SiO2 into the composition of composites increases the activation energy of isothermal oxidation of the substrate.
POPULATION DENSITY OF RESIDENT AND NON-RESIDENT FOREST SMALL MAMMALS
Authors: Kalinin A. A.
Published: April 2024

When assessing the abundance of small mammals using traditional methods, an abundance index, the number of individuals per unit of trapping effort, is usually applied. Due to the different relationships of species to various traps and baits, the true ratio of species in nature may not coincide with the estimated one. In most cases, the presence of a non-resident component in the population size remains outside the attention of researchers, while dispersal is a key element for many demographic processes. A method is proposed for calculating the density (individuals per area) of resident and non-resident animals when using mark-recapture live-traps arranged in lines. For three mass species of small forest mammals (red-backed voles, common shrew and masked shrew), the dynamics of the density of the resident and non-resident population were studied over 18 years. In most cases, the red-backed vole dominated the population of small mammals. According to long-term average data, the proportion of non-resident individuals in the population of the three species did not differ, averaging 12.6% of the total density. The dependence of the level of non-resident activity in the red-backed vole on the density of resident animals was shown. In shrews, the density of non-residents did not depend on the density of resident ones. The technique allows for a wide range of ecological problems to be solved and it can be used to monitor the state and structure of communities of small mammals.
FORAGING BEHAVIOUR OF THE RED-NECKED STINT (CALIDRIS RUFICOLLIS, SCOLOPACIDAE, CHARADRIIFORMES) DURING THE AUTUMN MIGRATION AT VARIOUS LOCALITIES OF THE RUSSIAN PACIFIC COAST
Authors: Vinogradov A. A. , Rezanov A. G.
Published: April 2024

The foraging behaviour of the Red-necked stint (Calidris ruficollis, Scolopacidae, Charadriiformes) was analyzed in detail. The observations were carried out by the authors on the coasts of the Sea of Okhotsk near Magadan and Ola (August 2010), and on Urup Island, Kuriles (August-September 2021, as part of the complex expedition of the second field season “Eastern Bastion – Kuril Ridge”, organized jointly by the Expeditionary Center of the Ministry of Defense of the Russian Federation and the Russian Geographical Society. The diversity of stint species-specific feeding techniques was assessed, and their list compiled, based on a digital coding system. A schematic presentation of the foraging strategies of the Red-necked stint has been proposed.
DISCOVERY OF ALIEN INVADERS IN THE GALLS OF THE DRYOCOSMUS KURIPHILUS HALTWORK (HYMENOPTERA, CYNIPIDAE) IN THE NORTHERN CAUCASUS
Authors: Gninenko Yu. I. , Gninenko A. Yu. , Chilakhsaeva E. A. , Chernova U. A.
Published: April 2024

The Eastern chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu 1951, after having appeared in forests with the participation of the common chestnut in Russia, soon began to cause significant damage. The study of its biology revealed the presence of several insects in its galls, which use them as a new habitat. In fact, the use of galls by alien inhabitants of local chestnut consumers new to aboriginal forest communities has started. The role of these consumers for the eastern chestnut gall washer is currently unknown.
ON THE RISKS OF SIBERIAN CRANE (LEUCOGERANUS LEUCOGERANUS PALLAS 1773, GRUIDAE, GRUIFORMES) REINTRODUCTION
Authors: Ilyashenko V. Yu.
Published: April 2024

The reintroduction of Siberian Cranes reared from the Oka Crane Breeding Center of the Oka State Nature Reserve goes on for 30 years. During this time, 47 eggs were placed into Eurasian Crane nests, and 190 juveniles were released into the wild, including 57 in Eurasian Crane staging areas. In order to optimize the methods of captive breeding and to mitigate the risks for releasing Siberian Cranes, it is necessary to take into account the results of the reintroduction of Whooping and Red-crowned cranes, as well as the features of Eurasian Crane biology.
MARINE MAMMALS: MORPHOMETRIC PARAMETERS OF ERYTHROCYTES
Authors: Seliverstova T. V.
Published: April 2024

Morphological and morphometric parameters of erythrocytes (size, shape and color) were studied in five species of marine mammals. A comparative assessment of oxygen reserves in the blood of the Harp (Pagophilus groenlandicus (Erxleben 1777)) and in Grey seal (Halichoerus grypus (Fabricius 1791)) puppies during adaptations to the aquatic environment, as well as of Bottlenose dolphins during the period of adaptation to captivity conditions is given. Morphometric parameters of red blood cells has been established to vary depending on the age, habitat conditions and phylogenetic position of the animals.
FROM AN AGROPHILE TO A SYNURBIST: HOW THE COMMON HAMSTER (CRICETUS CRICETUS) IS SETTLING INTO THE URBAN ENVIRONMENT
Authors: Surov A. V. , Karmanova T. N. , Zaitseva E. A. , Katsman Е. A. , Feoktistova N. Yu.
Published: April 2024

In this review, using our own and published data, we discuss the processes that occur in populations of small mammals when they adapt to and master the urban environment, using the common hamster as an example. Originally, the common hamster was apparently associated with the forest-steppe zone, but with the development of agriculture, it became an agrophile, populating the outskirts of fields, which provided it with a good food base throughout the year. Changes in farming culture (fragmentary fields replaced with vast areas of arable land occupied by monocultures, the use of poisons and fertilizers) led to a shift in the ecological optimum of the species to areas occupied by gardens, kitchen gardens and urban ecosystems. This led to changes in the genetic structure of populations, a greater (compared to suburbs) diversity of alleles of the major histocompatibility complex responsible for resistance to pathogens, a reduced hibernation period up to its complete abandonment, and a reduced aggressiveness to conspecifics which allows for more burrows to be arranged in a limited space and for general food storages to be shared and consumed. The use of food wastes as an additional food resource by this species may have led to changes in its digestive and other systems. All of this has allowed the common hamster to successfully exist in an urbanized environment, despite the reduction in life expectancy due to many stressors (parasitic load, pollution etc.). It is assumed that not all of the above traits have been formed in the process of synurbization. Many adaptations acquired earlier, before urbanization, proved to be effective in its development of the urban environment. Obviously, the path taken by the common hamster from a non-commensal species to an agrophile, and finally a synurbist is not unique; many other species of mammals and birds have passed or are on this evolutionary path at the present time.
PARASITIODS (HYMENOPTERA, EULOPHIDAE, BRACONIDAE) AS A MORTALITY FACTOR FOR THE LIME LEAF MINER (PHYLLONORYCTER ISSIKII, LEPIDOPTERA, GRACILLARIIDAE) IN TRANS-URALIA AND WESTERN SIBERIA
Authors: Ermolaev I. V. , Yefremova Z. A. , Belokobylskij S. A. , Tyul’kin Yu. A. , Yegorenkova E. N.
Published: April 2024

The assemblage of hymenopteran parasitoids associated with the invasive lime leaf miner, Phyllonorycter issikii (Lepidoptera, Gracillariidae) developing on the lime (Tilia cordata) was studied in the Kurgan Province (Madvezh’ye Lake), and in the cities of Tobolsk, Omsk, and Novosibirsk during 2018−2019. Twenty-one species of parasitoids of Ph. issikii were recognized: Pteromalus sp. (Pteromalidae), Cirrospilus diallus, Elachertus sp., Hyssopus geniculatus, H. nigritulus, Pnigalio mediterraneus, Pnigalio sp., Sympiesis dolichogaster, S. gordius, S. sericeicornis, Chrysocharis laomedon, Ch. pentheus, Ch. pubicornis, Ch. viridis, Chrysocharis sp., Neochrysocharis formosus, Minotetrastichus frontalis (Eulophidae), Colastes braconius, Apanteles sp., Pholetesor circumscriptus and Cotesia sp., (Braconidae). Chrysocharis viridis has been reported as a parasitoid of lime leaf miner for the first time. The role of the complex of parasitoids in the mortality of the miner is negligible, the mortality rate ranging from 1.9 ± 0.4 (Novosibirsk) to 23.7 ± 3.3% (Omsk).
DENTAL VARIATION IN AN INVASIVE SPECIES AT THE DISPERSAL STAGE: MICROTUS ROSSIAEMERIDIONALIS (ARVICOLINAE, RODENTIA) IN THE IRKUTSK OBLAST’, SOUTHERN CIS-BAIKAL REGION
Authors: Markova E. A. , Borisov S. A. , Zykov S. V. , Sibiryakov P. A. , Yalkovskaya L. E. , Bulycheva S. V.
Published: April 2024

The East European vole is a facultative synanthropic species that actively spreads in the eastern part of northern Eurasia. The distribution area of the species in the Irkutsk Oblast’ has been known as a disjunct part of the range since the 1980s. Our dataset includes 98 individuals caught in 2016–2017 and 2021–2023 in the eastern segment of the species’ dispersal area, where the East European vole was first discovered in the early 2010s. Animals were caught in anthropogenically transformed areas spanning from the outskirts of the city of Irkutsk to kilometer 23 of the Goloustnensky Tract; trapping in natural biotopes revealed no M. rossiaemeridionalis. Species identification was based on molecular genetic markers. Morphological and fine structural characteristics of molar teeth were studied using both light and scanning electron microscopy. The complexity of the occlusal surface, the alternation patterns of the enamel cutting edges (occlusal regularity), and the presence or absence of atypical extra elements such as prismatic folds and prisms in places of the early cricetid dental features were assessed. The estimates of complexity and regularity patterns fell within the range of dental variability known for the continuous distribution area of the species. The atypical extra elements on molars were described for the first time in M. rossiaemeridionalis based on material coming from two trapping sites. The extra elements were confined to the posterior lobes of the lower molars, where an additional reentrant angle separated an extra prism in place of a hypoconid. Enamel walls of the extra prism showed an inversion of the enamel types (a thin layer of radial enamel on the anterior wall and a thick layer of lamellar plus radial enamel on the posterior wall) that was contrary to the evolutionary patterns and functional requirements known for Microtus. The local micropopulation studied is concluded to show phenotypic consequences of a reduced number of founders. Apparently, the species could have faced sequential establishment events in the study area. Our results indicate that dental features are useful for monitoring the arvicoline species, the distribution limits of which are subject to significant spatial changes in the relatively short time intervals available for observation.
ANALYSES OF THE AVIFAUNA AND BIRD POPULATIONS OF THE ISLAND OF ITURUP, GREAT KURIL ISLANDS
Authors: Romanov A. A. , Koblik E. A. , Smirnov P. A. , Vinogradov A. A. , Red’kin Ya. A. , Zhigir D. R.
Published: April 2024

Ecological patterns in the formation of the avifauna and bird populations of the Iturup Island were analyzed. Route counts were used along transects of unlimited width. As many as 116 bird species were registered, including 36% revealed to be ubiquitous, another 34% local and further 26% highly local. 71 species were shown to nest. The taxonomic structure of the avifauna, represented by species from 15 orders, corresponded to the zonal and landscape features of the island’s territories located at the eastern margins of northern Eurasia. Passeriformes (37%), Charadriiformes (22%), Anseriformes (9%), Procellariiformes (8%) prevailed. The zoogeographic peculiarity of the local avifauna was a combination of elements of the Far Eastern island, Pacific, Siberian and Chinese faunistic complexes, some Siberian-American and widespread species, as well as Japanese island endemics. The avifauna around the Iturup Island, formed by a system of general zonal-landscape and altitudinal-belt patterns, united ecological groups of marine and land species, including montane ones (n = 9). Local avifauna in coastal marine habitats included 41 species, vs 55 in forests, 37 in light forests, and 46 in tall grasses, the population density being 607, 785, 968, 518 individuals/km2, respectively. The similarity coefficients for the populations of forest habitats were 19–48%, vs 22% for light forests, 20–37% for tall grasses, while in the sea coast and adjacent water areas they amounted to 21–52%. The populations of terrestrial habitats were dominated by the Oriental Turtle-dove, the Pacific Swift, the Siberian Rubythroat, the Japanese Bush-warbler, the Marsh Tit, the Coal Tit, the Eurasian Nutcracker, the Oriental Greenfinch, the Eurasian Siskin, the Long-tailed Rosefinch, the Masked Bunting, and the Grey Bunting. The populations of the coast and adjacent sea area were dominated by the Japanese Cormorant, the Rufous-necked Stint, the Slaty-backed Gull, the Black-tailed Gull, and the Black-backed Wagtail. In open sea areas, the most common were the White-winged Scoter, the Black-footed and Laysan albatrosses, the Northern Fulmar, and the Short-tailed Shearwater.
OCCURRENCE AND COASTAL MORTALITY OF CETACEANS ON THE ARCTIC COAST OF CHUKOTKA PENINSULA IN THE WATERS OF CAPE VANKAREM IN 2017–2021
Authors: Zargebelniy S. V.
Published: April 2024

Six species of cetaceans have been found to occur in the Chukchi Sea adjacent to the Pacific walrus rookery at Cape Vankarem: the Grey whale, the Bowhead whale, the Humpback whale, the Killer whale, the Beluga whale, and the Fin whale. The Humpback whale is noted to have become abundant in the Chukchi Sea in the summer in recent years. The coastal mortality of cetaceans in a 100-km section in the western part of the distribution range of both Gray and Bowhead whales has been established to average 1.66 and 0.3 whales per year, respectively. Mostly young animals of 1–2 years of age appear to die, the main cause of death of which being predation by killer whales. The most common whales in that area in the summer-autumn period are humpback whales, which at the same time form significant concentrations in the coastal waters during the accumulation of the main food items. Both bowhead and gray whales are much less frequent, also being rather irregular to be found, while despite the relative scarcity of encounters these species account for the lion’s share of all dead cetaceans.
ON SMALL CONTINENTAL MAMMOTHS AND DWARFISM
Authors: Kirillova I. V. , Markova E. A. , Panin A. V. , Van der Plicht J. , Titov V. V.
Published: April 2024

In the evolution of proboscideans, the appearance of dwarf and semi-dwarf forms occurred repeatedly, in different territories and at different times, due to a lack of resources caused by geographic isolation on islands and by landscape isolation on the mainland. Despite a significant amount of information on the insular forms of mammoths and elephants, the question of the relationship between a decrease in body size and morphological changes in the dental system remains a matter of debate. Some data show that dwarfism was accompanied by a decreasing number of plates (lophs) and by tooth enamel thickening. Other data show that changes in the dental system on the islands indicate that the number of plates could either decrease or remain unchanged, or even increase. Taking into account the importance of the number of plates as a diagnostic feature in the species identification of proboscidean taxa and the lack of a consensus on the stability of the trend towards a decrease in the number of plates from large continental ancestors to insular dwarf descendants, we (1) summarize the data on the records of small tooth-mammoths of the genus Mammuthus with a reduced number of plates in sites across northern Eurasia, (2) provide new radiocarbon dates, and (3) consider the number of plates as a possible sign of dwarfization in continental mammoths. The small teeth of the last generation of M. primigenius from the coastal part of northeastern Siberia and a comparison with data from other regions show that the posterior sections of mammoth cheek teeth are the most variable and represent a reduction complex. For the woolly mammoth, reduction primarily affects that part of the crown which became more complex by the gradually increasing number of plates during the phyletic evolution in the Middle to Late Pleistocene. The rapid loss of the evolutionary achievements through reduction is not a unique feature of woolly mammoth teeth. This has been observed in other mammals as well. Similar reduction complexes are observed for the cheek teeth of proboscideans and rodents of the subfamily Arvicolinae, as is shown by a decrease in the number of serially homologous crown elements: plates in proboscideans and pairs of prisms in voles. A comparison of the number of plates with the size of the teeth of M. primigenius suggests that a decrease in the number of dental plates, while retaining other specific features of the tooth, can be used as a criterion for separating semi-dwarf and small specimens of the woolly mammoth. The largest decrease in size of mainland mammoths is observed during warming periods, which also showed significant transformations of landscapes in a reduction of available resources.
THE FIRST DATA ON MICROTURBELLARIANS (PLATHELMINTHES, RHABDITOPHORA) OF THE BOGUCHANSKY RESERVOIR. 2. THE FAMILIES MACROSTOMIDAE, MICROSTOMIDAE AND PROVORTICIDAE, WITH THE DESCRIPTION OF BAICALELLIA NASONOVI SP. N.
Authors: Krivorotkin R. S. , Zaytseva E. P. , Timoshkin O. A.
Published: April 2024

This is the second contribution in series devoted to the study of the microturbellarian fauna (Plathelminthes, Rhabditophora) of the Boguchansky Reservoir, lower section of the Angara River, eastern Siberia. It provides information on the taxonomy, the structure of the male copulatory organ, and zoogeography of one species each from the families Provorticidae Beklemischev 1927, Macrostomidae Benden 1870, and Microstomidae Luther 1907. The faunas of these worms in the Angara River and Lake Baikal are still poorly studied. Three species from these families were recorded and described more than 90 years ago from the Angara River before our study, but the original descriptions were accompanied by highly schematic and non-informative sketches which do not allow us to perform exact species identifications and comparisons, as a rule. In the research process of the lower section of the Angara River, we found representatives of further three species: Macrostomum johni Young 1972, Microstomum rogozini Timoshkin et Krivorotkin 2023, and Baicalellia nasonovi Timoshkin et Krivorotkin, sp. n. The stylets of M. johni from the Angara River and Lake Baikal were revealed to be almost identical in structure and size to those of specimens of the type series from Great Britain. M. rogozini is one of the most common species of Microstomidae that inhabits the coastal zone of Lake Baikal. The stylet structure of Baicalellia species resembles that of Baicalellia baicali Nasonov 1930 and Baicalellia nigrofasciata Nasonov 1930, but their available descriptions do not allow us to make reliable comparisons with the species found. Therefore, we propose to consider both these names as nomina nuda and attribute those individuals to B. nasonovi, a species new to science. Despite rhe significant geographic isolation, the stylets of Baikal and Boguchan specimens are identical in structure and size. Similarly to Kalyptorhynchian species (see contribution 1), the discovery of provorticids and microstomids of Baikal origins in such a remote section of the Angara River considerably expands their distributions and demonstrates their capacities to colonize water bodies hydrographically connected to Lake Baikal. Illustrated descriptions of Boguchan and Baikal specimens of M. johni, M. rogozini and B. nasonovi, comparisons with the most similar species and zoogeographic information are given. In addition, a complete checklist of the Angara River microturbellarian fauna known so far, one currently including 35 species from nine families, is presented.
THE USHKAN’Y ISLANDS, LAKE BAIKAL, AND THEIR ROLE AND SIGNIFICANCE IN THE LIFE OF THE BAIKAL SEAL (PUSA SIBIRICA GMELIN 1788, PINNIPEDIA) IN MODERN CONDITIONS
Authors: Petrov E. A. , Kupchinsky A. B. , Syrovatsky A. A.
Published: April 2024

For the first time, a detailed description of the coastline of the Ushkan’y Islands, Lake Baikal is given in order to assess the use of the shore by the Baikal seal (Pusa sibirica Gm.) as haulouts, and the role these haulouts play in the annual cycle of seals. To do this, video material obtained using the DJI UAV Mavic 2 Zoom (take-off weight 905 g) and Air 2 S (take-off weight 595 g), as well as long-term field observations were used. A complete survey of the coastline of all four islands was carried out on May 29th and 30th, 2022 (at a water level of 456.40 m a.s.l.) and on August 12th and 24th (water level 456.79 and 456.83 m, respectively). Based on lithological characteristics, about 30% coastline on the Bolshoy Island, the largest one, is shown to be suitable for use by seals, but currently this is not the case. Among the three smaller islands, the most favorite place for the formation of seal haulouts is the Kruglyi Island, based on the total number of animals recorded on the island and in coastal waters, followed by the Tonkiy Island and then the Dolgiy Island, the latter supporting a stationary video system transmitting information online. On all islands, coordinates of specific haulout/rookery locations have been determined. Currently, about 35% length of the coastline of the three smaller Ushkan’y Islands are being used by seals for haulouts to one degree or another. Under current climatic conditions, the rookeries on the smaller Ushkan’y Islands seem to play extremely important roles for a significant part of the population (several thousand individuals visit them every season), since most other rookeries and locations that seals could use as such are highly susceptible to anthropogenic impacts.
Complexes R2Sn(IV)L with O,N,O'-Donor Schiff Bases: Synthesis, Structures, and Redox Properties
Authors: Smolyaninov I. V. , Burmistrova D. A. , Pomortseva N. P. , Voronina Yu. K. , Poddel’sky A. I. , Berberova N. T. , Eremenko I. L.
Published: April 2024

New tin(IV) complexes with O,N,O'-donor Schiff bases (L1H2–L4H2) of the (Ln)SnR2 type (R = Ph (I–III), Et (IV–VII)) are synthesized and characterized. The molecular structures of compounds I–III, VI, and VII in the crystalline form are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2181140 (I), 2181142 (II), 2181143 (III∙CH3CN), 2181141 (VI), and 2181139 (VII)). Tin complexes I–III and VI are mononuclear pentacoordinate compounds. Crystalline complex VII forms dimers via the pairwise bridging coupling between the oxygen and tin atoms of the mononuclear fragments. The redox-active ligand in the synthesized compounds exists as the iminobis(phenolate) dianion. The electrochemical properties of free ligands and complexes I–VII are studied. In the case of compounds I, II, IV, and V with tert-butyl substituents in the redox-active ligand, the formation of relatively stable monocationic and monoanionic species is electrochemically detected for the first time. The presence of the electroactive nitro group results in the destabilization of the oxidized forms of the complexes and induces the appearance of an additional peak in the cathodic range. The energy gaps between the frontier redox orbitals are determined by the electrochemical and spectral methods. The obtained parameters are close and vary in a range of 2.43–2.68 eV.
A Surprising Example of Crystal Structure Retention for 3,5-Di-(tert-butyl)-2-hydroxyazobenzene Ligand during the Formation of Ni(II) and Pd(II) Complexes
Authors: Aldoshin S. M. , Tkachev V. V. , Utenyshev A. N. , Bozhenko K. V.
Published: April 2024

The structures of 3,5-di-(tert-butyl)-2-hydroxyazobenzene (L) in the free state and in complexes with Ni2+ (I) and Pd2+ (II) cations are studied by X-ray diffraction (XRD). The same space group R3¯с with close unit cell parameters, the same crystal structure motif, and unusual conformations of the cupola-shaped coordination polyhedra of complexes I and II are revealed by XRD for ligand L. In complexes I and II based on this compound as the ligand, the coordinating atoms form trans-planar coordination nodes.
Halide Complexes [(2-Br-5-MePy)2ZnX2] (X = Cl, Br): Structure and Noncovalent Interactions in the Crystal Structure
Authors: Vershinin M. A. , Novikov A. S. , Adonin S. A.
Published: April 2024

The heteroligand complexes [(2-Br-5-MePy)2ZnX2] (X = Cl (I), Br (II)) were prepared by the reaction of zinc(II) chloride or bromide with 2-bromo-5-methylpyridine and studied by X-ray diffraction (CCDC nos. 2204966 (I) and 2204967 (II)). The crystals of I and II contain Cl···Br and Br···Br halogen bonds, which connect the [MX2L2] moieties into supramolecular chains. The energies of these noncovalent interactions were estimated using quantum chemical calculations.
Adducts of Sterically Hindered Tellurium Catecholate with Ethers
Authors: Petrov P. A.
Published: April 2024

Adducts of tellurium(IV) 3,6-di-tert-butyl catecholate (Te(Cat36)2) with 1,2-dimethoxyethane (Dme), bis(2-methoxy)ethyl ether (diglyme), and crown ether 18-crown-6 (18c6) ([Te(Cat36)2(Dme)]2 (I), [Te(Cat36)2(diglyme)] (II), and [Te2(Cat36)4(18c6)] (III), respectively) are synthesized and characterized by X-ray diffraction (XRD) (CIF files CCDC nos. 2208717 (I), 2208718 (II), and 2208719 (III)). The complexes are also characterized by NMR (1H, 125Te) and IR spectroscopy.
Ligand Metathesis in Nickel(II) Complexation with closo-Decaborate Anion
Authors: Avdeeva V. V. , Kubasov A. S. , Nikiforova S. E. , Goeva L. V. , Malinina E. A. , Kuznetsov N. T.
Published: April 2024

Nickel(II) complexation with the closo-decaborate anion in water and acetonitrile is studied. Complexes [Ni(solv)6][B10H10] (solv = H2O (I) or CH3CN (II)) are isolated. The complexes are characterized by elemental analysis and IR spectroscopy. Complex [Ni(CH3CN)5(H2O)]0.75[Ni(CH3CN)4(H2O)2]0.25[B10H10]·0.5H2O (III) is isolated from an acetonitrile–water system. The structure of complex III is solved by X-ray diffraction (XRD) (CIF file CCDС no. 2224702). A mechanism of ligand metathesis in the complexation of nickel(II) is proposed.
Copper(II) o-Iminophenolate Complexes Based on Catecholaldimines
Authors: Baryshnikova S. V. , Arsen’ev M. V. , Rumyantsev R. V. , Yakushev I. A. , Poddel’skii A. I.
Published: April 2024

The exchange reactions of 4,6-di-tert-butylpyrocatechols containing in position 3 different N‑aryliminomethyl groups (aryl is p-halophenyl; halogen is fluorine (I), chlorine (II), bromine (III), and iodine (IV); p-tolyl (V)) with copper(II) acetate in a molar ratio of 2 : 1 afford planar square copper(II) o‑iminophenolate complexes of the general formula [(R-CatH)2Cu], where R is the aryl substituent in the Ar–N=CH group. The molecular structures of complexes I, III, and V in the crystalline state are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2227448 (I), 2226727 (III), and 2227449 (V)). The electrochemical properties of compounds I–V are studied by cyclic voltammetry.
Thin Films of Cobalt(II) Clathrochelate for Molecular Spintronic Devices
Authors: Zlobin I. S. , Aisin R. R. , Sinel’nikov A. N. , Novikov V. V. , Nelyubina Yu. V.
Published: April 2024

The possibility of preparing thin films of cobalt(II) cage complex (clathrochelate) that undergoes a temperature-induced spin transition by thermal sublimation was demonstrated using UV spectroscopy. The films were more uniform and more thermally stable than the films formed by centrifugation of the solution on a substrate surface. In combination with scanning electron microscopy data, this revealed the dependence of the spin transition temperature on the method of film preparation and dependence of the supramolecular organization in the films on the substrate material, indicating that transition metal clathrochelates show the spinterface effect at the interface with a metal electrode. In addition to the possibility of controlling the magnetic properties of this unique class of coordination compounds by molecular design methods, this effect opens up broad opportunities for creating molecular spintronic devices with characteristics tailored for the researcher requirements.
Synthesis, Structure, and Properties of the Iron Nitrosyl Complex with 2-Ethyl-4-pyridinecarbothioamide
Authors: Sanina N. A. , Shilov G. V. , Ovanesyan N. S. , Mumyatova V. A. , Balakina A. A. , Terent’ev A. A. , Pokidova O. V. , Aldoshin S. M.
Published: April 2024

The synthesis and data on the physicochemical characteristics and biological activity of the newiron nitrosyl complex (Q+)2[Fe2(S2O3)2(NO)4]2– (I), where Q+ is protonated 2-ethyl-4-pyridinecarbothioamide(C8H11N2S), are presented. The structure and properties of the complex were studied by X-ray diffraction,elemental analysis, IR and Mössbauer spectroscopy, and amperometry. The complex showed antibacterialactivity and efficiently inhibited cyclic guanosine monophosphate phosphodiesterase (cGMP PDE),which may suggest its antihypertensive, anti-aggregation, and vasodilator activities.
Mixed-ligand complex [Cu4(bpy)4(PO4)2(CO3)(H2O)2]: synthesis, crystal structure and biological properties
Authors: Koshenskova K. A. , Makarenko N. V. , Baravikov D. E. , Dolgushin F. M. , Bekker O. B. , Eremenko I. L. , Lutsenko I. A.
Published: April 2024

The interaction in the system {Сu(OAc)2·H2O–phytic acid–2,2`-bipyridine (bpy)} in an aqueous-methanol solution led to the formation of a molecular mixed-ligand tetranuclear complex [(Cu4(bpy)4(PO4)2(CO3 )(H2O)2]13H2O (I), the structure of which was established based on the results of an X-ray diffraction experiment (CCDC 2262998). According to X-ray diffraction data, the molecule contains four nonequivalent Cu2+ cations, which coordinate two phosphate anions (PO43-, remaining as a result transformation of the phytate cycle), four neutral bpy, two water molecules and one carbonate anion fragment (CO32-). The presence of a large number of solvate water molecules in the outer coordination sphere created a hydrogen-bonded framework involved in the stabilization of the crystal packing. Study of antimycobacterial activity of I in against the non-pathogenic strain Mycolicibacterium smegmatis showed its high bioeffectiveness.
Template Synthesis of the Trinuclear Cobalt(III) Complex with Diarylimidazole-Based Ligands: Synthesis and Properties
Authors: Nikovskii I. A. , Karnaukh K. M. , Aliev T. M. , Polezhaev A. V. , Spiridonov K. A. , Dan’shina A. A. , Nelyubina Yu. V. , Novikov V. V.
Published: April 2024

The trinuclear cobalt(III) complex [(Bipy)5Co3(L)2](Cl)3 (I) is synthesized by the template reaction of 2,2'-(1H-imidazole-4,5-diyl)bis(4-ethylphenol) (L) and bis(2,2-bipyridine)cobalt(II) dichloride in the presence of diazabicycloundecene. The complex is isolated in the individual state and characterized by elemental analysis, cyclic voltammetry, UV-VIS spectroscopy, and X-ray diffraction (XRD) (CIF file СCDC no. 2201135). According to the obtained data, the cobalt ions in trinuclear complex I have the oxidation state +3, and the complex formation occurs with the oxidation of the initial cobalt(II) ions.
Forecasting of Gold-Silver Mineralization within the Pepenveem Ore Zone of the Chukchi Peninsula Based on Space Surveys of Resource, Canopus and ASTER
Authors: Milovsky G. A. , Kirsanov A. A. , Lipiyainen K. L. , Aparin A. D.
Published: April 2024

When deciphering the materials of space sensing of the eastern part of the Chukchi Peninsula on a scale of 1 : 50 000, structural elements of tectonic-volcanogenic genesis were revealed, represented by linear, arc, annular, zonal-concentric structural elements of various ranks. Ring structures with a diameter of up to 2 km and their dissecting disjunctiva mainly of the north-eastern and submeridional strike control the localization of gold mineralization of the Pepenveem ore-placer zone. On the basis of computer processing of the ASTER infrared satellite image in the Pepenveem zone, the areas of development of hydrothermally altered rocks (berezites, secondary quartzites, sericite-hydrosluidic-quartz metasomatites) genetically associated with mineralization were identified. The use of high-resolution satellite imagery in conjunction with geophysical data made it possible, on a scale of 1 : 10 000, to identify gold-prospective areas associated with volcanic dome structures, which are characterized by an increased density of lineaments and are associated with the formation of subvolcanic rhyolites.
Development of a Technique for Automatic Lineament Allocation Based on a Neural Network Approach
Authors: Grishkov G. A. , Nafigin I. O. , Ustinov S. A. , Petrov V. A. , Minaev V. A.
Published: April 2024

The purpose of the scientific work is to study the potential of neural network technologies in the field of extracting linear structures from digital terrain models SRTM. Linear structures, also known as lineaments, play an important role in the verification of known faults, the identification of fault-fracture structures, the detailing of the framework of discontinuous faults, as well as in the exploration of minerals. Their accurate and effective extraction in solving the designated tasks is of fundamental importance. The use of neural network technologies provides a number of advantages over sequential algorithms, including the ability to search for universal criteria for selecting lineaments based on a training sample. The paper considers a comprehensive innovative methodology that includes several key stages. The first stage is the author’s method of data preparation, which helps to ensure the quality of the training sample and minimize the impact of noise. The second stage is to develop an algorithm for vectorizing the results of the neural network, which allows you to easily export the results (lineaments) to a geographic information system (GIS). The third stage provides a method for minimizing the noise component of the training sample and optimizing the selection of synaptic weighting coefficients by retraining the neural network using simulated data reflecting various localization conditions of the lineaments. To verify the results obtained, a spatial comparison of linear structures extracted by a neural network and lineaments isolated by the operator was carried out. The results of this comparison demonstrate the high potential of the proposed approach and show that the use of neural network technologies is an actual and promising approach to solving the problem of extracting linear structures from digital terrain models. Positive conclusions are made about the expediency of using the results obtained for their practical application in the field of Earth sciences.
Calculation of the number of conduction channels in a single-electron reservoir network on metal-organic framework polymers
Authors: Pankratov S. A. , Parshintsev А. А. , Presnov D. E. , Shorokhov V. V.
Published: April 2024

Single-particle energy spectra of one-dimensional metal-organic framework chain’s fragments were obtained with the density functional theory method. An effective resistance of an organic part of the polymer, coulomb energy and effective capacitance of a charge center were calculated. The number of conductive channels in an experimentally studied reservoir network based on the observed polymer chains was estimated.
Study of the possibility of existence of multistability near the boundary of generalized synchronization in systems with a complex attractor topology
Authors: Evstifeev E. V. , Moskalenko O. I.
Published: April 2024

Using the local Lyapunov exponents approach it was found that multistability near boundary of generalized synchronization can occur in systems with a complex attractor topology both in unidirectional and mutual coupling cases.
Non-equilibrium processes in a semiconductor laser based on AlAs/(Al,Ga)As/GaAs microcavity under electric pulses excitation
Authors: Maksimov A. A. , Filatov E. V. , Filatov V. V. , Tartakovskii I. I.
Published: April 2024

Stimulated radiation with a high circular polarization degree in chiral semiconductor microcavities was studied in a wide temperature range. The kinetics of the spectra emission rearrangement in injection laser nanostructures during the action of a rectangular electric excitation pulse is studied in detail.
A systematic study of SERS spectra of cationic Raman dyes adsorbed on citrate-stabilized silver nanoparticles
Authors: Gribanyov D. A. , Rudakova E. V. , Zavyalova E. G.
Published: April 2024

The adsorption (kinetics and signal stability) of cationic triarylmethane dyes and an acridine derivative with various counter-ions on citrate-stabilized hydroxylamine-reduced silver sols was studied using SERS spectroscopy. The influence of the method of nanoparticle synthesis, as well as the composition and ionic strength of the medium on the stability of nanoparticle–dye complexes was investigated.
Spectra of the effects of magnetic birefringence and dichroism in magnetic colloids with different particle sizes
Authors: Yerin C. V. , Vivchar V. I. , Shevchenko E. I.
Published: April 2024

Experimental studies of the spectral dependences of the effects of birefringence and dichroism in magnetic colloids with magnetite nanoparticles with an average size of 5.5 and 8 nm have been carried out. It is shown that the magnitude of the effects in a sample with larger particles is approximately two times greater at the same volume concentration. Possible reasons for this difference are analyzed, considering the polydispersity of the samples, as well as the possibility of the presence of magnetically hard and superparamagnetic particles in them. The calculations of the spectra of the effects of birefringence and dichroism showed good agreement with the experimental data.
Effect of the magnetic field configuration on the detachment of gas bubbles in a magnetic fluid
Authors: Ryapolov P. A. , Sokolov E. A. , Kalyuzhnaya D. A.
Published: April 2024

The process of detachment of gas bubbles in a vertical channel filled with a magnetic fluid from a gas cavity in uniform magnetic field is studied. The behavior of the air–magnetic fluid interface now of separation is considered and dependences of the size of the detached bubbles on the configuration of the magnetic field, concentration of the magnetic fluid, and channel thickness are shown.
Dynamics of the magnetization vector of the spin-valve free layer with planar anisotropy under the action of magnetic fields of the arbitrary direction
Authors: Skidanov V. A. , Iusipova Iu. A.
Published: April 2024

The dynamics of the magnetization vector of the free layer of the spin-valve structure with planar layers anisotropy is simulated in the magnetic fields of the arbitrary direction. The bifurcation analysis of the dynamical system made it possible to determine the conditions of the changing singular points type and classify the magnetization dynamics by types.
Control of spin wave propagation modes in the yttrium iron garnet waveguide by means of local laser heating
Authors: Gubanov V. A. , Kruglyak V. V. , Sadovnikov A. V.
Published: April 2024

The results of micromagnetic modeling of the magnetic structure on the surface of a film of yttrium iron garnet (YIG) are presented, where a region of altered saturation magnetization was created by focused laser radiation. Based on the constructed amplitude-frequency characteristics of signal transmission through a magnon structure with a heating region, the possibility of implementing spin-wave signal filtering modes with a change in the diameter of the heated region on the YIG surface is shown.
Ferromagnetism and two magnetic phases in rutile (TiO2) implanted with cobalt ions: effect of substrate temperature and orientation
Authors: Begishev E. M. , Vakhitov I. R. , Lyadov N. M. , Nuzhdin V. I. , Valeev V. F. , Bazarov V. V. , Kuzina D. M. , Khaibullin R. I.
Published: April 2024

Room-temperature ferromagnetism and two magnetic phases: cobalt metal nanoparticles and a solid solution of divalent cobalt ions have been observed in single-crystal rutile (TiO2) implanted with cobalt ions to high dose level. Here we present the results of our structural and magnetic studies showing an influence both the temperature and the orientation of TiO2 substrate during a cobalt ion implantation, as well the effect of post-implantation thermal annealing (in air or in vacuum) on ferromagnetism value and magnetic phase composition of Co-implanted rutile.
Microwave switching in the magnetic and elastic subsystems of a three-layer magnetic structure
Authors: Kotov L. N. , Dianov M. Yu. , Vlasov V. S. , Mironov V. V.
Published: April 2024

Three modes of magnetic and elastic vibrations of the layers were revealed when a three-layer planar magnetic structure was excited by a microwave magnetic field. These modes are: microwave switching, low-frequency oscillations, microwave sinusoidal oscillations. Each mode of oscillation of the layers in a certain range of amplitudes of the alternating field is observed depending on the dc magnetic field and the magnetoelastic constant of the layer.
Investigation of heterostructures based on hafnium oxide
Authors: Sharifullina Y. I. , Gumarova I. I. , Mamin R. F. , Nedopekin O. V.
Published: April 2024

We presented ab initio calculations of bulk structures and thin films of hafnium oxide, and heterostructures based on hafnium oxide in the tetragonal phase and silicon, structural and electronic properties are investigated. The density of states spectra is considered, the results obtained are analyzed, and some of them are compared with previously obtained data (for the studied systems).
Coherence of high-power laser diodes radiation and their spectral-spatial characteristics
Authors: Rzhanov A. G.
Published: April 2024

Possible physical mechanisms affecting the coherence length of the radiation of high-power laser diodes during their slow degradation are considered. The relationship between the coherence of radiation during laser degradation and the spatial-spectral separation of high-power laser radiation into separate generation channels is discussed.
Photoinjector complex in IAP RAS: design parameters and current state of realization
Authors: Peskov N. Yu. , Afanasiev A. V. , Bandurkin I. V. , Vikharev A. A. , Gorbachev A. M. , Mineev K. V. , Oparina Yu. S. , Savilov A. V.
Published: April 2024

The calculated parameters of the photoinjector electron accelerator currently being implemented at the Institute of Applied Physics are presented, and the current state of work is described. The complex provides a step-by-step increase of the average energy of particles in dense electron bunches up to 20 MeV, which opens possibilities for the implementation on its basis of a wide class of electromagnetic radiation sources.
Effect of microstructure on the thermo-power of thermoelectric composite of the Bi2Te3 (matrix) + xNi (filler) system
Authors: Zhezhu M. , Vasil’ev A. E. , Ivanov O. N.
Published: April 2024

The patterns of effect of the ferromagnetic filler content on the features in the microstructure of “Ni core–shell NiTe2” inclusions, changes in the Seebeck coefficient and electron concentration in samples of the Bi2Te3 (matrix) + xNi (filler) composites with x = 0.00; 0.50; 0.85; 1.25 and 1.50 wt % have been found. It is shown that the Seebeck coefficient in the composites x = 0.50 and 0.85 exceeds the calculated values, which may be due to additional scattering of electrons by the magnetic moments of inclusion atoms.