bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterogeneous Phosphine-Containing Hydroformylation Catalysts Based on Modified Porous Organic Framework
Authors: Van Khanlin' , Nenasheva M. V. , Kulikov L. A. , Akopyan A. V. , Gorbunov D. N.
Published: April 2024

A series of heterogeneous phosphine-containing rhodium hydroformylation catalysts based on porous aromatic frameworks (PAFs) were prepared. The catalysts PAF30-MDEA-TPPTS-Rh (TPPTS is trisodium triphenylphosphine-3,3',3''-trisulfonate, MDEA is methyldiethanolamine fragment) and PAF-30-Im-TPPTS-Rh (Im is imidazole fragment) showed the highest stability in repeated use in 1-hexene hydroformylation. The catalyst PAF-30-MDEA-TPPTS-Rh before and after use in hydroformylation was characterized by elemental C,N,H,S analysis, inductively coupled plasma atomic absorption spectroscopy, low-temperature nitrogen adsorption–desorption, transmission electron microscopy, IR spectroscopy, and X-ray photoelectron spectroscopy. The effect of temperature, pressure, and solvent on the course of hydroformylation in the presence of PAF-30-MDEA-TPPTS-Rh was studied. The catalyst is active in hydroformylation of a series of unsaturated compounds, including functionalized substrates and olefins with internal double bond.
Acrylonitrile-Structured Ternary Co-oligomers of 4-Isopropenylphenol, Phenol, and Formaldehyde as Sorbents for Recovery of Uranyl Ions from Aqueous Systems
Authors: Bayramov M. R. , Mekhtieva G. M. , Nagiev Dzh. A. , Gulieva Sh. Dzh. , Agaeva M. A. , Magerramov A. M.
Published: April 2024

Triple co-oligomers of 4-isopropenylphenol, phenol and formaldehyde were synthesized and used for the first time as precursors in the structuring reaction in the presence of acrylonitrile and the initiator benzoyl peroxide. The yield of cross-linked copolymers is 84% (of theory). The use of hydrolyzed cross-linked copolymers is shown to be effective as sorbents for the extraction of UO22+ ions from model aqueous systems under batch conditions, and the degree of their sorption significantly depends on the medium pH, the initial concentration of UO22+ ions and the exposure time. The best results were achieved at pH 7 and 9, at which the degree of extraction of UO22+ ions from an aqueous solution with their initial concentration of 134 ± 0.5 mg L–1 is ~93.5% (room temperature, 24 h), while the sorption capacity of the cross-linked copolymer is ~210 mg g–1. The highest sorption capacity of the copolymer reaches 300 ± 30 mg g–1. The possibility of regeneration of the sorbent with mineral acid (НNO3, HCl) was revealed; the maximum degree of desorption of UO22+ ions is ~91%.
THE FIRST RECORD OF THE SCALLOP, AEQUIPECTEN OPERCULARIS (L. 1758) (MOLLUSCA, PECTINIDAE), IN RUSSIA’S WATERS
Authors: Alexeyev D. O. , Evseeva N. V.
Published: April 2024

A juvenile specimen of the scallop, Aequipecten opercularis, was found in 2007 in the eastern part of the Varanger-Fjord, Kola coast of the Barents Sea. The northern range limit of this species has earlier been drawn much more southerly, at the Atlantic coast of Norway. This record is the first in Russia’s waters, probably being related to climate warming in the southern part of the Barents Sea since the early 2000’s.
Two New Species of Eulohmannia Berlese 1910 (Acari, Oribatida, Eulohmanniidae) From the Russian Far East and Kashmir
Authors: Ermilov S. G. , Norton R. A.
Published: April 2024

In surveying material of the genus Eulohmannia Berlese 1910, representatives of two new species were discovered. Eulohmannia aborigensis sp. n., described based on all instars, is known only from alpine environments of the Kolyma Highlands in Magadan Oblast, Russia. It is the largest species of the genus known (length often well over 800 µm) and appears to be bisexual. Adults are unique among the known species of Eulohmannia in having a relatively long femur IV (about 2 times the length of trochanter IV), three setae on trochanter III, 14 setae on tarsus IV, and a minute tooth or spine at the base of each lateral claw. Eulohmannia juvenalis sp. n., described based on adults and a single tritonymph, is known only from forest soil in the Kashmir Valley (Kashmir). Among the known species of the genus, adults are unique in having paedomorphic legs, resulting from several specific neotenic characters. The most conspicuous is a monodactylous pretarsus on all legs and the retention of a single seta on trochanters III and IV, but several other setae are delayed or fail to be developed.
THE SOFT-SHELL CLAM, MYA ARENARIA LINNAEUS 1758 (MYIDAE), IN THE SHALLOW WATERS OF ZELENETSKAYA AND YARNYSHNAYA INLETS OF THE BARENTS SEA: ALLOMETRIC GROWTH
Authors: Smolkova O. V. , Meshcheryakov N. I.
Published: April 2024

Information concerning the allometric growth of the bivalve mollusk Mya arenaria populations in the intertidal zones of Zelenetskaya and Yarnyshnaya inlets, Barents Sea is presented. The population density in the Zelenetskaya Inlet averages 40 ind./m2, biomass 280 g/m2, vs 62.6 ind./m2 and 142 g/m2 in the Yarnyshnaya Inlet, respectively. A detailed analysis of the granulometric composition of the intertidal zone’s bottom sediments and the content of organic matter are determined for the first time. The study areas are found to differ in the composition of bottom sediments. The organic matter in the Zelenetskaya Inlet averages 0.8, vs 2.2% in the Yarnyshnaya Inlet. Shell formation is determined by adaptations to living conditions, also reflecting the different size and age structure of M. arenaria populations. Among the mollusks of older age groups, the shell grows allometrically, following the principle of weak negative allometry, vs. isometrically among young individuals.
BOOTSTRAP METHOD APPLICATION IN BEHAVIORAL DATA ANALYSIS AND THE DATA VISUALIZATION METHOD OF CHOICE FROM THREE OBJECTS
Authors: Dudorova A. V. , Podgrudkov D. A. , Kruchenkova E. P.
Published: April 2024

Both bootstrap analysis method and data presentation in behavioral tests are suggested to transcribe preference choice and/or multiple choices, the study of the Egyptian fruit bat pup (Rousettus aegyptiacus) preferences serving as an example. The use of the bootstrap method allows for the reliability of a given result from poor data to be evaluated. The new method of visualization proposed allows to clearly present data at a complex choice.
Birds as Hosts of Parasitic Louse Flies (Diptera) in the South of the Russian Far East
Authors: Nartshuk E. P. , Matyukhin A. V. , Shokhrin V. P.
Published: April 2024

In 2017–2020, 3833 birds representing 103 species were captured at two localities in the Lazovsky State Nature Reserve, Primorye Territory, Russian Far East. All birds were ringed and released on site. The research team recorded the presence of louse flies in 646 birds representing 62 species (51 nestlings, 11 migrants), while 41 species from two orders, Charadriiformes and Apodiformes, were found to be uninfested. A total of1184 specimens of louse flies from two subfamilies, Ornithomyinae (3 genera, 6 species) and Lipopteninae (1 genus, 2 species), were revealed. Forty-seven species of birds were recorded to be infested by Ornithoica momiyamai Kishida 1932, most of these serving as hosts new to this louse fly. Forty-two bird species were infested by Ornithomya avicularia (L. 1758) s. l., 11 bird species were found hosts to O. fringillina (Curtis 1856). Ornithoica unicolor Speiser 1900 was revealed on 11 bird species, being the most abundant on the Ural owl (Strix uralensis). Ornithomya comosa (Austen 1930) and Crataerina hirundinis (Curtis 1856) were found on Hirundinidae birds and Parus palustris. Lipoptena cervi (Linnaeus 1758) and L. fortisetosa Maa 1965 were recorded as uncommon bird parasites, as both species were only found on six bird species.
A New Species of Pseudotocepheus Balogh 1960 (Acari, Oribatida, Otocepheidae) from Dipterocarpus alatus in Vietnam, with a Key to the Known Species of the Genus from the Oriental Region
Authors: Ermilov S. G. , Salavatulin V. M.
Published: April 2024

A new mite species of the genus Pseudotocepheus (Oribatida, Otocepheidae), collected from the bark of Dipterocarpus alatus in the Cat Tien National Park, southern Vietnam, is described. Pseudotocepheus cattienensis sp. n. differs from P. setiger in a smaller body size, a fusiform bothridial seta, two pairs of medial prodorsal condyles, poorly developed medial notogastral condyles, the lamellar seta being distinctly removed from the bothridium, a tuberculate posterior part of the notogaster, and a setiform seta d on leg femora I and II. In addition, an identification key to the species of Pseudotocepheus from the Oriental Region is given.
FAUNISTIC STUDIES ON MAMMALS: HISTORY OF APPROACHES AND RECENT TRENDS
Authors: Lissovsky A. A.
Published: April 2024

An analysis of faunistic studies on mammals has been carried out over the past two and a half centuries. Historical changes in faunistics and their link to arealogical concepts are traced. The main factors that hindered the development of arealogy, despite the constant growth of faunistic information, are identified. Recently, the problems of storing and searching for faunistic information have been solved due to the technological and theoretical changes that have taken place over the last decades, approaches to the use of amateur data have been developed, the necessary structure of the collected faunistic information has been formulated, and the problem of planning the collection of material has been solved. Actively using the faunistic data in species distribution modelling has made it possible to understand their necessary spatial distribution for a species range description.
BIOLOGY OF EPTESICUS NILSSONII (VESPERTILIONIDAE, CHIROPTERA) IN THE MIDDLE URALS, SVERDLOVSK REGION
Authors: Pervushina E. M. , Bolshakov V. N.
Published: April 2024

In the Middle Urals, Sverdlovsk Region, detailed information, both previously published and new, is provided on the bat species inhabiting urbanized areas, as well as data on the biology of the species wintering in caves. Stationary studies of the biology of Eptesicus nilssonii Keyserling et Blasius 1839 were carried out during the period of activity outside the caves. Reproductive groups of animals and the autumn rut in summer habitats are described for the first time.
THE THERIOLOGICAL SOCIETY AT THE RUSSIAN ACADEMY OF SCIENCES IS 50 YEARS OLD
Authors: Rozhnov V. V.
Published: April 2024

The history of the creation of the Theriological Society at the Russian Academy of Sciences and its activities for 50 years are considered.
FIRST DATA ON THE DYTISCIDAE (COLEOPTERA) FROM THE COASTAL TUNDRA OF YUGORSKY PENINSULA, POLAR RUSSIA
Authors: Bizin M. S. , Prokin A. A. , Yefeikin B. D.
Published: April 2024

In July 2018, diving beetles were collected in the most typical water bodies and other habitats in the vicinity of Amderma, Kara Sea coast, northern Yugorsky Peninsula. The fauna comprises 15 dytiscid species from 7 genera. The most diverse genera were Agabus and Hydroporus. The record of Dytiscus lapponicus was the northernmost for this species, while the reports of Hydroporus cf. fuscipennis and Agabus pallens were the northernmost for the Palaearctic parts of their distribution ranges. Original photographs illustrate peculiar specimens of Dytiscus lapponicus with dark head, pronotum and scutellum. Most of the species show vast Holarctic Arcto-Boreal or Arcto-Boreal-Montane distributions. The species composition of the Dytiscidae is quite similar to those of the northernmost mainland regions of the European Northeast (Pakhancheskaya Bay, Kara Tundra and Pamal), as well as the Vaigatch and Dolgyi islands, being less similar to those of the south tundra regions (Kanin Peninsula, Bolvanskaya Bay and Antipayuta village, Gydan Peninsula). Among the study habitats, the most diverse beetle assemblage inhabited thermokarst lakes (up to 14 species, the maximum density noted was 1150 ind./100 trap-days). On the contrary, on salt marshes, only 2–3 beetle species were recorded and the total abundance was significantly lower (1.8–3.6 ind./100 trap-days).
THE DIVERSITY AND DISTRIBUTION OF SCORPIONS AND SOLIFUGIDS (ARACHNIDA, SCORPIONES, SOLIFUGAE) IN EASTERN TRANSCAUCASIA
Authors: Novruzov N. E.
Published: April 2024

All available data on the taxonomy and distribution of scorpions and solifugids are summarized in order to obtain a complete picture of the current state of their faunas in the territory of eastern Transcaucasia. When compiling the taxonomic checklist of species, material from all available literary sources, data on faunistic studies, the results of processing the collection of the Institute of Zoology of Azerbaijan and our own collections were used. Updated information on the taxonomy and distribution of scorpions and solifugids in eastern Transcaucasia is presented, with two species of scorpions and three species of solifugids being new to this region. Thus, by 2022, the order Scorpiones in the study region is represented by 5 species from 3 genera and one family, while the order Solifugae by 14 species from 7 genera and 5 families. Maps showing the localities in eastern Transcaucasia are presented for 15 species.
INCREASE IN THE ABUNDANCE OF THE AMUR LEOPARD CAT (PRIONAILURUS BENGALENSIS EUPTILURA, FELIDAE, CARNIVORA) IN THE SOUTHERN AMUR REGION
Authors: Tkachenko K. N.
Published: April 2024

The Amur leopard cat (Prionailurus bengalensis euptilura Elliot 1871) in the south of the Russian Far East mainly lives in flat and foothill landscapes, which have now been mostly transformed by man. The data were collected in 1987–2022 in the southern Amur region (the left bank of the Amur River in the south of the Jewish Autonomous Oblast (JAO) and the right bank of the Amur River (the right bank of the estuary of the Ussuri River), Khabarovsk Krai). Traces of cats and dead animals were recorded, and camera traps were used. The data of 4560 diaries of employees of the Department of protection of the Bolshekhekhtsirsky Reserve, located in the research area, for 1964–2009 were used. Now on the left bank of the Amur River in the south of the JAO, the Amur leopard cat lives constantly, although in the 2010s it was believed that it rarely enters this territory. Number of sightings of cat tracks in the study area on the right bank of the Amur in 2011–2021 compared to the period 2000–2010 increased about two times. It has populated areas within the range where it has never been noted. The increase in the number and the process of settlement of the Amur leopard cat, both on the left bank and on the right bank of the Amur River began in the 2000s, and since the beginning of the 2010s it has been observed constantly. Currently, the cat lives sedentary in the southern Amur region, which is confirmed by the findings of its broods. The cat mainly lives on agricultural land, which is due to its ability to adapt well to anthropogenic changes in the habitat.
THE FIRST RECORD OF STENOTHOE CF. TERGESTINA (NEBESKI 1881) (CRUSTACEA, AMPHIPODA, STENOTHOIDAE) IN THE BLACK SEA
Authors: Grintsov V. A.
Published: April 2024

Numerous individuals of an amphipod previously unreported from the Black Sea were found in 2017 on structures of a mussel and oyster marine farm, near the outer roadstead of the Sevastopol Bay, Crimea. The species discovered was morphologically especially similar to Stenothoe tergestina (Nebeski 1881), provisionally identified as Stenothoe cf. tergestina. The morphology, population structure and ecology of this species were studied. An analysis of the population structure of S. cf. tergestina in 2017–2022 showed that adult females, males and juveniles were present in the samples all over the year. The animals preferred to dwell on surfaces overgrown with periphyton colonies of the hydroid polyp genus Aglaophenia Lamouroux 1812. In the collections of amphipods from the periphyton of the farm structures, S. cf. tergestina turned out to be the most abundant (70–90% of the total number of identified amphipod individuals). The length of adult females was up to 4.5 mm, vs up to 3.6 mm in males.
OCCURRENCE OF PATHOGENS IN THE BARENTS SEA POLAR BEAR (URSUS MARITIMUS) SUBPOPULATION
Authors: Naidenko S. V. , Klyuchnikova P. S. , Ivanov E. A. , Mordvintsev I. N. , Platonov N. G. , Isachenko A. I. , Lazareva R. E. , Rozhnov V. V.
Published: April 2024

The Polar bear’s seropositivity from the Barents Sea subpopulation to a number of pathogens was analyzed: Canine distemper virus, Herpes simplex virus, Parvovirus, Toxoplasma, Trichinella (Trichinella sp.), Mycoplasma (Mycoplasma sp.), Candida (Candida sp.) and Chlamydia (Chlamydia sp.). Seropositive animals have been identified for Canine distemper virus and Trichinella (Trichinella sp.). The proportion of seropositive animals to Trichinella was the maximal. Over the last 10 years, an increased share of animals seropositive to Trichinella and Canine distemper virus has been noted in the study area.
Makaroviella exigua (Acari, Oribatida, Licnobelbidae), a new genus and species from Cuba
Authors: Ermilov S. G.
Published: April 2024

A new oribatid mite genus collected from Cuba – Makaroviella gen. n. (Oribatida, Licnobelbidae), with Makaroviella exigua sp. n. as type species – is proposed and described. It can be distinguished from both known licnobelbid genera (Flabellobelba and Licnobelba) mostly by: the number and the localization of notogastral setae, the localization of rostral setae and adanal setae ad1, and the absence of lateral enantiophyses. An identification key to the known species of Licnobelbidae is provided.
FINE STRUCTURE OF THE SHELL OF DIPLOID AND TRIPLOID OYSTERS, CRASSOSTREA GIGAS (THUNBERG 1793) (BIVALVIA, OSTREIDAE) REARED IN THE BLACK SEA
Authors: Pirkova A. V. , Ladygina L. V.
Published: April 2024

The fine structure and chemical composition of the shell growth margin were compared in diploid and triploid oysters, Crassostrea gigas (Thunberg 1793), reared to commercial size in a Crimean marine farm. The diploid oysters were deposited from plankton, whereas the triploid ones were obtained from an Atlantic coast nursery. An electron scanning microscope SEM Hitachi U 3500 with built-in software Oxford Ultin Max 65 for microanalysis was employed in the study. The shell growth margin is shown to consist of two layers: periostracum and prismatic. The periostracum in diploid oysters is smooth and porous, whereas the periostracum of triploid oysters is volumetric and shows longitudinal folds. The prismatic layer of both right and left shell valves consists of prisms surrounded by organic membranes. In contrast to diploid oysters, triploid ones have longer prism facets, their calcite filling is significantly lower than normal, their interprismatic organic membranes are discontinuous and contain calcium carbonate. The proportion of organic matter in diploid oyster shells is significantly higher than that in triploid ones. The factors affecting the fine structure of oyster shells differing in ploidy are discussed.
ECOLOGY AND ANNUAL CYCLES OF BUNTINGS (EMBERIZIDAE, AVES) IN NORTHWESTERN SIBERIA AS A REFLECTION OF ADAPTATIONS TO THE SUBARCTIC AND ARCTIC
Authors: Ryzhanovskiy V. N.
Published: April 2024

Annual cycles in buntings have a lot in common. The differences in the programs of the annual cycle are mainly manifested in the post-nesting period. These differences lie in timing the onset of the post-juvenile molt, the type of molt control (photoperiodic or endogenous), the duration of molts, the degree of the combination of the post-marital molt with nesting, the combination of the migration state and molt. The arrival, the occupation of nesting sites, and the maturation of the gonads are shortened in the pre-nesting period. The development in the Subarctic does not lead to reduced periods of incubation and feeding, and it takes less than a month from laying the first egg to the departure of the last chick, like in temperate latitudes.
A contribution to the knowledge of the oribatid mite genus Fenichelia Balogh 1970 (Acari, Oribatida, Micreremidae)
Authors: Ermilov S. G. , Salavatulin V. M.
Published: April 2024

The genus Fenichelia (Oribatida, Micreremidae) is recorded from the Oriental Region for the first time. Anew species – Fenichelia arborea sp. n. – is described, based on adults collected from tree branches of Dipterocarpus alatus in the Cat Tien National Park, Vietnam. The morphology of the gnathosoma and the identification of leg setae and solenidia are presented for the first time for a representative of this genus. A revised generic diagnosis of, an identification key to, as well as distribution and habitat data for the known species of Fenichelia are provided.
Cu(II), Ni(II), Co(II), Zn(II), and Pd(II) Complexes with (4Z)-4-[(2-Furylmethylamino)methylene]-5-methyl-2-phenylpyrazol-3-one: Synthesis, Structures, and Properties
Authors: Vlasenko V. G. , Burlov A. S. , Milutka M. S. , Koshchienko Yu. V. , Uraev A. I. , Lazarenko V. A. , Makarova N. I. , Metelitsa A. V. , Zubenko A. A. , Garnovskii D. A.
Published: April 2024

(4Z)-4-[(2-Furylmethylamino)methylene]-5-methyl-2-phenylpyrazol-3-one (HL) and its Cu(II), Ni(II), Co(II), Zn(II), and Pd(II) complexes with the ML2 composition are synthesized. The structures of the complexes are studied by elemental C,H,N analysis, IR spectroscopy, magnetochemical measurements, and quantum chemistry. The crystal structures of the copper(II) and cobalt(II) complexes are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2177619 and 2177622, respectively). Two deprotonated ligands are coordinated to the metal ions via the chelate mode by the nitrogen atom of the imino group and the oxygen atom of the hydroxy group of the ligand. The geometry of the copper(II) ion environment corresponds to a distorted planar square, whereas the cobalt(II) ion exists in a distorted tetrahedral environment. In the series of the compounds studied, fluorescence with a maximum at 431 nm and a quantum yield of 0.29 is observed for the Zn(II) complex in a solution of CH2Cl2. The synthesized enamine and metal complexes are tested for antibacterial, protistocidal, and fungistatic activities. All compounds are shown to have no fungistatic and antibacterial activities, and only a weak protistocidal activity is found for the copper and zinc complexes.
Bicompatible Metal-Organic Framework for Functional Packing of Food Products
Authors: Pak A. M. , Zakharchenko E. N. , Maiorova E. A. , Novikov V. V.
Published: April 2024

Biocompatible metal-organic framework [Zn4(GA)4(H2O)4]·4H2O (H2GA is glutamic acid) is tested as a “container” with bioactive hydrophobic components of jasmine essential oil for the preparation of functional composite materials based on a hydrocolloid matrix containing kappa-carrageenan and hydroxypropyl methylcellulose. The prepared composite film coatings exhibit high antimicrobial and antioxidant activities in the model experiment with a long-term storage of fruits, which indicates broad prospects for the practical use of these materials as an active packing of food products.
Specific Features of Binding Bioactive Organic Molecules with the Metallic Matrix of Heteronuclear 3d-4f Structures Containing Soft and Hard Metallocenters Using the Nd(III)–Cu(II) Complex as an Example
Authors: Katkova M. A. , Zhigulin G. Yu. , Baranov E. V. , Zabrodina G. S. , Muravyeva M. S. , Ketkov S. Yu. , Fomina I. G. , Eremenko I. L.
Published: April 2024

The polynuclear alanine hydroximate metallamacrocyclic complex Nd(C8H7NO4)(H2O)[15-MCCu(II)Alaha-5](CH3COO) with the axial 3-hydroxy-4-pyridinone ligand is synthesized for the first timefrom the (3-hydroxy-2-methyl-4-oxo-4H-pyridin-1-yl) acetate ligand. The X-ray diffraction (XRD) (CIFfile CCDC no. 2242224) and quantum chemical methods show that the interaction of ligand L with the Nd3+ion retained due to ionic bonds with the oxygen atoms in the copper-containing metallamacrocyclic matrixresults in the formation of axial bonds (having a covalent contribution) between Nd3+ and the dioxolene fragmentof the pyridinone ligand. In topological and energy characteristics, these axial bond approach the bondsof Cu2+ with the amine nitrogen atoms of the alanine hydroximate metallamacrocycle.
Trans-Platinum Complexes with Diclofenac, Aspirin, and 2,6-Di-tert-Butylphenol Fragment: Synthesis and Biological Activity
Authors: Antonenko T. A. , Shpakovskii D. B. , Gracheva Yu. A. , Lysenko K. A. , Milaeva E. R.
Published: April 2024

A series of σ-aryl platinum complexes with the sterically hindered phenol group of the general formula RPt[PPh3]2X (R = 3,5-di-tert-butyl-4-hydroxyphenyl; X = Cl (I), diclofenac (II), aspirin (III), and OOCR (IV)) is synthesized and characterized by 1H, 13C, and 31P NMR spectroscopy, IR spectroscopy, and elemental analysis. The molecular structure of compound I is determined by X-ray diffraction (XRD) (CIF file CCDC no. 2243100). The electron and hydrogen atom transfers are studied by spectrophotometry in the CUPRAC and DPPH tests. Complexes I, II, and IV are active reducing agents of Cu(II). The antioxidant activity is studied as the ability of the compounds to inhibit lipoxygenase (LOX-1B). Compound I is found to be an inhibitor of LOX-1B. The antiproliferative properties of the complexes are studied in vitro on the HCT-116, MCF-7, and A-549 cancer cells and WI-38 normal cells. The synthesized compounds have a lower antiproliferative activity than that of cisplatin.
Coordination Polymer or Cluster: Zinc Bis(3,5-di-tert-octyl-semiquinolate) with Pyrazine
Authors: Maleeva A. V. , Trofimova O. Yu. , Kocherova T. N. , Yakushev I. A. , Bogomyakov A. S. , Piskunov A. V.
Published: April 2024

New zinc bis-o-semiquinolate complexes based on 3,5-di-tert-octyl-o-benzoquinone bearing the N-donor ligand (pyrazine) coordinated to the metal are synthesized. Two different products can be obtained depending on the synthesis method: coordination polymer (direct oxidation of metallic zinc with o-quinone (CIF file CCDC no. 2250574 (I)) or polynuclear cluster (exchange reaction (CIF file CCDC no. 2250575 (II)). The coordination polymer is linear and free of intermolecular π,π interactions between the aromatic fragments of the adjacent molecules. The magnetochemical study of complexes I and II shows that intramolecular antiferromagnetic exchange interactions between spins of the o-semiquinolate radical centers dominate.
Synthesis and optical properties of a heterocarboxylate complex with metalcore Zn2Eu
Authors: Uvarova M. A. , Taidakov I. V. , Shmelev M. A. , Nefedov S. E. , Eremenko I. L.
Published: April 2024

It has been shown that boiling aqueous europium(III) acetate with trifluoroacetic acid in a dioxane-acetonitrile mixture leads to the formation of a polymer {[Eu(μ-OOCCF3)3(OH2)2]}n (I) containing solvate dioxane molecules. The interaction of I in CH2Cl2 with [Phen2Zn2(µ-OOCBut)2(OOCBut)2] (II) at room temperature forms a precipitate, recrystallization of which from acetonitrile gives an unusual trinuclear heterometallic heteroanionic complex Phen2Zn2Eu(µ3-OH)(OOCBut)4(OOCCF3 )2 (III). The structure of the obtained compounds was established according to X-ray diffraction data (CCDC No. 2235937-2235939). The optical properties of complex III were studied.
Registration Peculiarities of Wind Waves Breaking From Unmanned Aerial Vehicles
Authors: Korinenko A. E. , Malinovsky V. V. , Kubryakov A. A.
Published: April 2024

The results of using an unmanned aerial vehicle (UAV) to study the processes of gravitational wave breaking are presented. The experiments were carried out in the coastal zone of the western Crimea (the area of Sevastopol) in the range of wind speeds from 5.5 to 9.5 m/s. The determination of the geometric dimensions of breaking and their speeds was carried out according to video recordings of sea surface obtained from the UAV. It is shown that the spatial resolution of the transformed image plays a key role in separating the active phase of breaking and residual foam. Errors occur in determining the kinematic properties of the breaking with a rough spatial resolution. The proportion of the sea surface covered with foam of breaking waves, the ratio of the maximum length of the spume to the length of the breaking wave, the distribution of the total breaking length in the intervals of movement speeds per surface unit (obtained from UAVs with a spatial resolution better than 0.5 m) are in agreement with results of other authors. Data analysis shows that the use of unmanned aerial vehicles makes it possible to study the statistical characteristics and kinematics of wind wave breaking. At the same time, it is necessary to take into account the effect of spatial resolution in the video frame, which can lead to distortion or omission of measurement data at values comparable to or exceeding the breaking scale.
Influence of Wind and Yukon River Runoff on Water Exchange between the Bering and Chukchi Seas
Authors: Andreev A. G. , Pipko I. I.
Published: April 2024

The analysis of water exchange between the Bering (Pacific Ocean) and Chukchi (Arctic Ocean) seas in the summer period was carried out using satellite data on sea level, geostrophic currents, and measurement data of water discharge in the Bering Strait. It is shown that there is good agreement (r = 0.85, July–October 1997−2019) between the velocities of geostrophic currents (satellite data) and measurements of water transport (buoy station data) through the Bering Strait. It has been established that the temporal variability of water discharge through the Bering Strait is determined by sea level variations in the southern part of the Chukchi Sea (66°–68° N, 170°–172° W). Strengthening of the eastern (western) winds is accompanied by a decrease (increase) in the sea level in the southern part of the Chukchi Sea and, as a result, an increase (decrease) in the flow of water through the Bering Strait. Increase (decrease) in the flow of the Yukon River is accompanied by a rise (decrease) in sea level and changes in water circulation in the northern Bering Sea and the southern Chukchi Sea.
Study of Thermokarst Lake Size Distribution in the Eastern Part of the Russian Arctic Based on Combining Sentinel-2 and Kanopus-V Images
Authors: Muratov I. N. , Baysalyamova O. A. , Polishchuk Y. M.
Published: April 2024

The article is devoted to the issues of remote studies of the size distribution of thermokarst lakes in the territory of the eastern part of the Russian Arctic. The studies were carried out in the Arctic territories of the Northeastern (Yakutia) and Chukotka tundras, which represent relatively homogeneous areas in terms of their natural properties, referred to here as ecoregions. Remote studies of the distribution of thermokarst lakes by area were conducted using satellite images from the Kanopus-B and Sentinel-2 (with spatial resolution of 2.1 and 20 m, respectively), obtained in the summer months of 2017–2021. The lakes were interpreted using Sentinel-2 satellite image mosaic, which provides full coverage of the study territories, Kanopus-B images at 12 test sites, and QGIS 3.22 tools. We briefly described the method of integration (combination) of data from Kanopus-B and Sentinel-2 images for plotting synthesized histograms of lakes distribution by their sizes. The technique allowed us to get histograms of lake distribution in a very wide range of their sizes from 50 to 108 m2 in the studied Arctic ecoregions. The histogram plots show a similar behavior in both ecoregions, manifesting itself in an increase in the number of lakes as their size decreases. It is shown that the main contribution to the number of lakes in the Northeastern tundra is made by much larger lakes than in the Chukchi tundra, which may indicate a significant difference in the geocryological conditions in different Arctic territories of the eastern part of the Russian Arctic. The degree of the lakeing of the territories was assessed. It was shown that the lakeing of the Northeastern tundra is 7 times higher than in the studied territories of Chukotka.
Mapping of Arable Lands in Agro-Landscapes of the Volgograd Region According to Remote Sensing Data
Authors: Sinelnikova K. P. , Berdengalieva A. N. , Matveev Sh. , Balynova V. V. , Melikhova A. V.
Published: April 2024

Currently, more and more attention is being paid to the development of technologies for satellite monitoring of land use and the state of agricultural landscapes. The lack of up-to-date information about the boundaries of individual agricultural fields does not allow us to fully assess the state of arable land and take them into account. The available statistical sources have discrepancies and do not have information about the spatial distribution of used and unused agricultural fields. The purpose of this work is to establish the spatial distribution of cultivated and uncultivated arable lands of the Volgograd region according to remote sensing data. The paper presents the results of mapping the actual boundaries of arable lands of the Volgograd region as of 2021. High-resolution Sentinel-2 and Google Earth PRO data in the geographic information program QGIS3 were used to decrypt arable land. As a result, 6.05 million hectares of arable land were mapped. The data obtained were compared with official statistics for 2021, as a result of which, an excess of 12% was noted in comparison with the results of decryption. It is noted that over the past 20 years, according to statistical data, the areas of arable land and deposits have practically not changed. When comparing the decryption results with the data on arable lands of the Vega service, a difference of 4% was noted, which is quite high accuracy. According to the All-Russian Agricultural Census of 2016, the area of arable land used was exceeded by 8%. According to the SRTM digital terrain model, morphometric parameters of arable land were calculated throughout the region. It is determined that agricultural fields are located mainly on the slopes of the western exposure (37%), which is due to the predominance of the general slope of the relief to the west. Most (78%) of the field areas are on slopes with a steepness of up to 1°, and about 2% occupy areas of more than 3°. Water erosion is noted on steep slopes. The smoothest relief in the Volga region is on the territory of the Caspian lowland. Using remote methods, the assessment of the areas of fallow lands was carried out: about 960 thousand hectares. According to various sources, from 4.8 to 891 thousand hectares of unused arable land are noted. The resulting geoinformation basis will allow to fully account for and assess the condition of cultivated and uncultivated arable lands, as well as to develop projects for the rational use of land resources to increase yields and prevent degradation of agricultural landscapes.
(2D + 1) optical vortices in a tunnel-coupled waveguide
Authors: Bryantsev B. S. , Kalinovich А. А. , Zakharova I. G.
Published: April 2024

The process of formation and propagation of vortex solitons in a tunnel-coupled waveguide with cubic nonlinearity in the case of anomalous dispersion is investigated by computer modeling methods. Obtaining stable solutions could be possible due to the introduction into the structure of an analogue of the spin-orbit coupling realized in binary Bose–Einstein condensates.
Microwave photonics matched filter for fast processing of ultra-wideband input signal
Authors: Kulagin V. V. , Valuev V. V. , Burkitbaev D. , Kornienko V. N. , Cherepenin V. A.
Published: April 2024

A scheme of a specialized analog processor implementing a microwave photonics correlation receiver in the form of a matched filter for processing an ultra-wideband microwave signal is proposed. The operation of such a filter is numerically investigated, its characteristics are found (accuracy of determining the position of the maximum of the output signal, potential performance).
Features of ultrasonic visualization of layered objects
Authors: Petronyuk Y. S. , Titov S. A. , Bogachenkov A. N. , Levin V. M. , Grigorieva I. G.
Published: April 2024

Pulsed acoustic microscopy (100–200 MHz) was used to study layers of pyrolytic graphite on a glass substrate with a thickness comparable to wavelength of the probing sound. Mechanism of natural amplification of acoustic contrast in visualization process of such structures is shown. Images interpretation of the inhomogeneous structure of the layer-substrate contact is supported by a quantitative assessment of acoustic impedances.
Wedge acoustic waves in a fluid-filled crack
Authors: Mozhaev V. G.
Published: April 2024

The existence of wedge acoustic modes of a special fluidic type in solids is demonstrated using the ray theory of slow Krauklis-wave propagation in a fluid-filled wedge-shaped crack. It is found that the phase velocities of the modes at small crack opening angles are proportional to the square root of the angle. The number of localized modes in the semi-infinite crack model is not limited.
Waves and bubbles of drop impact
Authors: Ilinykh A. Yu.
Published: April 2024

High-speed video recording methods have been used to visualize a wide range of thin fast flows (capillary waves, ligaments, vortex structures) caused by the processes of surface energy conversion into other forms (pressure and temperature fluctuations, formation, and movement of new components) during the destruction of contact surfaces in confluence of a freely falling drop with a target fluid.
A new electroencephalography marker of the cognitive task performance
Authors: Smirnov N. M. , Badarin A. A. , Kurkin S. A. , Hramov A. E.
Published: April 2024

Universal biomarker based on the calculation of the dispersion of the ratio of alpha- and beta-rhythms energy in the registered electroencephalography signals and reflecting the level of the components of the cognitive resource of the learner was revealed. Using the Bourdon test (proofreading test) as an example, it is shown that this biomarker significantly correlates with the main indicators of success and performance of standardized cognitive tasks.
Anomalous magnons in quantum Hall ferromagnet with strong interaction at filling factor 2
Authors: Vankov A. B. , Koreyev A. S. , Berezhnoy P. S. , Kukushkin I. V.
Published: April 2024

In two-dimensional electronic systems, at large values of the Wigner–Seitz parameter, an anomalous branch of magnons was found. In a quantum Hall ferromagnet state with ν = 2, the magnon dispersion reveals a magnetoroton minimum with depth dependent on electron density. Magnetorotons with opposite momenta are shown to attract each other.
Luminescence kinetics of Eu3+ ions in tungstates (Lu1 – xEux)2(WO4)3 and molybdates (Lu1 – xEux)2(MoO4)3
Authors: Zaitsev S. V.
Published: April 2024

The luminescence kinetics of the electron transition 5D0 → 7F2 (~613 nm) of Eu3+ ions has been studied in tungstates (Lu1 – xEux)2(WO4)3 and molybdates (Lu1 – xEux)2(MoO4)3. Luminescence decay times are very close in both compounds at x ≥ 0.2, while a significant difference is observed at x 0.1. Observed behavior is attributed to the difference in electronic structure of compounds.
Investigation of the glow of the Herzberg I band of molecular oxygen in the Earth’s night sky
Authors: Antonenko O. V. , Kirillov A. S.
Published: April 2024

The calculated seasonal altitude distributions of the volumetric intensity iν'ν" (cm–3 · s–1) of the luminescence of the Herzberg I band of molecular oxygen in the Earth’s atmosphere at night depending on the altitude for high and low solar activity are presented. The calculated volume intensity values demonstrate that the greatest seasonal variations are observed at altitudes of ≈87–97 km for both high and low solar activity. The results of calculations of the integrated luminosity Iν'ν" (cm–2 · s–1) are also presented, while the volumetric radiation intensity values are recalculated into integral values using the approximation of an optically thin layer. It is shown that the calculation results are in good agreement with the experimental data obtained from both the space shuttle and ground-based observations.
Adsorption of organic dyes by Fe3O4@C, Fe3O4@C@C, Fe3O4@SiO2 magnetic nanoparticles
Authors: Ivanova O. S. , Edelman I. S. , Sokolov A. E. , Svetlitsky E. S. , Zharkov S. M. , Sukhachev A. L. , Lin Ch. R. , Chen Yu. Zh.
Published: April 2024

The Fe3O4@C, Fe3O4@C@C, and Fe3O4@SiO2 core-shell nanoparticles were synthesized using thermal decomposition and co-precipitation techniques and characterized by X-ray spectroscopy, transmission electron microscopy and magnetometry. It is shown that the magnetic core of all nanoparticles is nanocrystalline with crystal parameters corresponding to only one Fe3O4 phase, which is covered with a uniform shell of amorphous carbon or silicon oxide about 8 nm thick. The main attention was paid to the adsorption properties of nanoparticles with respect to four dyes: methylene blue, Congo red, eosin Y, and rhodamine C. The high selectivity of Fe3O4@C nanoparticles with respect to various dyes was revealed.
Structure and FMR characteristics of magnetic composite films (CoFeB + SiO2)
Authors: Kotov L. N. , Ustyugov V. A. , Vlasov V. S. , Utkin A. A. , Kalinin Yu. E. , Sitnikov A. V.
Published: April 2024

Composite films (FeCoB + SiO2) with a low metal alloy concentration x 0.35 have a small spread of film surface elevations. At large x 0.53, a greater scatter of elevations and their smooth distribution in the films are observed. The concentration dependence of the FMR linewidth exhibits a maximum at x = 0.45, which is related to the percolation structure in the films.
Aging effects in critical behavior of Heisenberg anisotropic ultrathin films
Authors: Shlyakhtich M. A. , Prudnikov P. V.
Published: April 2024

We present the results of Monte-Carlo studies of the non-equilibrium properties of ferromagnetic Heisenberg films. Aging effects were observed in non-equilibrium critical behavior. The calculations were carried out for both high-temperature and low-temperature initial states. The characteristic correlation time, which diverges at the transition temperature in the thermodynamic limit, was obtained as a function of system size and waiting time.
Control of the direction of magnetization of a ferromagnetic layer in two-layer heterostructure ferromagnet/ferroelectric
Authors: Kamashev A. A. , Leontyev A. V. , Garifullin I. A. , Mamin R. F.
Published: April 2024

We studied two-layer ferromagnet/ferroelectric heterostructures, where iron, cobalt, and nickel were used as ferromagnetic layers, and lithium niobate was used as a ferroelectric substrate. According to our studies, applying an electric field from 10 to 50 V to a ferroelectric lithium niobate substrate is sufficient to register a change in the direction of the magnetization vector of the ferromagnetic layer.
Charge carrier transport and polarization in M/PZT/M structures
Authors: Delimova L. A. , Yuferev V. S.
Published: April 2024

A model of non-stationary charge carrier transport in M/PZT/M ferroelectric structures has been developed. It is assumed that, at room temperature, electrons generated by oxygen vacancies are captured by Ti+3 levels and move between them under the action of electric fields caused by the external bias and polarization. The polarization distribution in a PZT film is described with varying degrees of complexity, from a constant value outside the defect layers to one determined by the equation following from the Landau–Ginzburg theory. The numerical simulation performed made it possible to explain the reasons and conditions for the appearance of current–voltage characteristics with unusual current peaks, to show the existence of several solutions in the Landau–Ginzburg model for a film with Schottky barriers, and to reveal the response of charged domain walls to an applied voltage.
Mechanical response of amorphous Ni62Nb38 metallic alloy under uniaxial deformation
Authors: Galimzyanov B. N. , Doronina M. А. , Mokshin A. V.
Published: April 2024

The mechanical properties of amorphous Ni62Nb38 alloy associated with uniaxial compression and uniaxial tensile are studied at the temperature 300 K based on the large-scale molecular dynamic’s simulations. Stress-strain curves, Young’s modulus, yield strength, and tensile strength are determined for this system. For the first time, some correspondence was found between the values of Young’s modulus and the yield strength, which fits into the experimentally established linear law, which is the same for metallic glasses with different compositions. It is shown that the mechanical and strength properties of amorphous Ni62Nb38 alloy are more pronounced than those of metallic glasses with a different composition.
Effect of geometric parameters of two-section axisymmetric overdimensional relativistic diffraction generators on their output characteristics
Authors: Gallyamova O. V. , Khudyakov S. V.
Published: April 2024

The effect of variation the length of drift tube of two-section structure of axisymmetric relativistic diffraction generator on its output power operation and sustainability of generation is considered. A comparison is made of the electromagnetic field strength distribution for structures with two types of discontinuity: sinusoidal corrugation and half-torus on pedestal.
Analytical solution for the diffraging intense gaussian beam in the framework of a modular nonlinearity model
Authors: Gusev V. A. , Zharkov D. A.
Published: April 2024

A model of modular nonlinearity has been developed for calculating the field of high-intensity bounded acoustic beams. The exact solution of this problem is obtained. The influence of diffraction and nonlinear effects on the time profile is demonstrated. It is shown that as the aperture decreases, a sequence of short positive high-amplitude pulses is formed, which was observed experimentally.
High-harmonic large-orbit terahertz gyrotrons for physical applications
Authors: Bandurkin I. V. , Kalynov Yu. K. , Osharin I. V. , Savilov A. V. , Semenov E. S. , Shchegolkov D. Yu.
Published: April 2024

An overview is given of works on two experimental installations that implement large-orbit gyrotrons (LOG) operating in the sub-terahertz frequency range at high harmonics of the electronic cyclotron frequency. At the installation of a pulsed LOG (80–100 keV/0.7–1.0 A), a radiation source with a frequency of 1 THz with a kilowatt output power level is being developed, which is planned to be used in plasma applications. A continuous subterahertz LOG (30 keV/0.7 A) is being created as a prototype of a universal multi-frequency source for spectroscopic applications. Complex electrodynamic systems are also described, designed to increase the selectivity and efficiency of excitation of high cyclotron harmonics in these devices, as well as to ensure the tuning of the generation frequency.
Magnetic integrals minimization methods for superconducting insertion devices
Authors: Zorin A. V. , Mezentsev N. A. , Shkaruba V. A. , Tsukanov V. M. , Volkov A. A. , Tarasenko O. A. , Kanonik P. V. , Kazantsev F. P.
Published: April 2024

Stretched wire with direct current magnetic measurements method is used for producing synchrotron radiation generation insertion devices. The method allows to measure and to minimize the first and the second magnetic field integrals. The paper focuses on the wire sag problem.
Investigation of irradiation effect on the thermal transformation process of hexaaminonitrowurtzitane crystals using synchrotron radiation
Authors: Mikhailenko М. A. , Sharafutdinov M. R. , Gerasimov K. B. , Artemova E. V. , Kalmykov P. I. , Korobeinikov M. V. , Tolochko B. P. , Pimenov P. A.
Published: April 2024

Using the method of small-angle scattering of synchrotron radiation the thermal transformations of ε-form a hexaaminonitrowurtzitane crystals subjected to electron beam processing are studied. It is shown that the destruction of crystals treated with an electron beam begins significantly below the polymorphic transition point. An assumption was made about the effect of radiolysis products on the process of crystal destruction. A mechanism for the destruction of crystals is proposed.