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Contourite drifts were found for the first time on the SW Kara Sea shelf based on the analysis of bathymetry and seismoacoustic data obtained in the cruises 41 (2019) and 49 (2020) of R/V Akademik Nikolai Strakhov. These drifts are confined to a narrow NS depression with a depth of 240 m. They are separated from underlying sediments by the basal unconformity caused by the bottom current formed in the marine environment after melting of the Barents–Kara ice sheet during the Late Pleistocene–Holocene time. Hydrological measurements carried out in the cruise 89-1 (2022) of R/V Akademik Mstislav Keldysh made it possible to reveal the bottom current with a measured velocity of up to 10 cm/s. [ABSTRACT FROM AUTHOR]

The Pd/AlO catalysts were prepared by the impregnation of aluminum hydroxide, which was synthesized by precipitation in the presence of polyvinyl alcohol, with a solution of palladium nitrate and were heat-treated at different temperatures. The resulting samples were characterized by X-ray diffraction, electron microscopy, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy and were tested in CO oxidation in two modes: in a temperature-programmed reaction and under isothermal conditions at 20°C in the absence and in the presence of water vapor. The activity of the catalysts in the former mode was almost independent of support preparation conditions, but it was different in the latter mode. The catalyst whose support was obtained in the presence of polyvinyl alcohol and treated at 300°C in an atmosphere of nitrogen exhibited the highest activity in CO oxidation at 20°C. In the absence of water vapor from the reaction mixture, the initial conversion of CO reached 40% and then decreased. In the presence of water vapor, a continuous increase in the conversion of CO to 88% was observed, and the activity was stabilized at this level. The smallest size of palladium metal nanoparticles, the nearly monolayer carbon surface coverage, and the presence of OH groups, which are formed upon the dissociation of water present in the reaction mixture, facilitate an increase in activity. [ABSTRACT FROM AUTHOR]

A size effect was found in the low-temperature steam reforming of bioethanol (15 vol. % ethanol in water) on copper catalysts supported on yttrium-stabilized zirconia: the specific rate of the conversion of ethanol into the key reforming product, acetaldehyde, is virtually independent on the mean diameter of the copper particles in the range 6-10 nm but drops significantly for particles with diameter 1-2 nm. Hypotheses for this observed effect are presented. [ABSTRACT FROM AUTHOR]

The long-term strength of a system of single-crystal nickel alloy ZhS36-VI with Cr – Al gas circulation coating (GCC) + Ni – Cr – Al – Ta – Re – Yion-plasma coating (IPC) + Al – Ni – Cr – Yion-plasma coating (IPC) is analyzed under conditions close to the operating ones after a hold for 1 – 1000 h in a temperature range of 1050 – 1300°C. [ABSTRACT FROM AUTHOR]

A complex coating consisting of three layers, i.e., a gas-circulation coating and a two-layer ion-plasma coating with an internal Ni − Cr − Al − Ta − Re − Y layer and an external Al − Ni − Cr − Y layer for protecting single crystal turbine rotor blades from high-temperature oxidation is considered. The fine structure and the phase composition of the complex coating and of the reaction zone of interaction with single-crystal alloy ZhS36-VI after high-temperature holds in a range of 1050 − 1300°C for 1-1000 h are studied. [ABSTRACT FROM AUTHOR]

Published data on the application of modern X-ray diffraction methods in the investigation of nanomaterials are reviewed. Examples of investigations on refinement of the phase composition, defect structure, and microstructure of catalytic subjects (supports and deposited catalysts) are presented. The effect of structural defects on the functional characteristics of the catalysts is demonstrated. [ABSTRACT FROM AUTHOR]

A method describing processes in cold-rolled steel and reproducing dynamic hysteresis loops in certain core components (legs and yokes) is proposed. A method that takes into account magnetic fluxes in a nonmagnetic medium that makes the transformer model reversible is described. Transients initiated by sub-sequent energizing of a three-phase group of four-limb transformers in a 500-kV network are simulated. [ABSTRACT FROM AUTHOR]

We show that bicomponent supported catalysts M-Cu/ZrO (M = Fe, Co, Ni) are considerably more efficient than Cu/ZrO in steam reforming of ethanol at 350-550 °C. We have found that Fe-Cu/ZrO has increased activity and selectivity in ethanol steam reforming, due to the presence of highly dispersed copper particles and iron oxide particles, which are active in the water-gas shift reaction, and as a result carbon monoxide (a secondary product of ethanol steam reforming) is converted to the target CO and H. [ABSTRACT FROM AUTHOR]

The article presents a study that was conducted to estimate the influence of geological, geomorphological, hydrogeochemical, and climatic factors on accumulation of uranium. It further investigates forms of uranium deposition in the lake systems of Western Mongolia with reference to the example of the uranium-bearing soda Shaazgai Nuur Lake. It informs that the investigation of the lake was performed during the International Interdisciplinary Russian-Mongolian Hydrogeochemical Expedition in 2011.

The Piaoak tin-bearing granite-leucogranites located in the Caobang Province of Northern Vietnam compose a stock-like hypabyssal body. Host rocks are represented by Early Devonian carbonate sequences and Early Triassic 'black' shales. The geochronological age of the Piaoak granite-leucogranites corresponds to the Late Cretaceous: T = 83.5 ± 6.2 Ma, Rb/Sr method; T = 89.7 ± 1.0 Ma, Ar/Ar method. The massif has a simple basic to acid order: two-mica and muscovite granite-leucogranite → raremetal aplites, pegmatites → tin-bearing greisens and hydrothermal veins. The petrographic and microstructural studies revealed a sharp change in crystallization conditions of the granite-leucogranite magma at the late magmatic stage and formation of muscovite via incongruent melting of protolithionite. The study of melt and coexisting fluid inclusions showed that solidus crystallization occurred under fluid-saturated conditions at 635-600°C. In composition, the granite-leucogranites of the Piaoak Massif correspond to the raremetal-plumasite geochemical type (according to L.V. Tauson), and reach Li-F facies in terms of their rare-element composition. The composition of aplites and pegmatites demonstrates that granite-leucogranite magma did not accumulate lithophile and volatile components in the residual melt during differentiation, but was initially enriched in rare-metals. It is most probable that the melt was generated from Proterozoic lithotectonic complexes and overlaying Lower Triassic 'black' shales. [ABSTRACT FROM AUTHOR]

The effect of surfactants (polyvinyl alcohol and cetyltrimethylammonium bromide), which were introduced at the aluminum hydroxide synthesis stage, on the structure and texture characteristics of aluminum oxide was studied by a set of physicochemical techniques. The introduction of the above surfactants did not cause considerable changes in the thermal transformations of aluminum hydroxides, but it affected the genesis of the formed carbon. An analysis of the diffuse reflectance spectra and electron micrographs indicated that the aluminum oxide obtained in the presence of polyvinyl alcohol and calcined at 300°C was covered with polyene-type coke. An increase in the treatment temperature to 550°C led to the formation of condensed aromatic coke; in this case, the specific surface area of the sample increased from 125 to 500 m/g. The samples calcined at 550°C were γ-AlO with a unit cell parameter of 7.933 Å and a crystallite size of no more than 30-40 Å. The pore size distribution was bimodal, with maximums at 35-65 and 380-415 Å, regardless of treatment temperature. [ABSTRACT FROM AUTHOR]

The article offers information on the research regarding the structure of the transition zone located between Hovgaard ridge and Spitsbergen plateau in Norway as part of the research project of the Russian Academy of Science. It says that the research was carried out through the use of Research Vessel (RV) Academik Nikolai Strakhov, with A. V. Zayoncheck as chief scientist. It mentions various results of the survey, including the fault depression found through bathymetric survey, identification of grabens, faults, and flexures through high-frequency profiling, and a pseudobottom reflector was found out. It adds that increase in the heat flow in the ridge occurs in the ridge.

The article focuses on the effect of poly (N-ethyl-4-vinylpyridinium) (PEVP) charge density on its complexes with oppositely charged surfactant in aqueous solution. It states that polyion charge density could lead to an inversion of thermosensitivity of polyelectrolyte surfactant complexes (PSCs) in aqueous solution. It mentions that infrared (IR) spectroscopy was used to determine the degree of quaternization.

nalysis of major- and trace-element compositions of water in hypersaline soda closed basin lakes of Northwestern Mongolia and Chuya basin (Gorny Altai) shows high enrichment in U (up to 1 mg/l). Proceeding from new data, uranium accumulation in water has been attributed to (i) location of the lakes and their watersheds in potential provinces of U-bearing rocks and (ii) uranium complexing with carbonate in presence of carbonate (bicarbonate) anions. Among the explored hypersaline soda lakes of the area, the greatest uranium resources are stored in Lake Hyargas Nuur (about 6000 ton). [ABSTRACT FROM AUTHOR]

The article presents a study of the 26th cruis of research vessel (R/V) Akademik Nikolai Strakhov on the structure of the transition zone of the Barents Sea Shelf to the Knipovich Ridge Northward from Medvezhii Island. In this study, data collection of the sedimentary cover was made with hydroacoustic system REASON. The survey was conducted by continuous seismic profiling (CSP) and by equipment developed at GIN RAS, and the heat flow and sound velocity profiles were measured with acoustic probes GEOS M and SVP 24. The result shows that an uplift of shelf zone has been discovered in the Medvezhii Island which causes intensive erosion processes. Moreover, the survey in Knipovich Ridge from 74º40' to 75º20' N indicates the increase of neotectonic activity.

A series of copper-cerium oxide catalysts was prepared by the Pechini method, and their physicochemical and catalytic properties in CO oxidation in hydrogen-containing gas mixtures were studied. The method chosen for catalyst preparation yields finely dispersed copper and cerium oxides in the catalyst. [ABSTRACT FROM AUTHOR]

The formation of individual and modified high-purity aluminum oxides (γ-Al2O3) prepared from aluminum alcoholates was studied. In the study of the hydrolysis of aluminum alcoholates and modified (Zr, Ti, and Si) aluminum alcoholates, it was found that an increase in the chain length of the alkoxy group and an increase in the aging temperature or aging time in mother liquor resulted in a decrease in the concentration of an amorphous phase, an increase in the concentration of a pseudoboehmite phase, and an improvement in its crystal structure. Hydrolysis in alkaline (a 0.5 wt % solution of ammonia) or neutral solutions made it possible to obtain samples with an almost 100% pseudoboehmite content. At the same time, the samples prepared by hydrolysis in an acidic solution (a 0.1 M solution of HCl) contained a considerable amount of an amorphous phase. It was found that the specific rate of dehydration of n-butanol on the modified aluminum oxide samples linearly decreased with the concentration of donor sites and linearly increased with the concentration of acceptor sites, whose concentration was measured using the spin probe method. [ABSTRACT FROM AUTHOR]

The influence of hydrothermal treatment conditions (temperature, duration, acidity of the medium) on the structural and chemical transformations of the complex H2[Pt(OH)6] was studied. The composition and structure of the resulting compounds were determined by several physicochemical methods. Thermal analysis coupled with mass spectrometry showed that, as the hydrothermal treatment temperature is raised from 25 to 120 and 150°C, the product composition in terms of empirical formulas changes as follows: PtO2 · 4H2O → PtO2 · 3.5H2O → PtO2 · 1.5H2O. X-ray diffraction and UV and IR spectroscopy demonstrated that the changes in the chemical composition are accompanied by the amorphization of the structure and Pt-O bond strengthening. X-ray structure determination using the radial electron density distribution method showed that polynuclear species ∼10–15 Å in size with a structure similar to that of orthorhombic PtO2 form in the complexes subjected to “hard” hydrothermal treatment ( T ≥ 150°C). [ABSTRACT FROM AUTHOR]

The influence of the texture of γ-Al2O3 on the formation of Co(Ni)-Mo catalysts for hydrodesulfurization of the diesel fraction is studied. As shown by low-temperature N2 adsorption, X-ray diffraction, IR spectroscopy of adsorbed molecules, and high resolution electron microscopy (HREM), use of a support with a larger specific surface and a lower total concentration of terminal OH groups makes it possible to prepare more active catalysts. The electron density radial distribution method shows that the finely dispersed cobaltcontaining catalyst in its initial state contains CoMoO4, Al2(MoO4)3, and CoAl2O4, the last two phases being present in trace amounts. After the reaction, this catalyst contains cobalt-doped molybdenum sulfide. According to HREM data, the active phase of the cobalt-containing catalyst consists of layered sulfide association species Co1.3Mo2S3.3, which differ in composition from the bulk phase CoMo2S4. It is assumed that, out of the 1.3 cobalt atoms in Co1.3Mo2S3.3 0.3 Co occurs at the edges of the association species and 1.0 Co is intercalated into their interlayer space, and 0.7 S at the boundary between the association species and the Al2O3 phase is replaced by the corresponding amount of oxygen. [ABSTRACT FROM AUTHOR]

Cu-CeO2 catalysts deposited on a commercial ZrO2 support have been investigated. The catalyst composition has been optimized: the optimum copper content was found to be 5–10 wt % at a cerium oxide content of 23 wt %. The catalysts were investigated by X-ray diffraction analysis and X-ray photoelectron spectroscopy. According to the X-ray diffraction data, the support consists of the monoclinic ZrO2 phase and cubic CeO2 phase with an enlarged lattice parameter, while the catalysts contain CuO. The X-ray photoelectron data indicate the presence of a highly dispersed CuO2 phase interacting with cerium oxide and zirconia on the surface of the catalyst having the optimum copper content. [ABSTRACT FROM AUTHOR]

The mechanical properties of carbon-free single-crystal alloy ZhS36VI [001] are studied. The effect of test temperature on alloy short-term mechanical properties after standard heat treatment, and also the effect of γ′-phase particle size after on stress-rupture strength at 975°C and mechanical properties at 20°C are determined. A Larsen-Miller parametric curve is plotted for alloy stress-rupture strength. [ABSTRACT FROM AUTHOR]

The fine structure, phase composition, and segregation inhomogeneity of carbonless single-crystal rhenium-alloyed alloy ZhS36VI in cast and heat-treated conditions are studied. The structural and phase stability of the alloy is determined at elevated temperatures and loads. [ABSTRACT FROM AUTHOR]

Cerium dioxide samples of different dispersivity, obtained by different methods, have been investigated by X-ray diffraction (XRD) analysis, full-profile analysis of diffraction patterns, calculation of radial distribution function (RDF) of electron density, and extended X-ray absorption fine-structure (EXAFS) spectroscopy. According to the XRD data, the samples studied can be identified in the fluorite structure with conventional unit-cell parameters. However, the local structure of highly dispersed samples, determined by the RDF and EXAFS methods, changes: the coordination spheres for the Ce-O distances are represented by two distances. [ABSTRACT FROM AUTHOR]

An effect of the composition of reacting components during mechanochemical activation on the ZrO2 structure stabilized with additives of In2O3, CaO, and Y2O3 oxides has been revealed. It is established that mechanochemical activation of oxide mixtures leads to the formation of dispersed solid solutions based on cubic zirconia. It is shown that interaction depth of the components during mechanochemical activation increases in the series of oxides In2O3 < CaO < Y2O3. [ABSTRACT FROM AUTHOR]

The basic properties of aluminum hydroxide compounds, namely, the flash product and the centrifugal thermal activation (CTA) product both before and after heat treatment at 400–1100°C are considered. The hydration conditions for obtaining 100% pseudoboehmite from the CTA product are determined. The structure, morphology, and texture of pseudoboehmite aluminum hydroxide synthesized from the CTA product and of the aluminum oxides obtained from this hydroxide in the temperature range 600–1100°C are described. [ABSTRACT FROM AUTHOR]

The interaction between the amorphous product of the centrifugal thermal activation of hydrargillite (CTA HG) and aqueous electrolytes (pH 5–11) under mild conditions (15–35°C, atmospheric pressure) has been investigated by a variety of physicochemical methods. This interaction causes material morphologic and phase changes in CTA HG, and the product composition is governed by the pH of the electrolyte and by the hydration temperature and time. The product that forms in a basic medium or water in <24 h contains up to 50% pseudoboehmite. Raising the pH or temperature or extending the hydration time results in the formation of bayerite as the major phase (∼80%). An X-ray amorphous hydroxide forms in acid media. The heat treatment of this hydroxide at 550°C yields aluminum oxides differing from alumina prepared via hydroxide reprecipitation. Products with new, unusual properties can thus be obtained. [ABSTRACT FROM AUTHOR]

A variety of physicochemical methods were used to characterize the product of the rapid thermal decomposition of hydrargillite in a centrifugal flash reactor under the following conditions: the average particle size of the reactant, 80–120 μm; the temperature of the solid heating surface (plate or cylinder), 300–700°C; hot-zone residence time, ∼1 s; transfer of the product to the cooled zone of the reactor. The composition of the product and the extent of decomposition of hydrargillite were determined as a function of the processing temperature. The centrifugal thermal activation (CTA) of hydrargillite affords an X-ray-amorphous, highly reactive product with a developed surface and a disordered and inhomogeneous porous structure. This structure is capable of forming different modifications of aluminum hydroxide and oxide. The properties of the CTA product are compared with the properties of the earlier reported hydrargillite rapid decomposition products obtained using a gaseous heat-transfer agent (thermochemical activation product) or a fluidized bed of a granular heat-transfer agent (thermal dispersion product). [ABSTRACT FROM AUTHOR]

The formation of composite nickel and nickel-platinum catalysts reinforced with steel gauze was studied. The catalysts were prepared by sintering powdered nickel metal and a supported nickel catalyst (GIAP-3 or NIAP-18) with a chromium oxide additive in the case of nickel-containing composite catalysts or by sintering powdered nickel, aluminum, and a supported platinum catalyst in the case of catalysts containing nickel-platinum. With the use of electron microscopy, mercury porosimetry, and X-ray electron probe microanalysis, it was found that a metal matrix, in the pores of which supported catalyst particles were distributed, was formed in the composite catalysts. The reinforced nickel catalysts prepared were active in the reaction of methane steam reforming, and the catalysts containing nickel-platinum were active in the reaction of hydrogen oxidation. An increase in the activity of reinforced nickel catalysts in the course of the reaction was found. It is believed that the increase of the activity was due to the reduction of nickel oxide from an inactive difficult-to-reduce oxide film containing nickel and chromium oxides under the action of the reaction atmosphere. [ABSTRACT FROM AUTHOR]

Abstract—The article briefly describes the results of integrated geological, geophysical, and hydrophysical studies on the shelves of the Barents and Kara seas. The research was aimed at substantiating the most probable scenario of development of natural conditions of Russia's Western Arctic against ongoing climate warming, sea level rise, and increasing anthropogenic impact. Studies have confirmed widespread modern hazardous geological and geomorphological processes of different genesis in the Barents–Kara region. [ABSTRACT FROM AUTHOR]

Changes in the volume and surface properties of thermally activated hydrargillite, so-called centrifugal thermal activation (CTA) product (empirical formula Al2O3 · 0.85H2O), during its calcining in air with gradually increasing temperature from 90 to 1100°C were studied. At each stage of calcining, weight loss, phase composition, texture characteristics, and the heat of wetting with water at 25°C were determined. Measurements of the heat of wetting showed that the energy and, therefore, chemical state of the surface changed during thermal treatment. The data obtained were used to calculate the heats of adsorption qads of water vapor by CTA samples with different water contents; the range of qads variations was 50–250 kJ/mol. The values obtained are compared with literature data. [ABSTRACT FROM AUTHOR]

The Kalguty ore-magmatic system comprises two intrusive complexes: the Kalguty granite-leucogranite complex and Eastern Kalguty complex of dikes and small intrusions. U-Pb dating of individual zircon grains from granites of the main intrusive phase demonstrated that the crystallization age of small grains of magmatic habits and outer rims of large grains is almost concordant and is 216 ± 3 Ma. Ar-Ar isotope study shows that the K-Ar system of biotites from granites of the main phase within the Kalguty ore field was disturbed (radiogenic Ar was partially lost) and gave an age of 202 ± 1 Ma. The Ar-Ar dating of muscovites from intraore and postore dikes of the Eastern Kalguty complex devoid of signatures of postmagmatic recrystallization and superimposed greisenization gave similar ages of 205–201 Ma. This date is considered as the emplacement age of the Eastern Kalguty dikes and associated complex W-Mo-Bi-Be ore mineralization. Sm-Nd and Pb-Pb isotopic study of granites, ongonites, and elvans of the Kalguty ore-magmatic system and host rocks shows that these systems were closed. For example, recalculation of Nd isotopic ratios for corresponding ages of crystallization of magmatic systems (216 and 205 Ma) shows that ɛNd(T) values decrease from −1.9 to −3.5 ... −5.08 with transition from granite-leucogranite to subvolcanic granite porphyry, ongonite, and elvan dikes with corresponding increase of model ages of protoliths from 1.0 to 1.25 Ga. Lead isotopic ratios for leaching residues of whole-rock samples of all rock varieties (206Pb/204Pb = 18.305–18.831; 207Pb/204Pb = 15.527–15.571) are plotted well below the line of average crustal lead evolution according to the Stacey-Kramers model. [ABSTRACT FROM AUTHOR]

The Ru-Cs+/MgO and Ru-Cs+/γ-Al2O3 catalysts, which were prepared by an impregnation method using RuOHCl3 and Cs2CO3 as precursor compounds and reduced with H2 at 450°C, are characterized by X-ray diffraction, high-resolution transmission electron microscopy (with X-ray microanalysis), and X-ray photoelectron spectroscopy (XPS). The Cs+/MgO(Al2O3) systems, Ru-Cs+ black, and model systems prepared by cesium sputtering onto polycrystalline ruthenium foil are studied as reference samples. It is found that, in the Ru-Cs+/MgO sample, cesium is present as a Cs2 + x O cesium suboxide, which weakly interacts with the support, localized on the surface of Ru particles or near them. In the case of Ru-Cs+/γ-Al2O3, cesium occurs as a species that is tightly bound to the support; this is likely surface cesium aluminate, which prevents promoter migration to Ru particles. The Ru-Cs+/MgO sample exhibits a considerable shift of the Ru3 d line in the XPS spectra toward lower binding energies, as compared to the bulk metal. It is hypothesized that this shift is due to a decrease in the electron work function from the surface of ruthenium because of the polarizing effect of Cs+ ions in contact with Ru particles. Based on the experimental results, the great difference between the catalytic activities of the Ru-Cs+/MgO and Ru-Cs+/γ-Al2O3 systems in ammonia synthesis at 250–400°C and atmospheric pressure is explained. [ABSTRACT FROM AUTHOR]

Approaches to design of zirconia pillared clays via control of the properties of pillaring species in solutions were elaborated. Structural features of pillars and Pt + Cu active components fixed at these nanoparticles were shown to determine catalytic properties of pillared clays in NO x selective reduction by hydrocarbons in the oxygen excess. [ABSTRACT FROM AUTHOR]

Conditions for the preparation of stable aqueous monometallic and bimetallic colloidal solutions (sols) of noble metals (Ru, Rh, Pd, Pt, Ir, Ag, and Au) in the presence of polyoxometalates containing W, Mo, V, and Nb were found. The stability of sols against coagulation at room temperature was studied. The metal/C samples prepared by metal adsorption from sols were studied by powder X-ray diffraction analysis and transmission electron microscopy. The following factors of importance for the preparation of a stable sol are discussed: (1) the formation of a sol of a metal polyhydroxo complex stabilized by a polyoxometalate (preliminary stage) and (2) the formation of polyoxometalate-metal clusters in the course of reduction of polyhydroxo complexes. [ABSTRACT FROM AUTHOR]