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Том 484, № 1 (2019)
- Год: 2019
- Статей: 8
- URL: https://journals.rcsi.science/0012-5008/issue/view/9308
Chemistry
Formation of Nanoscale Sodium Dodecahydro-closo-Dodecaborate Na2[B12H12] on the Surface of a Silicate Matrix
Аннотация
The method of synthesis of nanoscaled sodium dodecahydro-closo-dodecaborate Na2[B12H12] is presented. The desired product has been prepared by heating to 200°C the composite formed by the introduction of the triethylammonium salt [Et3NH]2[B12H12] into the silicate matrix of sodium liquid glass. The morphology and phase composition of the synthesized sample have been studied by SEM and X-ray diffraction methods in comparison with regular Na2[B12H12] salt. According to the obtained data, the sample under study is an amorphous composite, on the surface of which nanoscale crystals of Na2[B12H12] are formed.
1-4
Morphologic, Chemical, and Spectral Analyses of Combustion Products of Micro- and Nanodispersed Particles of Aluminum Borides
Аннотация
The results of studying flame propagation in the air suspension of nanodispersed particles of powdered aluminum polyboride are presented. Spectral, morphologic, and mass spectrometry analyses of condensed combustion products formed during burning of the air suspension of this powder have been performed.
5-7
Interaction of Ionic Liquids with Sulfur
Аннотация
The interaction of tri-n-butylmethylphosphonium dimethyl phosphate and 1,3-dimethylimidazolium dimethyl phosphate with elemental sulfur in a benzene medium has been described. According to 13C and 17O NMR and high-resolution mass spectrometry, the chemical reaction involves only the dimethyl phosphate anion. The reaction mechanism and the reaction product composition have been proposed.
8-11
Electroreduction of the Bromate Anion on a Microelectrode in Excess Acid: Solution of the Inverse Kinetic Problem
Аннотация
Acidic aqueous solutions of bromic acid salts (bromates) are promising electrolytes for redox flow batteries due to their record high power capacity and the rate of electrode reactions proceeding in the autocatalytic regime. The paper gives a comparison of the results of mathematical modeling and experimental measurements of steady-state currents of bromate anion electroreduction in sulfuric acid medium on microelectrodes of various radii. An algorithm of solving the inverse problem suitable for determination of the key transport and kinetic process parameters was proposed and tested.
12-15
New Metal Oxide Composite Materials as Efficient Catalysts of Partial Oxidation of Methane
Аннотация
Single-phase complex oxides Nd2 – yCayCoxNi1 – xO4 have been synthesized for the first time. Composites prepared by the reduction of these compounds with hydrogen and containing Nd2O3, CaO, and cobalt and nickels metals have been used for the first time as catalysts of the partial oxidation of methane. The maximal methane conversions (97%) and syngas yields (96%) at 900°С have been detected in the presence of the composite obtained from Nd1.5Ca0.5NiO4. At T < 850°C, the nickel–cobalt composite synthesized from Nd1.3Ca0.7Co0.4Ni0.6O4 turned out to be more selective in the formation of syngas. Decreasing the partial oxidation temperature from 900 to 750°С leads to the oxidation of metallic nickel and cobalt to oxides and to partial resynthesis of complex oxides with perovskite and K2NiF4 structures. The observed differences in temperature dependence of the catalytic properties of composites with various Ni/Co ratios can be associated with the participation of complex oxides in catalysis of the partial oxidation of methane at low temperatures.
16-18
Chemical Technology
Synthesis of Nickel Nanoparticles with Controlled Pyrophoricity and Average Size
Аннотация
19-23
Effect of the Initial Temperature on the Modes of Passivation of Pyrophoric Powders: Macrokinetic Approach
Аннотация
The thermal modes of passivation of pyrophoric nanopowders at a reduced initial temperature of a nanopowder bed were studied by analytical and numerical methods using a macrokinetic approach. It was shown that a decrease in the initial temperature of a nanopowder leads to a transition from the layer-by-layer passivation mode to the bulk passivation mode, which makes it possible to control the acceptable warmup level in passivation even if the oxidizer concentration in the gas is high. Analytical expressions for determining the boundaries of the layer-by-layer and bulk passivation modes were derived and confirmed by numerical calculations.
24-28
Computer-Aided Multiagent Model of Chemicophysiological Processes in the Human Gastrointestinal Tract as a Living Biochemical System
Аннотация
A methodology was proposed to develop an original computer-aided multiagent model of chemicophysiological processes in the human gastrointestinal tract (GIT) as a complex living biochemical system (LBCS), which simulates chemicophysiological processes of interaction of biologically active parts and organs of GIT in models of intelligent organoid agents. The model vividly represents chemicophysiological processes of the complex LBCS as a whole and also predicts its viability and homeostasis in cases of various physiological and biochemical external actions, internal abnormalities, and malfunctioning of GIT organs.
29-32