Energy spectrum in the force field of an electrostatic image

Moscow State University. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 78, No. 1, pp. 109–115, January, 1989.     

Reactivity of trimethylsilylated derivatives of cysteine and 2-mercaptoethylamine relative to aromatic aldehydes

Conclusions Trimethylsilyl derivatives of alkylaminothiols are convenient reagents for the synthesis of thiazolidines from aromatic aldehydes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 228–229, January, 1986.     

A comparative TEM study of the 3D lattice of tellurium nanoclusters fabricated by different techniques in an opal host

An electron-microscope study of synthetic opals containing tellurium introduced into the regular void array either by melt injection or by evaporation from solution is reported. In the first case, a three-dimensional array of tellurium clusters interconnected by bridges was revealed. The clusters retain the same crystallographic orientation as one moves from one cluster to another. This suggests that cooling after inserting tellurium results in its directional crystallization, which is possibly controlled by the interconnecting channels. The second technique of tellurium introduction produces a nonuniform cluster array, with three-dimensional clusters growing not in all voids. The surface of most of the silica spheres is coated by a thin discontinuous layer of tellurium. This structure of the cluster array accounts for the nonlinear current-voltage characteristic of the object as a whole. A possibility of engineering cluster lattices differing in structural parameters has been demonstrated. Fiz. Tverd. Tela (St. Petersburg) 39, 2090–2095 (November 1997)     

Relaxation processes from highly-excited vibrational levels of fluorenone molecules

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 51, No. 5, pp. 818–822, November, 1989.     

1-Nitro-2-thio(sulfonyl)alkenes in Reactions with Thiols

Reactions of 1-nitro-2-sulfonylalkenes with arenethiolates result in replacement of the sulfonyl group; the reactions with alkanethiolates are accompanied by subsequent addition of the reagent at the double bond to afford thioacetals. Less reactive -nitro--R-thiostyrenes with thiolates at reduced temperature form addition products which are converted into the corresponding substitution products on storage at room temperature, in keeping with the addition-elimination mechanism of nucleophilic vinyl substitution. Nitro(arylthio)- and nitro(heterylthio)alkenes react with alkanethiolates at room temperature, resulting in replacement of the arylthio (heterylthio) group by alkylthio.     

Investigation on the TeO2-MoO3-V2O5 System I. Phase Equilibrium

The phase equilibrium in the TeO₂-MoO₃-V₂O₅ system has been determined in air at atmospheric pressure. Differential thermal analysis (DTA), X-ray diffraction and optical microscopy were used for establishing the phase transitions. Two congruently melting ternary compounds (Te₃Mo₂V₂O₁₇ and TeMoV₂O₁₀) were identified by the above methods. Their fields of primary crystallization are entirely within the glass-formation range. The character and behaviour of the phases, the invariant points as well as the temperature maxima have been discussed. The glass-formation range correlates with the phase distribution in the system and includes all ternary invariant points.     

Synthesis of 2-trichloromethyloxazolidin-5-ones by reaction of chloral with N,O-trimethylsilyl derivatives of amino acids

The corresponding 2-trichloromethyloxazolidin-5-ones were obtained by reaction of chloral with trimethylsilyl (TMS) derivatives of some amino acids. The corresponding oxazolidin-5-ones could not be obtained by the action of chloral on aspartic and glutamic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1472–1473, November, 1978.     

S4N4 und seine Derivate: Darstellung und Röntgenstrukturanalyse von CuCl2 · S4N4

Phase equilibrium in the TeO₂? Cu₂O system was determined in air at atmospheric pressure. Differential thermal analysis (DTA), X-ray powder diffraction and optical microscopy were used to identify the phase transitions. Two congruently melting compounds Te₃Cu₂O₇ and TeCu₂O₃ were obtained. They possess monoclinic and hexagonal symmetry respectively. The morphology, optical properties and indexed powder pattern up to 1.3 Å are submitted for these compounds. Experiments realized by the DTA indicated the existence of an oxidation process with beginning and rate dependent on the composition. The glass formation limits determined for 2 g and 10 g tellurite glass melts correlate with the invariant points in the system.     

Electron probe X-ray microanalysis of archeological finds of the Baikal region

A procedure was developed for determining Fe, Ni, Sn, and Zn in copper by electron probe X-ray microanalysis. The dependence of the detection limits for analytes on excitation conditions was studied and the optimum conditions for measuring the analytical signal were found. It was shown that the precision of quantitative electron probe microanalysis depends on the homogeneity of the reference samples. Individual certified reference samples of copper alloys previously synthesized for spectrochemical and chemical analysis were applied to electron probe microanalysis and justified. Performance characteristics of the proposed procedure were evaluated. Examples of using the procedure for determining the composition of archeological finds from a burial place in the Baikal region are presented.     

Selective oxidation of hydrocarbons into synthesis gas at short contact times: Design of monolith catalysts and main process parameters

This review summarizes the main achievements of the Boreskov Institute of Catalysis (Siberian Division, Russian Academy of Sciences) in the development of efficient and stable monolith catalysts for selective oxidation of hydrocarbons into synthesis gas at short contact times. Research in this field has included (1) design of new types of active component based on metal oxides, (2) design of new types of monolith support and development of supporting procedures for active components, and (3) optimization of process parameters for different types of fuel (natural gas, isooctane, and gasoline) and oxidant (air oxygen, including its mixtures with water and carbon dioxide), including the start-up regime. Design of active components (platinum, nickel, or their combination) supported on fluorite-like solid solutions based on cerium dioxide and rare-earth (samarium, gadolinium, and praseodymium) or zirconium cations has been aimed at separating hydrocarbon activation (on metal sites) and oxidation (on the support) and conjugating the separated steps of hydrocarbon oxidation at the metal-oxide interface. Optimization of oxygen mobility in the support lattice by varying the nature and concentration of doping cation along with optimization of hydrocarbon activation on supported metal clusters allow hydrocarbons to be completely converted into synthesis gas by selective oxidation or dry or steam reforming at contact times of a few milliseconds, ruling out undesirable carbon build-up on the catalyst surface. The development of new types of monolith support has targeted the enhancement of thermal shock resistance, including testing of supports based on thermally stable metal foils and composites (cermets). The main steps of the production of these supports have been refined, including unique technologies of blast dusting and hydrothermal treatment. The electric conductivity of these systems allows a quick startup of selective oxidation to be performed by passing electric current, and their thermal conductivity minimizes the temperature gradient arising from heat transfer in the bed. Procedures for loading monolith supports with active components have been developed, including impregnation, washcoating, or encapsulation in cermet matrices. The catalysts produced show a high efficiency and an operational stability adequate to the above tasks in the selective oxidation and steam-air autothermal reforming of natural gas (including processes under pressure), isooctane, and gasoline into synthesis gas.__________Translated from Kinetika i Kataliz, Vol. 46, No. 2, 2005, pp. 243–268.Original Russian Text Copyright © 2005 by Sadykov, Pavlova, Bunina, Alikina, Tikhov, Kuznetsova, Frolova, Lukashevich, Snegurenko, Sazonova, Kazantseva, Dyatlova, Usoltsev, Zolotarskii, Bobrova, Kuzmin, Gogin, Vostrikov, Potapova, Muzykantov, Paukshtis, Burgina, Rogov, Sobyanin, Parmon.