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41.
A. S. Ivanova M. V. Mikhan' G. M. Alikina G. S. Litvak E. M. Moroz E. B. Burgina 《Kinetics and Catalysis》2000,41(6):816-825
The possibility for the formation of garnet structures in the Mn–Fe–Zr–O and Ca–Sm–Zr–O systems obtained by the precipitation of the corresponding salts is studied. It is shown that, in the Mn–Fe–Zr–O system, garnet is crystallized at 860–920°C, for which probable cation distribution is estimated to be {Zr2.5
4+Mn0.5
2+}[Mn2
2+](Fe2.5
3+Mn0.5
3+)O12. In the Ca–Sm–Zr–O system, the perovskite CaZrO3, pyrochlore Sm2Zr2O7, and CaO are formed at 900–1200°C, but compounds with garnet structures are not found. The reported systems are characterized by surface areas of 300–450 m2/g at 450°C, and they have the polydisperse distribution of pores over sizes. The introduction of surfactants at the stage of component mixing enables an increase in the overall pore volume and mechanical strength of these systems. The Mn–Fe–Zr and Ca–Sm–Zr compositions are active catalysts for the complete oxidation of hydrocarbons. 相似文献
42.
Grinevich V. I. Ivanova N. V. Kostrov V. V. 《Russian Journal of Applied Chemistry》2003,76(4):561-565
Data on the kinetics of plasma-enhanced and plasma-enhanced catalytic oxidation of carbon(II) oxide with IK-1-6 catalyst are presented. The influence exerted by IK-1-6 catalyst on the conversion of carbon-containing components of the CO-CO2-CH4-SO2-air gas mixture in barrier-discharge plasma is analyzed. 相似文献
43.
E. I. Voronina G. M. Ostapchuk T. M. Ivanova T. A. Babushkina L. B. Shagalov N. N. Suvorov 《Chemistry of Heterocyclic Compounds》1984,20(3):275-277
It is shown that, in addition to the usually formed 3-formyl-4,5-benzindole, 2-formyl-4,5-benzindole can be obtained via the Vilsmeier reaction. The IR, PMR, and UV spectra of the 2- and 3-formyl isomers are compared, and their possible conformations are discussed.See [1] for Communication 22.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 343–345, March, 1984. 相似文献
44.
The geometry of the 4′-cyano-(4′-CNPTB) and the 4′-methoxy-(4′-MePTB) phenylthiolbenzoates were obtained by ab initio calculations
employing 6–31G basis set at Hartee-Fock level of theory. The results predict an extended form of the molecules and torsional
angle between the phenyl rings at 90.85(6)0 and 90.87(3)0, respectively. On the basis of vibrational analysis the frequency assignment was carried out. The calculated frequencies
were compared with the experimental IR spectral data in carbon tetrachloride, carbon disulfide solutions and in solid state. 相似文献
45.
E. V. Ivanov E. Yu. Lebedeva V. K. Abrosimov N. G. Ivanova 《Russian Chemical Bulletin》2004,53(4):751-757
Densities of Bun
4NBr solutions in MeOH, MeOD, and CD3OH were measured at salt concentrations of up to 1.5 solvomolality units (nearly 2.63·10–2 mole fraction) at 278.15, 288.15, 298.15, 308.15, and 318.15 K. The limiting partial molar volumes of Bun
4NBr dissolved in these alcohols were calculated. The isotope effects in the volume characteristics of the stoichiometric mixture of ions, [Bun
4N+ + Br–], are mainly due to the vibrational changes in the solvent structure upon deuteration of different molecular fragments. Structural transformations in infinitely dilute solution of Bun
4NBr in methanol are governed by non-specific solvation of the symmetrical Bun
4N+ cation. 相似文献
46.
Ivanova N. A. Khusainova A. A. Shangiraeva F. G. Akhmetvaleev R. R. Miftakhov M. S. 《Russian Journal of Organic Chemistry》2003,39(10):1489-1492
The reduction of 2-chloro-4,4-ethylenedioxy-3-phenylsulfanyl-2-cyclopentenone with sodium tetra-hydridoborate in ethanol yields 3-chloro-4-hydroxy-2-phenylsulfanyl-2-cyclopentenone, while with the use of lithium aluminum hydride in tetrahydrofuran or the system Zn/NH4Cl in methanol products of more profound reduction are obtained. 相似文献
47.
M. N. Repkova M. I. Meshchaninova T. M. Ivanova N. I. Komarova D. V. Pyshnyi A. G. Venyaminova 《Russian Chemical Bulletin》2002,51(7):1194-1197
A solid-phase H-phosphonate procedure was developed for the synthesis of oligoribonucleotides containing aliphatic amino linkers with different lengths at the N(4) atom of cytosine. The hybridization properties of modified oligoribonucleotides were studied. Thermal stability of the RNA—RNA* and DNA—RNA* duplexes depends on the position of modified cytosine in the chain and the type of the duplex. 相似文献
48.
The Ward correspondence between self-dual Yang-Mills fields and holomorphic vector bundles is used to develop a method for reducing the Lax pair for the self-duality equations of the Yang-Mills model ind=4 with respect to the action of continuous symmetry groups. It is well known that reductions of the self-duality equations lead to systems of nonlinear differential equations in dimension 1d3. For the integration of the reduced equations, it is necessary to find a Lax pair whose compatibility conditions is these equations. The method makes it possible to obtain systematically a Lax representation for the reduced self-duality equations. This is illustrated by a large number of examples.N. N. Bogolyubov Theoretical Physics Laboratory, JINR, 141980 Dubna, Russia. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 102, No. 3, pp. 384–419, March, 1995. 相似文献
49.
A flame AAS method is used for the determination of dopants and impurities in potassium titanylphosphate (KTP) single crystals. Sample digestion using sulphuric acid and hydrofluoric acid is proposed as being the most appropriate procedure. The effect of major and minor components in the sample solution on the analytical signal is studied. The content of the dopants Cr, Mn and Ni (at a level of about 1 mg g(-1)) as well as the content of the impurities Fe, Na, Mg, W and Al (from 4 mug g(-1), depending on the trace metal) in the KTP single crystals is determined. The precision of the method is characterized by a relative standard deviation of 3-10%. The accuracy is checked by comparison with ICP-AES data for the trace element content in the KTP single crystals. 相似文献
50.