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1.
E. Yu. Asalieva L. V. Sineva E. A. Zhukova V. Z. Mordkovich B. M. Bulychev 《Russian Chemical Bulletin》2015,64(10):2371-2376
The phase composition and physicochemical and catalytic properties of three samples of cobalt–aluminum–zeolite systems were studied. The catalytic properties of the systems are related to the application of a highly porous acidic support and the presence of cobalt oxide crystallites of an optimal size (6–12 nm). The occurrence of an efficient heat-conductive spatial net formed by metallic aluminum particles is also important for catalytic performance. 相似文献
2.
Polyakov K. M. Mordkovich N. N. Safonova T. N. Antipov A. N. Okorokova N. A. Dorovatovskii P. V. Veiko V. P. 《Crystallography Reports》2021,66(5):786-790
Crystallography Reports - Crystals of mutants of uridine phosphorylase from Shewanella oneidensis MR-1 at the active-site threonine residue were obtained, and the three-dimensional structures of... 相似文献
3.
We report here an experimental observation of field emission from arrays of multiwall carbon nanotubes. Current densities
in the range 10–30 mA/cm2 with excellent long-term stability were recorded. A detailed study of the destruction of nanotubes at extreme operation conditions
is performed. We established that field evaporation of nanotubes accompanies field emission from a cold cathode at electric
fields higher than 2 V/?. Electron microscopy of the evaporation products reveals irregularly shaped carbon nanoparticles
with a hollow core. The diameter of the particles is ∼20 nm. A mechanism of the process is proposed and discussed.
Received: 6 October 2000 / Accepted: 28 April 2001 / Published online: 27 June 2001 相似文献
4.
V. Z. Mordkovich 《Molecular Crystals and Liquid Crystals》2013,570(1):775-780
Abstract Interaction between multiwall nanotubes and intercalating agents (K or FeCl3) was studied using seven different nanotube materials. SEM, TEM, X-ray diffraction, Raman spectroscopy and other techniques were employed to study the reaction products. It was found that the reaction way is determined by nanotube structural type and that nanotubes may exhibit three types of reaction behaviour: intershell intercalation: no-reaction; and intercalation-assisted break-up. 相似文献
5.
The interaction of a Pt6 nanoparticle with different oxide supports, viz., γ-Al2O3, FAU and MFI zeolites, was investigated using the density functional theory. The interaction with the basic oxygen anions of the lattice and with hydroxyl groups of the support affects the electronic structure of the metal particles. The transfer of H atoms of the hydroxyl groups to the metal particle suppresses the Brönsted acidity of the support, and the activation energy of proton transfer decreases with an increase in the acidity of the support. The potential energy profiles were calculated for the transfer processes, and changes in the electronic structures and charge distribution of the supported particles were outlined. The H atom transfer results in positive charging by the metal particles, whereas the interaction with basic sites leads to the appearance of electron-enriched metal clusters. 相似文献
6.
Effect of epitaxial growth on the formation of the cobalt catalysts of the Fischer-Tropsch synthesis
Ya. V. Mikhailova S. A. Sviderskii M. N. Mikhailov I. V. Mishin V. Z. Mordkovich 《Russian Chemical Bulletin》2007,56(9):1922-1926
Mixed oxides CoxAlyO4 with different Al/Co ratios applied as supports for the catalysts of the Fischer-Tropsch synthesis were prepared using the
solid-state chemical reaction. The CoxAlyO4 supports were prepared by modifying gibbsite with various cobalt salts (acetate, nitrate, and basic carbonate). The use of
basic cobalt carbonate gives the Co(20%)/CoxAlyO4 catalyst, which provides an increased yield of hydrocarbons C5+ and a decreased methane content compared to the impregnation catalyst Co(30%)/Al2O3. The introduction of small amounts of rhenium additives makes it possible to enhance the yield of hydrocarbons C5+ (179 g m−3) and also to increase the selectivity with respect to the C5–C18 fraction. The introduction of basic cobalt carbonate into the support, most likely, creates favorable conditions for the
epitaxial growth of the precursor of the active phase.
Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1856–1860, September, 2007. 相似文献
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8.
Sineva L. V. Nalivaiko E. O. Gryaznov K. O. Mordkovich V. Z. 《Kinetics and Catalysis》2022,63(3):321-329
Kinetics and Catalysis - The role of a zeolite in the H-form in heat and mass transfer in pellets of a composite Co catalyst for Fischer–Tropsch synthesis (FTS) has been studied. It has been... 相似文献
9.
K. D. Shcherbachev M. I. Voronova V. T. Bublik V. N. Mordkovich D. M. Pazhin V. I. Zinenko Yu. A. Agafonov 《Crystallography Reports》2013,58(7):1030-1036
The influence of the implantation of silicon single crystals by fluorine, nitrogen, oxygen, and neon ions on the distribution of strain and the static Debye-Waller factor in the crystal lattice over the implanted-layer depth has been investigated by high-resolution X-ray diffraction. The density depth distribution in the surface layer of native oxide has been measured by X-ray reflectometry. Room-temperature implantation conditions have ensured the equality of the suggested ranges of ions of different masses and the energies transferred by them to the target. It is convincingly shown that the change in the structural parameters of the radiation-damaged silicon layer and the native oxide layer depend on the chemical activity of the implanted ions. 相似文献
10.
K. D. Shcherbatchev V. T. Bublik Yu. F. Trush A. S. Markevich V. N. Mordkovich 《Crystallography Reports》2003,48(2):187-191
The influence of photoexcitation on the formation of the defect structure in GaAs crystals implanted with 200 keV Ar+ ions at doses of 1 × 1013, 3 × 1013, and 5 × 1013 cm?2 has been studied by high-resolution Xray diffractometry. It was found that photoexcitation gives rise to annihilation of radiation-induced Frenkel pairs, and, thus, decreases the residual concentration of radiation-induced point defects. It is established that amorphization of the damaged layer proceeds via the formation and growth of clusters of radiation-induced point defects. The vacancy-and interstitial-type clusters are spatially separated—the former are located closer to the crystal surface than the latter. Photoexcitation hinders cluster growth and stimulates diffusion of interstitial defects into the substrate depth. 相似文献