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1.
D. N. Kamaev S. A. Archugov G. G. Mikhailov 《Russian Journal of Applied Chemistry》2005,78(3):347-350
The system Al2O3-ZrO2 at temperatures of up to 2100°C was studied by differential thermal analysis.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 353–356.Original Russian Text Copyright © 2005 by Kamaev, Archugov, Mikhailov. 相似文献
2.
A. D. Chervonnyi 《Russian Journal of Inorganic Chemistry》2010,55(4):556-559
The A1, O, AlO, A12O, Al2O2, WO2, and WO3, partial pressures in the vapor over Al2O3 in a tungsten Knudsen effusion cell between 2300 and 2600 K were derived from A1+, O+, AlO+, A12O+, Al2O2+, WO2+, and WO3+, ion intensities. The mass spectrometer was calibrated against the equilibrium constant of the WO3(g) = WO2(g) + O(g) reaction. Refined values of the ionization cross sections of AlO and A12O2 were used in the partial pressure calculations. The enthalpies of atomization of aluminum suboxides were determined to be
Δat
H
o(AlO, g, 0) = 510.7 ± 3.3 kJ mol−1, Δat
H
o(Al2O, g, 0) = 1067.2 ± 6.9 kJ mol−1, and Δat
H
o(Al2O2, g, 0) = 1556.7 ± 9.9 kJ mol−1. 相似文献
3.
4.
A. B. Velichenko V. A. Knysh T. V. Luk’yanenko D. Devilliers F. I. Danilov 《Russian Journal of Electrochemistry》2008,44(11):1251-1256
The regularities of electrodeposition of composite materials based on PbO2 containing zirconium dioxide particles are studied. The contents of various phases in the composite depend on the electrolyte composition and conditions of deposition. When a dispersed phase is incorporated into the composite coating, the dimensions of lead dioxide crystals decrease to submicrons. 相似文献
5.
O. V. Al’myasheva E. A. Vlasov V. B. Khabenskii V. V. Gusarov 《Russian Journal of Applied Chemistry》2009,82(2):217-221
Catalytic properties in relation to the hydrogen oxidation reaction and thermal stability of materials based on the nanocomposite amorphous Al2O3-nanocrystalline ZrO2 were studied. 相似文献
6.
Liquid-phase reduction NO
3
−
using monometallic and bimetallic catalysts (5% Rh/Al2O3, 5% Rh-0.5% Cu/Al2O3, 5% Rh-1.5% Cu/Al2O3, 5% Rh-5% Cu/Al2O3 and a physical mixture of 5% Rh/Al2O3 and 1.5% Cu/Al2O3) was studied in a slurry reactor operating at atmospheric pressure. Kinetic measurements were performed for a low concentration
of nitrate (0.4 × 10−3−3.2 × 10−3 mol dm−3) and the temperature range 293–313 K. From the experimental data, it was found that the reduction of nitrate is first order
with respect to nitrate. On the basis of the rate constants, the apparent activation energy was established using a graphic
method.
Published in Russian in Kinetika i Kataliz, 2007, Vol. 48, No. 6, pp. 881–886.
This article was submitted by the authors in English. 相似文献
7.
Al2O3-Cr2O3 solid solutions with 0, 4, 7, 10 and 20 mol% of corundum were synthesized using a high-pressure/high-temperature apparatus
and characterized by X-ray powder diffraction.
Calorimetric measurements were carried out using DSC-111 (Setaram). Heat capacity was measured by the enthalpy method in a
temperature range of 260–340 K, near magnetic phase transition in pure Cr2O3 (305 K). Magnetic contribution into the heat capacity was derived and found to change irregularly with the composition. 相似文献
8.
Yu. F. Kargin S. N. Ivicheva L. I. Shvorneva 《Russian Journal of Inorganic Chemistry》2008,53(8):1297-1299
Phase relations in the MgO-Bi2O3-B2O3 system have been investigated by X-ray powder diffraction analysis and DTA. No ternary compounds have been found in the system. Quasi-binary sections have been the 600°C determined and isothermal section of the system has been constructed. 相似文献
9.
Coexisting solid solutions with spinel and corundum structure were synthesized at 1773 K and two pressures, 1 bar and 25 kbar.
Samples were analyzed by electron microprobe analysis and X-ray powder diffraction.
Pressure and temperature were shown to affect the properties of the solid solutions in different ways. Pressure governs the
composition of the defect spinel Mg1−xAl2O4, and temperature changes the cation distribution between coexisting phases. This allows one to separate the effects of cation
exchange and magnetic contribution to the heat capacity in thermodynamic modeling. The defect spinel itself can form only
because γ-Al2O3 exists, polymorph with spinel structure. 相似文献
10.
M. G. Zuev 《Russian Journal of Inorganic Chemistry》2007,52(3):424-426
The phase composition has been studied and an equilibrium phase diagram has been designed for the Al2O3-Li2O-R2O5 (R = Ta or Nb) systems in the subsolidus region up to 1000°C and 85 mol % Li2O. New phases with the composition Li1+x Al1?x O2?x , where x = 0–0.67, have been found. 相似文献
11.
It has been presented that the bulk mechanical alloying occurring in the Ni-hydroxycarbonate-aluminium mixture can produce
homogeneously refined composite of nickel aluminides with aluminium oxide. The control of mechanochemical phenomenon was carried
out by phase identification of milling products as well as their structural and morphological characterization. As a result
the thermoanalytical and X-ray powder diffraction measurements as well as scanning electron microscopy with backscattered
electron images (BSE) and X-ray energy dispersive spectroscopy (EDS) were applied. It was found that the kinetics of mechanochemical
reactions depends on the chemical nature of initial salt.</o:p> 相似文献
12.
Summary A series of Al2O3-SnO2 catalysts with Al2O3 to SnO2 molar ratio of 1:1, 1:0.5, 1:0.2 and 1:0.1 were synthesized by sol-gel technique and characterized by thermal analysis and FTIR. In the case of binary gels - addition of tin component leads to better crosslinking than in pure alumina gel and as a result to a much uniform texture structure. 相似文献
13.
E. A. Tugova 《Russian Journal of General Chemistry》2016,86(11):2410-2417
Regularities of formation of complex aluminates with structure of P/RS intergrowth type phases in the Ln2O3–MO–Al2O3 systems (Ln = rare-earth element, M = Mg, Ca, Sr, Ba) have been considered. Systematization of the data on formation of complex compounds coexisting with one-layer phases in the Ln2O3–MO–Al2O3 systems and analysis of geometry criteria of LnMAlO4 stability is a promising approach to prediction of novel compounds with structure of Ruddlesden–Popper phase. 相似文献
14.
T. L. Lekanova Yu. I. Ryabkov O. A. Sevbo V. N. Filippov 《Russian Journal of Applied Chemistry》2005,78(8):1223-1228
Interactions in the Al2TiO5-Ti2O3 system were studied and the regions of existence of Al2?2xTi 2x 3+ Ti4+O5 solid solutions with a pseudobrookite structure were determined. 相似文献
15.
Qiang Chen Shaohua Zheng Shikuan Yang Wei Li Xiaoyun Song Bingqiang Cao 《Journal of Sol-Gel Science and Technology》2012,61(3):501-508
Monodispersed and hydrophobic ZnO/Al2O3 composite nanoparticles are prepared by a nonhydrolytic sol–gel method. ZnCl2 and AlCl3 are dissolved in acetone and used as precursors. Oleic acid is adopted as an oxygen donor. The tribology properties of the
prepared ZnO/Al2O3 composite nanoparticles are studied by the four-ball friction and thrust ring friction test. It is demonstrated that the
average friction coefficient and the wear scar diameter are reduced by 37.5 and 26.2%, respectively, in comparison with pure
lubricating oil. Moreover, the ZnO/Al2O3 composite nanoparticles bear the merits of ZnO and Al2O3 when used as lubricant additives, exhibiting both excellent antifriction and antiwear behaviors simultaneously. The ZnO/Al2O3 composite nanoparticles improve the lubrication effect not only by turning the sliding friction into rolling friction, but
also forming a hard Al2O3 protective film onto the thrust-ring surface containing ZnO/Al2O3 nanoparticles, which have much potentiality in industrial applications. 相似文献
16.
A. V. Egorysheva V. D. Volodin T. Milenov P. Rafailov V. M. Skorikov T. D. Dudkina 《Russian Journal of Inorganic Chemistry》2010,55(11):1810-1817
A physicochemical study of glasses based on the MO-Bi2O3-B2O3 and SrO-Bi2O3-B2O3 systems was performed. Glass formation regions were found. The structural and optical properties, as well as the thermal
behavior of the glasses, were studied. 相似文献
17.
The adsorption of carboxymethylcellulose (CMC) in the presence or absence of the surfactants: anionic SDS, nonionic Triton
X-100 and their mixture SDS/TX-100 from the electrolyte solutions (NaCl, CaCl2) on the alumina surface (Al2O3) was studied. In each measured system the increase of CMC adsorption in the presence of surfactants was observed. This increase
was the smallest in the presence of SDS, a bit larger in the presence of Triton X-100 and the largest when the mixture of
SDS/Triton X-100 was used. These results are a consequence of formation of complexes between the CMC and the surfactant particles.
Moreover, the dependence between the amount of surfactants’ adsorption and the CMC initial concentration was measured. It
comes out that the surfactants’ adsorption amount is not dependent on the CMC initial concentration and moreover, it is unchanged
in the whole measured concentration range. The influence of kind of electrolyte, its ionic strength as well as pH of a solution
on the amount of the CMC adsorption at alumina surface was also measured. The amount of CMC adsorption is larger in the presence
of NaCl than in the presence of CaCl2 as the background electrolyte. It is a result of the complexation reaction between Ca2+ ions and the functional groups of CMC belonging to the same macromolecule. As far as the electrolyte ionic strength is concerned
the increase of CMC adsorption amount accompanying the increase of electrolyte ionic strength is observed. The reason for
that is the ability of electrolyte cations to screen every electrostatic repulsion in the adsorption system. Another observation
is that the increase of pH caused the decrease of CMC adsorption. The explanation of this phenomenon is connected with the
influence of pH on both dissociation degree of polyelectrolyte and kind and concentration of surface active groups of the
adsorbent. 相似文献
18.
K. Wieczorek-Ciurowa K. Gamrat Z. Sawłowicz 《Journal of Thermal Analysis and Calorimetry》2005,80(3):619-623
Summary Reactive milling of Cu-hydroxycarbonate - powder aluminium mixture brings many complex chemical reactions such as decomposition, aluminothermic reduction and mechanical alloying resulting in the formation of nanometer size composites that contain intermetallic phases, -Cu9Al4 and -CuAl2, with aluminium oxide. 相似文献
19.
N. V. Lyskov Yu. G. Metlin K. I. Astaf’eva Yu. D. Tret’yakov L. S. Leonova Yu. A. Dobrovol’skii 《Russian Journal of Electrochemistry》2007,43(4):390-397
Composites ZrO2-(Bi2CuO4+ 20 wt % Bi2O3) (50–80 vol % ZrO2) are synthesized and their physicochemical properties are studied. It is demonstrated that the composites comprise triple-phase mixtures of ZrO2 of a monoclinic modification, Bi2CuO4, and solid solution Bi2?x Zr x O3 + x/2 and retain their mechanical strength up to 800°C. Impedance spectroscopy is used to examine their electroconductivity at 700–800°C in the interval of partial oxygen pressures extending from 37 to 2.1 × 104 Pa. Contributions made by electronic and ionic constituents to their overall conductivity are evaluated. The best specimens’ conductivity is ~0.01 S cm?1, with the electronic and ionic transport numbers nearly equal. The composite consisting of 50 vol % ZrO2 and 50 vol % (Bi2CuO4 + 20 wt % Bi2CuO4) is tested in the role of an oxygen-separating membrane. The selective flux of oxygen in the temperature interval 750–800°C amounts to (2.2–6.3) × 10?8 mol cm?2 s?1, testifying that these materials may be used as gas-separating membranes. 相似文献
20.
Emil D. Krumov Dimitar G. Popov Nikolay S. Starbov 《Central European Journal of Chemistry》2005,3(4):668-673
Thick aluminum oxide films are prepared on Al plates by anodizing. On the ceramic surface thus obtained a very thin Ag film
is deposited via vacuum thermal evaporation. The Ag/Al2O3/Al samples prepared are irradiated by Nd:YAG laser through a suitable metal mask in order to remove the top metal film in
the exposed areas. Thus, a negative silver image of the copied mask is obtained. Further, the samples are processed in Ni
electroless chemical bath activated by the rest of silver. All processing steps are studied by scanning electron microscopy
(SEM). EDS X-ray mapping is applied to study the final distribution of Al and Ni in the processed areas. In addition, the
DC conductivity of the fabricated Ni wires obtained is measured. The proposed new method for selective chemical deposition
of electroconductive Ni onto laser microstructured Ag/Al2O3/Al samples is simple, versatile and not restricted to the metal/ceramic system studied as well as to the electroless deposited
metal. 相似文献