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排序方式: 共有117条查询结果,搜索用时 109 毫秒
41.
42.
Natalie Smirnova Anna Eremenko Vladimir Gayvoronskij Irina Petrik Yuriy Gnatyuk Galina Krylova Andrey Korchev Alexej Chuiko 《Journal of Sol-Gel Science and Technology》2004,32(1-3):357-362
Titania and silica-based porous coatings have been produced via sol–gel route in the presence of pore-creating agents PEG and viscous solvent -terpineol, or template agents CTAB, as well as triblock copolimer Pluronic P123. Porous titania films were characterised by HR TEM, UV-Vis, XRD, ellipsometry, ARS methods. The dispersion of the refractive index, the porosity (32–39%) and the thickness of the samples were estimated by integrating sphere transmission and reflection spectra with 3D angular resolved light scattering. The catalytic activity of mesoporous TiO2 and TiO2/ZrO2 as well as SiO2-benzophenone films in the process of CrVI to CrIII and Ag+ to Ag0 photoreduction have been studied. 相似文献
43.
Vladimir V. TretyakovRID=""ID="" To whom correspondence should be addressed Sergey A. Rukolaine Alexandr S. Usikov Serge V. Makarov 《Mikrochimica acta》2000,132(2-4):361-364
Procedures for the preparation of bevels and the determination of their geometrical parameters have been developed. Using
these procedures study of compositional and optical spatially resolved inhomogeneities of AlxGa1−xN layers grown on (0001) sapphire have been studied by EPMA and cathodolu-minescence. It has been found that the nonuniform
distribution in depth of Al in epitaxial layers grown under constant conditions is connected with presence of stresses in
the layer. 相似文献
44.
具有中孔结构的SO4^2—/Zr—HMS型固体超强酸的合成和结构表征 总被引:6,自引:0,他引:6
用TEOS-Zr-HAD-H2O-Etheanol体系合成了Zr-HAD的中孔分子筛,脱除模板剂后用0.5mol/L硫酸处理和550℃高温焙烧3h,制得一种中孔SO4^2-/Zr-HAD超强酸催化剂,采用XRD对其结构进行表征,用指示剂法,TG和NH3-TPD对其酸性进行了表征。结果表明,经过一系列处理后制得的SO4^2-/Zr-HAD催化剂具备HMS中孔分子筛的结构特征,其酸强度可达H0=-13.75,在锆及SO4^2-含量远远低于SO4^2-/ZrO2的条件下,SO4^2-/Zr-HAD催化剂对于苯酐和正丁醇酯化反应的活性仍高于SO4^2-/ZrO2催化剂。 相似文献
45.
Remsing RC Petrik ID Liu Z Moyna G 《Physical chemistry chemical physics : PCCP》2010,12(44):14827-8; discussion 14829-30
46.
Du Y Petrik NG Deskins NA Wang Z Henderson MA Kimmel GA Lyubinetsky I 《Physical chemistry chemical physics : PCCP》2012,14(9):3066-3074
Combined scanning tunneling microscopy, temperature programmed desorption, photo stimulated desorption, and density functional theory studies have probed the formation and reactivity of highly-hydroxylated rutile TiO(2)(110) surfaces, which were prepared via a novel, photochemical route using trimethyl acetic acid (TMAA) dissociative adsorption and subsequent photolysis at 300 K. Deprotonation of TMAA molecules upon adsorption produces both surface bridging hydroxyls (OH(b)) and bidentate trimethyl acetate (TMA) species with a saturation coverage of nearly 0.5 monolayers (ML). Ultra-violet light irradiation selectively removes TMA species, producing a highly-hydroxylated surface with up to ~0.5 ML OH(b) coverage. At high coverages, the OH(b) species typically occupy second-nearest neighbor sites along the bridging oxygen row locally forming linear (2 × 1) structures of different lengths, although the surface is less ordered on a long scale. The annealing of the highly-hydroxylated surface leads to hydroxyl recombination and H(2)O desorption with ~100% yield, thus ruling out the diffusion of H into the bulk that has been suggested in the literature. In agreement with experimental data, theoretical results show that the recombinative H(2)O desorption is preferred over both H bulk diffusion and H(2) desorption processes. 相似文献
47.
Petrik M. V. Medvedeva N. I. Kadyrova N. I. Za?nulin Yu. G. Ivanovski? A. L. 《Physics of the Solid State》2010,52(8):1709-1713
The electronic structure and magnetic properties of double perovskite ErCu3V4O12 have been investigated in the framework of the projector augmented-wave method. It has been shown that the electron correlations
play an important role: the calculations in the one-electron approximation predict that the ground state of ErCu3V4O12 is a magnetic metallic state, while with the inclusion of electron-electron correlations, it is a ferrimagnetic semimetallic
state. It has been found that the magnetic Cu-Cu and V-V couplings are ferromagnetic and that the Cu-V magnetic coupling is
antiferromagnetic. 相似文献
48.
P. Basa P. Petrik M. Fried L. Dobos B. Pcz L. Tth 《Physica E: Low-dimensional Systems and Nanostructures》2007,38(1-2):76
Low-pressure chemical vapour deposited Si3N4/nc-Si/Si3N4 layers prepared on Si substrates were characterized by spectroscopic ellipsometry. Model Dielectric Function (MDF) was applied to obtain the thickness and the dielectric spectra of the middle nc-Si layer. Sensitive effect of the deposition time was obtained on the MDF parameters. A comparison is presented between the studied samples and reference materials. 相似文献
49.
A. Laznickova M. Petrik P. Hermann I. Lukes 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):583-586
The complex formation of the bifunctional monophosphinic acid DOTA analogue DO3APABn (1,4,7,10-tetraazacyclododecane-4,7,10-triacetic-1-{methyl[(4-aminophenyl)methyl] phosphinic acid}) with 111In at a tracer level was analyzed. Formation of a complex between 111In and DO3APABn was very rapid even at room temperature and high radiolabeling yields were achieved. As introducing the methylphosphinic
acid arm to the DOTA structure generated a chiral centre, more than one peak (probably corresponding to various diastereoisomers)
of 111In-DO3APABn were separated on HPLC. Four peaks were separated by HPLC, they probably correspond to four diastereoisomers of 111In-DO3APABn originating from combination of chirality of complexes of DOTA-like ligands with chirality of coordinated phosphorus atom.
Studies in rats showed rapid elimination of radioactivity from the blood and other organs and tissues. The results indicate
that DO3APABn represents a promising ligand for radiolabeling of target-specific biomolecules with radiometals. 相似文献
50.
Metal-organic chemical vapor deposition (MOCVD) made layers of strontium-bismuth-tantalate (SBT) were characterized by spectroscopic ellipsometry (SE) using the Adachi model [S. Adachi, Phys. Rev. B 35 (1987) 7454-7463]. The evaluated optical parameters were correlated with the physical and chemical behavior examined by X-ray diffraction (XRD).As a result, it was possible to fit the measured spectra with the Adachi model in a wide range covering the region of the band gap. The Adachi model provides electronic layer parameters like the transition energy E0 and broadening Γ. Our investigations established a correlation between XRD-determined average grain size and the electronic layer parameters. 相似文献