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11.
V. Ya. Kavun N. F. Uvarov A. B. Slobodyuk V. K. Goncharuk A. Yu. Kotenkov I. A. Tkachenko A. V. Gerasimenko V. I. Sergienko 《Russian Journal of Electrochemistry》2005,41(5):501-509
Methods of (19F, 1H) NMR and impedance spectroscopy are used to investigate the internal mobility and ionic conduction in solid solutions arising in the system PbF2-ZrF4 and polycrystals KSnZrF7, Li(Na)(NH4)6Zr4F23, and M2ZrF6 (M = K, NH4). Factors responsible for the form of ionic motions and their energetics at 170–550 K are considered. It is established that the phase transitions in these compounds are connected with the crystal transition to a superionic state and that the high ionic (superionic) conductivity of beta phases is due to the diffusion of fluoride ions, ammonium cations, and possibly alkali metal cations. The obtained data testify to a substantial role of chainlike aggregation of anionic groupings and a variableness of structural mechanisms of formation of such chains in fluorozirconates for the development of translational diffusion in these compounds.__________Translated from Elektrokhimiya, Vol. 41, No. 5, 2005, pp. 573–582.Original Russian Text Copyright © 2005 by Kavun, Uvarov, Slobodyuk, Goncharuk, Kotenkov, Tkachenko, Gerasimenko, Sergienko. 相似文献
12.
V. Ya. Kavun N. A. Didenko A. B. Slobodyuk I. A. Tkachenko A. V. Gerasimenko N. F. Uvarov V. I. Sergienko 《Journal of Structural Chemistry》2005,46(5):839-847
The mobility of fluoride and ammonium ions (180–480 K) in compounds K2? n (NH4)nZrF6 (0.2 ≤ n ≤ 1.70) was investigated by 19F and 1H NMR. Correlations have been found between the composition of the cation sublattice, the character of ion motions, and phase transition temperature in these compounds. The hightemperature modifications with n ≥ 0.85 of the compounds are characterized by translational diffusion of fluoride and ammonium ions and by uniaxial anisotropy of the 19F magnetic shielding tensor. The electrophysical characteristics of these compounds were studied in the temperature range 300–480 K. 相似文献
13.
Effects of the bead-bead potential on the restricted rotational diffusion of nonrigid macromolecules
The influence of the bead-bead interaction on the rotational dynamics of macromolecules which are immersed into a solution has been investigated by starting from the microscopic theory of the macromolecular motion, i.e., from a Fokker-Planck equation for the phase-space distribution function. From this equation, we then derived an explicit expression for the configuration-space distribution function of a nonrigid molecule which is immobilized on a surface. This function contains all the information about the interaction among the beads as well as the effects from the surrounding solvent particles and from the surface. For the restricted rotational motion, the dynamics of the macromolecules can now be characterized in terms of a rotational diffusion coefficient as well as a radial distribution functions. Detailed computations for the rotational diffusion coefficient and the distribution functions have been carried out for HOOKEAN, finitely extensible nonlinear elastic, and a DNA type bead-bead interaction. 相似文献
14.
D. A. de Vekki V. M. Uvarov V. K. Bel’skii N. K. Skvortsov 《Russian Journal of General Chemistry》2006,76(8):1288-1294
The transformations of platinum(II) and platinum(IV) complexes with inner-and outer-sphere ligands by the action of (+)-α-pinene and (+)-limonene were studied. Reduction of the metal complex is the main process whose rate increases in the following outer-sphere ligand series: (Me2SO)2H+ < Et3NH+ < K? < H+. The reaction of K2PtCl4 with α-pinene gave cis-terpine monohydrate and dichloro-η4-[p-mentha-1,8(9)-diene]platinum(II), and their structure was proved by X-ray analysis. The complex belongs to monoclinic crystal system, the Pt-Cl and Pt-C bonds therein have different lengths, the ClPtCl angle is 85.88°, and the C=C bond plane is orthogonal to the square coordination core. Dichloro-η4-[p-mentha-1,8(9)-diene]-platinum(II) was tested as catalyst in the hydrosilylation of acetophenone with diphenylsilane. 相似文献
15.
16.
Asanbaeva Nargiz B. Rychkov Denis A. Tyapkin Pavel Yu. Arkhipov Sergey G. Uvarov Nikolay F. 《Structural chemistry》2021,32(3):1261-1267
Structural Chemistry - The crystal and molecular structure of tris(tetrabutylammonium) pentanitratoplumbate(II) was determined and characterized by single-crystal and powder X-ray diffraction and... 相似文献
17.
D. V. Uvarov 《Physics of Particles and Nuclei Letters》2011,8(3):272-278
We review the Type IIA superstring on the AdS 4 × ??3 background in the κ-symmetry light-cone gauge characterized by the choice of the light-like directions from the D = 3 Minkowski boundary of AdS 4 both in the Lagrangian and Hamiltonian formulations. 相似文献
18.
Dynamic fragmentation scaling is analyzed using basic statistical distributions and statistical models that take into account the role of wave effects on the fragment size. The application of symmetry analysis to the modeling of solids with defects based on self-similar solutions for stress and defect density fields is discussed. Fragmentation statistics is described as critical phenomena during evolution of the defect system. 相似文献
19.
Grigoriev M. V. Krivonosov Yu. S. Buzmakov A. V. Chukalina M. V. Asadchikov V. E. Uvarov V. I. 《Crystallography Reports》2021,66(6):1100-1108
Crystallography Reports - X-ray microtomography is used for non-destructive reconstruction of the internal morphological structure of objects. The influence of the tomographic experiment conditions... 相似文献
20.
V. Ya. Kavun N. F. Uvarov L. A. Zemnukhova A. S. Ulikhin N. A. Didenko O. V. Brovkina V. I. Sergienko 《Russian Journal of Electrochemistry》2013,49(7):633-644
The ion mobility, phase transitions, and ionic conductivity in the crystal phases in the KF-NH4F-SbF3 system were studied by NMR, DTA, and impedance spectroscopy. An analysis of the 19F and 1H NMR spectra showed how the character of ionic motions in the fluoride and proton sublattices changed with temperature. The types and temperature ranges of ionic motions were determined. Diffusion of the fluoride and partially ammonium ions was found to be the dominant form of ionic motion in the high-temperature modifications formed as a result of phase transitions. According to the electrophysical data, the high-temperature K1 ? x (NH4) x SbF4 phases (0.05 ≤ x ≤ 0.75) are superionic, their conductivity reaching ~10?2–10?3 S/cm at 450–500 K. 相似文献