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991.
Yu. F. Ivanov V. E. Gromov N. A. Soskova Yu. A. Denisova A. D. Teresov E. A. Petrikova E. A. Budovskikh 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(11):1246-1252
We present the results from investigating the phase composition, structure, and properties of surface layers of titanium alloys subjected to combined treatment that includes plasma alloying the electric explosion of a carbon fiber with a quantity of TiB2 powder and subsequent irradiation with a high-intensity electron beam. The formation of a multilayer, multiphase structure in the submicro- and nano-sized ranges is observed. It is shown that the properties of a alloyed layer exceed those of a bulk sample many times over. 相似文献
992.
I. P. Aleksandrova A. A. Sukhovsky Yu. N. Ivanov I. P. Raevsky 《Physics of the Solid State》2012,54(2):316-323
The local structure of the ferroelectric-relaxor PbSc1/2Nb1/2O3 in the temperature range from 550 to 220 K has been investigated using 45Sc nuclear magnetic resonance. It has been found that, in the paraelectric phase at temperatures below 550 K, the crystal
consists of regions of an ordered elpasolite structure and inclusions of the disordered tetragonal perovskite phase with displacements
along directions of the [001] type. The relative weight of the tetragonal structure in the region of the paraelectric phase
is approximately equal to 0.28. Below the temperature of the phase transition from the disordered modification to the polar
phase, the relative weight of the tetragonal phase decreases with decreasing temperature. The tetragonal structure is replaced
by the trigonal polar structure. In a wide temperature range (∼50 K), there exists a heterophase structure that is characteristic
of relaxors. Note that the correlation length of displacements in the tetragonal phase should be very small to explain the
absence of indications of the existence of this phase in the diffraction data. 相似文献
993.
Threshold, power, and spectral characteristics of a semiconductor emitter with a fiber Bragg grating
V. S. Zholnerov A. V. Ivanov V. D. Kurnosov K. V. Kurnosov A. V. Lobintsov V. I. Romantsevich R. V. Chernov 《Technical Physics》2012,57(6):797-802
The threshold, power, and spectral characteristics of an emitter with a fiber Bragg grating are calculated. The effect of heating of the active region of a laser diode, its thermal resistance, and radiation power extracted from the cavity of the emitter on these characteristics is investigated. It is shown that satisfactory agreement between the theory and experiment is observed when the heating of the active zone of the laser diode by the pump current flowing through it and the radiation power extracted from the cavity of the emitter are taken into account. 相似文献
994.
V.?B.?Kosterev Yu.?F.?Ivanov V.?E.?GromovEmail author O.?Yu.?Efimov S.?V.?Konovalov 《Russian Physics Journal》2012,54(9):1034-1045
Results of investigations of the structure-phase state and dislocation substructure formation during thermomechanical hardening
of Fe–0.09C–2Mn–1Si steel in different regimes are presented. Methods of transmission electron microscopy reveal the formation
of gradient states characterized by regular changes of the structure, phase composition, types, and parameters of the dislocation
substructures over the structure cross section. 相似文献
995.
N. N. Koval Yu. F. Ivanov A. P. Laskovnev V. V. Uglov N. N. Cherenda Yu. A. Kolubaeva Ye. A. Markova A. D. Teresov P. V. Moskvin 《Russian Physics Journal》2012,54(9):1024-1033
A film/substrate system has been treated with a submillisecond high-intensity electron beam. Examinations have shown that
the electron-beam treatment of the film/substrate system resulted in alloying of the surface layer of the material throughout
the melt which was accompanied by the formation of nanodimensional phases. 相似文献
996.
M. Ivanov J. Krug 《The European Physical Journal B - Condensed Matter and Complex Systems》2012,85(2):72
We report new results on the non-conserved dynamics of parallel steps on vicinal surfaces in the case of sublimation with
electromigration and step-step interactions. The derived equations are valid in the quasistatic approximation and in the limit
f
-1 ≫ l
D
≫ l
± ≫ l
i
, where f is the inverse electromigration length, l
D
the diffusion length, l
± the kinetic lengths and l
i
the terrace widths. The coupling between crystal sublimation and step-step interactions induces non-linear, non-conservative
terms in the equations of motion. Depending on the initial conditions, this leads to interrupted coarsening, anticoarsening
of step bunches or periodic switching between step trains of different numbers of bunches. 相似文献
997.
Mentink JH Hellsvik J Afanasiev DV Ivanov BA Kirilyuk A Kimel AV Eriksson O Katsnelson MI Rasing T 《Physical review letters》2012,108(5):057202
We propose a general theoretical framework for ultrafast laser-induced spin dynamics in multisublattice magnets. We distinguish relaxation of relativistic and exchange origin and show that when the former dominates, nonequivalent sublattices have distinct dynamics despite their strong exchange coupling. Even more interesting, in the exchange dominated regime sublattices can show highly counterintuitive transitions between parallel and antiparallel alignment. This allows us to explain recent experiments with antiferromagnetically coupled sublattices, and predict that such transitions are possible with ferromagnetic coupling as well. In addition, we predict that exchange relaxation enhances the demagnetization speed of both sublattices only when they are antiferromagnetically coupled. 相似文献
998.
E. N. Viktorova A. A. Korolev V. A. Ivanov T. R. Ibragimov A. A. Kurganov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(9):1473-1478
Monolithic capillary columns based on polydivinylbenzene with monolith structure, optimized for the separation of high-molecular compounds, are synthesized. The structure of the monolith is optimized by varying the chemical composition of the porogene. It is shown that monolithic columns with the maximum amount of free volume can be obtained by using a porogene consisting of nonanol and toluene or mesitylene. On the basis of Van Deemter functions measured for the synthesized columns, it was concluded that for sorbates differing strongly in molecular weight and thus their diffusion coefficients, we cannot find a single optimum flow rate, and the optimum separation of polymeric sorbates requires that we reach a certain compromise. It was shown that in these circumstances, monolithic columns with the optimum structure of monolite allow almost completely separation of a mixture of 15 low molecular weight polymeric sorbates into individual components. 相似文献
999.
M. A. Shevchenko M. I. Ivanov V. V. Berezutski V. G. Kudin V. S. Sudavtsova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(12):1779-1784
Partial and integral mixing enthalpies of melts of binary systems Mn-Sc and Mn-Y at 1873 and 1830 K, respectively, are determined by calorimetry. It is found that the minima of the mixing enthalpies are ?7.1 ± 0.4 and -3.2 ± 0.2 kJ/mol at x Mn = 0.60 and 0.61, respectively. The initial partial mixing enthalpies of Sc and Y are ?33.2 ± 2.1 and ?16.6 ± 0.8 kJ/mol, respectively. The thermodynamic properties of melts of binary Mn-Sc(Y) systems are calculated using the ideal associated solution (IAS) model. It is found that the activities of the components exhibit slight negative deviations from the ideal solutions, and the excess Gibbs energies reach ?3.0 and ?1.6 kJ/mol, respectively. 相似文献
1000.
M. V. Rogozina V. N. Ionkin A. I. Ivanov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(4):667-674
The processes of intramolecular electron transfer from the second excited electron state accompanied by superfast reverse
transfer to the first excited state are studied. The kinetics of the populations of the first and second excited states, along
with that the charge-separated states, is calculated within the generalized stochastic model, taking into account the reorganization
of the medium and intramolecular high-frequency vibrations. It is shown that variations in the relaxation rate of the high-frequency
vibrational modes can change the population of the quenching products by a factor of two to three. It is established that
in the case of the weak exothermicity of the charge separation process, the population of the charge-separated states declines
upon an increase in the vibrational relaxation rate, while the population of the first excited state increases; in the region
of high exothermicity, these dependences change to ones that are opposite. To reveal the scales of these effects in real systems,
the kinetics of the photo-induced processes in the zinc-porphyrin derivatives, including electron-acceptor imide groups covalently
coupled with porphyrin rings, are calculated. It is shown that the results from calculating the kinetics of the population
of the first and the second excited states agree well with the experimental data on the kinetics of the fluorescence of these
states. The absolute values of the population of the charge-separated state and the first excited state are determined. The
key role of the hot electron transitions that occur in parallel with the relaxation of the medium and intramolecular vibrations
in the considered process is shown. 相似文献