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191.
Russian Chemical Bulletin - 相似文献
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The initiation of H2/O2/H2O mixture combustion when asymmetric vibrations in H2O molecules are excited by a resonant IR laser radiation is considered. It is shown that the vibrational excitation of the molecules gives rise to new efficient channels for the formation of chemically active O and H atoms and OH radicals. As a result, the chain mechanism of combustion in the mixtures is enhanced and, as a consequence, the induction time is cut and the ignition temperature is lowered. Even at a minor radiant energy flux delivered to the gas (Ein≈2.5 J/cm2), the ignition temperature of the stoichiometric H2/O2 mixture containing only 5% of H2O may become as low as 300 K. 相似文献
194.
S. N. Titova G. A. Domrachev S. Ya. Khorshev A. M. Ob”edkov L. V. Kalakutskaya S. Yu. Ketkov V. K. Cherkasov B. S. Kaverin K. B. Zhogova M. A. Lopatin V. L. Karnatsevich E. A. Gorina 《Physics of the Solid State》2004,46(7):1365-1370
A modified method is proposed for preparing fullerene compounds with alkali metals in a solution. The compounds synthesized have the general formula Me n C60(THF)x, where Me = Li or Na; n=1–4, 6, 8, or 12; and THF = tetrahydrofuran. The use of preliminarily synthesized additives MeC10H8 makes it possible to prepare fullerene compounds with an exact stoichiometric ratio between C 60 n? and Me +. The IR and EPR spectra of the compounds prepared are analyzed and compared with the spectra of their analogs available in the literature. The intramolecular modes T u (1)-T u (4) for the C 60 n? anion are assigned. The splitting of the T u (1) mode into a doublet at room temperature for Me n C60(THF)x (n=1, 2, 4) compounds indicates that the fullerene anion has a distorted structure. An increase in the intensity of the T u (2) mode, a noticeable shift of the T u (4) mode toward the long-wavelength range, and an anomalous increase in the intensity of the latter mode for the Li3C60(THF)x complex suggest that, in the fullerene anion, the coupling of vibrational modes occurs through the charge-phonon mechanism. The measured EPR spectra of lithium-and sodium-containing fullerene compounds are characteristic of C 60 ? anions. The g factors for these compounds are almost identical and do not depend on temperature. The g factor for the C 60 n? anion depends on the nature of the metal and differs from the g factor for the C 60 ? anion. 相似文献
195.
T. M. Uljanova L. V. Titova N. P. Krut'ko E. M. Zub 《Mechanics of Composite Materials》1999,35(4):345-350
The process of formation of a fibrous spinel in the Al2O3–MgO system is investigated. The dependences of the spinel structure and properties on technological parameters of the process of synthesis is studied. Optimal relations between the fiber constituents for obtaining a stoichiometric spinel are determined and a two-stage mechanism of its formation has been found. Some ceramic materials are obtained from fibrous dispersions, and their physicomechanical characteristics have been estimated.Institute of General and Inorganic Chemistry, Belarus National Academy of Sciences, Minsk, Belarus. Translated from Mekhanika Kompozitnykh Materialov, Vol. 35, No. 4, pp. 509–516, July–August, 1999. 相似文献
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Filatova E. S. Fedorova O. V. Titova Yu. A. Slepukhin P. A. Kravchenko M. A. Skornyakov S. N. Rusinov G. L. Charushin V. N. 《Russian Chemical Bulletin》2016,65(5):1360-1364
Russian Chemical Bulletin - A method for the preparation of 3-oxobutanoate-containing podands differing in the length of the polyether fragment by acetoacetylation of oligo(ethylene glycols) with... 相似文献
199.
S. G. Kadmensky V. E. Bunakov L. V. Titova 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(11):1177-1181
T-odd asymmetries in the ternary fission of oriented target nuclei, induced by cold unpolarized neutrons and accompanied by emission of ?? particles, are described using quantum fission theory. The differential cross section for the reaction in question is obtained using the spin density matrix of the target nucleus by considering the Coriolis interaction of the spin of a fissioning compound nucleus with the orbital momentum of an ?? particle and interference from the fission amplitudes of various pairs of neutron resonances excited in the compound nucleus as the target nucleus captures a cold neutron. It is shown that in the case under consideration, T-odd asymmetries occur only at odd values of the target nucleus??s order of orientation. It is demonstrated that the concepts of TRI and ROT asymmetries are preserved while the absolute values of the coefficients for these asymmetries can change noticeably in comparison to the similar coefficients for the fission of unoriented target nuclei induced by cold polarized neutrons. 相似文献
200.
On the basis of quantum-mechanical fission theory, the features of true quaternary nuclear fission are studied by treating this fission process as a sequence of three processes following one another in the course of time. The first two processes are the escape of the first and then the second of the two light particles emitted from the neck of a fissioning nucleus because of a nonadiabatic character of the collective deformation motion of this nucleus. Finally, the third process is the separation of the fissioning nucleus into two rather heavy fission fragments. The differences that arise in the emission probabilities and in the angular and energy distributions upon going over from the first emitted to the second emitted prescission third and fourth particles are analyzed by invoking experimental data on the spontaneous and thermalneutron-induced fission of nuclei, and it is shown that these differences are caused by the changes both in the geometric configuration of the fissioning nucleus and in the shell structure of its neck after the first prescission particle is emitted from it. 相似文献