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31.
Line widths in the 6Li, 7Li, 23Na, 39K, 85Rb, 87Rb and 133Cs N.M.R. spectra of solutions of the alkali salts of biphenyl and fluorenone are reported as a function of solvent and temperature. From a numerical analysis of the room temperature data the contribution of the various relaxation mechanisms to the line widths are established. It is shown that the results are consistent with the observed solvent and temperature dependence of the line widths. Values of the electron spin correlation time are obtained and a value of 1·6 ± 0·4 Å is found for the ‘Van der Waals radius’ of the biphenyl anion. Line width expressions for the static and the dynamic ion pair model are presented. It is demonstrated that the static ion pair model applies to solutions of caesium biphenylide. Semi-empirical rules are presented concerning the importance of various relaxation mechanisms for the different alkali nuclei in the type of solution studied here. 相似文献
32.
33.
We introduce families $ \mathcal{B}_n^S\left( {{z_1},\ldots,{z_n}} \right) $ and $ \mathcal{B}_{{n,\hbar}}^S\left( {{z_1},\ldots,{z_n}} \right) $ of maximal commutative subalgebras, called Bethe subalgebras, of the group algebra $ \mathbb{C}\left[ {\mathfrak{S}n} \right] $ of the symmetric group. Bethe subalgebras are deformations of the Gelfand?Zetlin subalgebra of $ \mathbb{C}\left[ {\mathfrak{S}n} \right] $ . We describe various properties of Bethe subalgebras. 相似文献
34.
Tarasov S. V. Kocharovsky Vl. V. Kocharovsky V. V. 《Radiophysics and Quantum Electronics》2019,62(4):293-310
Radiophysics and Quantum Electronics - A change-over of the quasiparticle wave functions and spectrum under a variation in an interparticle interaction in a Bose-Einstein condensed gas of bosons... 相似文献
35.
Tarasov VF Forbes MD 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,(2):245-263
A new approach to the theory of the EPR of spin correlated radical pairs (SCRP) is formulated. It is based on spectral exchange methods as applied to the two-site model and takes into account explicitly both the motion of one quantum (transverse magnetization) and two quantum coherences (polarizations) of SCRPs. This innovation allows for the interpretation of anti phase structure (APS) spectral shape asymmetry and for the transformation of the initially created ST0RPM polarization into the APS spectral pattern. The results of this method as applied to micellized spin correlated radical pairs have been compared with the exact numerical solution of the corresponding stochastic Liouville equation and is commented on. 相似文献
36.
V. V. Tarasov N. F. Kovalenko N. E. Kruchinina S. A. Shilin 《Russian Journal of Applied Chemistry》2006,79(8):1286-1290
The Eley-Rideal and Langmuir concepts of surface reactions were used to develop a model of heterogeneous hydrodynamic coagulation of diluted “oil-in-water” emulsions (0.1–2.0 vol %). The mathematical model was verified, and factors that govern the coagulation rate were revealed. 相似文献
37.
The mechanism of changes in the molecular-mass distribution of interjunction chains in crosslinked poly(ether urethane) elastomers under deformation has been studied by the method of NMR spectroscopy. In the course of tensile drawing, the molecular-mass distribution changes nonmonotonically. The character of stress-induced changes shows that the breakdown of some bonds is accompanied by formation of new bonds and the development of network fragments with short chains. The strength and thermal stability of poly(ether urethane) elastomers are characterized by extremal dependences on the width of the molecular-mass distribution of interjunction chains. In the case of densely crosslinked and unannealed polyepoxides, mechanical impact (pressure and shear; grinding) is accompanied by changes in their supramolecular structure; in turn, these changes entail an increase in the thermal stability of the samples. 相似文献
38.
V. R. Gorelik V. F. Tarasov S. R. Shakirov E. G. Bagryanskaya 《Russian Chemical Bulletin》2008,57(7):1416-1427
The multispin systems consisting of spin-correlated radical pairs (SCRPs) and stable nitroxide radicals, localized in micelles
of sodium dodecyl sulfate (SDS), were studied by ESR and pulse laser photolysis techniques. In all the systems studied, the
stable nitroxide radicals exert no effect on the shape of the ESR spectra of the SCRPs (in particular, on the shape of their
antiphase structure) and on the decay kinetics of the ESR signal of the SCRPs. In the SDS micelles, the electron spin polarization
transfer from the nonequilibrium electron spin states of the molecular triplets (SCRP precursors) is the most efficient mechanism
of generation of the electron spin polarization in nitroxide radicals. The experimental data also show that the nitroxide
radicals and SCRP radicals are most probably distributed uniformly in the micellar phase.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1390–1401, July, 2008. 相似文献
39.
R. M. Shlenev S. I. Filimonov A. V. Tarasov A. S. Danilova P. A. Agat’ev 《Russian Journal of Organic Chemistry》2016,52(2):240-243
Methods were developed of indirect introduction of sulfonamide group in the structures of pyrido-[2,1-b]quinazolin-11-one and pyrido[1,2-a]quinazolin-6-one underlain by cyclocondensation of 2-halo-5-(Rsulfamoyl) benzoyl chlorides with derivatives of 2-aminopyridine. The fact of thermal rearrangement of 8-(morpholin-4-ylsulfonyl)pyrido[1,2-a]quinazolin-6-one into isomeric 2-(morpholine-4-ylsulfonyl)pyrido[2,1-b]-quinazolin-11-one was experimentally registered. 相似文献
40.
V. V. Korak S. V. Vinogradov V. A. Vasnev und A. I. Tarasov 《Colloid and polymer science》1978,256(1):89
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