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4-Chloro-2-oxo-2,3-dihydrothiazole-5-carbaldehyde reacted with monosubstituted ureas to give cis-(Z)-and trans-(E)-N-(2,4-dioxothiazolidin-5-ylidenemethyl)ureas via rearrangement involving oxide ion transfer, cis (Z) Isomers were formed in methanol or dimethylformamide, while both individual cis (Z) and trans (E) isomers and their mixtures were isolated in the reaction performed in acetic acid. 相似文献
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Chernysh Yu. E. Borodkin G. S. Korobov M. S. Luk'yanov B. S. Stankevich N. V. Borodkina I. G. Vdovichenko V. Yu. Korobov Yu. M. 《Russian Journal of Coordination Chemistry》2002,28(3):170-174
A novel technique of 2D exchange NMR with suppression of the coherent magnetization transfer is suggested for the collection of useful chemical information on the basis of standard 2D exchange spectroscopy. In this technique, only one nucleus of the coupled spin system involved in chemical exchange is excited (so-called multiplet selectivity or semiselective excitation). In this case, the multiplet structure of the selectively irradiated nucleus behaves as an uncoupled multisite system. 相似文献
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Kovaleva V. V. Kuznetsov N. M. Vdovichenko A. Yu. Zagoskin Y. D. Grigoriev T. E. Chvalun S. N. 《Doklady Physical Chemistry》2022,502(2):23-27
Doklady Physical Chemistry - The rheological behavior of a 1 wt % suspension of highly porous chitosan particles in polydimethylsiloxane in a high electric field has been studied as a function of... 相似文献
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The Nambu-Jona-Lasinio model at nonzero values of an external magnetic field H and of the chemical potential is considered in the strong-coupling region G>G c. The phase portrait of the model exhibits an infinitely large number of massless chiral-invariant phases and massive phases resulting from a spontaneous breakdown of chiral invariance. This phase structure is responsible for aperiodic oscillations of some thermodynamic parameters of the system, including the dynamical fermion mass, as functions of H ?1. 相似文献
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Gorkunenko O. A. Vdovichenko A. N. Chervinskii A. Yu. Kapkan L. M. Vaiman G. E. 《Theoretical and Experimental Chemistry》2004,40(1):12-16
The contributions from anisotropic magnetic screening and electronic effects to the relative chemical shifts of the NH protons in the amides and N,N-dimethylhydrazides of succinic and glutaric acids were calculated. It was shown that the splitting of the signals of the NH protons is largely determined by the redistribution of electron density in the molecule during the conformational transition. 相似文献
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We study the field structure and dispersion properties of a hybrid eigenmode guided by a nonuniform magnetized plasma waveguide.
It is shown that the rotational and quasi-potential waves contribute to the formation of such a mode in the whistler frequency
range. Depending on the plasma density, the rotational component of the hybrid mode is determined by either waves with complex
transverse wave numbers or whistler waves, or by true surface waves. In the presence of an axial nonuniformity of the plasma
in a channel, the transverse field structure of the propagating mode changes, which is stipulated by changes in both the values
of transverse wave numbers and their dependence on the radial coordinate. It is found that the spectrum of axial wave numbers
of eigenmodes of a plasma waveguide undergoes a pronounced condensation when smoothing the waveguide walls. The damping of
the hybrid mode of a nonuniform waveguide due to electron collisions is found and it is shown that collisional losses determine
the damping of waves trapped in the waveguide in the experiments on ionization self-channeling of whistler waves. We have
found the effect of “displacing” the strong field from the inner core to the background outer region of the waveguide with
increasing plasma density on its axis and broadening background region.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 7, pp. 607–617, July 2006. 相似文献
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A. A. Shubin R. S. Mitchenko T. V. Bezbozhnaya A. N. Vdovichenko 《Russian Chemical Bulletin》2005,54(10):2456-2459
A procedure was developed for the synthesis of previously unknown β-chlorovinyl derivatives of PtIV chloride complexes by chloroplatination of terminal alkynes catalyzed by PtII chloride complexes. The reaction is highly stereoselective and gives only the products of trans-anti-addition of platinum and chlorine atoms. The regioselectivity of the catalytic reaction formally corresponds to Markovnikov’s
rule, e.g., in alkynes containing electron-donating substituents, platinum attacks the terminal carbon atom. The σ-vinyl derivatives
of PtIV chloride complexes were characterized by IR spectroscopy and 1H and 13C NMR spectroscopy.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2380–2384, October, 2005. 相似文献