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41.
G. G. Skvortsov B. V. Trzhtsinskaya L. F. Teterina V. K. Voronov M. N. Popova 《Chemistry of Heterocyclic Compounds》1977,13(11):1250-1252
A mixture of 1,2,4-triazol-3-yl vinyl sulfide and N,S-divinyl derivatives is formed in the reaction of 1,2,4-triazole-3-thione with acetylene under pressure. The mixture of N,S-divinyl derivatives was separated into two isomers by gas-liquid chromatography. The hydrogenation, polymerization, and complexing of 1,2,4-triazol-3-yl vinyl sulfide were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1561–1563, November, 1977. 相似文献
42.
V. P. Rybalkin A. D. Dubonosov E. N. Shepelenko L. L. Popova V. A. Bren'' V. I. Minkin 《Russian Journal of Organic Chemistry》2001,37(7):1034-1037
2-N-(4-Aminobenzo-15-crown-5)methylene-2,3-dihydrobenzo[b]thiophen-3-one and its acetyl derivative were synthesized. Their treatment with lithium, sodium, or potassium iodide in acetonitrile solution leads to formation of the corresponding crown-metal complexes. Irradiation of the acylated compounds at 436 nm induces NO migration of the acetyl group to give O-acyl isomer which is characterized by a considerable blue shift of the long-wave absorption band ( = 70 nm). The quantum yields of the photo- induced acylotropic reaction for the free ligand and its complexes with alkali metal cations change in the series: L > K+ > Na+ > Li+. 相似文献
43.
Mircho Georgiev Tatiana Popova Zhorro S. Nickolov Nikolay Goutev Georgi Georgiev Hiroatsu Matsuura 《Central European Journal of Chemistry》2004,2(4):617-626
The hypothesis that the degree of hydration of poly(oxyethylene) (POE) in aqueous solution depends on the mole ratio of water
molecules to ether oxygen atoms in the molecule has been verified by studying the isotropic Raman spectra in the O−H stretching
region for four short-chain POEs (C 1E
n
C 1 withn=1−4). Excellent coincidence of the O−H stretching Raman band for all four POEs studied in the range of mole ratio H2O/O
ether
from 25 to 0.6 was observed, thus confirming the assumption stated above. A conclusion that all ether oxygen atoms in the
POE molecule participate in hydrogen bonding with water molecules has been made. 相似文献
44.
K. M. Dyumaev E. P. Popova I. F. Mikhailova L. I. Shibaeva L. D. Smirnov 《Chemistry of Heterocyclic Compounds》1974,10(6):699-701
The nitration of 3-hydroxyquinoline with concentrated nitric acid in sulfuric acid at ?30 to +30°C gives 5-nitro-3-hydroxyquinoline (85–92%) and 7-nitro-3-hydroxyquinoline (7–12%). 4-Nitro-3-hydroxyquinoline is formed in 70% yield by nitration in acetic acid. 4,5-Dinitro-3-hydroxyquinoline is formed by further nitration of 4- and 5-nitro-3-hydroxyquinolines. 相似文献
45.
I. V. Kamenskaya M. A. Krivov E. V. Malisova V. C. Morozov M. P. Nikiforova E. A. Popova S. S. Khludkov 《Russian Physics Journal》1979,22(7):771-776
The electrophysical properties and cathode luminescence spectra of gallium arsenide with a high tellurium concentration (n = 2·1018 cm–3) alloyed with copper are investigated under different diffusion conditions. Centers are determined from measurements of the Hall effect with an ionization energy of 0.190 ± 0.006 eV whose concentration does not depend on the arsenic vapor pressure (0.1 and 1 atm) and the cooling rate of the samples from the diffusion temperature. A band with hm = 1.30–1.32 eV whose intensity depends on the cooling conditions of the samples was observed in the cathode luminescence spectra of these samples. The nature of the observed defects is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 93–99, July, 1979.In conclusion of this article the authors express their gratitude to L. K. Tarasova for preparation of the samples. 相似文献
46.
The conditions of existence and stability of spatial structures of ferroparticles of the type of isolated and periodic strata
that are formed in fixed layers of magnetizable fluid in a constant homogeneous magnetic field are studied. 相似文献
47.
48.
E. A. Popova S. A. Klimin M. N. Popova R. Klingeler N. Tristan B. Büchner A. N. Vasil’ev 《Journal of Experimental and Theoretical Physics》2014,118(4):611-620
The temperature dependences of the heat capacity, the magnetic susceptibility, and the splitting of the ground Kramers doublet of the Nd3+ ion in the chain magnet Nd2BaNiO5 are studied. An antiferromagnetic phase transition manifests itself as anomalies in all these dependences. The parameters of the Nd-Ni and Nd-Nd interactions are estimated. The field dependence of the magnetization has two anomalies. A strong magnetic anisotropy prevents the magnetic moments of the Nd3+ ion from deviating from axis c in the crystal even in an external magnetic field. The processes of magnetization and the internal specific features of a chain of spins S = 1 are discussed. 相似文献
49.
This paper deals with the development of spectrumdichotomy methods for matrices with large norms. Such matrices often result from discretizations of differential operators. The results of some numerical experiments, including an investigation of the stability of plane-parallel Poiseuille flow, are given. 相似文献