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61.
The 2,2,2-trichloroethoxycarbonyl (Troc) protecting group was efficiently removed from Troc-protected aliphatic and aromatic amines and also some Troc, Tos- and Troc, Ac-protected amines using activated mischmetal (MM). All reactions were performed by refluxing in dry tetrahydrofuran under an argon atmosphere and gave moderate to excellent yields. Several new compounds were synthesized, and new data about reactivity of Troc group were obtained. 相似文献
62.
63.
Journal of Solid State Electrochemistry - The potential dependence of the wetting angle on a gold electrode in sodium, potassium, and cesium bromide and iodide melts was studied to establish the... 相似文献
64.
The results of long-term continuous measurements of surface ozone concentrations, performed in 2010–2016 in the relatively low-urbanized region in the north of the Privolzhskii Federal Region of the Russian Federation (Vyatskie Polyany, Kirov oblast) are presented. A regular increase in the amplitude of diurnal variations of yearly average surface ozone concentrations is detected. The possible causes of this phenomenon can be both an increase in the atmospheric concentration of pollutants, i.e., precursors of tropospheric ozone, and climatic changes. 相似文献
65.
S. V. Stepanov V. M. Byakov Yu. D. Perfiliev L. A. Kulikov D. S. Zvezhinskii L. V. Dubov 《High Energy Chemistry》2016,50(2):109-114
Process of formation of the Auger blob (nanosized cloud of two or three hundred of ion–electron pairs) around a 57Co radioactive atom after E-capture followed by the emission of a cascade of Auger electrons by the daughter atom 57Fe has been considered. The effect of local temperature elevation in the Auger blob caused by energy emission during ionization slowing down of Auger electrons and the secondary electrons generated by them is discussed. Some consequences of this effect have been noted. 相似文献
66.
Searches for nuclear-stable multineutrons among products originating from the fission of 238U nuclei that is induced by 62-MeV alpha particles were performed by the activation method. The reaction involving the transfer of four neutrons and occurring on the isotope 88Sr, 88Sr( x n, (x ? 4) n)92Sr??92Y, was used to identify nuclear-stable multineutrons. A line at the energy of E = 1384 keV was found in the measured gamma-ray spectra of irradiated samples. This line, together with the measured time dependence of the decrease in its activity, is indicative of the formation of the beta-active nucleus 92Sr. This result was reproduced in repeated measurements. It suggests the possible existence of nuclear-stable multineutrons ( x n) for x ?? 6. The differential cross section for the x n yield at an angle of 30° in the alpha-particle-induced fission of 238U was about 6 × 10?2 mb/sr. 相似文献
67.
68.
I. E. Kuznetsova V. V. Kolesov B. D. Zaitsev A. S. Fionov A. M. Shihabudinov G. V. Stepanov E. Yu. Kramarenko 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(8):945-949
Magnetoactive elastomers are promising for use in designing of magnetically operated devices for signal processing and sensors. The results from studying the electrophysical and acoustic properties of new magnetoactive elastomers structured by a nonuniform magnetic field are presented. It is shown that the prestructuring of the magnetic disperse filler by a magnetic field during composite synthesis substantially improves the coefficient of the transmission of electromagnetic radiation through the sample. The effect gets stronger as the mass fraction of filler increases. As the filler concentration grows, the transmission coefficient falls by 50%, and the ref lection coefficient grows by a factor of 150%. The longitudinal elastic modulus and the density vary within the ranges of 1.4–1.8 GPa and 2485–3362 kg m–3, respectively, depending on the magnetic filler concentration and the sample’s structuring. The obtained results demonstrate the potential of usinf structured magnetoactive elastomers as radar absorbing materials. 相似文献
69.
V. V. Negrebetskii I. N. Pervukhina B. I. Stepanov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The phosphorines (VIII-XI) were obtained in the reaction 3,3-bis(dimethylamino)triphenylphosphine (I) and bis(3-dimethylaminophenyl) pentafluorophenylphosphorine (II) with benzaldehyde (III) and its 4-methoxy (IV), 4-dimethylamino (V), 2-fluro (VI), pentafluoro (VII) derivatives according to the scheme (1). 相似文献
70.
S. M. Aldoshin Z. G. Aliev A. A. Astrat’ev T. K. Goncharov D. V. Dashko Yu. M. Milekhin A. I. Stepanov N. I. Shishov 《Journal of Structural Chemistry》2013,54(2):462-464
The crystal structure of a new energetic compound of 4,4″-dinitro-[3,3′:4,3″]-tris-[1,2,5]-oxadiazole is studied. 相似文献