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1.
M. M. Shemyakin V. A. Puchkov N. S. Vul'fson V. N. Bochkarev Yu. A. Ovchinnikov A. A. Kryushkin V. T. Ivanov E. I. Vinogradova M. Yu. Feigina 《Russian Chemical Bulletin》1966,15(9):1483-1486
Conclusions The fragmentation of cyclodidepsipeptides during electron impact was investigated. The nature of the hydroxy and amino acid residues contained in the 2,5-diketomorpholines can be established on the basis of the mass spectra.For the preceding Communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1539–1543, September, 1966. 相似文献
2.
N. S. Vul'fson V. A. Puchkov Yu. V. Denisov B. V. Rozynov V. N. Bochkarev M. M. Shemyakin Yu. A. Ovchinnikov V. K. Antonov 《Chemistry of Heterocyclic Compounds》1967,2(4):468-474
Analysis of mass-spectra of various 2, 5-diketopiperazines gives the basic fragmentation rules for their molecular ions, and the effects of nature and positions of substituents on the process.Mass-spectrometry Laboratory of the Institute of the Chemistry of Natural Compounds.Antibiotics Chemistry Laboratory of the Institute of the Chemistry of Natural Compounds. 相似文献
3.
A. A. Akimov S. V. Puchkov Yu. V. Nepomnyashchikh A. L. Perkel’ 《Kinetics and Catalysis》2013,54(3):270-278
The kinetics of oxygen uptake in the azobisisobutyronitrile-initiated oxidation of 2-hydroxycy-clohexanone (RCH(OH)C(O)R) at 323 K has been investigated (chlorobenzene solvent, [RCH(OH)C(O)R] = 0.15-1.30 mol/L, initiation rate of w i = 0.016–0.473 mol L?1 s?1). The effective oxidizability parameter k p, eff(2k t,eff)?0.5 has been determined by solving the inverse kinetic problem using the entire data array obtained while varying [RCH(OH)C(O)R] and w i. The rate constants of chain propagation and termination and the equilibrium constant of the addition of the hydroxyperoxyl radical to the ketoalcohol have been derived from the dependence of the oxidizability parameter on the substrate concentration. The rate constant of bimolecular chain initiation has been calculated to be k 0 = 9.7 × 10?7 L mol?1 s?1. The ratio of the rate constants of quadratic-law peroxyl radical recombination reactions without and with chain termination (k eff′/k t,eff′) increases with increasing [RCH(OH)C(O)R], passes through a maximum at a substrate concentration of 0.8 mol/L, and then falls off. It is demonstrated that this effect is due to the variation of the proportions of the hydroperoxyl and organic (1-hydroxy-2-oxocyclohexylperoxyl or 1,2-dihydroxy-1-cyclo-hexylperoxyl) radicals in the reaction medium. 相似文献
4.
V. A. Semenov Zh. A. Kozlov L. Krachun G. Mateescu V. M. Morozov A. I. Oprea K. Oprea A. V. Puchkov 《Physics of the Solid State》2010,52(5):988-991
The temperature dependence of the frequency spectrum of tantalum in the temperature range from room temperature to 2300 K
has been studied for the first time using inelastic slow-neutron scattering. The inelastic slow-neutron scattering spectra
have been measured at different temperatures on a DIN-2PI time-of-flight spectrometer installed at the IBR-2 nuclear reactor
(Joint Institute for Nuclear Research, Dubna, Russia) with the use of a TS3000K high-temperature thermostat. From the measured
spectra, the frequency spectra of the tantalum crystal lattice have been determined at temperatures of 293, 1584, and 2300
K by the iteration method. As the temperature increases, the frequency spectrum, on the whole, is softened and the specific
features manifested themselves at room temperature are smoothed. The variations observed have been explained by the increase
in the role of the effects of vibration anharmonism at high temperatures. 相似文献
5.
6.
A. S. Borisov A. V. Vargasov Z. M. Guseva V. G. Denisova E. A. Kanevskaya V. M. Maksimenko V. S. Puchkov S. E. Pyatovskii S. A. Slavatinskii 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(4):516-518
γ Families with halos detected in the “Pamir” experiment have been analyzed. Comparison of the experimental data with the results of calculation within the quark-gluon string model (MC0 code) made it possible to determine the efficiency of halo formation by protons, α particles, and heavy nuclei, as well as the fraction of protons in the mass composition of primary cosmic rays at an energy of 1016 eV. It is shown that halos are formed predominantly by protons. The fraction of protons in the mass composition of primary cosmic rays at an energy of 1016 eV is 20%. 相似文献
7.
The I–V characteristics taken of thin films of the oxidized and reduced forms of poly[Ni(Salen)] metallopolymer are studied. The
data obtained indicate that states localized in the volume may experience thermofield ionization. It is found that the electroactivity
of the oxidized form of the polymer is higher. The parameters of the thermally activated mechanism of charge transfer are
determined. 相似文献
8.
The charge transfer in the oxidized and reduced forms of poly-[NiSalen] metal-containing polymer films is investigated. It is established that the voltage dependence of the differential conductivity for the polymer in the oxidized form exhibits a nonlinear behavior, which indicates a high electrical activity of this state. The microscopic parameters characterizing the charge transfer are calculated within the space-charge-limited current theory. Differences in the surface morphology of two forms of the poly-[NiSalen] films are revealed using atomic-force microscopy. 相似文献
9.
Lauter H Apaja V Kalinin I Kats E Koza M Krotscheck E Lauter VV Puchkov AV 《Physical review letters》2011,107(26):265301
We demonstrate by neutron scattering that a localized superfluid component exists at high pressures within solid helium in aerogel. Its existence is deduced from the observation of two sharp phonon-roton spectra which are clearly distinguishable from modes in bulk superfluid helium. These roton excitations exhibit different roton gap parameters than the roton observed in the bulk fluid at freezing pressure. One of the roton modes disappears after annealing the samples. Comparison with theoretical calculations suggests that the model that reproduces the observed data best is that of superfluid double layers within the solid and at the helium-substrate interface. 相似文献
10.
B. V. Rozynov N. S. Vul'fson V. A. Puchkov V. A. Tartakovskii A. A. Onishchenko S. S. Novikov 《Chemistry of Heterocyclic Compounds》1969,5(1):28-30
The mass spectra of dimethyl- and methylphenyl-8-nitroisoxazolizidines have been studied, and the possibility of establishing the position of the substituents on the basis of an analysis of these spectra has been shown. The main routes of the fragmentation of compounds of this class under the influence of electron impact are discussed. 相似文献