排序方式: 共有26条查询结果,搜索用时 250 毫秒
1.
2.
S. N. Gapan’kova S. D. Brinkevich I. P. Edimecheva V. P. Kurchenko O. I. Shadyro 《High Energy Chemistry》2011,45(3):196-201
The effect of some hydroxylated aromatic aldehydes on the radiation-chemical transformations of deaerated ethanol during continuous
radiolysis has been studied. The data obtained show that these compounds effectively inhibit radiation-induced processes involving
α-hydroxyethyl radicals (α-HER). Benzaldehyde and its hydroxylated derivatives (II, III) predominantly oxidize, and compounds
containing the cinnamic moiety, (IV–VI), add α-HER to a carbonyl group or -C=C bond. 相似文献
3.
Physics of Atomic Nuclei - Processes of accumulation of radionuclides in the cooling circuit water of the Cyclone 18/9-HC cyclotron were studied under proton irradiation of the Nirta Fluor target.... 相似文献
4.
The interaction of indole, imidazole, and their derivatives with α-hydroxyethyl radicals has been studied by the radiation and peroxide initiation of free-radical processes. The enthalpies of H-atom addition to the multiple bonds of the test compounds, which characterize their oxidation properties, have been calculated within the framework of the density functional theory. The set of experimental and theoretically calculated data indicate that serotonin or β-carboline alkaloids (harmine, harman, and harmaline) inhibit the formation of 2,3-butanediol—the main radiolysis product of deaerated ethanol—mainly due to reduction and addition or the oxidation of α-hydroxyethyl radicals, respectively. Enhancement of oxidation properties in the above order of β-carboline alkaloids has been observed. Pyrrole, indole, melatonin, imidazole, 1-methylimidazole, and 2-mercapto-1-methylimidazole exhibit low reactivity toward α-hydroxyethyl radicals. 相似文献
5.
The effect of ascorbic acid and its analogue 5,6-O-isopropylidenyl-2,3-O-dimethylascorbic acid (I), which has been synthesized for the purpose and does not contain mobile hydrogen atoms, on the
formation of the products of continuous radiolysis of deaerated ethanol and its aqueous solutions has been studied. The ionization
potentials, the molecular orbital energies, the enthalpies of homolytic dissociation of C-H and O-H bonds, and the enthalpies
of H atom addition to the C=O group of the test compounds have been calculated by ab initio methods. The array of the experimental
and calculated theoretical data suggests that both ascorbic acid in the undissociated form and compound I can oxidize α-hydroxyethyl
radicals, whereas the monoanion of ascorbic acid acts as a reducing agent in the reactions with these transient radicals.
The reduction of α-hydroxyethyl radicals in aqueous solutions by the ascorbic acid monoanion can follow both the hydrogen
transfer and electron transfer mechanisms. 相似文献
6.
The effects of coenzyme Q0, ascorbic acid, and 2-O-α-D-glucopyranosylascorbic acid on the radiation-induced dephosphorylation of 1-glycerophosphate, glucose-1-phosphate, and
glucose-6-phosphate in deaerated aqueous solutions at pH 7 were studied by means of continuous radiolysis. It was found that
the test compounds efficiently suppressed the radiation-induced dephosphorylation of organic phosphates in equimolar concentrations
by interactions with water radiolysis products. At an organic phosphate to additive concentration ratio of 100: 1, ascorbic
acid and coenzyme Q0 can suppress the radiation-induced dephosphorylation of the initial substances in aqueous solutions by the reduction and
oxidation of hydroxyl-containing carbon-centered radicals, respectively. 相似文献
7.
8.
D. I. Brinkevich N. V. Vabishchevich S. A. Vabishchevich A. N. Petlitski V. S. Prosolovich Yu. N. Yankovskii 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(6):1217-1220
The influence of an oxide coating on the strength characteristics of single-crystal silicon surface layers is investigated by the microindentation method. It is shown experimentally that a strengthened layer with a thickness of 0.2–0.4 μm and a microhardness of 20–35 GPa, which is two or three times as much as the microhardness of bulk single-crystal silicon, is present near the SiO2/Si interface. The thickness and microhardness of this layer depends on the growth conditions of the oxide. The formation of this layer is most probably caused by interstitial silicon atoms formed near the SiO2/Si interface during silicon oxidation. 相似文献
9.
Kosobutskii V. S. Tugai O. V. Sverdlov R. L. Brinkevich S. D. 《High Energy Chemistry》2022,56(4):277-279
High Energy Chemistry - The γ-radiolysis of 0.001 M fluoromethoxyethane solutions has been studied in an inert atmosphere and in the presence of oxygen. The yield of fluoride ions decreases... 相似文献
10.
G. B. Tolstorozhev M. V. Bel’kov T. F. Raichenok I. V. Skornyakov O. I. Shadyro S. D. Brinkevich S. N. Samovich O. K. Bazyl’ V. Ya. Artyukhov G. V. Mayer 《Optics and Spectroscopy》2013,115(5):717-726
We have measured the absorption, fluorescence, fluorescence excitation spectra, fluorescence quantum yields, and IR Fourier-transform spectra of aromatic acids in solutions. We have considered spectroscopic particular features of benzoic acid, its hydroxylated and methoxylated derivatives. Using quantumchemistry methods, we have calculated and interpreted electronic spectra. Data of calculations have been compared with experimental results. We have ascertained the main channels and mechanisms of photophysical relaxation processes in the molecules under study. Proton-acceptor properties of molecules of aromatic acids have been evaluated. We have analyzed in detail mechanisms by which hydrogen bonds are formed, intramolecular charge redistribution is realized, and the electron density of oxygen atoms changes. Spectroscopic indications of participation of oxygen-containing groups in intramolecular interactions and in intermolecular interactions with the formation of cyclic dimers have been revealed. 相似文献