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1.
The concepts of the selective inhibition of reactions with the participation of HO
2· radicals by nitrobenzene in accordance with a cyclic mechanism were supported using cyclohexanol oxidation as an example. It was demonstrated that the nitroxyl radical generated from nitrobenzene selectively reacts with HO2
·
to form hydrogen peroxide and nitrobenzene. A decrease in the rates of oxidation of esters, carboxylic acids, and ketones with specially chosen structures in the presence of nitrobenzene, as well as the detection of H2O2 and corresponding ,-unsaturated compounds among the reaction products, indicated that the degradation of -peroxyl radicals of the above compounds occurred under conditions of the liquid-phase oxidation of organic substances that result in the formation of the HO2· radical and an unsaturated compound.Translated from Kinetika i Kataliz, Vol. 45, No. 6, 2004, pp. 814–820.Original Russian Text Copyright © 2004 by Nepomnyashchikh, Nosacheva, Perkel. 相似文献
2.
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
3.
E. V. Mal’chukova A. I. Nepomnyashchikh B. Boizot T. S. Shamirzaev G. Petite 《Physics of the Solid State》2010,52(9):1919-1924
The two-photon absorption that leads to the ultraviolet upconversion luminescence in the SiO2-Al2O3-B2O3-Na2O3-Zr2O: Cd3+ glass has been investigated. The inference has been made that no photon cascade emission takes place under excitation by
monochromatic light corresponding to the maximum of the absorption band of the Cd3+ ion (204 nm). The mechanisms of concentration quenching and energy transfer between Cd3+ ions and optically active defects of the aluminoborosilicate glass have been discussed. 相似文献
4.
V. S. Mal’kov D. A. Kokova A. S. Knyazev T. I. Izaak D. V. Nepomnyashchikh L. N. Kurina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(4):690-694
A procedure for the purification of aqueous glyoxal (obtained by the partial oxidation of glycol) from carboxylic acids was
described. Mono- and dibasic organic acids can be removed from solution without any substantial losses of glyoxal by using
weakly basic EDE-10P and AN-31 anionites. A mechanism of the adsorption of carboxylic acids on weak resins was suggested based
on the IR spectra recorded in a study of AN-31 anion-exchange resin. Using this method of purification also allowed the removal
of the glyoxal condensation products from solution. 相似文献
5.
Chueshova A. G. Pavlova L. A. Peshcherova S. M. Nepomnyashchikh A. I. 《Crystallography Reports》2021,66(7):1206-1215
Crystallography Reports - The orientation of grains and the special boundaries formed by them in multicrystalline silicon has been studied by electron backscattered diffraction. It is found that... 相似文献
6.
Yu. V. Nepomnyashchikh S. V. Puchkov O. V. Abdulova A. L. Perkel’ 《Kinetics and Catalysis》2009,50(5):609-616
Short reaction chains participate in the oxidation of C3-C6, C8, C10, and C12
n-carboxylic acids. The quadratic-law recombination of peroxy radicals occurs both without and with chain termination. The
ratio of the rate constants of these reactions increases to k′/k
t
= 4.5 on passing from propanoic acid to pentanoic acid, and then it decreases almost to zero for dodecanoic acid. The anomalous
variation of the k′/k
t
ratio is explained by the fact that the radicals resulting from carboxylic acid oxidation at the CH bonds nearest to the
functional group make different contributions to the recombination process, depending on the carbon chain length. The cross
recombination of secondary hydrocarbon peroxy radicals with the HO2· radicals resulting from the oxidation of carboxylic acids at the β-C-H bonds proceeds without chain termination. 相似文献
7.
Yu. V. Nepomnyashchikh S. V. Puchkov A. L. Perkel’ O. I. Arnatskaya 《Kinetics and Catalysis》2012,53(2):155-161
The kinetics of oxygen uptake and the kinetics of accumulation of methyl hexanoate oxidation products in the presence of tert-butyl hydroperoxide have been investigated to determine the partial rate constants for the interaction of the tert-butylperoxy radical with C-H bonds of the ester at 373 K. The ester group deactivates the C-H bonds in the 2- and 3-positions
and does not deactivate the same bonds in the 5-position, which are similar in reactivity to the methylenic C-H bonds of hydrocarbons.
The C-H bonds of the methoxyl group of methyl hexanoate are substantially more reactive than the C-H bonds of the methyl group. 相似文献
8.
Elena Litsyn Yurii Nepomnyashchikh Arcady Ponosov 《Nonlinear Analysis: Theory, Methods & Applications》2006
Control linear systems in the plane are studied under the assumption of incomplete observation and incomplete control. In this situation ordinary static output controls may fail to stabilize the system. That is why special dynamic output feedback controls with finitely many states (hybrid feedback controls) are applied. Necessary and sufficient conditions are offered that guarantee exponential convergence/divergence of the solutions at an arbitrary rate. It is also shown that the general case can be reduced to two particular cases which are treated in detail. 相似文献
9.
A.?A.?ShalaevEmail author N.?S.?Bobina A.?S.?Paklin R.?Yu.?Shendrik A.?I.?Nepomnyashchikh 《Bulletin of the Russian Academy of Sciences: Physics》2015,79(2):263-266
Results from spectral studies of the optical and luminescent properties of single crystals of lithium fluoride grown using the Czochralski technique and doped with ions of copper and magnesium, are presented. The effect of heat treatment regimes and the dependence of the concentration of magnesium impurities on the sensitivity of crystals of LiF:Mg, Cu to ionizing radiation are discussed. 相似文献
10.
Nepomnyashchikh A. I. Shalaev A. A. Sizova T. Yu. Paklin A. S. Sapozhnikov A. N. Pavlova L. A. 《Crystallography Reports》2018,63(2):290-294
Crystallography Reports - A complex analysis of the crystallization of quartz glass from quartzites of the Bural-Sardyk deposit (the Eastern Sayan) has been performed. A mineralogical and... 相似文献