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Ivan M. Kumanyaev Margarita A. Lapitskaya Ljudmila L. Vasiljeva Kasimir K. Pivnitsky 《Mendeleev Communications》2012,22(3):129-131
The stable pyridinium salt of o-iodoxybenzoic acid (PIBX) that is easy to obtain can serve as a convenient substitute of IBX as an oxidant. PIBX is safer, has neutral properties behaves as an equivalent to IBX in the oxidation of alcohols to ketones or aldehydes in polar solvents (DMF, DMSO), and provides higher oxidation rate in THF due to better solubility. 相似文献
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Konstantinova LS Rakitin OA Rees CW Souvorova LI Golovanov DG Lyssenko KA 《Organic letters》2003,5(11):1939-1942
[reaction: see text] In a remarkable cascade reaction, triethylamine is converted into the thienopentathiepin 2a and the heptathiocane 3a by a preequilibrated solution of disulfur dichloride and DABCO in chloroform. 相似文献
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Tatjana Ovchinnikova Irina Zhuravleva Ljudmila Bush Nicolay Il'in 《Macromolecular Symposia》1999,144(1):303-311
The study of glycolide (GL) and ethylenoxalate (EO) copolymerization with the use of SnCl2 2 H2O as a catalyst was carried out by 1H NMR spectroscopy. Monomer reactivities are found to be close and equal to 1,1 and 1,11 for GL and 0,71 and 0,85 for EO at 150 and 170 °C, respectively. Kinetic data obtained show that the reaction proceeds without induction period up to entire consumption of every monomer. The detailed identification of 1H spectra enables to follow the polymer microstructure in the course of copolymerization. Thermal properties of copolymers and their biodegradation abilities have been studied. The biodegradation rate is shown to increase with growing EO proportion in the copolymer. The lactone biodegradation mechanism where the electrophility of carbon and nucleophility of OH group are playing the most important role, is suggested. The correlation between the biodegradation rate and the chemical shift in 13C NMR spectra of the carbon atom of the carbonyl group has been established. 相似文献
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Vavilin Vasily A. Rytov Sergei V. Lokshina Ljudmila Ya. 《Applied biochemistry and biotechnology》1997,(1):45-57
The various equations of hydrolysis kinetics included into the generalized simulation model (METHANE) were tested on the anaerobic
digestion of cellulose, sludge, and cattle manure. The good agreement between the model simulation results and experimental
data was obtained. The Contois equation, taking into account a hydrolytic biomass, and the firstorder equation with respect
to the particulate substrate only, were shown to be the approximations of two-phase hydrolysis kinetics. 相似文献
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Journal of Russian Laser Research - Based on a quantum-mechanical model with a non-Hermitian Hamiltonian, we theoretically describe the tunneling current in a heterostructure containing a quantum... 相似文献
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Being aware of the importance to consider every step in the evaluation of the combined measurement uncertainty of the result,
the purpose of this work was to evaluate the contribution of the radial thermal neutron flux gradient to the uncertainty budget
for trace level uranium determination in biological materials by a radiochemical neutron activation analysis (RNAA). Determination
of uranium via the short-lived nuclide 239U was based on solvent extraction with TBP and measurement of the chemical yield from the gamma-ray spectrum of the isolated
fraction via 235U. It has been shown previously, that radial neutron flux gradient, could have a relevant effect on the final result obtained
by RNAA. In the present work, radial neutron flux gradient within the irradiation assembly generally accepted in our lab (standards
tapped beside the sample), varied between 93 and 108% around the mean value and contributes approximately 20% to the combined
measurement uncertainty of the result. 相似文献
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