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111.
María A. Rubio Eduardo Lissi Nicol Olivera Jael L. Reyes Camilo López‐Alarcon 《国际化学动力学杂志》2014,46(3):143-150
The reaction of phenols with nitrite (nitrous acid HONO, or its conjugated base, NO2?) is of importance in stomach fluids (low pH) and in atmospheric hydrometeors (mild acid and basic pH). The initial reaction associated with the oxidation/nitration of 4‐substitued phenols promoted by HONO/NO2 depends on the pH of the solution. At low pH, the initial step involves the reaction between HONO and phenol, whereas at basic conditions this involves an electron transfer from the phenoxy anion to nitrogen dioxide (NO2) producing the nitrite anion. The rate of both processes is determined by the donor capacity of the substituent at the 4‐position of the phenol, and the data obtained at pH 2.3 follow a linear Hammett‐type correlation with a slope equal to –1.23. The partition of the gaseous intermediates (NO and NO2) makes the rate of HONO‐mediated oxidation dependent on their gas–liquid distribution. At low pH, the main process is phenol oxidation, even in oxygen‐free conditions, and the presence of any 4‐substituted phenol decreases the rate of HONO auto‐oxidation. 相似文献
112.
Fabricio Augusto Barone Rangel Giancarlo Thales Camilo da Silva José Abdalla Helay?l-Neto 《Brazilian Journal of Physics》2012,42(1-2):120-124
We present an alternative approach to justify the electric charge quantization by means of non-global electromagnetic potentials. We adopt a non-global potential whose singularity does not goes over to infinity and can be entirely embedded into an arbitrarily small closed ball. 相似文献
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Marcelle de Lima Ferreira Bispo Raoni Schroeder Borges Gonçalves Camilo Henrique da Silva Lima Laura Nogueira de Faria Cardoso Maria Cristina Silva Lourenço Marcus Vinícius Nora de Souza 《Journal of heterocyclic chemistry》2012,49(6):1317-1322
Two series of pyrazinamide (PZA) derivatives have been synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv. Some compounds exhibited minimum inhibitory concentration activity of 50–100 μg/mL, greater than the first line antituberculosis drug PZA in Alamar Blue assay (>100 μg/mL). The obtained activities can be considered promising results, which characterizes these compounds as good start points to development of new antitubercular agents. 相似文献
115.
We predict the formation of optically trapped, metal-dielectric nanoparticle clusters above photonic crystal microcavities. We determine the conditions on particle size and position for a gold particle to be trapped above the microcavity. We then show that strong field redistribution and enhancement near the trapped gold nanoparticle results in secondary trapping sites for a pair of dielectric nanoparticles. 相似文献
116.
A.Camilo P. Alves J.Michael Hollas Hamdan Musa Trevor Ridley 《Journal of Molecular Spectroscopy》1985,109(1):99-122
Single vibronic level fluorescence (SVLF) spectra of tropolone from vibronic levels in the electronic state, in combination with recently reported supersonic jet spectra, have enabled the assigning of many absorption bands in the region of 000 which had previously been impossible. Some of the complexity in these bands has been shown to be due to a large Duschinsky effect involving the two lowest b1 vibrations, ν25 and ν26. It has been shown that these vibrations have wavenumbers of 176 and 110 cm?1, respectively, in the state, and 172 and 39 cm?1 in the state. This last value shows how unresistent the molecule is in the state to out-of-plane bending in the region of the five-membered ring. Other aspects of the vibrational complexity are due to the effect of ν′26 in increasing the barrier to tunnelling of the hydrogen-bonding proton in the state contrasting with very little effect of ν″26 in the state. 相似文献
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Edilene Delphino Rodrigues Denise Brentan da Silva Dionéia Camilo Rodrigues de Oliveira Gil Valdo José da Silva 《Magnetic resonance in chemistry : MRC》2009,47(12):1095-1100
2D DOSY 1H NMR has proved to be a useful technique in the identification of the molecular skeleton of the four major compounds of ethyl acetate extract of aerial parts of Bidens sulphurea (Asteraceae). The combination of this technique with HPLC, mass spectrometry and other NMR techniques enabled the identification of four flavonoid glycosides: quercetin‐3‐O‐β‐D ‐galactopyranoside, quercetin‐3‐O‐β‐D ‐glycopyranoside, quercetin‐3‐O‐α‐L ‐arabinofuranoside and quercetin‐3‐O‐β‐D ‐rhamnopyranoside. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
120.
An effective procedure for deciding permutativeness of one-directional cellular automata on the one-sided full shift is presented. It is then implemented in C++, and used to test permutativeness of elementary cellular automata (those of radius 3). 相似文献