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991.
Ferreira da Silva P Lima JC Freitas AA Shimizu K Maçanita AL Quina FH 《The journal of physical chemistry. A》2005,109(32):7329-7338
Color intensification of anthocyanin solutions in the presence of natural polyphenols (copigmentation) is re-interpreted in terms of charge transfer from the copigment to the anthocyanin. Flavylium cations are shown to be excellent electron acceptors (E(red) approximately -0.3 V vs SCE). It is also demonstrated, for a large series of anthocyanin-copigment pairs, that the standard Gibbs free energy of complex formation decreases linearly with EA(Anthoc) - IP(Cop), the difference between the electron affinity of the anthocyanin, EA(Anthoc), and the ionization potential of the copigment, IP(Cop). Based on this correlation, copigmentation strengths of potential candidates for copigments can be predicted. 相似文献
992.
Stoffelbach F Aqil A Jérôme C Jérôme R Detrembleur C 《Chemical communications (Cambridge, England)》2005,(36):4532-4533
A simple, cheap and tunable approach for the decoration of carbon nanotubes by magnetite nanoparticles and their orientation in a magnetic field is reported. 相似文献
993.
Cacciarini M Azov VA Seiler P Künzer H Diederich F 《Chemical communications (Cambridge, England)》2005,(42):5269-5271
The partially bridged resorcin[4]arene cavitand featuring a cleft-shaped recognition site formed by two anti-quinoxaline bridges and four convergent HO-groups was prepared in three steps and characterised by X-ray crystallography; cavitand was found to be a selective receptor for steroidal substrates in CDCl3, with the best binding observed for steroids with a flat A-ring and two H-bonding sites on rings A and C/D. 相似文献
994.
Bayrakçeken F Yaman A Hayvali M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(5):983-987
An ultraviolet light-induced photophysical and Photochemical changes of coumarin-481 in cyclohexane have been studied by photolysis technique at room temperature, due to its potential applications in photonics, photochemistry, and electronic spectroscopy. During the optical pumping, coumarin-481 showed photochemical changes, therefore as the concentration of coumarin-481 decreased, a photoproduct concentration increased rapidly. An absorption band of the product was observed at around 250 nm. Photoproduct emission spectra characteristics show that photoproduct molecules can also be used as a laser-dye at different emission frequency. 相似文献
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Tanguy Briançon Mohammed Hayouni Michel Pierre 《Calculus of Variations and Partial Differential Equations》2005,23(1):13-32
We prove local Lipschitz continuity of the solution to the state equation in two kinds of shape optimization problems with constraint on the volume: the minimal shaping for the Dirichlet energy, with no sign condition on the state function, and the minimal shaping for the first eigenvalue of the Laplacian. This is a main first step for proving regularity of the optimal shapes themselves.Received: 11 November 2003, Accepted: 10 May 2004, Published online: 8 February 2005Mathematics Subject Classification (2000):
49Q10, 35R35, 49K20, 35J20 相似文献