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791.
Juan C. Lpez Georges Wlodarczak Jean Demaison 《Journal of Molecular Spectroscopy》1996,180(2):337-344
The millimeter-wave spectrum of 2,3-dihydrofuran in the ground and five ring-puckering excited states has been measured in the frequency range 100–250 GHz. The ground and first ring-puckering excited states have been fitted to a two-state Hamiltonian including Coriolis coupling interaction. The determined energy difference of 18.684(7) cm−1between these states and theaandbtype coupling parameters are consistent with the ring-puckering potential function and the previously observed dependence of the centrifugal distortion constants ΔJK, ΔK, and δK. A small ring-puckering dependence of the quartic centrifugal distortion constants ΔJand δJhas been also observed. This dependence is well accounted for in terms of the ring-puckering potential function and the vibrational dependence of the rotational constants. 相似文献
792.
Octaethyltetraoxaporphyrin-Dikation – Pendant des Octaethylporphyrins in der Tetraoxaporphyrin-Reihe
793.
794.
795.
This paper deals with the existence of solutions to the periodic and the Sturm-Liouville boundary value problems for second order ordinary differential equations with singular nonlinearity. The results are obtained by use of some continuation theorems in the absence of a priori bounds of Capietto-Mawhin-Zanolin. 相似文献
796.
797.
Henk Schierbeek Denise Rook Frans W. J. te Braake Kristien Y. Dorst Gardi Voortman Jean‐Philippe Godin Laurent‐Bernard Fay Johannes B. van Goudoever 《Rapid communications in mass spectrometry : RCM》2009,23(18):2897-2902
Determination of glutathione kinetics using stable isotopes requires accurate measurement of the tracers and tracees. Previously, the precursor and synthesized product were measured with two separate techniques, liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) and gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). In order to reduce sample volume and minimize analytical effort we developed a method to simultaneously determine 13C‐glutathione as its dimeric form (GSSG) and its precursor [1‐13C]glycine in a small volume of erythrocytes in one single analysis. After having transformed 13C‐glutathione into its dimeric form GSSG, we determined both the intra‐erythrocytic concentrations and the 13C‐isotopic enrichment of GSSG and glycine in 150 µL of whole blood using liquid chromatography coupled to LC/IRMS. The results show that the concentration (range of µmol/mL) was reliably measured using cycloleucine as internal standard, i.e. with a precision better than 0.1 µmol/mL. The 13C‐isotopic enrichment of GSSG and glycine measured in the same run gave reliable values with excellent precision (standard deviation (sd) <0.3‰) and accuracy (measured between 0 and 5 APE). This novel method opens up a variety of kinetic studies with relatively low dose administration of tracers, reducing the total cost of the study design. In addition, only a minimal sample volume is required, enabling studies even in very small subjects, such as preterm infants. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
798.
Jacques Lalevée Mohamad El‐Roz Xavier Allonas Jean Pierre Fouassier 《Journal of polymer science. Part A, Polymer chemistry》2008,46(6):2008-2014
New systems for the visible‐light‐induced polymerization of cationic resins working through a free‐radical‐promoted process are presented. They are based on a photoinitiator (camphorquinone, isopropylthioxanthone, Eosin), a silane, and a diphenyl iodonium salt, the new compound being the silane. The overall efficiency is strongly affected by the silane structure. The rates of polymerization and final percent conversion are noticeably higher than those obtained in the presence of already studied reference systems. Moreover, contrary to previously investigated free‐radical‐promoted cationic polymerizations, oxygen does not inhibit the process and an unusual enhancement of the polymerization kinetics is found in aerated conditions: such an observation seems to have never been reported so far. The excited state processes and the role of oxygen as revealed by laser flash photolysis are discussed. The particular behavior of the silyl radicals is outlined. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2008–2014, 2008 相似文献
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800.