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SVL fluorescence spectra from principal bands in the S1 state of pyridine h5 and -d5 were measured. A large displacement of the normal coordinate origin of v6a and the Duschinskii rotation of v10a and v16a were established. 相似文献
84.
Masuhiro Tsukada Giuliano Freddi Yoko Gotoh Nobutami Kasai 《Journal of Polymer Science.Polymer Physics》1994,32(8):1407-1412
Physical and chemical structure, as well as thermal behavior of solution-cast regenerated films, prepared from tussah (Antheraea pernyi) silk fibroin, were compared with those of solution-cast native films, in order to ascertain whether treatment (degumming, dissolution) used for preparation affected their properties. Regenerated fibroin films exhibited a higher thermal stability than native ones, as shown by differential scanning calorimetry, thermomechanical analysis, and dynamic mechanical behavior. Glass transition temperature and other relevant thermal transitions of the regenerated silk specimen shifted to higher temperatures compared with those of native specimen. Molecular conformation and crystalline structure did not show significant differences between the two kinds of silk films. Amino acid composition and molecular weight, however, distribution changed markedly after dissolving tussah silk fibroin fiber in concentrated LiSCN in polypeptide size was the main features for the regenerated silk fibroin. © 1994 John Wiley & Sons, Inc. 相似文献
85.
Kazutoshi Nose Yoko Nunome Takaharu Kondo Syuki Araki Takao Tsuda 《Analytical sciences》2005,21(6):625-628
We investigated whether methane, ethylene and ethane gas can be detected in gas emanating from human skin, which is called skin gas. Skin gas was collected with a homemade stainless-steel trap system, which was cooled with liquid nitrogen, and analyzed with a gas chromatograph fitted with a flame ionization detector (FID). Skin-gas samples were obtained by covering a hand for 30 min with a polyfluorovinyl bag in which pure helium gas was introduced. The bag, the trap system and GC were set up online to avoid any contamination by air. Methane, ethylene and ethane in skin gas were successfully collected at an average amount emanated for 30 min (from ten subjects) of 150 +/- 63, 20 +/- 11 and 17 +/- 8 [mean +/- SD] pg/cm2, respectively. 相似文献
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Maeda H Yamamoto K Nomura Y Kohno I Hafsi L Ueda N Yoshida S Fukuda M Fukuyasu Y Yamauchi Y Itoh N 《Journal of the American Chemical Society》2005,127(1):68-69
Fluorometric detection of O2-* is performed based on desulfonylation of 3 to the corresponding fluoresceins 4 through nucleophilic substitution, and this fluorescing process is quite specific toward O2-* over H2O2, t-BuOOH, NaOCl, 1O2, HO*, NO*, and ONOO-. Furthermore, effects of glutathione, cytochrome P450 reductase/NADPH, and diaphorase/NADH are relatively small on the fluorescing process of probe 3 with X = Y = F, which is useful to detect O2-* released from neutrophils stimulated by phorbol myristate acetate with satisfactory sensitivity. 相似文献
89.
Yoko Nambu Takeshi Endo Makoto Okawara 《Journal of polymer science. Part A, Polymer chemistry》1980,18(9):2793-2802
Lipoic acid was immobilized on crosslinked polystyrene beads to generate a polymeric reagent. The acyl transfer reaction of the p-nitrobenzoyl group from the polymer-bound lipoic acid to cyclohexylamine was investigated spectrophotometrically and was compared with a monomeric model compound. The acceleration effect of silver ion on the acyl transfer reaction also was studied. 相似文献
90.
Shimizu Y Ohte Y Yamamura Y Saito K Atake T 《The journal of physical chemistry. B》2006,110(28):13970-13975
Heat capacities of liquid, stable crystal, and liquid-quenched glass of a room-temperature ionic liquid (RTIL), 1-hexyl-3-methylimidazolium bis(trifluromethylsulfonyl)imide were measured between 5 and 310 K by adiabatic calorimetry. Heat capacity of the liquid at 298.15 K was determined for an IUPAC project as (631.6 +/- 0.5) J K(-1) mol(-1). Fusion was observed at T(fus) = 272.10 K for the stable crystalline phase, with enthalpy and entropy of fusion of 28.34 kJ mol(-1) and 104.2 J K(-1) mol(-1), respectively. The purity of the sample was estimated as 99.83 mol % by the fractional melting method. The liquid could be supercooled easily and the glass transition was observed around T(g) approximately 183 K, which was in agreement with the empirical relation, T(g) approximately ((2)/(3)) T(fus). The heat capacity of the liquid-quenched glass was larger than that of the crystal as a whole. In the lowest temperature region, however, the difference between the two showed a maximum around 6 K and a minimum around 15 K, at which the heat capacity of the glass was a little smaller than that of crystal. 相似文献