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991.
Watanabe T Ueda S Inuki S Oishi S Fujii N Ohno H 《Chemical communications (Cambridge, England)》2007,(43):4516-4518
One-pot N-arylation and oxidative coupling can be promoted by a common palladium catalyst in the presence of appropriate additives: palladium-catalyzed N-arylation of anilines with aryl triflates under the standard conditions followed by addition of acetic acid under oxygen or air atmosphere afforded various types of functionalized carbazoles in good to excellent yields. 相似文献
992.
Tamaki Y Furube A Murai M Hara K Katoh R Tachiya M 《Physical chemistry chemical physics : PCCP》2007,9(12):1453-1460
The transient absorption of nanocrystalline TiO(2) films in the visible and IR wavelength regions was measured under the weak-excitation condition, where the second-order electron-hole recombination process can be ignored. The intrinsic dynamics of the electron-hole pairs in the femtosecond to picosecond time range was elucidated. Surface-trapped electrons and surface-trapped holes were generated within approximately 200 fs (time resolution). Surface-trapped electrons, which gave an absorption peak at around 800 nm, and bulk electrons, which absorbed in the IR wavelength region, decayed with a 500-ps time constant due to relaxation into deep bulk trapping sites. It is already known that, after this relaxation, electrons and holes survive for microseconds. We interpreted these long lifetimes in terms of the prompt spatial charge separation of electrons in the bulk and holes at the surface. 相似文献
993.
Sakakibara N Nakatsubo T Suzuki S Shibata D Shimada M Umezawa T 《Organic & biomolecular chemistry》2007,5(5):802-815
The present study established a system for comprehensive metabolic analysis of the cinnamate/monolignol and lignan pathways by the use of a stable-isotope-dilution method. The system was successfully applied to characterization of the pathways in Carthamus tinctorius cv. Round-leaved White maturing seeds in combination with administration of stable-isotope-labelled precursors. Experimental results obtained using this technique strongly suggested the intermediacy of ferulic acid in lignan biosynthesis in the plant. 相似文献
994.
Plasma Chemistry and Plasma Processing - Thermal polymer-ablation phenomena have been investigated by direct irradiation of thermal plasmas to polymer bulk specimens using inductively coupled... 相似文献
995.
Wataru Ando Toshiaki Nagashima 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2)
Abstract Dye sensitized photooxidation of sulfides proceeds by way of singlet oxygen to give sulfoxides and sulfones, and the evidence for several intermediates has been reported. We now report that photooxidation of aromatic sulfides gives the product of an unusual type; and the reaction may proceed by either superoxide or hydroperoxysulfurane. 9-Ethylthiofluorene was photooxidized in dichloromethane or acetone with methylene blue as sensitizer. Three main products were isolated and identified as fluorenone (15%), 9-fluorenyl ethyl sulfoxide (19%) and 1-hydroxyl-9-fluorenone (23%). 相似文献
996.
Masahiro Takeda Toshiaki Yoshimura Choichiro Shimasaki Hiroyuki Morita 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):461-462
The thermal reaction of phenacyl sulfoxide bearing some heterocycles in the presence of butadiene afforded the thiapyarn derivatives, which is considered to be formed by the Diels Alder reaction of diene with thiocalbonyl compound. 相似文献
997.
Toshiaki Nonaka Ji Li Ayako Ogawa Barbara Hornung Wolfgang Schmidt Rainer Wingen 《Liquid crystals》2013,40(11):1599-1602
We describe the material properties of a fast switching active matrix ferroelectric liquid crystal mode. The mode relies on a monostable monodomain having a high transmission and full grey scale capability. Experimental data are compared with the results of switching model calculations and the switching mechanism is discussed. The mode is suitable for video and multimedia application and compatible with conventional amorphous silicon thin film transistors due to the small value of the spontaneous polarization. 相似文献
998.
999.
Temperature-dependent polarized infrared spectra were measured over the temperature range 105-30°C for a ferroelectric liquid crystal with a naphthalene ring (FLC-1) in the isotropic, smectic A (SmA), and chiral smectic C (SmC*) phases to investigate its molecular conformation, interactions, and alignment in each phase. It has been found, from the temperaturedependent spectral changes in the 1610-1600 cm-1 region, that the degree of twist between the naphthalene and benzene rings of FLC-1 changes with temperature. The peak intensity of the band at 1606 cm-1 containing contributions from both the benzene and naphthalene ring stretching modes begins to decrease, not suddenly but gradually, upon going from the SmA phase to the SmC* phase, suggesting that the molecular orientation of the two rings changes gradually between the two phases. The frequencies of two CH2 stretching bands suggest that the disorder of the alkyl chain of FLC-1 is similar for the liquid crystal phase and the isotropic liquid phase. The splitting of the core C=O stretching band indicates that the resonance system consisting of the benzene ring and the C=O group in the core part of FLC-1 is involved in two kinds of intermolecular interaction between adjacent molecules in the liquid crystal phase. 相似文献
1000.
Masato Otagiri Crisanto M. Lopez Katsuhiko Kitamoto Manabu Arioka Toshiaki Kudo Shigeharu Moriya 《Applied biochemistry and biotechnology》2013,169(6):1910-1918
The termite symbiotic system is one of the efficient lignocellulose degradation systems. We tried to express and characterize a novel cellulolytic enzyme from this system. Here, we report the isolation of an endo-β-1,4-glucanase gene homolog of glycoside hydrolase family 45 from a symbiotic protistan community of Reticulitermes speratus. Heterologous expression of this gene was performed using the expression system of Aspergillus oryzae. Analysis of enzymatic properties revealed 786 μmol/min/mg protein in specific activity, a V max of 833.0 units/mg protein, and a K m value of 2.58 mg/ml with carboxymethyl cellulose as the substrate. Thin-layer chromatography analysis showed that RsSymEG2 produces cellobiose from cellodextrins larger than cellohexaose. This enzyme showed high specific activity like other endo-β-1,4-glucanases from the symbiotic system of termites. It means that the termite symbiotic system is a good resource for highly active endo-β-1,4-glucanases. 相似文献