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排序方式: 共有203条查询结果,搜索用时 15 毫秒
1.
Shoji Watanabe Kyoichi Suga Tsutomu Fujita Nobuo Takasaka 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1974,24(11):639-643
Various terpene alcohols were prepared from isoprene oligomers via two steps: epoxidation with peracetic acid and isomerisation with aluminium triisopropoxide. For example, 2-methylene-6-methyl-7-octene-1-o1 was prepared from 2,6-dimethyl-1,7-octadiene. From 2,6-dimethyl-2,7-octadiene, 3,3,6-trimethyl-1,5-heptadiene, 2,7-dimethyl-2,6-octadiene, 2,6-dimethyl-1,3,6-octatriene, 1-methyl-4-isopropenyl-1-cyclohexene, and 1,5-dimethyl-1,5-cyclooctadiene, the corresponding alcohols were obtained, respectively. 相似文献
2.
The glass transition behavior of emulsion-polymerized poly(methyl methacrylate) and polystyrene films containing sodium laurylsulfate as emulsifier was studied by measurements of dynamic mechanical properties and thermal depolarization current. The film specimens of the emulsion-polymerized polymers were prepared by casting from their benzene solutions. The glass transition temperatures of the emulsion-polymerized films are higher than those of the bulk-polymerized films. The higher glass transition temperature of the emulsion-polymerized films is attributed to the colloidal properties of sodium laurylsulfate in the process of the film formation. The restriction of the molecular chains in the emulsion-polymerized films is attributed to the interaction between the hydrophobic groups of sodium laurylsulfate and the polymer molecules. 相似文献
3.
Komeiji Yuto; Uebayasi Masami; Someya Jun-ichiro; Yamato Ichiro 《Protein engineering, design & selection : PEDS》1992,5(8):759-767
The Ser88Cys mutant of the trp-repressor showed a lower affinityfor the corepressor than the wild-type repressor [G = 1.7 ±0.3 kcal/mol, Chou and Matthews (1989) J. Biol. Chem., 264,1831418319].A molecular dynamics/free energy cycle perturbation study wasperformed to understand the origin of the decreased affinity.A value (G = 1.58 ± 0.28 kcal/mol) comparable with theexperimental value was obtained by the simulation. Free energycomponent analysis revealed that destabilization of the vander Waals interaction between Ser88 and Trp109 (corepressor)mainly contributed to the decreased affinity of the mutant.The rotational transition of the hydroxyl (sulfhydryl) groupof Ser88 (Cys88) during the simulations affected the contributionsof Arg84 and water to the free energy change in the aporepressorand those of Arg84 and Trp 109 to that in the holorepressor.However, the contributions from different residues compensatedeach other, and the total free energy changes were almost invariablein the various simulations. 相似文献
4.
Kyoichi Osada Koretaro Takahashi Mutsuo Hatano 《Journal of the American Oil Chemists' Society》1990,67(12):921-922
The degree of glyceride syntheses by lipase TOYO (Chromobacterium viscosum) and lipase OF (Candida cylindracea) using individual free fatty acids C18∶1, C18∶2, C18∶3, C18∶4, C20∶4, C20∶5 and C22∶6 were compared. Lipase TOYO incorporated each of the fatty acids into glycerol at levels of greater than 89%. Lipase OF incorporated
most of the fatty acids at levels above 70% (docosahexaenoic acid incorporation was 63%). It was concluded that these two
lipases are feasible for producing glycerides from unsaturated fatty acids. 相似文献
5.
The occurrence and fate of a herbicide CNP (2,4,6-trichlorophenyl-4′-nitrophenylether) in rivers and agricultural drainages was investigated. CNP residues in water samples were extracted by adsorption on a macroreticular XAD-2 resin column and subjected to gas chromatographic analysis using an electron capture detection after desorption from the column and concentration. The minimum detectable amount was 0.04 ng and a positive identification of CNP residue in water samples was obtained with a combined gas chromatography-mass spectrometry-computer system when 500 ng of CNP was injected. CNP residues were detected in water samples taken in June to September, and these levels were between 0.01 and 16.67 μg l−1. The maximum level was found in a sample taken on 13th July, 1977, about a month after beginning rice seedling transplantation, and the minimum level was detected on August 29th, 1977. However CNP residue levels were increased again in September because flooded water on the paddy fields was excluded. CNP was more persistent in the aquatic environment than a herbicide benthiocarb. 相似文献
6.
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8.
Ning Wang Huawei Li Yaoshuai Ba Yifeng Wang Chunlei Wan Kyoichi Fujinami Kunihito Koumoto 《Journal of Electronic Materials》2010,39(9):1777-1781
The effect of yttria-stabilized zirconia (YSZ) with a low thermal conductivity on the thermoelectric properties of Nb-doped
SrTiO3 bulk materials, which were fabricated by the conventional normal pressure sintering method in an Ar atmosphere, was examined.
YSZ additions reduced the thermal conductivity but significantly enhanced the electrical conductivity. However, the Seebeck
coefficient was nearly independent of YSZ content. Thus, the ZT value was enhanced, and a sample with 3 wt.% YSZ displayed the maximum ZT value, 0.21, at 900 K. Additionally, the reason for the reduced thermal conductivity and enhanced electrical conductivity
by YSZ additions was investigated in detail. 相似文献
9.
Takayuki Goto Takao Watanabe Kyoichi Kinoshita Azusa Matsuda Masafumi Sera Tetsuo Fukase 《Journal of Low Temperature Physics》1996,105(3-4):401-406
Cu-NMR spectra and the nuclear spin-lattice relaxation rate T
1
-1
have been studied intensively on the bilayer type high-Tc cuprate La1.89Ca1.11Cu2O6+ (La2126). The resonance line shift showed a monotonic decrease with lowering temperature in the normal state, indicating that this compound belongs to the lightly-doped region. The Curie-Weiss temperature dependence of (T1T)–1 in the normal state shows that the pseudo spin-gap does not always exist in the light-doped bilayer systems. 相似文献
10.
Hydration of cyanopyridine on CeO2(110) surfaces was studied using periodic DFT+U calculations. One of two adsorption modes of 2-cyanopyridine occurs with two-point interaction which causes substrate specificity. A catalytic cycle for the hydration of 2-cyanopyridine was proposed. Cooperativity of Lewis and Brønsted acid sites was found to stabilize the intermediates for the hydration. 相似文献