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排序方式: 共有181条查询结果,搜索用时 62 毫秒
121.
122.
Taizo Hatta Shuntaro Mataka Masashi Tashiro Katsutoshi Numano Satoshi Tanimoto Akiyoshi Tori-I 《Journal of heterocyclic chemistry》1990,27(7):1861-1865
[23]Paracyclophane derivative 3 of keto-S-phenylthioxime which is the hydrolyzed product of the hypothetical intermediate in the reaction of 1,2,5-thiadiazole with organometallic reagents, was obtained, together with diketone 1 , in the reaction of 1,2,5-thiadiazolo[23]paracyclophane 2 with two equivalents of phenylmagnesium bromide. Contrary, [23]metacyclophane 7 gave only diketone 12 in the reaction with phenylmagnesium bromide under the same conditions. 相似文献
123.
Kuromatsuene and longifolene are identical with junipene, and kuromatsuol and longiborneol are identical with juniperol. 相似文献
124.
Watanabe M Suzuki H Tanaka Y Ishida T Oshikawa T Tori-I A 《The Journal of organic chemistry》2004,69(23):7794-7801
Helical aromatics (1) were synthesized via one step in good quantity by solvent-free condensation of N,N'-p-phenylenediamine (2) and various carboxylic acids in the presence of a Lewis acid. Microwave irradiation greatly facilitated the condensation reaction to furnish 1 with a 100% diastereo- and a 50% enantioselectivity, when a chiral carboxylic acid was utilized. 1f, derived from 2-methylglutaric acid, was quite stable, no racemization taking place even at 200 degrees C. The assignment of the absolute configurations to the helical aromatics has been achieved by experimental and theoretical CD spectra calculated by time-dependent density functional theory. 相似文献
125.
Takeshi Yabuta Kanji Tsuru Satoshi Hayakawa Akiyoshi Osaka 《Journal of Sol-Gel Science and Technology》2004,32(1-3):273-276
Erbium tris 8-hydroxyquinoline (ErQ) was successfully incorporated into the sol–gel hybrid material (HYBRIMER) synthesized by using methyltriethoxysilane, vinyltriethoxysilane, and phenyltrimethoxysilane even though it has poor solubility in general organic solvent. The composition and microstructure of the HYBRIMER film doped with ErQ was analyzed using Rutherford backscattering method and scanning electron microscope. The refractive index of the HYBRIMER film was also investigated with ErQ concentration. The HYBRIMER film doped with ErQ showed a clear photoluminescence (PL) at 1.5 m. PL intensity increased with ErQ concentration without concentration quenching until Er/Si ratio reached 5 at%. 相似文献
126.
Large-scale preparation of ordered titania nanorods with enhanced photocatalytic activity 总被引:4,自引:0,他引:4
Wu JM Zhang TW Zeng YW Hayakawa S Tsuru K Osaka A 《Langmuir : the ACS journal of surfaces and colloids》2005,21(15):6995-7002
A titania layer with ordered nanostructures is expected to be of high photocatalytic activity due mainly to its high specific surface area. In the present work, large-area films with ordered titania nanorods were deposited on titanium substrates through a solution approach. The nanorods, with the phase composition of a mixture of anatase and rutile, grew on top of a condensed anatase interlayer along mainly the rutile [001]-axis. The photocatalytic activity was evaluated by decomposing rhodamine B in water and compared with the general sol-gel derived titania films and a commercial DP-25 titania coating. It is found that the as-deposited titania nanorods exhibited extremely high initial photocatalytic activity but declined to a poor value after the consumption of beneficial oxidative peroxo complexes coordinated to Ti(IV). A subsequent thermal treatment eliminated such complexes but at the same time improved the crystallinity of the titania nanorods. The photocatalytic activity of the thermally treated titania nanorods was stable and significantly higher than that of the sol-gel derived film and commercial DP-25 coating. 相似文献
127.
We report a recent developed membrane called carbon whisker membrane (CWM). The CWMs consist of a tubular ceramic membrane covered by a layer of carbon film and carbon whiskers formed on the surface of the carbon film. Hydrocarbons such as methane and a modified chemical vapor deposition apparatus were employed for fabricating uniformed CWMs. Because of the unique feature of the CWMs, the filtration performance of the CWMs was investigated and it was found that the CWMs possess a function of anti-attachment of particles and/or biomaterials on the membranes so that the permeate flux and the cleaning process of the membrane can be improved. 相似文献
128.
Sabu A Kondo S Saito R Kasai Y Hashimoto K 《The journal of physical chemistry. A》2005,109(9):1836-1842
The intermolecular potential energy surface of O(2)-H(2)O was investigated at ab initio MP2 and MRSDCI levels using the aug-cc-pVTZ basis set. The vibrational levels were evaluated by numerically solving the Schr?dinger equations for the nuclear motions with the ab initio potential functions using one- to three-dimensional finite-element methods. On the basis of the calculated partition functions, the equilibrium constant of the complex, K(p), was studied. The K(p) values at atmospheric temperatures of 200-300 K were found to be 1-2 orders of magnitude less than previous estimates from the harmonic oscillator approximation. 相似文献
129.
Measurement of the streaming potential over an affinity column is used as a means of following affinity binding of proteins to immobilized ligands. The system designed operates with one sample column and one reference column and the differential signal is a good measure of the amount of affinity-bound material. The system is used for the determination of albumin in discrete samples as well as for continuous measurements. Assays of rabbit anti-albumin antibodies are also reported; and various glycoproteins which bind to immobilized concanavalin A can be quantified. The limit of detection for proteins (down to 10?9 moles l?1) seems to be lower than that which is required for applications to process control. 相似文献
130.
Yoshio Saito Hideki Tachibana Hidechika Hayashi Akiyoshi Wada 《Photochemistry and photobiology》1981,33(3):289-295
Abstract— The efficiencies of the excitation–energy transfer from tyrosine to tryptophan residues in eight globular proteins in the native and denatured states are obtained by studying the wavelength dependence of the fluorescence quantum yield. The measurements are made over a wide wavelength range using a computer-controlled spectrophotometer which can measure the fluorescence and absorbance simultaneously in one sample solution (Wada et al. , 1980). The values of the energy transfer efficiencies ranged from 0.17 ± 0.12 to 0.69 ± 0.06 in the native state and from -0.04 ± 0.09 to 0.12 ± 0.06 in the denatured state. These values are considerably lower than the values reported by Kronman and Holmes (1971); in particular, an almost complete absence of energy transfer for the denatured state is shown. 相似文献