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941.
942.
Yasuyoshi Miki Yosiyuki Aoki Hideaki Miyatake Toshie Minematsu Hajime Hibino 《Tetrahedron letters》2006,47(29):5215-5218
1-Benzenesulfonylindole-2,3-dicarboxylic anhydride was reacted with methyl 1-benzenesulfonylindole-2-acetate to give the corresponding 2-acylindole-3-carboxylic acid as the sole product in high yield, which could be converted to caulersin in four steps. In a similar manner, three isomers A, B, and C were synthesized by reaction of indole-2,3-dicarboxylic anhydrides with methyl indoleacetates. 相似文献
943.
Hajime AraiMasayuki Tsuda Keiichi SaitoMasahiko Hayashi Koji TakeiYoji Sakurai 《Journal of solid state chemistry》2002,163(1):340-349
We report the structural and thermal characteristics of highly delithiated (lithium extracted) compounds LixNiO2, which can be called “nickel dioxide.” We obtained Li0.10NiO2 and Li0.04NiO2 by treating LiNiO2 with sulfuric acid. Both products contained phases with NiO2 stacking similar to cadmium chloride (O3-type), but the latter also included a phase with NiO2 stacking similar to cadmium iodide (O1-type). We examined their thermal behavior using high temperature X-ray diffraction analysis together with thermogravimetric analysis and found that novel polymorphs, with similar chemical compositions but different structures, were obtained by heating them at appropriate temperatures. We discuss these results together with those for LixNiO2 obtained by electrochemical delithiation. We also report acid-treated products derived from Li0.93Ni1.07O2. 相似文献
944.
T. Okamoto E. Ohmura T. Sano Y. Morishige I. Miyamoto 《Applied Physics A: Materials Science & Processing》2005,81(3):639-643
We made considerations for microstructures on chromium film observed after femtosecond laser irradiation through an analytical study. Laser diffraction through an optical system with a rectangular aperture was analyzed for the estimation of intensity distribution at the focal point. Molecular dynamics (MD) simulation was also performed for the examination of laser ablation of metal by taking account of the electron–phonon relaxation. From results of diffraction calculation, it was shown that a typical surface pattern is significantly affected by laser intensity distribution. On the other hand, it may be estimated through the MD simulation that the porosity formation evolves by cumulative pulses with energy close to the ablation threshold and their surrounding grows to microcolumns with volume expansion. PACS 68.08.De; 68.35.-p 相似文献
945.
Preparation of CeO2-ZrO2 Mixed Oxide Powders by the Coprecipitation Method for the Purification Catalysts of Automotive Emission 总被引:1,自引:0,他引:1
Toshio Nakatani Hiroshi Okamoto Rikuo Ota 《Journal of Sol-Gel Science and Technology》2003,26(1-3):859-863
Influence of CeO2 content on the specific surface area (SA), oxygen storage capacity (OSC) and crystalline structure of the powders in the CeO2-ZrO2 system were investigated. The change of SA value by heat-treatment is almost proportional to that of OSC. The lattice parameters of the powders had a linear relationship with the OSC value. In the CeO2-ZrO2 system, powders with 20 mol% CeO2 was found to show the highest OSC value and the highest durability of SA value after calcined at high temperatures. 相似文献
946.
Chikara Tsutsumi Katsuhiro Yamamoto Akiko Ichimaru Mitsufumi Nodono Katsuhiko Nakagawa Hajime Yasuda 《Journal of polymer science. Part A, Polymer chemistry》2003,41(22):3572-3588
Diblock copolymerizations of L - or D,L -lactide (LA) with trimethylene carbonate (TMC) or 2,2-dimethyltrimethylene carbonate (2,2-DTMC) with SmMe(C5Me5)2-(tetrahydrofuran) as an initiator and triblock copolymerizations of L - or D,L -LA/cyclic carbonates/L - or D,L -LA with [Sm(C5Me5)2]2(PhCCCCPh) as an initiator generated the desired block copolymers. This article describes the comparison of biodegradabilities by proteinase K and a compost and mechanical properties between the resulting di- or triblock copolymers and random copolymers composed of L - or D,L -LA and cyclic carbonates. The scanning electron microscopic profiles of resulting polymers were measured to understand the morphological change during biodegradation. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3572–3588, 2003 相似文献
947.
948.
Kenzo Yamaguchi Masamitsu Fujii Tadanobu Niimi Masanobu Haraguchi Toshihiro Okamoto Masuo Fukui 《Optical Review》2006,13(4):292-296
A micrometer-sized nonlinear optical resonator constituted of a silica microsphere coated with J-aggregates has been fabricated
by the sol-gel process. We determined the scattering light spectrum and discuss the application of the observed effect for
the realization of an optical switching element. Optical evaluation of the sphere has been performed in the attenuated-total-reflection
(ATR) configuration. We excited a whispering gallery mode and measured the nonlinear ATR signal dependence on excitation intensity.
The experimental result agrees very well with the simulation results obtained using the Mie theory and the finite-difference
time-domain method taking into account optical Kerr nonlinearity. The permittivity of the film of J-aggregates was measured
by ATR method at several wavelengths and the value at the desired wavelength was determined by extrapolation using the Lorentz
function. 相似文献
949.
Oxidative (δ>0) nonstoichiometry in the perovskite ‘LaMnO3+δ’ has been known to be manifested not with O interstitials but rather with cation vacancies of equal amounts at the two cation sites, La and Mn, i.e. La1−xMn1−yO3 with x=y. Here, we report the fabrication of samples with record-high cation-vacancy concentrations (x>0.12 or δ>0.4) by means of a variety of high-pressure oxygenation techniques. Linear (negative) dependence of the cell volume on x was observed within the whole x range investigated, down to 56.9 Å3 (per formula unit) for a sample oxygenated at 5 GPa and 1100 °C using Ag2O2 as an excess oxygen source. With increasing degree of cation deficiency in La1−xMn1−xO3, the ferromagnetic transition temperature was found to follow a bell shape with respect to x exhibiting a maximum of ∼250 K about x≈0.1. For moderately oxygenated samples large magnetoresistance effect was evidenced. 相似文献
950.
Kazuhiro Tanaka Yasuharu Osada Hidetoshi Kita Ken-ichi Okamoto 《Journal of Polymer Science.Polymer Physics》1995,33(13):1907-1915
Polyimides with large aromatic rings were prepared from 3,6-diaminocarbazole (CDA), N-ethyl-3,6-diaminocarbazole (ECDA), 2,7-diaminofluorene (DAF), 2,7-diaminofluorenon (DAFO), and dimethyl-3,7-diaminodibenzothiophene-5,5-dioxide (DDBT) with 2-bis(2,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA). Their physical properties, including gas permeability and permselectivity, were investigated in comparison with those of the related polyimides from 1,3-phenylenediamine (mPD). Glass transition temperatures of the polyimides with large aromatic rings were much higher than those of the mPD-based polyimides as a result of increased rigidity of the former polymer chains. With changing diamine from mPD to the large aromatic diamines, charge transfer (CT) interaction between the moieties of acid anhydride and diamine seems to be enhanced, judging from the red shift of absorption edge of the polyimide films and the red shift of CT excitation band of the 6FDA-based polyimides in solution. Fraction of free space (VF) was a little smaller for the polyimides with large aromatic rings except DDBT than for the mPD-based polyimides, probably because of enhancement in polymer chain-chain interactions as a result of the increased CT interaction. The DDBT-based polyimides had large VF than the mPD-based polyimides because of the nonplanar structure of neighboring dibenzothiophene-5,5-dioxide and imide rings. For the 6FDA-based polyimides, permeability coefficients to H2, O2, N2, CO2, and CH4 were in the order, DAFO < mPD ~ DAF < CDA < ECDA < DDBT. As for the membrane performance for H2/CH4, CO2/CH4, and O2/N2 systems, it is significant to change diamine from mPD to DDBT or CDA, but not to DAF or DAFO. The DDBT-based polyimides were excellent for H2/CH4 and CO2/CH4 separations. © 1995 John Wiley & Sons, Inc. 相似文献