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排序方式: 共有477条查询结果,搜索用时 15 毫秒
1.
Atsuhiro Fujimori Mikako Ishitsuka Hiroo Nakahara Eisuke Ito Masahiko Hara Kaname Kanai Hisao Ishii Yukio Ouchi Kazuhiko Seki 《Journal of Polymer Science.Polymer Physics》2004,42(12):2329-2336
Photopolymerization of cadmium 10,12-pentacosadiynoate (CdDA) in Langmuir–Blodgett (LB) films, with the molecular packing well arranged by moderate preannealing, was investigated with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Greenish films of polydiacetylene with an absorption wavelength of 705 nm were obtained through the photopolymerization of preannealed monomer LB films, and this resulted in an extended π-conjugate system based on the well-ordered monomer in a two-dimensional arrangement. The electronic structures of the polydiacetylenes were found to be correlated to the variation of the molecular arrangements in the films from the changes in the NEXAFS spectra through photopolymerization in the LB films. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2329–2336, 2004 相似文献
2.
Hisao Fujita Yashima et Saliha Hamdous 《Rendiconti del Circolo Matematico di Palermo》2007,56(1):79-89
On considére l’équation stochastique decrivant un systéme den espéces avec une perturbation stochastique du type environnemental et une diffusion dans un territoire de chaque espéce.
On suppose la compétition avec un effet limité entre le espéces différentes, tandis que l’effet logistique pour chaque espéce
est supposé quadratique. Sous une condition convenable pour les coefficients, on démontre l’existence d’une mesure invariante
pour cette équation stochastique, oú la densité de population de chaque espéce est presque surement positive.
相似文献
3.
Reduction of dislocation density and improvement of optical quality in ZnO layers by MgO-buffer annealing 总被引:1,自引:0,他引:1
Hiroki Goto Hisao Makino Agus Setiawan Takuma Suzuki Chihiro Harada Tsutomu Minegishi Meoung-Whan Cho Takafumi Yao 《Current Applied Physics》2004,4(6):637-639
Optical properties of ZnO thin films with/without MgO-buffer annealing were investigated by low and room temperature photoluminescence measurements. The ZnO films were grown on c-sapphire substrates by plasma-assisted molecular-beam epitaxy employing a thin MgO-buffer layer. Dislocation density of ZnO layer was reduced from 5.3 × 109 to 1.9 × 109 cm−2 by annealing MgO-buffer prior to the growth of ZnO. The intensity of free exciton emission from the sample with MgO-buffer annealing was almost twice of that from the sample without annealing, while the deep level emission from the sample with MgO-buffer annealing was about 1/3 of that without annealing. The MgO-buffer annealing improves optical quality of overgrown ZnO films. 相似文献
4.
Hisao Yoshihara 《manuscripta mathematica》1989,64(2):169-187
We study a plane curve C whose singular points are cusps and the surface which is a triple covering of 2 branched along C. As a result, especially we obtain an inequality for the sum of the Milnor numbers at the singularities of C and new surfaces of general type. 相似文献
5.
Yamamoto Y Ishii J Nishiyama H Itoh K 《Journal of the American Chemical Society》2004,126(12):3712-3713
The Ru(II)-catalyzed [2+2+2] cyclotrimerization of alkynylboronates, propargyl alcohol, and terminal alkynes proceeded chemo- and regioselectively to give rise to arylboronates, which were subjected to Suzuki-Miyaura cross-coupling with aryliodides to afford highly substituted biaryls in 53-76% yields. 相似文献
6.
Hisao Morisaki Kunihiko Nakagawa Haruki Shiraishi 《Colloids and surfaces. B, Biointerfaces》1996,6(6):347-352
A parallel-plate flow chamber consisting of two transparent electro-conductive glass plates was constructed. The two glass plates were set parallel to each other and connected to a potentiostat apparatus to regulate the strength of the electric field between the plates. A microbial cell suspension was flowed through the chamber. This system enabled the application of an electrostatic force to suspend charged particles, e.g. microbial cells, existing between the two plates. The time course of the cell attachment of Pseudomonas syringae pv. atropurpurea NIAES 1309 suspended in 10 mM phosphate buffer solution (pH 7.0) to the glass plate was investigated at various electric field strengths ranging from −4.2 to +4.1 V cm−1. The attachment rate and the maximum number of attached cells increased linearly with the increase in the strength of the positive electric field. In contrast, the rate and the number of cells decreased linearly with the decrease in the strength of the negative electric field. These linear relations gave a specific value for the strength of the electric field (−5.9 ± 0.7 V cm−1) where the electrostatic repulsion and the microbial attachment force were thought to be equal, resulting in no cell attachment. From this value, the electrostatic repulsion, i.e. the microbial attachment force, was calculated to be 5.0 × 10−11 N cell−1 for cells of average size. 相似文献
7.
Tsutomu Kagiya Shizuo Narisawa Taizo Ichida Kenichi Fukui Hisao Yokota Masatsune Kondo 《Journal of polymer science. Part A, Polymer chemistry》1966,4(2):293-299
The copolymerization of carbon monoxide and aziridines such as ethylenimine and propylenimine was carried out by γ-ray irradiation. Aziridines and carbon monoxide were allowed to copolymerize under γ-ray irradiation from a Co60 source and gave a crystalline solid copolymer. The yield of the copolymer increased with reaction temperature. The composition of copolymers obtained did not depend on the feed ratio of monomers and was found to be almost equimolar. The copolymer of ethylenimine and carbon monoxide melted at about 322–335°C. with decomposition and has an infrared spectrum identical with that of poly-β-alanine obtained by the hydrogen-migration polymerization of acrylamide. The hydrolyzed product of the ethylenimine–carbon monoxide copolymer was confirmed to be β-alanine by paper chromatography. These results lead to the conclusion that the copolymerization of aziridines and carbon monoxide took place alternatively by γ-ray irradiation, and produced crystalline poly-β-alanines. 相似文献
8.
Akiko Sekihara Hidekazu Honma Tadahiro Fukuju Kiminori Maeda Hisao Murai 《Research on Chemical Intermediates》1998,24(8):859-877
Photooxidation (charge transfer) reactions of carbazole derivatives by maleic anhydride (MA) in alcoholic media are studied
by a time-resolved cw-ESR (TRESR) and Fourier transform ESR (FTESR) techniques. The CIDEP spectra observed in the systems
(methyl-, ethyl-, and phenyl-substituted carbazoles with MA) remarkably depend on the MA concentration. Under the high concentration
conditions, an emissive TM (triplet mechanism) polarization with a slight A/E (absorption/emission) pattern of the RPM (radical
pair mechanism) is observed. In the low concentration of MA, a TM-like absorptive polarization is superimposed on the A/E
pattern of the RPM. Since this reaction takes place exclusively through the triplet state, this spectral phase reveals that
the singlet state of the radical-ion pair (RIP) has an energy higher than that of the triplet state, in other words, the sign
of the apparent exchange interaction of the present RIP systems is positive. The total absorptive polarization observed in
the low concentration of MA is tentatively explained by the polarization transfer from the excited triplet state of carbazoles
in thermal equilibrium. 相似文献
9.
Chemical ionization (CI) and fast atom bombardment (FAB) mass spectra of simple bifunctional aromatic compounds were compared. Some significant differences were revealed with respect to the site of protonation and extent of fragmentations. Unlike conventional CI ionization, the protonated molecule formation by FAB could not be accounted for by ordinary proton transfer reactions in the gas phase. The observed ions under FAB conditions appear to be regulated by proton exchange reactions through frequent collisions in some particular region between the matrix and the gas phase. 相似文献
10.
Akihiko Sugie Hiromi Shimomura Junki Katsube Hisao Yamamoto 《Tetrahedron letters》1979,20(28):2607-2610
A stable PGI2 analog (methanoprostacyclin ) was synthesized starting from 5-norbornene-2,3-dicarboxylic anhydride. 相似文献