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排序方式: 共有296条查询结果,搜索用时 15 毫秒
1.
Yoshiaki Yasuno Yasunori Sutoh Shuichi Makita Masahide Itoh Toyohiko Yatagai 《Optical Review》2003,10(5):498-500
A spectral interferometric optical coherence tomography (OCT) system which has polarization sensitivity is developed. This system reduces the mechanical scanning dimension by employing the principle of spectral interferometry, and measures a two dimensional cross-sectional image of biological tissue with one dimensional mechanical scanning. Sixteen OCT images with different polarization conditions are measured, and two dimensional distributions of each element of the Müller matrix of a sample to be measured are calculated. 相似文献
2.
The effect of surface modification with 3-aminopropyltriethoxysilane (APTES) and n-propyltriethoxysilane (PTES) on photo-catalytic activity and UV-shielding ability of fine TiO2 particles were investigated. The number of surface groups (NR) [nm−2] which shows the density of modifier on TiO2 surface was calculated from the results of elemental analysis and BET measurement. The modified samples of which NR are different were obtained by changing the concentration of modifier. When the photo-catalytic activity and UV-shielding ability of modified samples were evaluated, it was found that APTES was more effective modifier than PTES to obtained samples with low photo-catalytic activity and high UV-shielding ability. This is probably because the adsorption mechanisms on TiO2 surface between modifiers were different and NR is a key factor to control the performances of fine TiO2 particles. The result of zeta potential showed that surface character of modified samples was varied by changing NR. It suggested from these results that NR affected the photo-catalytic activity and UV-shielding ability because NR changed surface character of modified samples. 相似文献
3.
Masahide Terazima 《Research on Chemical Intermediates》1997,23(9):853-901
In this article, applications of the TG method to measurements of the translational diffusion of photochemically created intermediate species are reviewed. The intermediate species include unstable isomers, photochromic charged molecules, transient radicals created by photochemical reactions, and the electronically photoexcited species. Diffusional behaviors of these intermediates are different from those of stable molecules, which have been investigated extensively so far. The investigations of the diffusion of these species will provide opportunity to reveal the unique intermolecular interaction between the intermediates and matrix. Furthermore, by using products of photochemical reactions as probe molecules, the molecular dynamics of the system can be studied. This information will be valuable for understanding photochemistry in solution. 相似文献
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5.
Masahide Shimokawabe Atsushi Ohi Nobutsune Takezawa 《Reaction Kinetics and Catalysis Letters》1994,52(2):393-397
Over metal oxides (SiO2, ZrO2, Al2O3, MgO, La2O3, and CaO) with-H values of metal oxide formation higher than 700 kJ/mol, C3H6 reacts with NO2 in preference to O2. 相似文献
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7.
Tsutomu Shiragami Katsunori Tanaka Yoshito Andou Shin-ichiro Tsunami Jin Matsumoto Hongxia Luo Yasuyuki Araki Osamu Ito Haruo Inoue Masahide Yasuda 《Journal of photochemistry and photobiology. A, Chemistry》2005,170(3):287-297
Tetraphenylporphyrinatoantimony(V) complexes, linked to boron-dipyrrin chromophores on axial ligands, were synthesized. The fluorescence spectra of 1a, 1b and 1c (3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo(methoxo)antimony(V) tetraphenylporphyrin bromide (1a); 6-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]hexyloxo(methoxo)antimony(V) tetraphenylporphyrin bromide (1b); bis{3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo}antimony(V) tetraphenylporphyrin bromide (1c)) were analyzed under the excitations of N,N′-difluorobornyl-5-dipyrrinylphenyl (Bdpy) and tetraphenylporphyrinatoantimony(V) (Sb(TPP)) chromophores. Under the irradiation of Bdpy chromophore, the excitation energy was transferred from Bdpy chromophore to the Sb(TPP) moiety at 0.13–0.40 of the quantum yields, even in a polar solvent. On the other hand, the emission of Sb(TPP) chromophores was quenched by Bdpy chromophores at rate constants of 108–109 s−1, independent of on the solvent polarity. Under the excitation of the Bdpy chromophore of 1d (3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo(phenyloxo)antimony(V) tetraphenylporphyrin bromide) involving both the Bdpy and the phenoxy chromophores on the axial ligands, the excited singlet state of the Sb(TPP) chromophore generated by the energy transfer from the Bdpy chromophore was quenched by the phenoxy ligand via non-radiative processes involving electron transfer. However, rapid back electron-transfer may occur because no absorption of the anion radical of Sb(TPP) was observed by nanosecond laser photolysis. 相似文献
8.
9.
Abstract The activation field for the switching time (τ1/2) in the truly ferroelectric liquid crystal 8SI* (CE8; ΔS-(+)-4-(2′-methylbutyl) phenyl-4′-n-octylbiphenyl-4 carboxylate) has been studied for various surface conditions of the transparent electrode (SnO2), in order to understand the memory effect, the polarization reversal mechanism and its surface effect. We prepared five different surfaces, namely one coated with polyvinyl alcohol (PVA) and the other four by scratching N-times(N = 0, 10, 20 and 30) with a paste made of Cr2O3 powder (about 0·1 μm). The number and the area of scratches on the electrode surface obviously increase with N. The polarization reversal processes are influenced by this treatment. τ1/2 decreases with increasing N, but no change is observed in the contrast of the light transmittance. Two different activation fields, E a1, for the applied field E > E 0 and E a2 for E < E 0 are observed, where E 0 is a certain field depending on the sample. Here E a1 is much larger than E a2; typically E a1, = 260 kV cm?1 and E a2 = 144 kV cm?1 for N = 0. This means that nucleation for the higher field needs a large activation energy which therefore has strong barriers. In contrast with this, nucleation for the low field occurs easily. Changing a surface condition, E a2 clearly decreases with increasing N although E a1 is almost independent of the surface scratching. This may suggest that E a1 corresponds to the activation field for the bulk pinning and nucleation, and E a2 for the surface pinning. The PVA treatment gives an intermediate influence between N = 0 and 10. 相似文献
10.
Toshiaki Yamashita Shuhei Matsushita Takuya Nagatomo Ryosuke Yamauchi Masahide Yasuda 《Research on Chemical Intermediates》2013,39(1):111-126
Photoirradiation of Me2CO–H2O solution of pent-4-en-1-ol (1a) with a high-pressure mercury lamp in a test tube gave 8-hydroxyoctan-2-one (3a) in 66 % yield along with oxetane (4a) and the isomer (4a′) in 10 % yield. Irradiation of the running Me2CO–H2O solution of 1a in the flow system of a microchannel reactor (MCR) gave mainly 4a. The photoreaction of 1,1-diphenylethene (2a) with triethylamine gave a Markovnikov-type adduct (5a) and an anti-Markovnikov-type adduct (6a). The use of the MCR enhanced the production of 5a. These phenomena were explained by the light-path length effects of the MCR. 相似文献