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81.
Nobutake Nakatani Marina Ueda Hirotaka Shindo Kazuhiko Takeda Hiroshi Sakugawa 《Analytical sciences》2007,23(9):1137-1142
The hydroxyl radical (OH radical) formation rates from the photo-Fenton reaction in river and rain water samples were determined by using deferoxamine mesylate (DFOM), which makes a stable and strong complex with Fe(III), resulting in a suppression of the photo-Fenton reaction. The difference between the OH radical formation rates with and without added DFOM denotes the rate from the photo-Fenton reaction. The photoformation rates from the photo-Fenton reaction were in the range of 0.7 - 45.8 x 10(-12) and 2.7 - 32.3 x 10(-12) M s(-1) in river and rain water samples, respectively. A strong positive correlation between the OH radical formation rate from the photo-Fenton reaction and the amount of fluorescent matter in river water suggests that fluorescent matter, such as humic substances, plays an important role in the photo-Fenton reaction. In rain water, direct photolysis of hydrogen peroxide was an important source of OH radicals as well as the photo-Fenton reaction. The contributions of the photo-Fenton reaction to the OH radical photoformation rates in river and rain water samples were in the ranges of 2 - 29 and 5 - 38%, respectively. Taking into account the photo-Fenton reaction, 33 - 110 (mean: 80) and 42 - 110 (mean: 84)% of OH radical sources in river and rain water samples, respectively, collected in Hiroshima prefecture were elucidated. 相似文献
82.
H. Nakatani T. Kita O. Kojima O. Wada K. Akahane M. Tsuchiya 《Journal of luminescence》2008,128(5-6):975-977
We have investigated effects of the strain-compensating spacer layer on photoluminescence (PL) properties of excitons in the multilayered self-assembled quantum dots (SAQDs). The PL decay time of excitons in the sample with a thin spacer layer is longer than that with a thick spacer layer. This is attributed to the lowering of the oscillator strengths owing to reduction of the overlap integral between the electrons and holes envelope functions because of spatially extended electron envelope functions in the growth direction. In addition, the PL intensity of the transverse-magnetic mode in the sample with the thinner spacer layer has been found to be enhanced in the polarized PL measurement from the cleaved edge surface of the samples. These results indicate the possibility of QDs connecting along the growth direction via penetration of the electron envelope function. 相似文献
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84.
Masanori Shinohara Hiromichi Shibata Tatsuyuki Nakatani Keishi Okamoto Hiroshi Fujiyama 《Applied Surface Science》2007,253(14):6242-6247
We investigated evolution of hydrocarbon species on a Si surface during methane plasma both with and without substrate bias, using infrared spectroscopy in multiple internal reflection geometry (MIR-IRAS). We found that the relative density of the sp3-CH or sp3-CH2 species to the sp3-CH3 species was low in the low exposure regions, but that the relative density of the sp3-CH or sp3-CH2 species increased as the exposure was higher. Substrate temperatures rose as the plasma exposure was higher. The changes of ratios would be ascribed to the substrate heating effect by plasma exposure, which would enhance the etching and/or hydrogen abstraction effects. We also found the change of CH1-2/CH3 ratios was enhanced when the high substrate bias was applied. The enhancement of the ratio was due to ion effects. 相似文献
85.
Satomi Nakatani Masaaki Sato Hiroshi Hirota Masami Ishibashi 《Tetrahedron letters》2005,46(2):267-271
Melleumin A (1), a novel peptide lactone, has been isolated from the laboratory-cultured plasmodium of myxomycete Physarum melleum, and its structure was elucidated by spectral data. Melleumin A (1) consisted of four residues (p-methoxybenzoic acid, l-threonine, glycine, and an unusual amino acid, a tyrosine-attached acetic acid). 相似文献
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87.
The magnetic properties of CuCr2Se4 single crystals, which were grown by chemical transport reactions using iodine as a carrier, have been investigated. The magnetic moment at 0 K is found to be 5.07 μB per mole. The susceptibility at high temperatures follows a Curie-Weiss law with an asymptotic Curie temperature 430 K and a Curie constant 2.55 emu · . The magnetocrystalline anisotropy constants K1 and K2 are ? 6.9x 105 and ? 0.9x 105, respectively, at 5.1 K.In order to examine the effects of annealing on the magnetocrystalline anisotropy, the ferromagnetic resonance at room temperature was measured after annealing in vacuum and subsequently in an atmosphere of Se. It is found that the absolute values of K1 and K2 decrease after annealing in vacuum and increase to the initial values after annealing in an atmosphere of Se. 相似文献
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