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81.
The photochemical reaction of tetraphenylhydrazine in an SDS micellar solution is studied using a transient absorption detected magnetic resonance (ADMR) method. This system is photo-dissociated via the singlet excited state and forms a transient radical pair. Strong microwave irradiation of this system under an × band EPR magnetic field provides an ADMR spectrum of the singlet born radical pair as the optical absorbance change of the diphenylaminyl radical. The employment of a short duration microwave pulse that efficiently flips the electron spin quantum (Δm s = 1) controls the reaction of the radical pair, and the reaction rate constant of this system is determined. Furthermore, changing the microwave duration shows the quantum beat of this system induced by the electromagnetic field. This beat signal carries both a single beat that corresponds to the Rabi frequency and a double-frequency beat that is due to simultaneous two-spin controlling. 相似文献
82.
83.
Y. Nakajima H. Hidaka T. Tamegai T. Nishizaki T. Sasaki N. Kobayashi 《Physica C: Superconductivity and its Applications》2009,469(15-20):921-923
We report the upper critical field Hc2 in a ternary iron-silicide superconductor Lu2Fe3Si5 with Tc 6 K obtained by the resistivity measurements. We find that Hc2 increases linearly with decreasing temperature down to Tc/3, and Hc2(T = 0) exceeds the orbital depairing field described by the Werthamer–Helfand–Hohenberg theory. We also find that the anisotropy of Hc2 is nearly independent of temperature and the angular dependence of Hc2 is well-described by the anisotropic Ginzburg–Landau model. These results strongly indicate the presence of two distinct superconducting gaps in Lu2Fe3Si5 although the behavior is slightly different from that of the typical two-gap superconductor MgB2. 相似文献
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87.
T Yamane T Hashizume K Yamashita K Hosoe T Hidaka K Watanabe H Kawaharada S Kudoh 《Chemical & pharmaceutical bulletin》1992,40(10):2707-2711
Benzoxazinorifamycin reacted with various secondary amines to yield various 5'-substituted aminobenzoxazinorifamycin derivatives. The derivatives exhibited potent activities against gram-positive bacteria and mycobacteria. The antimicrobial activities of these compounds against Mycobacterium tuberculosis and Mycobacterium intracellulare were superior to those of rifampicin. Some of these compounds showed good plasma levels after oral administration in rats. 相似文献
88.
Single crystals of Perovskite-type oxide BaPb1−xBixO3 are grown from BaCO3-PbO2-Bi2O3 solutions which are weighed in two kinds of mixing ratios: X/2 mol % BaCO3 − (100−X) mol % PbO2 − X/2 mol % Bi2O3 and (10+X/2) mol % BaCO3 − (90−X) mol % PbO2 − X/2 mol % Bi2O3 These room temperature crystal structures are examined by using an X-ray powder diffraction method. The crystals grown from X/2−(100−X)−X/2 mol % solutions are orthorhombic at room temperature, while the structures are tetragonal with crystals grown from relatively Ba rich and Pb poor ( (10+X/2)−(90−X)−X/2 mol % ) solutions. This result indicates that the difference in the mixing ratio of the initial materials brings about a drastic structural change. The orthorhombic and the tetragonal crystals of x0.25 exhibit superconducting transition at 10K and 12K, respectively. The transition temperature in the latter is 2K higher than the former. In the light of this result, some difference between orthorhombic and tetragonal crystals is considered to influence superconductivity in this system. 相似文献
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90.
Ling Zang Ping Qu Jincai Zhao Tao Shen Hisao Hidaka 《Journal of molecular catalysis. A, Chemical》1997,120(1-3):235-245
The photocatalytic bleaching of p-nitrosodimethylaniline (P) has been investigated in aqueous suspensions of TiO2. It was found that both charge carriers (hole and electron) were reactive to P to result in a bleaching. The roles of O2 and several hole scavengers (HCOO−, EDTA, I−) have also been examined. A reaction mechanism has been proposed with consideration of several primary processes photoinduced on TiO2 surface. The results of the kinetic analysis fit fairly well to those of the experiments. The rate constant (khp) of the reaction between P and the adsorbed hydroxyl radical was estimated to be in the order 1010 M−1 s−1, which is in good agreement with that obtained from the homogeneous reaction of P with free OH radicals. Of particular interest is the pH dependence of the photobleaching rate. Around both pKa of P and pHZPC of TiO2, the photobleaching of P was steeply enhanced. This can be reasonably attributed to the mutual interaction (repulsion versus attraction) between P and TiO2 particles in different pH ranges. 相似文献