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101.
Miyatake K Zhou H Uchida H Watanabe M 《Chemical communications (Cambridge, England)》2003,(3):368-369
Novel sulfonated polyimides containing fluorenyl groups show good thermal and oxidative stability as well as a high proton conductivity of 1.67 S cm(-1) at 120 degrees C and 100% RH. 相似文献
102.
Kakeshita T Uchida S Kojima KM Adachi S Tajima S Gorshunov B Dressel M 《Physical review letters》2001,86(18):4140-4143
A transverse optical plasma mode is observed at far-infrared frequencies within the superconducting gap region by measuring the c-axis optical reflectivity for single crystals of T* cuprate superconductors SmLa0.85Sr0.15CuO4-delta and Nd1.4Sr0.4Ce0.2CuO4-delta. These T* cuprates have two different insulating layers sandwiching the superconducting CuO2 planes, leading to two longitudinal plasmons. Also, the transverse mode is directly observed due to the coupling of the infrared radiation with the current perpendicular to the superconducting layers which are regarded as an alternating array of two inequivalent Josephson junctions. 相似文献
103.
Maekawa T Kobayashi T Yamaguchi S Yoshinaga K Igami H Uchida M Tanaka H Asakawa M Terumichi Y 《Physical review letters》2001,86(17):3783-3786
Extraordinary (X) waves are perpendicularly injected for electron Bernstein (B) wave heating into an Ohmically heated plasma from the inboard side in the WT-3 tokamak. Measurements show that absorption does not take place at the electron cyclotron resonance layer nor the upper hybrid resonance layer, but does happen midway between them. This is consistent with the ray tracing prediction, i.e., the poloidal field and poloidal inhomogeneity of toroidal field lead the B waves to have a large parallel refractive index N( parallel) (>1), and the B waves are damped away via the Doppler-shifted cyclotron resonance. 相似文献
104.
Abstract We have compared the effect of hydrostatic pressure on the threshold current, Ith, and lasing energy, Elase, of 1.3 pm quantum-well devices based upon AlGaInAs and InGaAsP. Whilst we observe a very similar dependence of Elase on pressure for the two materials, we measure strikingly different variations of Ith. By applying pressure to 1.3 μm InGaAsP lasers, Ith typically decreases by ~ 10% over 1 GPa consistent with the reduction of Auger recombination, which forms ~ 50% of Ith at room temperature. However, for the 1.3 μm AlGaInAs-based lasers, we observe an increase in Ith by ~ 8% over the same pressure range. From these results we conclude that non-radiative recombination accounts for only ~ 20% of Ith in AlGaInAs-based devices. This is in good agreement with previous temperature dependence measurements and shows why AlGaInAs-based devices exhibit a reduced temperature sensitivity of Ith which is very important for telecommunications applications. 相似文献
105.
Summary The chromatographic efficiency and stability of a new octadecyl-bonded polymer (ODP) gel, developed for reversed phase liquid
chromatography (RPLC) by substitution of stearate ester groups for the hydroxyl groups of vinyl alcohol copolymer particles,
were investigated and compared with those of conventional gels. The efficiency of the column packed with the ODP gel was practically
unaffected by repeated alternating passages of distilled water and acetonitrile, apparently because the gel volume was affected
similarly by both solvents. Like conventional ODS columns, the ODP column demonstrated a close correlation between log k’
(capacity factor) and carbon atom number in alkyl alcohols in accordance with Martin’s rule and H ∼ 4 dp, thus indicating
a high column efficiency for these alcohols. The capacity factor of the ODP column for pyridine with acidic eluent was smaller
than that of ODS columns, and the pyridine peak was sharp and symmetrical. 相似文献
106.
Yukihiro Uchida 《Journal of Number Theory》2008,128(2):263-279
We estimate the bounds for the difference between the ordinary height and the canonical height on elliptic curves over number fields. Our result is an improvement of the recent result of Cremona, Prickett, and Siksek [J.E. Cremona, M. Prickett, S. Siksek, Height difference bounds for elliptic curves over number fields, J. Number Theory 116 (2006) 42-68]. Our bounds are usually sharper than the other known bounds. 相似文献
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110.
Ayumi Ishii Shinobu Kishi Hideki Ohtsu Toshifumi Iimori Takakazu Nakabayashi Nobuhiro Ohta Naoto Tamai Milan Melnik Miki Hasegawa Yuzo Shigesato 《Chemphyschem》2007,8(9):1345-1351
The electronic and structural behaviour of a Pr(III) complex with 4,7-diphenyl-1,10-phenanthroline, [Pr(bathophen)(2)(NO(3))(3)], is investigated with respect to the effect of configuration changes on the Pr(III) centre. [Pr(bathophen)(2)(NO(3))(3)] luminesces from the excited states of the ligand and the metal ion. The fluorescence, ff-emission ((1)D(2)-->(3)H(4)), and phosphorescence bands appear at 394, 608.2 and 482 nm, respectively, in the solid state. In acetonitrile, the complex also shows multiple emissions. From the time-resolved emission and the lifetime measurements, the excitation energy-transfer in [Pr(bathophen)(2)(NO(3))(3)] is clarified, that is, the upper excited triplet level of the ligand acts as an energy donor, while the (1)D(2) levels of Pr(III) is the acceptor. Additionally, the emission phenomena of the complex can be modified by molecular distortion, particularly by rotation of the phenyl groups in the ligand. 相似文献