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61.
Ken-Ichi Yoshino 《Proceedings of the American Mathematical Society》1998,126(9):2589-2591
We give a simple criterion for the parity of the class number of the cyclotomic field.
62.
The title compounds 1b and 1c were synthesized from manool. On treatment with either trifluoroacetic acid or formic acid 1b provided in nearly 100% yield 4a with a rearranged labdane skeleton. With sulfuric acid, however, 1b gave solely Δ8,9-isomer 5. Reduction of 4a with lithium diisobutylaluminum hydride afforded 4b. On treatment with sulfuric acid 4a reverted to 5. Rearrangement of the epoxide 6 with boron trifluoride- etherate led to a complex product mixture from which no pure substance was obtained. 相似文献
63.
Mutual annihilation of triplet excitons in Pt-phthalocyanine single crystal at 4.2 K has been studied under magnetic fields of up to 100 kG through the measurement of the phosphorescence decay by Q-switched ruby laser excitation. The maximum annihilation rate γ which is larger than that of zero magnetic field by 40–50% is obtained at magnetic fields of 30–40 kG. The annihilation rate γ is of the order of 10−12 cm3/s. 相似文献
64.
K. Yoshino S. Hayashi Y. Inuishi K. Hattori Y. Watanabe 《Solid State Communications》1983,46(7):583-585
The emission intensity in cis-(CH)χ increases a little and the emission peak shifts a little to shorter wavelength with increasing temperature, which can be interpreted by the distribution of several emission centers in energy. Photoluminescence is also observed in trans-(CH)χ at around 1.03 μm for the first time. 相似文献
65.
Within the framework of perturbative QCD, we investigate the hadroproduction of charmed particles via two-gluon as well as quark-pair annihilation. The total production cross section is found to be sensitive to the choice of the scale parameter Q2 and in general not free from non-perturbative effects. Charmed-particle production in the high-pT region is also studied. 相似文献
66.
The localization properties in the Anderson model of two dimensional square lattices are investigated numerically. Pretty large lattices composed of 104 (= 100 × 100) sites are dealt with, and the overall behaviors of the eigenvectors near the band center are directly examined. Fairly sharp transition and the exponentially decaying localized states are visualized. 相似文献
67.
A cluster method for the electronic structure of amorphous materials is presented with an application to amorphous diamond. Eight-atom cluster model gives a pseudogap in the density of states. 相似文献
68.
Tatsuhiko Kanmera Sannamu Lee Haruhiko Aoyagi Nobuo Izumiya 《Tetrahedron letters》1979,20(46):4483-4486
A series of cyclo (Δaminoacyl-L-Ala) () (Δ=α,β-dehydro) were prepared from cyclo(Gly-L-Ala) and corresponding aldehyde, and hydrogenated with Pd black in MeOH. Chiral inductions producing cyclo (L-aminoacyl-L-Ala) () from were 96–99% in the case of L-Aba (2-aminobutanoic acid), L-Val, L-Leu, and L-App (2-amino-5-phenylpentanoic acid) as an L-aminoacyl moiety in . Pure L-Leu, L-Aba, and L-App were synthesized in preparative scale from corresponding through asymmetric hydrogenation and acid-hydrolysis. 相似文献
69.
J. Yoshino T. Hoshi H. Ogawa T. Minegishi und Y. Tanizaki 《Colloid and polymer science》1979,257(9):1012
Ohne Zusammenfassung 相似文献
70.
The changes in the spectra of Xylenol Orange and Methylthymol Blue complexes with several bivalent metal ions have been investigated in terms of the chemical bonding between the phenolic oxygen atom and the metal ion, and the hard and soft character of the donor and acceptor. The value of this approach to indicator action is discussed. 相似文献