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Taichiro Kugo Tetsuji Kuramoto Shozo Uehara 《Zeitschrift fur Physik C Particles and Fields》1983,19(3):241-250
It is investigated to what extent the well-known algebra \(\left\{ {Q^S ,\bar Q^S } \right\} = \gamma ^\mu P_\mu \) in the rigid supersymmetry theory holds in quantum supergravity: The anti-commutator \(\left\{ {Q_\alpha ^S ,\bar Q_\beta ^S } \right\} = \gamma ^m \tilde P_m \) defines an “internal” translation generator \(\tilde P_m \) , quite another from the “external” translation generatorP μ. It is, however, shown that those two operators give the same matrix elements between any two physical states aside from a proportional factor. Such a “miracle” is caused by some particular properties of global gauge transformation charge universal in gauge theories. These properties are fully clarified in a general manner. 相似文献
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An infrared-absorption band centered at 0.85 eV, which is below the big optical absorption at the charge-density-wave (CDW) gap energy of 1.85 eV, has been observed for semiconducting single crystalline Ba(1-x)KxBiO3. With substituting K for Ba, the spectral weight of the new band increases with x, while that of the CDW-gap excitation decreases. Since the impurity state with the K substitution is known to be nonmagnetic at low temperatures, Bi3+ the state with 6s2 electrons surrounded by the six Bi5+ ions forms a small bipolaron by losing a pair of electrons in the Rice-Sneddon model. The new band is assigned to a transition from the lower-Peierls band to a state of the bipolaronic point defect. 相似文献
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A phosphine/Cu(II) complex catalyzes the dehydrative glycosylation of tri-O-benzylated 1-hydroxyribofuranose to give the ribofuranoside with high stereoselectivity. 相似文献
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Touge T Hakamata T Nara H Kobayashi T Sayo N Saito T Kayaki Y Ikariya T 《Journal of the American Chemical Society》2011,133(38):14960-14963
Newly developed oxo-tethered Ru amido complexes (R,R)-1 and their HCl adducts (R,R)-2 exhibited excellent catalytic performance for both asymmetric transfer hydrogenation and the hydrogenation of ketonic substrates under neutral conditions without any cocatalysts to give chiral secondary alcohols with high levels of enantioselectivity. 相似文献
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Hiroya Kitahata Kiyoharu Tadanaga Tsutomu Minami Norifumi Fujimura Taichiro Ito 《Journal of Sol-Gel Science and Technology》2000,19(1-3):589-593
Hexagonal YMnO3 has a ferroelectric property with an optimal remanent polarization along the c-axis. The c-axis oriented YMnO3 thin films with a small leakage current were prepared by the sol-gel dipping method. The c-axis orientation of the films was promoted by the addition of diethanolamine to the Mn precursor solution. A heat treatment with multiple steps led to a dense film structure with fine grains. The dense structure resulted in the decrease of the leakage current. Furthermore, when the films were heat-treated in a vacuum, the leakage current became considerably small and the ferroelectricity of the YMnO3 thin films was observed even at room temperature. 相似文献
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We show how spinors in space-times of dimension D = t + s, where t is the time dimension, are associated for s - t = 1, 2, 4, 8 (and if t = 0, 1, 2) with the number systems (division algebras), . For t = 1 and s - t = 1, 2, 4 this association is “realized” by the sequence of Lorentz groups S1(2,), S1(2;), S1(2;) for D = 3, 4, 6 respectively. We discuss how octonions may be related to D = 10. For D = 6 we give details of S1(2; ) spinors and construct supersymmetric models with them. These results explain various “empirical” observations in the literature relating quaternions and supersymmetry. 相似文献
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