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Hironao Kato 《Differential Geometry and its Applications》2012,30(2):153-163
We prove that any real Lie group of dimension ?5 admits a left invariant flat projective structure. We also prove that a real Lie group L of dimension ?5 admits a left invariant flat affine structure if and only if the Lie algebra of L is not perfect. 相似文献
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Pd/C-catalyzed deoxygenation of phenol derivatives using Mg metal and MeOH in the presence of NH(4)OAc 总被引:2,自引:0,他引:2
[STRUCTURE: SEE TEXT] A Pd/C-catalyzed deoxygenation method of phenolic hydroxyl groups via aryl triflates or mesylates using Mg metal in MeOH at room temperature was developed. The addition of NH4OAc dramatically affects the reactivity and reaction rate. This method is particularly attractive to provide an environmentally benign and widely applicable removal method of phenolic alcohols under quite mild reaction conditions. 相似文献
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A series of anthracene-clustering dendrimers bearing various aliphatic substituents at the terminal positions were synthesized using a direct coupling strategy. A remarkable effect of the side chains was imparted to chemical properties of the dendrimers such as drastically increased solubility. Although the multibranched anthracene arrays in the dendritic architectures exhibited no cooperativity in terms of the absorption feature and behaved as single chromophoric systems, investigations focusing on fluorescence properties revealed that a type of cooperativity was present as expressed in the reduced quantum yields of fluorescence. An alternative approach utilizing time-resolved fluorescence decay measurements clearly demonstrated that the most reasonable mechanism of the cooperative action should involve two discernible channels of intramolecular fluorescence resonance energy transfer (FRET) occurring from one chromophore to the others within and across junctions of the branching units. 相似文献
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Hiroyuki Takagi Hironao Koshimizu 《Journal of Mathematical Analysis and Applications》2011,377(1):135-144
J.R. Holub (1988) [10] introduced the concept of backward shift on Banach spaces. We show that an infinite-dimensional function algebra does not admit a backward shift. Moreover, we define a backward quasi-shift as a weak type of a backward shift, and show that a function algebra A does not admit it, under the assumption that the Choquet boundary of A has at most finitely many isolated points. 相似文献
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[reaction: see text] An efficient and extensive deuterium incorporation using heterogeneous Pd/C-D(2)O-H(2) system into many different types of unactivated C-H bond positions was developed. The present method provides a deuterium gas-free, totally catalytic, and post-synthetic deuterium labeling method in D(2)O media. 相似文献