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91.
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Letκ >ω be a regular cardinal and λ >κ a cardinal. Solovay’s classical result for κ[So] led Menas [Me] to conjecture that a stationary subset ofP κλ would split into λ stationary set of size κ+ (see[BT]), the conjecture implies that the size is (κ+) as well. Part of this work was done during the author’s stay at Boston University as one of the Japanese Overseas Research Fellows. He gratefully acknowledge Professor Akihiro Kanamori’s hospitality. He also wishes to thank members of the set theory seminar at Waseda University for their interest at the early stage.  相似文献   
94.
Swap the coins! The Pt2Au2, Pt2Au2Cu2, and Pt2Au2Ag2 complexes of 3,5‐dimethylpyrazolate exhibit yellow‐green, orange, and sky‐blue luminescence, respectively (see figure). The emission energies of Pt2Au2M2 complexes can be controlled by the change of the third coinage metal ions M. The Pt2Au2M2 complexes take the cis configuration with respect to the Au2M2 plane.

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The analysis of the yield process of mild steel in the plane problems is presented. The continuously distributed dislocations model of the edge component type is adapted with a new application technique as the method of solving the elastic-plane problems. Hahn's equation and the criterion of yield initiation proposed in the previous work [1] are employed as the constitutive relations of mild steel. Examples are taken for the bending of straight beams which is known to accompany the particular patterns with wedge-type plastic-zones. The calculated plastic-zone patterns exhibit close resemblance to the actually observed ones and the scale effect of the patterns given by the analysis is reconfirmed by the related pure bending experiments.  相似文献   
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Synthesis of the epimer of pericosine B from (-)-quinic Acid   总被引:2,自引:0,他引:2  
Synthesis of the epimer of pericosine B from (-)-quinic acid was achieved. This synthesis involves some regioselective and stereoselective processes. The desired product showed lower cytotoxic activity in comparison with natural pericosine B against the P388 leukemia cell line. The result implies that the stereocenter of C-6 in natural pericosine B plays an important role in this activity.  相似文献   
99.
The first total synthesis of (+)- and (-)-pericosine A has been achieved, enabling the revision and determination of the absolute configuration of this antitumor natural product as methyl (3S,4S,5S,6S)-6-chloro-3,4,5-trihydroxy-1-cyclohexene-1-carboxylate. Every step of this total synthesis proceeded well with excellent stereoselectivity. Structures of the intermediates in crucial steps were confirmed by detailed 2D NMR analysis.  相似文献   
100.
Let M be a compact n-dimensional Riemannian orbifold of Ricci curvature ≥n−1. We prove that for 1 ≤kn, the k th nonzero eigenvalue of the Laplacian on M is equal to the dimension n if and only if M is isometric to the k-times spherical suspension over the quotient S n k }Γ of the unit (nk)-sphere by a finite group Γ⊂O(nk+1) acting isometrically on S n k ⊂ℝ n k +. Received: 21 September 1998 / Revised version: 23 February 1999  相似文献   
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