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991.
Design and analysis of planar shape deformation 总被引:1,自引:0,他引:1
Shape deformation refers to the continuous change of one geometric object to another. We develop a software tool for planning, analyzing and visualizing deformations between two shapes in
. The deformation is generated automatically without any user intervention or specification of feature correspondences. A unique property of the tool is the explicit availability of a two-dimensional shape space, which can be used for designing the deformation either automatically by following constraints and objectives or manually by drawing deformation paths. 相似文献
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Herbert Becker 《Zeitschrift für Physik A Hadrons and Nuclei》1930,59(9-10):601-602
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Wenling Li Christian Köhler Prof. Zhi Yang Prof. Dietmar Stalke Dr. Regine Herbst-Irmer Prof. Herbert W. Roesky 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(5):1193-1197
Lewis base cAACs stabilized monomeric silylenes with halogen or methyl substituents at the silicon center have not been reported due to the strong σ-donor and π-acceptor character of cAAC. To prepare these monomeric silylenes, we used the silicon(IV) precursors 5 and 6 with a nitrogen donor group L (L=o-C6H4NMe2). The cAAC-stabilized (cAAC=C(CH2)(CMe2)2N-Ar, Ar=2,6-iPr2C6H3) silylenes LSiCl(cAAC) ( 7 ) and LSiMe(cAAC) ( 8 ) were synthesized by reduction of LSiCl3 and LSiMeCl2 with two equivalents of KC8 in the presence of one equivalent of cAAC, respectively. Compounds 7 and 8 were characterized by single-crystal X-ray crystallography, NMR spectroscopy, and elemental analysis. Compounds 7 and 8 are stable in the solid state as well as in solution at room temperature for at least four months under inert conditions. 相似文献
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Hedda Schrey Dr. Jana Backenköhler Dr. Herbert Kogler Dr. Markus Plaumann Prof. Dr. Peter Spiteller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(44):10333-10341
(5S,6S)-Aminotenuazonic acid, a new 3-acyltetramic acid, related to the well-known mycotoxin tenuazonic acid has been isolated from fruiting bodies of Laccaria bicolor. Its structure was mostly established by analysis of its 2D NMR and HR-(+)-ESI-MS spectra. A total synthesis starting from N-Boc-l -isoleucine gave (5S,6S)-aminotenuazonic acid in 8 % yield over nine steps (67 % de). The key steps of the total synthesis are a light-initiated Hofmann–Löffler–Freytag radical chain reaction and a Dieckmann cyclisation. The relative and absolute configurations of the natural product were determined by comparison of its NMR and CD spectra with those of the corresponding enantiopure synthetic compounds. Metabolic profiling of crude extracts of different mushrooms showed that aminotenuazonic acid is present in all four of the investigated Laccaria species. Aminotenuazonic acid shows phytotoxic activities against the root and shoot growth of Lepidium sativum, Pinus sylvestris and Arabidopsis thaliana comparable to those of tenuazonic acid. 相似文献
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