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551.
552.
Joel Feldman J. Magnen V. Rivasseau R. Sénéor 《Communications in Mathematical Physics》1986,103(1):67-103
The Euclidean massive Gross-Neveu model in two dimensions is just renormalizable and asymptotically free. Thanks to the Pauli principle, bare perturbation theory with an ultra-violet cut-off (and the correct ansatz for the bare mass) is convergent in a disk, whose radius corresponds by asymptotic freedom to a small finite renormalized coupling constant. Therefore, the theory can be fully constructed in a perturbative way. It satisfies the O.S. axioms and is the Borel sum of the renormalized perturbation expansion of the model 相似文献
553.
In population genetic theory, most analytical and numerical studies of the evolution of recombination have focused on diploid genetics. In studies of the foundations and applications of genetic algorithms (GA's), however, the bit-strings are usually treated as haploid genotypes. In this paper and its companion paper (Bergman et al., 1995), we compare results for the evolutionary dynamics of modifiers of recombination in haploids with results derived for diploids. In this paper, we study the evolution of an allele that controls the rate of recombination between two loci subject to directional selection. It is shown analytically that the fate of a recombination modifier in both haploids and diploids is determined in a complicated way by the sign of the epistasis (interaction in fitness) between the loci, the sign of the initial linkage disequilibrium, and the amount of recombination between the modifier and the genes under selection. This theory is deterministic in that the population is regarded as infinite and no sampling occurs to produce offspring from parents. In the companion paper (Bergman et al., Complexity, 1(2) 1995), we expand upon this work by addressing epistatic interactions among several loci in finite populations. 相似文献
554.
555.
[reaction: see text]p-Toluenesulfinate addition to 1-hydroxybut-3-ynyliodonium ethers triggers a sequence of reactions which ultimately delivers 2-substituted-3-p-toluenesulfonyldihydrofuran products along with 3-p-toluenesulfonyldihydrofuran as a major byproduct. A putative 1,2-alkyl shift within an unsaturated oxonium ylide (Stevens rearrangement) accounts for the oxygen-to-carbon transfer of the alkyl group. 相似文献
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Burchat PR Schmidke WB Yelton JM Abrams G Amidei D Baden AR Barklow T Boyarski AM Boyer J Breidenbach M Burke DL Butler F Dorfan JM Feldman GJ Gidal G Gladney L Gold MS Goldhaber G Golding L Haggerty J Hanson G Hayes K Herrup D Hollebeek RJ Innes WR Jaros JA Juricic I Kadyk JA Karlen D Lankford AJ Larsen RR LeClaire BW Levi M Lockyer NS Lüth V Matteuzzi C Nelson ME Ong RA Perl ML Richter B Riles K Ross MC Rowson PC Schaad T Schellman H Sheldon PD Trilling GH de la Vaissiere C Wood DR Zaiser aC 《Physical review letters》1985,54(23):2489-2492
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The syntheses of a bis indole and an indole salicylate with the required axial chirality for diazonamide A are reported. Atropselectivity in these biaryl systems is enforced by an sp(3) stereogenic center in a lactone tether in both cases. [structure: see text] 相似文献