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851.
Cristian Vladimirescu 《Journal of Global Optimization》2007,37(3):437-447
Several existence results for a class of perturbed inequality problems on various subsets of Banach spaces are proved. A concrete
application to a problem from Nonsmooth Mechanics illustrates is given.
This paper is dedicated to the memory of Professor P.D. Panagiotopoulos 相似文献
852.
We compute the pressure of the random energy model (REM) and generalized random energy model (GREM) by establishing variational
upper and lower bounds. For the upper bound, we generalize Guerra’s “broken replica symmetry bounds,” and identify the random
probability cascade as the appropriate random overlap structure for the model. For the REM the lower bound is obtained, in
the high temperature regime using Talagrand’s concentration of measure inequality, and in the low temperature regime using
convexity and the high temperature formula. The lower bound for the GREM follows from the lower bound for the REM by induction.
While the argument for the lower bound is fairly standard, our proof of the upper bound is new. 相似文献
853.
New active-iron based reducing system for carbonyl compounds and imines. Stereoselective reduction of cyclic ketones 总被引:1,自引:0,他引:1
The reaction of different carbonyl compounds and imines with a mixture of iron(II) chloride tetrahydrate, an excess of lithium powder, and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 5 mol%) in THF at room temperature, led to the formation of the corresponding alcohols and amines, respectively. The process was also applied to the transformation of α,β-unsaturated carbonyl compounds into the corresponding saturated alcohols. The new reducing system exhibited good to excellent diastereoselectivity toward the reduction of different monocyclic and polycyclic ketones. 相似文献
854.
855.
Pavel A. Abramov Maxim N. Sokolov Alexandr V. Virovets Eugenia V. Peresypkina Cristian Vicent Vladimir P. Fedin 《Journal of Cluster Science》2009,20(1):83-92
Reaction of [Mo6(μ3-Cl)8Cl6]2− with H2Se, generated in situ from ZnSe and 4 M HCl under hydrothermal conditions lead to the substitution of one or two bridging
chlorides, depending on the reagents ratio. With the Mo6/ZnSe 1:3 molar ratio [Mo6(μ3-SeCl7)Cl6]3− forms selectively in high yield. Further substitution is more hindered, and even at 1:20 cluster-to-selenide molar ratio
a mixture of [Mo6(μ3-SeCl7)Cl6]3− and [Mo6(μ3-Se2Cl6)Cl6]4− is formed. The products were characterized by X-ray, Raman spectra and electrospray ionization mass spectrometry. 相似文献
856.
Arnaud Bodin 《Israel Journal of Mathematics》2008,164(1):333-347
We prove an analogous of Stein theorem for rational functions in several variables: we bound the number of reducible fibers
by a formula depending on the degree of the fraction. 相似文献
857.
858.
859.
The present paper proposes a generalisation of the notion of disjunctive (or rich) sequence, that is, of an infinite sequence of letters having each finite sequence as a subword. Our aim is to give a reasonable notion of disjunctiveness relative to a given set of sequences F. We show that a definition like “every subword which occurs at infinitely many different positions in sequences in F has to occur infinitely often in the sequence” fulfils properties similar to the original unrelativised notion of disjunctiveness. Finally, we investigate our concept of generalised disjunctiveness in spaces of Cantor expansions of reals. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
860.
Alessandro Piergentili Fabio Del Bello Francesco Gentili Mario Giannella Wilma Quaglia Cristian Vesprini Russell J. Thomas Graeme M. Robertson 《Tetrahedron》2007,63(52):12912-12916
The solution-phase synthesis of the β-turn peptidomimetic ICG-001, a selective inhibitor of Wnt/β-catenin signalling, which has been found to be important for both initiation and progression of cancers of different tissues and has been exploited as an extremely useful chemogenomic tool, was developed. This route is particularly suitable for the multigram scale preparation of ICG-001. 相似文献