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861.
Cristian E. Gutierrez Carlos Segovia Jose Luis Torrea 《Journal of Fourier Analysis and Applications》1995,2(6):583-596
Given an n × n matrix B, positive definite and symmetric, let LB be the differential operator in Rn given by
A class of higher Riesz transforms associated with LB is defined by means of higher gradients of order k. It is shown that these transformations are bounded in the space
with respect to the measure that makes LB selfadjoint. The constants obtained are independent of the dimension n and depend only on k,p, and the number of different
eigenvalues of the matrix B. The proof of the results uses an extension of the Littlewood-Paley-Stein theory of square functions
to the vector-valued case and inequalities previously proved by one of the authors in the context of the Riesz transforms
of order one. 相似文献
862.
Cristian D. Gonzalez-Avilé s 《Transactions of the American Mathematical Society》1997,349(10):4181-4200
In this paper we complete Rubin's partial verification of the conjecture for a large class of elliptic curves with complex multiplication by .
863.
A series of experiments dealing with the reduction of cinnamaldehyde and parent compounds was carried out in completely aqueous media in order to assess the character of this process. We wish to show that the treatment of these substrates in water with Raney catalysts is an oxido-reductive process. 相似文献
864.
Cristian Vaida Petra Mela Helmut Keul Martin Möller 《Journal of polymer science. Part A, Polymer chemistry》2008,46(20):6789-6800
Biodegradable polyester resins were prepared via photo crosslinking of functional polyesters obtained by copolymerization of ε‐caprolactone and the functional cyclic esters γ‐acryloyloxy‐ε‐caprolactone (ACL) and γ‐methacryloyloxy‐ε‐caprolactone (MCL). The cyclic esters were prepared via Baeyer‐Villiger oxidation of the corresponding 4‐acyloyloxy‐cyclohexanone derivatives. Copolymers with different content of either acryloyloxy or methacryloyloxy functional groups were prepared via catalyzed ring‐opening polymerization (ROP) of γ‐acyloyloxy‐ε‐caprolactones and ε‐caprolactone using Al(OiPr)3 as catalyst and initiator. 2D‐ and 3D‐micropatterning of the copolymers was performed via UV‐crosslinking of polymer films on a suitable substrate and by UV replica molding on both rigid and elastic masters, showing the processability of these novel functional polyesters and their potential as substrates for biomedical devices. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6789–6800, 2008 相似文献
865.
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
866.
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
867.
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
868.
869.
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
870.