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991.
Novel 1,7-dihydro- or 1,2,6,7-tetrahydronaphthalene derivatives were obtained from naphthalene through a polysilylation/oxidation process as well as 1,4,6,7-tetrakis(trimethylsily)naphthalene, a regiospecific precursor of 1,4,6,7-tetrafunctional naphthalenes. 相似文献
992.
Helene Lavayssiere Jacques Satge Jacques Barrau Moussa Traore 《Journal of organometallic chemistry》1982,240(4):335-348
A new aspect of the reactivity of germanones and germathiones towards nitrilimines, nitriloxides and nitrones is investigated. The regioselectivity of the dipolar 1,3-cycloaddition reactions between germanones or germathiones and diphenylnitrilimine is discussed.
The structure of the adducts is determined from chemical or spectroscopic studies (13C NMR, IR).
Germa-oxa- or -thia-diazolines, germaoxathiazoles and germaoxathiazolidines are obtained and the thermal stability of these adducts reported. 相似文献
993.
994.
K. Appert D. Berger R. Gruber F. Troyon J. Rappaz 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1974,25(2):229-240
The eigenmodes of a cylindrical homogeneous plasma may be calculated analytically. There are three classes of solutions. The eigenvalues of the first class are well separated, those of the second class have a point of accumulation. The eigenvalue of the third class is infinitely degenerated. The eigenvalues and eigenmodes of the corresponding discrete finite element problem tend towards the true solution. The convergence properties are discussed. 相似文献
995.
The temperature dependences of g-factor and linewidth of C11,3NiCl2,13 single crystals have been measured from 10 to 400 K. The data indicate that nickel ions in graphite behave at low temperatures like Ising ions, with a phase transition occurring at about 30 K. 相似文献
996.
Jean-Pierre Crouzeix Jacques A. Ferland Siegfried Schaible 《Mathematical Programming》1983,27(3):342-354
We consider a generalization of a linear fractional program where the maximum of finitely many linear ratios is to be minimized subject to linear constraints. For this Min-Max problem, a dual in the form of a Max-Min problem is introduced and duality relations are established. 相似文献
997.
The migratory aptitude of the ethoxycarbonyl group in the pinacol rearrangement was deduced from the structure of the products observed after treatment of 2-substituted 2,3-dihydroxy-3-phenylbutyrates with fluorosulfonic acid at 0° for 3 minutes. The migratory aptitude of ethoxycarbonyl is comparable to that of ethyl, greater than that of methyl or hydrogen, but smaller than that of phenyl. Cyclization and fragmentation reactions were also observed. 相似文献
998.
999.
The absolute configuration of tri-o-thymotide was obtained from the crystal structure of the solvate with (R)-2-butanol in association with optical measurements. 相似文献
1000.
Summary We continue here the study of a general method of approximation of nonlinear equations in a Banach space yet considered in [2]. In this paper, we give fairly general approximation results for the solutions in a neighborhood of a simple limit point. We the apply the previous analysis to the study of Galerkin approximations for a class of variationally posed nonlinear problems and to a mixed finite element method for the NavierStokes equations.This work has been completed during a visit at the Université Pierre et Marie Curic and at the Ecole PolytechniqueSupported by the Fonds National Suisse de la Recherche Scientifique 相似文献