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11.
Ph. Laurent M. Abgrall Ch. Jentsch P. Lemonde G. Santarelli A. Clairon I. Maksimovic S. Bize Ch. Salomon D. Blonde J.F. Vega O. Grosjean F. Picard M. Saccoccio M. Chaubet N. Ladiette L. Guillet I. Zenone Ch. Delaroche Ch. Sirmain 《Applied physics. B, Lasers and optics》2006,84(4):683-690
In this paper we describe the cold atom clock PHARAO, designed for microgravity operation. All elements of the PHARAO engineering model have been manufactured and delivered to CNES, the French space agency. We present the clock design, its main characteristics, and initial science operation. PHARAO is one of the main components of the Atomic Clock Ensemble in Space payload that is scheduled to fly on board the International Space Station in 2010. PACS 07.87.+v; 06.30.Ft; 95.55.Sh; 32.80.Pj 相似文献
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Laurent Moret-Bailly 《Journal of Number Theory》2003,99(2):383-404
We give criteria for R-equivalence of torsors under finite constant group schemes over a field. In particular, using bitorsors, we obtain a Galois dévissage result which formalises and generalises a theorem of Philippe Gille in the case of local fields; for instance, Gille's theorem is shown to extend to higher local fields. 相似文献
14.
Laurent Gardes 《Comptes Rendus Mathematique》2003,337(4):287-292
The purpose of this Note is to propose an estimator of the extreme value index constructed by using only the number of points exceeding random thresholds. We prove the weak consistency and the asymptotic normality of this estimator. We deduce from this last result that the rate of convergence of our estimator is in a power of the sample size. To our knowledge, this rate of convergence is not reached by any other estimate of the extreme value index. Through a simulation, we compare our estimator to the moment estimator (Dekkers et al., Ann. Statist. 17 (1989) 1833–1855). To cite this article: L. Gardes, C. R. Acad. Sci. Paris, Ser. I 337 (2003). 相似文献
15.
Laurent Bartholdi 《Comptes Rendus Mathematique》2003,336(7):549-554
This Note constructs a finitely generated group W whose word-growth is exponential, but for which the infimum of the growth rates over all finite generating sets is 1 – in other words, of non-uniformly exponential growth.This answers a question by Mikhael Gromov (Structures métriques pour les variétés riemanniennes, in: J. Lafontaine, P. Pansu (Eds.), CEDIC, Paris, 1981).The construction also yields a group of intermediate growth V that locally resembles W in that (by changing the generating set of W) there are isomorphic balls of arbitrarily large radius in V and W's Cayley graphs. To cite this article: L. Bartholdi, C. R. Acad. Sci. Paris, Ser. I 336 (2003). 相似文献
16.
The convergence of iterative based domain decomposition methods is linked with the absorbing boundary conditions defined on the interface between the sub-domains. For linear elasticity problems, the optimal absorbing boundary conditions are associated with non-local Dirichlet-to-Neumann maps. Most of the methods to approximate these non-local maps are based on a continuous analysis. In this paper, an original algebraic technique based on the computation of local Dirichlet-to-Neumann maps is investigated. Numerical experiments are presented for linear elasticity problems with extreme contrasts in the coefficients. 相似文献
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Bombek S Lenarsic R Kocevar M Saint-Jalmes L Desmurs JR Polanc S 《Chemical communications (Cambridge, England)》2002,(14):1494-1495
An electrophilic amination of halogenated phenols with diisopropyl diazenedicarboxylate in the presence of ZrCl4 as a Lewis acid, accompanied by a halogen migration, was demonstrated for the first time; the fluorine, chlorine, bromine, or iodine atom migrated during the amination process under mild reaction conditions. 相似文献
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20.
G. Alvernhe A. Laurent K. Touhami R. Bartnik G. Mloston 《Journal of fluorine chemistry》1985,29(4):363-384
The addition of liquid hydrogen fluoride or Olah's reagent (pyridin-10 HF) to 1-aza bicyclo [n.1.0] alkanes leads to the formation of 3-fluoro 1-aza heterocyclic compounds. Isomeric 3-fluoro azetidines, 3-fluoro piperidines and a 3-fluoro azepine have been prepared by this procedure. 相似文献