Estimation consistante des paramètres d'un modèle non linéaire pour des données fonctionnelles discrétisées aléatoirement

We study a class of nonlinear regression models for scalar or vectorial response when the explanatory variable is a function. We introduce a consistent estimator of the parameters of models in this class when functions are evaluated at randomly chosen observation points. To cite this article: F. Rossi, B. Conan-Guez, C. R. Acad. Sci. Paris, Ser. I 340 (2005).     

Preparation of novel analgesics via diastereoselective nucleophilic addition to 1-dimethylamino-2-methylpentan-3-one

The diastereoselective synthesis of naphthyl amino alcohols via nucleophilic addition to racemic 1-dimethylamino-2-methylpentan-3-one was studied. The use of the appropriate experimental conditions allowed the synthesis of both diastereoisomers. The relative configurations were established via NOESY experiments.     

cos πρ theorems for δ-subharmonic functions

For ϕ a δ-subharmonic function, sharp results are obtained that connectA(r, ϕ), B(r, ϕ) andT(r, ϕ), whereA(r, ϕ)=inf_|z|=r ϕ(z),B(r, ϕ)=sup_|z|=r ϕ(z), andT(r, ϕ) is the Nevanlinna characteristics.     

C-Fe chains due to segregated carbon impurities on Fe(1 0 0)

Bulk carbon impurities segregate at the Fe(1 0 0) surface and, upon thermal annealing, can form metastable surface phases with local and long range order and peculiar electronic properties. We present a surface science study of C-segregated Fe(1 0 0) with scanning tunneling microscopy, angle resolved photoemission, and ab initio calculations of the surface structure and electron states. In particular the c(3√2 × √2) structure, observed for 0.67 atomic layers of C segregated at the iron surface, is found to be due to self-organized carbon stripes made of zig-zag chains. The strong hybridization between C and Fe was observed in ARPES spectra.     

Study of the peak effect phenomenon in single crystals of 2H-NbSe2

The weakly pinned single crystals of the hexagonal 2H-NbSe₂ compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order-disorder transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of the peak effect phenomenon in three crystals of 2H-NbSe₂, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability effects and pinning.     

Approche non paramétrique du filtrage de système non linéaire à temps discret et à paramètres inconnus

Particle filters are presently among the most powerful tools for filtering discrete time non linear systems. However the presence of unknown parameters in the system equations makes their use more complex and can even impair their convergence properties. This Note shows how an on-line consistent estimation of these parameters can be obtained simultaneously to that of the state variables to be filtered. This approach relies upon a kernel-based non parametric estimation of conditional probability densities from successive Monte Carlo generations of system particles. To cite this article: V. Rossi, J.-P. Vila, C. R. Acad. Sci. Paris, Ser. I 340 (2005).     

Novel intramolecular cyclization of N-alkynyl heterocycles containing proximate nucleophiles

Intramolecular cyclization of 2-acyl-1-propargyl-1H-indoles in the presence of ammonia provides an easy entry to pyrazino[1,2-a]indole nucleus.     

Crossing of shears bands in196Pb

High-spin states in¹⁹⁶Pb have been populated using the reaction¹⁷⁰Er(³⁰Si,4n). The previously observed shears bands in this nucleus have been extended and some of their transitions have been reordered. They now form regular bands with band crossings. One of the bands splits into two pathways at high spin.     

Trace element concentrations from São Francisco River - PR analyzed with PIXE technique

Summary Kulcsszavak (angolul, ha nem azonos az elozovel)