d′, d″, d″-cohomologies et intégration sur les cycles analytiques

Sans résumé     

Generation of ester enolates by reductive a-deacetoxylation

Diethyl allylmalonates or 2-arylalkanoic esters are prepared in good yield by reductive α-deoxygenation of the corresponding α-acetoxy or α-alkony esters. Since the intermediate ester enolates are generated under aprotic conditions, a one pot reductive-alkylation is also possible. One application of this procedure allows diethyl oxomalonate to serve as a conjunctive reagent for stitching together an alkene and an alkyl halide with a malonyl group as linchpin.     

Semi-empirical potential energy surfaces for hydrogen-atom transfer reactions

A method for constructing potential energy surfaces previously proposed by the author has been extended to hydrogen transfer reactions between halide, oxygen, and carbon atoms. A qualitative relation was found between the repulsive energy and the number of anti-bonding electrons. In general, the calculated kinetic isotope effect is in satisfactory agreement with observed values and the contributions by H-atom tunneling to the rate of reaction is smaller than that obtained from other surfaces.     

Ultra high resolution of 6.2 keV 181Ta in 2H-TaSe2

The 6.2 keV γ-rays of ¹⁸¹Ta have been used to study the hyperfine interaction of ¹⁸¹Ta in the trigonal prismatic charge density wave material 2H-TaSe₂. Using a region of interest drive and an unstrained single crystal sample, we are able to resolve the splitting between the nuclear transition $\text{±}\text{5}\text{2}\text{→ ±}\text{3}\text{2}$ and $\text{±}\text{7}\text{2}\text{→ ±}\text{5}\text{2}$. Our experimental linewidth is that of the Ta metal.     

Constructive solution of a bilinear control problem

We present an optimization method of a quantum control problem giving rise to a sequence of controls increasing monotonically the values of a cost functional. We first claim some results about the regularity of this cost functional. Those enable to extend an inequality due to ?ojasiewicz to the infinite dimensional case. Lastly, a sequence of inequalities proving the Cauchy character of the monotonic sequence is obtained, and we can also estimate the rate of convergence. The detailed proof will be given in [L. Baudouin, J. Salomon, Constructive solution of a bilinear quantum control problem, 2005, in preparation. [3]]. To cite this article: L. Baudouin, J. Salomon, C. R. Acad. Sci. Paris, Ser. I 342 (2006).     

Exploring the Link between Reformed Teaching Practices and Pupil Learning in Elementary School Mathematics

This study examined the classroom practices of beginning elementary school teachers' instruction of mathematics and how it connected to their pupils' learning. The Reformed Teaching Observation Protocol (RTOP) was used to measure the extent to which beginning teachers used reformed teaching practices. As a measure of pupil learning, we utilized assessment scores specific to the mathematics unit observed and correlated them with teachers' RTOP scores. We found that beginning teachers who implemented reformed teaching practices tended to have pupils who scored higher on the district mathematics test with a statistically significant correlation of 0.56 (p < .05). Implications of these findings and others are discussed in terms of using the RTOP to improve practice at the elementary school level and for future school‐based research.