Renormalization of the 2-Point Function of the Hubbard Model at Half-Filling

We prove that the Hubbard model at finite temperature T and half-filling is analytic in its coupling constant λ for where c is some numerical constant. We also bound the self-energy and prove that the Hubbard model at half-filling is not a Fermi liquid (in the mathematically precise sense of Salmhofer), modulo a simple lower bound on the first non-trivial self-energy graph, which will be published in a companion paper.submitted 09/09/04, accepted 20/12/04     

New and simple one-step cobalt-catalyzed preparation of functionalized arylstannanes from the corresponding aryl bromides or iodides

A variety of functionalized arylstannanes are obtained in moderate to excellent yields by a one-step chemical procedure from corresponding halides and tributylstannyl chloride via cobalt catalysis.     

Surface-directed capillary system; theory, experiments and applications

We present a capillary flow system for liquid transport in microsystems. Our simple microfluidic system consists of two planar parallel surfaces, separated by spacers. One of the surfaces is entirely hydrophobic, the other mainly hydrophobic, but with hydrophilic pathways defined on it by photolithographic means. By controlling the wetting properties of the surfaces in this manner, the liquid can be confined to certain areas defined by the hydrophilic pathways. This technique eliminates the need for alignment of the two surfaces. Patterned plasma-polymerized hexafluoropropene constitutes the hydrophobic areas, whereas the untreated glass surface constitutes the hydrophilic pathways. We developed a theoretical model of the capillary flow and obtained analytical solutions which are in good agreement with the experimental results. The capillarity-driven microflow system was also used to pattern and immobilize biological material on planar substrates: well-defined 200 microm wide strips of human cells (HeLa) and fluorescence labelled proteins (fluorescein isothiocyanate-labelled bovine serum albumin, i.e., FITC-BSA) were fabricated using the capillary flow system presented here.     

Détermination d'un champ de forces de valence pour le thiazole et ses dérivés deutériés: Étude du méthyl-2 et chloro-2 thiazole

The vibrational frequencies of thiazole and its deuterated derivatives have been used in valence force field calculations. The transferability of the force field is verified by the study of 2-chloro- and 2-methyl-thiazole. Previous assignments are discussed.     

Use of the CNDO/S method to elucidate the conformation of benzylidene aniline

The present study was aimed at clarifying the conformation of benzylidene aniline with the aid of the CNDO/S method. The non-planarity of benzylidene aniline is clearly established and the estimated deviation, 55°, is consistent with a recent experimental determination. An interpretation of the UV absorption of benzylidene aniline is presented. A linear relationship has been found between the orbital energies and the experimental ionization potentials, but the photoelectronic spectrum does not provide any definite information about the conformational problem.     

Les sous-algebres de Cartan reelles et la frontiere d'une orbite ouverte dans une variete de drapeaux

We show how the non compact imaginary roots of a non compact real semi-simple Lie algebra with respect to a Cartan subalgebra to allows us, alike the real roots of, to give a complete classification of the G-conjugacy classes of Cartan subalgebras of if G_c is a complex connected group whose algebra is the complexified of, if B is a Borel subgroup of G_c and G the analytic subgroup of G_c corresponding to the subalgebra of, we determine the G-orbits of codimension one in the boundary of an open G-orbit of the complex flag manifold G_c/B. If is a maximally compact Cartan subalgebra of contained in, we show how the imaginary non compact simple roots of allows us to determine such orbits.     

The behaviour of a non-differentiable stationary Gaussian process after a level crossing

A model process is obtained for the behaviour of a non-differentiable but continuous stationary Gaussian process after a level crossing. It is shown that the sampled process conditioned on a crossing of a fixed level in Slepian's sense, converges weakly towards the model process, when the sample distance decreases to zero. Further it is noticed that there is no difference between conditioning on a vertical window and on a horizontal window in this case.     

Novel polyhydronaphthalenic structures

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.