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961.
Laurent Herr 《Mathematische Annalen》2001,320(2):307-337
Sans résumé
Received July 11, 1999 / Accepted September 25, 2000 / Published online February 5, 2001 相似文献
962.
Christian Amatore Sabine Szunerits Laurent Thouin Jean-Stphane Warkocz 《Journal of Electroanalytical Chemistry》2001,500(1-2)
A model accounting for the role of convection in macroscopically immobile solutions (viz., not submitted to any macroscopic flow or any density gradient) is developed to predict the resulting alterations on electrochemical experiments performed at long time durations. The model is based on a seminal idea introduced by Levich, and shows that in macroscopically still solutions microscopic chaotic motion has the same effect as an apparent diffusion coefficient that depends on the distance from the electrode, x. When the electrochemical perturbation affects only the viscous sub-layer adjacent to the electrode, this apparent diffusion coefficient varies as x4. The model remarkably predicts the experimental distortions of chronoamperometric currents from their ideal Cottrellian behavior. The model is thoroughly tested with success by comparing its predictions to experimental results (current and concentration profiles) obtained for the oxidation of Fe(CN)64− in aqueous KCl. 相似文献
963.
Michel Legraverend Odile Ludwig Sophie Leclerc Laurent Meijer 《Journal of heterocyclic chemistry》2001,38(1):299-303
The synthesis of new purine derivatives designed to inhibit cell cycle regulating cyclin‐dependent kinases (CDKs), is reported. These compounds, related to olomoucine and roscovitine, are characterised by the presence of apyrrolidine methanol substituent at C‐2 and a variety of ortho, meta and/or para substituents on the C‐6 arylamino group. 相似文献
964.
Norma Negrete‐Herrera Jean‐Luc Putaux Laurent David Felix De Haas Elodie Bourgeat‐Lami 《Macromolecular rapid communications》2007,28(15):1567-1573
Transparent film materials with excellent mechanical and thermal properties were elaborated by drying a latex suspension of armored polymer/Laponite composite particles. Low‐temperature TEM observation of ultrathin cross‐sections of the films indicated a unique network morphology characterized by a “honeycomb” distribution of the Laponite platelets remindful of the original particles morphology.
965.
Laurent Denis 《Probability Theory and Related Fields》2000,118(3):406-426
We construct a Dirichlet structure related to a Poisson measure on ℝ+×M, where M is a general measured space, with compensator dt⊗dv. We obtain a criterion of density for variables in the domain of the Dirichlet form and we apply it to S.D.E. driven by this
Poisson measure.
Received: 15 May 1999 / Revised version: 23 February 2000 / Published online: 12 October 2000 相似文献
966.
Tatsuki Yasumitsu Gang Liu Jean-Marc Leveque Shuji Aonuma Laurent Duclaux Takahide Kimura Naoki Komatsu 《Ultrasonics sonochemistry》2013,20(1):37-39
Probe-type ultrasonication has been employed for surfactant-aided solubilization, or individualization, of single-walled carbon nanotubes (SWNTs). The resulting solution can be used not only for spectroscopic analyses such as absorption, photoluminescence, and circular dichroism, but also for separation by density gradient ultracentrifugation, dielectrophoresis, chromatography, and polymer wrapping. In spite of its importance, the sonochemical processing of SWNTs has not been considered seriously. Herein, we report on a more efficient cooling cell for probe-type ultrasonication. As compared with a conventional cylindrical cell, the concentration of the SWNTs solubilized in water was found to be almost double in a rosette cooling cell after ultracentrifugation. The efficiency of a rosette cell can be attributed to the higher efficiency in circulation and cooling of the SWNT dispersion as well as enhancement of the cavitation process. 相似文献
967.
Laurent Gosse 《Annali dell'Universita di Ferrara》2013,59(1):81-116
Efficient recovery of smooth functions which are s-sparse with respect to the basis of so-called prolate spheroidal wave functions from a small number of random sampling points is considered. The main ingredient in the design of both the algorithms we propose here consists in establishing a uniform L ∞ bound on the measurement ensembles which constitute the columns of the sensing matrix. Such a bound provides us with the restricted isometry property for this rectangular random matrix, which leads to either the exact recovery property or the “best s-term approximation” of the original signal by means of the ? 1 minimization program. The first algorithm considers only a restricted number of columns for which the L ∞ holds as a consequence of the fact that eigenvalues of the Bergman’s restriction operator are close to 1 whereas the second one allows for a wider system of PSWF by taking advantage of a preconditioning technique. Numerical examples are spread throughout the text to illustrate the results. 相似文献
968.
Elke Debroye Prof. Sophie Laurent Prof. Luce Vander Elst Prof. Robert N. Muller Prof. Tatjana N. Parac‐Vogt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(47):16019-16028
Six diethylene triamine pentaacetic acid (DTPA) bisamide derivatives functionalized with p‐toluidine (DTPA‐BTolA), 6‐aminocoumarin (DTPA‐BCoumA), 1‐naphthalene methylamine (DTPA‐BNaphA), 4‐ethynylaniline (DTPA‐BEthA), p‐dodecylaniline (DTPA‐BC12PheA) and p‐tetradecyl‐aniline (DTPA‐BC14PheA) were coordinated to dysprosium(III) and the magnetic and optical properties of the complexes were examined in detail. The complexes consisting of amphiphilic ligands (DTPA‐BC12PheA and DTPA‐BC14PheA) were further assembled into mixed micelles. Upon excitation into the ligand levels, the complexes display characteristic DyIII emission with quantum yields of 0.3–0.5 % despite the presence of one water molecule in the first coordination sphere. A deeper insight into the energy‐transfer processes has been obtained by studying the photophysical properties of the corresponding GdIII complexes. Since the luminescence quenching effect is decreased by the intervention of non‐ionic surfactant, quantum yields up to 1 % are obtained for the micelles. The transverse relaxivity r2 per DyIII ion at 500 MHz and 310 K reaches a maximum value of 27.4 s?1 mM ?1 for Dy‐DTPA‐BEthA and 36.0 s?1 mM ?1 for the Dy‐DTPA‐BC12PheA assemblies compared with a value of 0.8 s?1 mM ?1 for Dy‐DTPA. The efficient T2 relaxation, especially at high magnetic field strengths, is sustained by the high magnetic moment of the dysprosium ion, the coordination of water molecules with slow water exchange kinetics and long rotational correlation times. These findings open the way to the further development of bimodal optical and magnetic resonance imaging probes starting from single lanthanide compounds. 相似文献
969.
Wide‐angle X‐ray scattering study of the lamellar/fibrillar transition for a semi‐crystalline polymer deformed in tension in relation with the evolution of volume strain 下载免费PDF全文
Laurent Farge Julien Boisse Jérôme Dillet Stéphane André Pierre‐Antoine Albouy Florian Meneau 《Journal of Polymer Science.Polymer Physics》2015,53(20):1470-1480
This work is devoted to the study of the deformation mechanisms of a high‐density polyethylene deformed in tension. Specific treatments were applied to synchrotron wide‐angle X‐ray scattering patterns obtained in situ with the aim of quantifying: (i) the evolution of the apparent crystal sizes during the deformation process, (ii) the reorientation dynamics of the fragmented crystals while aligning their chains along the drawing axis during the establishment of the fibrillar morphology, and (iii) the reorientation dynamics of the amorphous chains. In addition, the volume strain evolution was measured using 3D digital image correlation. The cavitation phenomenon was found to mainly occur during the lamellae fragmentation phase. At the end of the deformation process, when the lamellar structure is destroyed, the fragmented crystals have new degrees of freedom and become free to rotate to align their chains along the drawing axis. Crystal fragmentation is then no longer needed to allow material deformation, and there is no further volume strain increase. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1470–1480 相似文献
970.