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131.
H. Casabianca J. B. Graff V. Faugier F. Fleig C. Grenier 《Journal of separation science》1998,21(2):107-112
The enantiomeric distributions of linalool and linalyl acetate in various natural products are measured by enantioselective gas chromatography on alkyl-substituted cyclodextrins. Different plant cultivars were investigated by four extraction processes: steam distillation, solvent extraction, supercritical fluid extraction, and headspace analysis. Careful attention must be paid to linalool which undergoes partial racemization under certain processing conditions. In most cases, enantiomeric distribution is a powerful tool for authenticity testing. 相似文献
132.
Marie-Florence Grenier-Loustalot Christine Lartigau Franck Metras Philippe Grenier 《Journal of polymer science. Part A, Polymer chemistry》1996,34(14):2955-2966
The mechanisms and kinetics of polymerization of mono- and difunctional cyanate esters are investigated using chromatographic (HPLC) and spectroscopic methods (UV, liquid and solid-state NMR, and FTIR). The results obtained after chromatographic separation and identification of the chemical species present in the reaction medium have enabled us to propose a reaction path and a kinetic model for these thermally polymerized systems. Finally, the polymerization of cyanate ester was studied in the presence of different catalysts (imidazole, AcAcCu and AcAcCr) added directly, without solvent, and showed their influence on mechanisms. © 1996 John Wiley & Sons, Inc. 相似文献
133.
Marie-Florence Grenier-Loustalot Ghita Mouline Philippe Grenier Daniel Serrano Daniel Harran Patrick Horny 《Macromolecular Symposia》1987,9(1):143-154
We have used three physicochemical methods, reverse phase gas chromatography, Calvet microcalorimetry and rheology to examine the kinetics of isothermal cross-linking in the polycondensation of epoxy-prepolymers with aromatic amines. Gas chromatography results further define those obtained with gel time meter and rheological methods, and furnish not only a “gel point” but also a “gelling zone” for the two systems investigated. 相似文献
134.
Laura Grenier Dr. Maryline Beyler Prof. Carlos Platas-Iglesias Taunia Closson Dr. David Esteban Gómez Prof. Dwight S. Seferos Dr. Peng Liu Dr. Olga I. Ornatsky Dr. Vladimir Baranov Prof. Raphaël Tripier 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(67):15387-15400
H2cb-te2pa, a cross-bridged cyclam functionalized by two picolinate arms, was used for the formation of an incredible inert InIII chelate. The inertness of the complex was evaluated by UV/Vis experiments in several competitive media and was highlighted by the comparison with [In(dota)]− and [In(dtpa)]2− (H4dota = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, H5dtpa = diethylenetriamine pentaacetic acid), which are currently used in biological applications. For the first time, a bifunctional analogue of H2cb-te2pa was prepared by C-functionalization to keep its coordination properties intact. However, this strategy leads to the formation of two diastereoisomers as evidenced and studied by NMR experiments and DFT calculations. Kinetic studies proved nevertheless that both isomers of the complex are equally inert. They were therefore used without distinction for their covalent grafting on polystyrene beads. The so-called metal-encoded beads were tested for imaging mass cytometry. The detection of 115In allows the generation of images with high quality, proving the great potential of the bifunctional [In(cb-te2pa)]+ derivatives for single-cell analysis by mass cytometry. 相似文献
135.
Misfit-type Ca3−xLaxCo4O9+δ (x=0, 0.3) oxides were synthesised to be evaluated as possible cathode materials for proton conducting fuel cells (PCFCs) based on BaCe0.9Y0.1O3−δ (BCY10) dense ceramic electrolyte. The electrical conductivity value of Ca2.7La0.3Co4O9+δ (σ≈53 S cm-1 at 600 °C) is in the range of usually required value for a cathode application (about 50-100 S cm-1). In order to test the performance of each compound as cathode material, impedance measurements were carried out on Ca3−xLaxCo4O9+δ/BaCe0.9Y0.1O3−δ/Ca3−xLaxCo4O9+δ symmetrical half cells over the temperature range 400-800 °C under wet air. A promising electrocatalytic activity has been observed with both compounds Ca3Co4O9+δ and Ca2.7La0.3Co4O9+δ. Factually, the area specific resistance obtained was about 2.2 Ω cm2 at 600 °C. 相似文献
136.
N. Grenier M. Antuono A. Colagrossi D. Le Touzé B. Alessandrini 《Journal of computational physics》2009,228(22):8380-8393
In the present work a new SPH model for simulating interface and free surface flows is presented. This formulation is an extension of the one discussed in Colagrossi and Landrini (2003) and is related to the one proposed by Hu and Adams (2006) to study multi-fluid flows. The new SPH scheme allows an accurate treatment of the discontinuity of quantities at the interface (such as the density), and permits to model flows where both interfaces and a free surface are present. The governing equations are derived following a Lagrangian variational principle leading to an Hamiltonian system of particles. The proposed formulation is validated on test cases for which reference solutions are available in the literature. 相似文献
137.
J. Dailly F. Mauvy M. Marrony M. Pouchard Jean-Claude Grenier 《Journal of Solid State Electrochemistry》2011,15(2):245-251
Three selected materials have been prepared and shaped as cathode of half cells using the proton-conducting electrolyte BaCe0.9Y0.1O3 − δ
(BCY10): two perovskite compounds, Ba0.5Sr0.5Co0.8Fe0.2O3 − δ
(BSCF) and La0.6Sr0.4Fe0.8Co0.2O3 − δ
(LSFC), and the praseodymium nickelate Pr2NiO4 + δ
(PRN) having the K2NiF4-type structure. The electrochemical properties of these compounds have been studied under zero current conditions (two-electrode
cell) and under polarization (three-electrode cell). Their measured area-specific resistances were about 1–2 Ω cm2 at 600 °C. Under direct current polarization, it appears that the three compounds show almost similar values of current densities
at 625 °C; however, at lower temperatures, BSCF appears to be the most efficient cathode material. 相似文献
138.
H Pledger JR. G.-S. Wu T. S. Young T. E. Hogen-esch G. B. Butler 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(9):1297-1307
Graft copolymers of acrylamide and yellow dextrin were prepared using cerium(IV) as initiator. The yellow dextrin had a very broad molecular weight distribution but was fractionated utilizing dialysis and ultrafiltration membranes. Initiator efficiencies were determined using size exclusion chromatography and were found to be between 2.4 and 34%. Initiator efficiency increased with acrylamide concentration at constant cerium (IV) and yellow dextrin concentrations, and decreased with increasing cerium(IV) concentration at constant acrylamide and yellow dextrin concentrations. Plots of acrylamide conversion and intrinsic viscosity vs initial acrylamide concentration at constant yellow dextrin and ceric ion concentrations showed a maximum at about 2.0 M. 相似文献
139.
The novel monomer, π-(2, 4-hexadiene- l-yl acrylate) tricarbonyliron (HATI), has been prepared by two routes. It was homopolymerized and copolymerized with acrylonitrile, vinyl acetate, styrene, and methyl acrylate in benzene solutions. In all cases azobisisobutyronitrile was the initiator. The relative reactivity ratios, where HATI is defined as M1, were determined: r1 = 0.34, r2 = 0.74, M2 = acrylonitrile; r1 = 2.0, r2 = 0.05, M2 = 0.74, M2 = acrylonitrile; r1 = 2.0, r2 = 0.05, M2 = vinyl acetate; r1 = 0.26, r2 = 1.81, M2 = styrene; and r1 = 0.30, r2 = 0.74, M2 = methyl acrylate. The homo-and copolymers had high values of Tg. When polymerizations are carried out at high concentrations, a very high molecular weight tail is observed in HATI hompolymerizations and in HATI-methyl acrylate copolymerizations. The polymers were characterized by IR, gel permeation chromatography, viscosity, and differential scanning calorimetry studies. Finally, thermal decompositions carried out in air resulted in decomposition of the Fe(CO)3 group, producing Fe2O3 as a fine powder. Thermal decomposition under nitrogen (in solution and on solids ground into KBr pellets) resulted in slow destruction of the Fe(CO)3 groups but the resulting polymer mass was insoluble, and the question of what form the iron exists in (Fe metal, oxides, carbides, etc.) has not been answered. 相似文献
140.
Mixtures of methane and olefins (ethylene, propylene, butenes, butadiene, and styrene) have been polymerized over HSO3 F-SbF3 to yield an oily oligomer with a molecular weight ranging from 100 to 700. The NMR spectra of each polymer showed a sharp peak at or near 1.25 &, suggesting the presence of block methylene in the polymer. The formation of block methylene is surprising considering the fact that the polymerization reaction is carbonium ion in nature. A primary cation has been invoked to explain the results. The formation of this primary cation must involve some extraordinary stabilization by some component in the acid. 相似文献