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81.
We have studied the elementary excitations of superfluid4He in a silica aerogel at 1.8 K and various filling fractions. The results do not show any departure from bulk4He behaviour, suggesting that previously observed anomalies in heat capacity and superfluid fraction data could be the effect of a distribution of He I and He II liquids inside pores of different sizes.This article was processed by the author using the LATEX style filepljour2 from Springer-Verlag. 相似文献
82.
Jean Galy Rene Enjalbert Patrick Rozier Patrice Millet 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):i6-i8
A single crystal of MoVAlO7, vanadium aluminium molybdate, has been grown. The present structure determination is more precise than a previous powder‐pattern investigation [Knorr, Jacubus, Dabrowska & Kurzawa (1998). Eur. J. Solid StateInorg. Chem. 35 , 519–530]. A three‐dimensional [MoAlO6]3n?n network surrounds infinite strings of [VO]3+ groups [V—O = 1.586 (4) Å] lying in the mirror planes. 相似文献
83.
Ana Paula V. Soares Manuel F. Portela Alain Kiennemann Jean Marc M. Millet 《Reaction Kinetics and Catalysis Letters》2002,75(1):13-20
Stoichiometric iron-molybdate has been prepared by coprecipitation and submitted to a long activity test to check the role of water in its deactivation behavior during methanol to formaldehyde oxidation. Water retards the reoxidation of the catalyst which is responsible for the acceleration of its deactivation. 相似文献
84.
Thorp-Greenwood FL Fernández-Moreira V Millet CO Williams CF Cable J Court JB Hayes AJ Lloyd D Coogan MP 《Chemical communications (Cambridge, England)》2011,47(11):3096-3098
A rhenium polypyridine-based molecular vessel is membrane impermeant when empty, but, upon loading with metal ions, the cationic form is taken up by MCF-7 cells, localising in nucleoli. The luminescence of the vessel and its copper binding ability suggest potential as a bimodal fluorescence/PET imaging agent. 相似文献
85.
Dr. Antoine Joosten Dr. Andreas K. Å. Persson Dr. Renaud Millet Magnus T. Johnson Prof. Jan‐E. Bäckvall 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(47):15151-15157
A highly selective oxidative palladium(II)‐catalyzed (Wacker‐type) cyclization of readily available allylic tosylcarbamates is reported. This operationally simple catalytic reaction furnishes tosyl‐protected vinyl‐oxazolidinones, common precursors to syn‐1,2‐amino alcohols, in high yield and excellent diasteroselectivity (>20:1). It is demonstrated that both stoichiometric amounts of benzoquinone (BQ) as well as aerobic reoxidation (molecular oxygen) is suitable for this transformation. The title reaction is shown to proceed through overall trans‐amidopalladation of the olefin followed by β‐hydride elimination. This process is scalable and the products are suitable for a range of subsequent transformations such as: kinetic resolution (KR) and oxidative Heck‐, Wacker‐, and metathesis reactions. 相似文献
86.
John Spencer Hiren Patel Jahangir Amin Samantha K. Callear Simon J. Coles John J. Deadman Christophe Furman Roxane Mansouri Philippe Chavatte Régis Millet 《Tetrahedron letters》2012,53(13):1656-1659
A 2-substituted-5-aminooxazole-4-carbonitrile library has been synthesised and modified via microwave-mediated and flow chemistries. One synthesised compound, 5-(1H-pyrrol-1-yl)-4-(1H-tetrazol-5-yl)-2-(thien-2-yl)oxazole, contains three distinct heterocycles attached to the central oxazole core, highlighting the structural diversity of this approach. Three oxazoles had micromolar ki values against cannabinoid (CB1/CB2) receptors. 相似文献
87.
88.
Junxia Wang Ludovic Tuduri Maurice Millet Olivier Briand Michel Montury 《Journal of chromatography. A》2009,1216(15):3031-3037
For low volatile pesticides, the applications of solid-phase microextraction (SPME) as an air sampler were reported with sampling time chosen in the linear stage of the sorption kinetics because of long equilibrium time. In these pre-equilibrium conditions, sampling rates (SRs) expressed as the volume of air sampled by the SPME sampler per unit of time, were used to estimate analytes concentrations in air. In the present study, to achieve good extraction performance and accurate calibration, the sorption kinetics of several pesticides with SPME were investigated in detail, with a focus on parameters influencing SRs. Linear air velocity was found to be the main parameter affecting SRs. For exposed fibers, with air velocities below 20–25 cm s−1, SRs increased with increasing air velocity. When linear air velocity was equal to or greater than 25–30 cm s−1, it had little effect on SRs. To improve the flexibility of SPME, different configurations of SPME were compared, i.e. different lengths of fibers exposed, retracted fibers, exposed fibers with grids. SRs were linearly proportional to exposed lengths of fibers. Using grids, lower SRs and wider calibration time range were achieved. SRs for retracted fibers were the lowest among the different experimented configurations. The accuracy of calibration was improved and more flexibility of SPME was provided. 相似文献
89.
90.
ESR measurements of Mg particles smaller than about 40 Å show evidence for a quantum size effect on the g-value. The large g-shift of our bulk Mg has allowed us to follow the evolution of the g-factor as a function of particle size. The theoretical model of Myles and Buttet, which predicts a gradual change from the bulk g-value to the free electron g-value when the size decreases is in qualitative agreement with the experimental data. 相似文献