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991.
Paolo Costantini Carla Manni 《Journal of Computational and Applied Mathematics》2010,233(7):1660-1673
In this paper we present a very efficient Hermite subdivision scheme, based on rational functions, and outline its potential applications, with special emphasis on the construction of cubic-like B-splines — well suited for the design of constrained curves and surfaces. 相似文献
992.
993.
Isabel C. Rigoli Tatiana Batista Carla C. S. Cavalheiro Miguel G. Neumann 《Macromolecular Symposia》2010,298(1):138-144
Summary: Composites of dimethacrylates/organoclay were obtained by in situ photopolymerization of Bis-GMA (Bisphenol A glycidyl methacrylate) and TEGDMA (tetraethyleneglycol dimethacrylate) in the presence of camphorquinone and DEEMA (2-(diethylamino)ethyl methacrylate). The composites contained up to 10% wt/wt of organoclays. Monomer conversion and polymerization kinetics were determined by real time Fourier-Transform Infrared Spectroscopy – Attenuated Total Reflectance (FTIR-ATR), and showed an increase of conversion with addition of the clay. The storage modulus E' of the composites also had a marked dependence on the composite composition and increased with addition of clay at all temperatures. Tg also increases with clay content. X-Ray Diffraction (XRD) analysis shows that the clay is completely exfoliated for the composites with a lower proportion of clay, whereas for larger clay/polymer proportions peaks corresponding to the interlamellar distance of the clay are still observed. This is probably due to the fact that the amount of monomers in the initial formulation was not sufficient to delaminate the clay. Scanning Electron Microscopy (SEM) images indicate a quite homogenous copolymer, with some clay aggregates that increase in size and number for the higher filler loadings in agreement with the XRD results. 相似文献
994.
Jean-Christophe Novelli 《Discrete Mathematics》2010,310(24):3584-3606
We introduce analogs of the Hopf algebra of Free quasi-symmetric functions with bases labeled by colored permutations. When the color set is a semigroup, an internal product can be introduced. This leads to the construction of generalized descent algebras associated with wreath products Γ?Sn and to the corresponding generalizations of quasi-symmetric functions. The associated Hopf algebras appear as natural analogs of McMahon’s multisymmetric functions. As a consequence, we obtain an internal product on ordinary multi-symmetric functions. We extend these constructions to Hopf algebras of colored parking functions, colored non-crossing partitions and parking functions of type B. 相似文献
995.
Ultrasonically assisted extraction of flavour compounds from different varieties of Mentha spicata, using 70% ethanol, have been carried out for 5, 10 and 15 min and coupled with under vacuum distillation. The ultrasound distilled extracts have been analysed by GC–MS and compared with essential oils obtained by hydrodistillation. The results have showed that ultrasonically assisted extraction in combination with under vacuum distillation have provided extracts with higher flavouring strength due to the increased concentration of desirable oxygenated compounds (from 5 to 8 times) compared with hydrodistillation. Extraction yields of flavour volatiles have been calculated giving a range 0.04–0.13% by ultrasound and 0.01–0.02% by hydrodistillation. 相似文献
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997.
Grochau Inês Hexsel Caten Carla Schwengber ten de Camargo Forte Maria Madalena 《Accreditation and quality assurance》2017,22(2):57-62
Accreditation and Quality Assurance - The number of laboratories worldwide seeking accreditation has increased considerably in the last years. These laboratories are from different institutions,... 相似文献
998.
Cover Picture: The Effect of Cholesterol on Membrane Dynamics on Different Timescales in Lipid Bilayers from Fast Field‐Cycling NMR Relaxometry Studies of Unilamellar Vesicles (ChemPhysChem 3/2014) 下载免费PDF全文
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