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211.
Proactive heuristic procedures for robust project scheduling: An experimental analysis 总被引:1,自引:0,他引:1
Stijn Van de Vonder Erik DemeulemeesterWilly Herroelen 《European Journal of Operational Research》2008
Solution-robust project scheduling is a growing research field aiming at constructing proactive schedules to cope with multiple disruptions during project execution. When stochastic activity durations are considered, including time buffers between activities is a proven method to improve the stability of a baseline schedule. 相似文献
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213.
Slavomíra Doktorovová Joana Araújo Marisa L. Garcia Erik Rakovský Eliana B. Souto 《Colloids and surfaces. B, Biointerfaces》2010,75(2):538-542
The aim of this study was to develop nanostructured lipid carriers (NLC) for topical delivery of fluticasone propionate (FP) with the aim to further improve the safety profile and decrease the adverse-side effects commonly reported in topical corticotherapy. NLC are colloidal drug-carriers consisting of a blend of a solid lipid and a small amount of liquid lipid since these carriers have proved to be effective in epidermal targeting in particular of glucocorticoids. NLC consisting of glyceryl palmito-stearate, and PEG-containing medium chain triglycerides mixture, stabilised by polysorbate 80 and soybean phosphatidylcholine were prepared. A mean particle size between 380 and 408 nm and entrapment efficacy of 95% were obtained for FP-loaded NLC. The crystallinity and polymorphic phase behaviour of FP-free and FP-loaded NLC were examined by differential scanning calorimetry and wide angle X-ray diffraction. Results revealed a low-crystalline structure and confirmed the incorporation of FP into the particles. The suitability of PEG-containing liquid lipids to form the lipid matrix of NLC was also confirmed. 相似文献
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216.
Seike H Sorensen EJ 《Synlett : accounts and rapid communications in synthetic organic chemistry》2008,2008(5):695-701
Three key reactions, an efficient Ugi four-component coupling, a regiospecific, base-mediated elimination reaction, and an intramolecular nitrone/alkene [3+2] cycloaddition, were used to achieve an effective synthesis of the tricyclic molecular framework of the immunosuppressant FR901483. The outcome of a control experiment supports the idea that an internal deprotonation by an alkoxide ion is the origin of the site selectivity observed in the base-induced elimination of hydroxy mesylate 17. 相似文献
217.
Erik A. van Doorn Nicky D. van Foreest 《Journal of Computational and Applied Mathematics》2009,233(3):847-851
We establish some representations for the smallest and largest zeros of orthogonal polynomials in terms of the parameters in the three-terms recurrence relation. As a corollary we obtain representations for the endpoints of the true interval of orthogonality. Implications of these results for the decay parameter of a birth-death process (with killing) are displayed. 相似文献
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Chemical reactions are often carried out in nano-structured materials, which can enhance reactions due to their large specific
surface area, their interactions with the reacting mixture and confinement effects. In this work, we present a systematic
study of the effect that the geometrical restrictions imposed by the pore walls can have on reactions that involve a three
dimensional rearrangement of the atoms in a molecule. In particular, we consider the isomerization of three 4-membered hydrocarbons—n-butane,
1-butene and 1,3-butadiene confined in carbon nanopores of slit geometry. Our results illustrate the fact that, in the molecular
sieving limit, the reaction rates change as the double exponential of the pore size (Santiso et al., in J. Chem. Phys., 2007a, submitted), and therefore the transition rates in nanopores can be many orders of magnitude different from the corresponding
bulk values. These results can be used as a guideline for the molecular-level design of improved catalytic materials. 相似文献
220.
Otto Pettersson 《Analytical and bioanalytical chemistry》1886,25(1):479-484