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731.
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733.
Adri van den Hoogenband Jack A.J. den Hartog Jos H.M. Lange Jan Willem Terpstra 《Tetrahedron letters》2004,45(46):8535-8537
A novel efficient synthetic route to the pharmaceutical key intermediate N-(piperidin-4-yl)-1,3-dihydroindol-2-one is described. The key step involves a high-yielding intramolecular palladium-catalyzed amination reaction using Buchwald’s X-Phos ligand under mild reaction conditions. 相似文献
734.
Summary Transition metal(II) ions and 5-cyanotetrazole (CNHT) form two types of compounds; type I with two 5-cyanotetrazolate (CNT) ions and an additional CNHT molecule and type II with only the two [CNT]– ions. Water molecules are invariable included in all compounds and are considered to be essential for the existence of the crystal structure. The complexes were identified and characterized by chemical analyses, i.r. and ligand field spectra. Some structural features have been predicted from these spectra and a polynuclear complex formation is apparent. 相似文献
735.
Willem Albers 《Annals of the Institute of Statistical Mathematics》1995,47(4):675-691
For the one-sample problem, a two-stage rank test is derived which realizes a required power against a given local alternative, for all sufficiently smooth underlying distributions. This is achieved using asymptotic expansions resulting in a precision of orderm
–1, wherem is the size of the first sample. The size of the second sample is derived through a number of estimators of e. g. integrated squared densities and density derivatives, all based on the first sample. The resulting procedure can be viewed as a nonparametric analogue of the classical Stein's two-stage procedure, which uses at-test and assumes normality for the underlying distribution. The present approach also generalizes earlier work which extended the classical method to parametric families of distributions. 相似文献
736.
737.
Willem D. Basson Jacobus F. van Staden Peter M. Cattin 《Fresenius' Journal of Analytical Chemistry》1981,307(5):373-377
Summary Based on the flow injection principle and by using small sample volumes and splitting of the colorimeter output, a good reliable and reproducible method for the determination of P2O5 in phosphate rock covering the range of 0–40% on a routine basis was achieved. The system described is suitable for the routine analysis of P2O5 in the prepared phosphate rock samples at a rate of approximately 90 samples per hour with a coefficient of variation of better than 1%.
Bestimmung von Phosphor (P2O5) als Molybdovanadophosphorsäure in Phosphatmineralien mit Hilfe einer Flow-injection-Methode
Zusammenfassung Ein zuverlässiges und gut reproduzierbares Verfahren wurde ausgearbeitet, das routinemäßig für den Bereich von 0–40% geeignet ist und auf dem Flow-injection-Prinzip bei kleinen Probevolumina und Splitting des Colorimeter-Output beruht. Etwa 90 Proben können pro Stunde analysiert werden (Variationskoeffizient besser als 1%).相似文献
738.
739.
Willem A Rijpkema Eligius M T Hendrix Roberto Rossi 《The Journal of the Operational Research Society》2015,66(12):2086-2091
In practical decision making, one often is interested in solutions that balance multiple objectives. In this study we focus on generating efficient solutions for optimization problems with two objectives and a large but finite number of feasible solutions. Two classical approaches exist, being the constraint method and the weighting method, for which a specific implementation is required for this problem class. This paper elaborates specific straightforward implementations and applies them to a practical allocation problem, in which transportation cost and risk of shortage in supplied livestock quality are balanced. The variability in delivered quality is modelled using a scenario-based model that exploits historical farmer quality delivery data. The behaviour of both implementations is illustrated on this specific case, providing insight in (i) the obtained solutions, (ii) their computational efficiency. Our results indicate how efficient trade-offs in bi-criterion problems can be found in practical problems. 相似文献
740.