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71.
The main results available on the use of black-and-white Petri nets for modelling, planning and scheduling manufacturing systems are presented. In the first part of the paper, the basics of Petri nets necessary to understand the subsequent presentation are introduced. Particular attention is paid to event graphs, a particular type of Petri nets used for modelling and evaluating ratio-driven systems. The second part of the paper is devoted to ratio-driven systems, their modelling and their scheduling. Job-shops, assembly systems, and KANBAN systems are used to illustrate this section. Finally, the general case is investigated of manufacturing systems subject to changing demands. An approach based on conflict-free Petri nets with input and output transitions is proposed for planning and scheduling this type of system. 相似文献
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Vincenzo Balzani Erik Berghmans Jean-Marie Lehn Nanda Sabbatini Robert Terrde Raymond Ziessel 《Helvetica chimica acta》1990,73(8):2083-2089
The Eu3+ complexes of the tripode and tetrapode ligands 1 and 2 , respectively, containing 2,2′-bipyridine coordinating units have been prepared. The UV absorption and luminescence spectra, lifetimes, and quantum yields have been measured under a variety of experimental conditions. The contributions of different paths to the decay of the luminescent excited state are evaluated, and the structures of the complexes are discussed on the basis of spectroscopic and photophysical data. 相似文献
75.
Jos Elguero Brian L. Johnson Jean-Marie Pereillo Guy Pouzard Michel Rajzmann Edward W. Randall 《Magnetic resonance in chemistry : MRC》1977,9(3):145-147
Different calculations, among them those utilizing the finite perturbation theory with INDO wave functions, have been effected to calculate the value of the 3J(1H ? N? N? 1H ) coupling constant in hydrazides as a function of the dihedral angle. Experimental coupling constants have been compared with calculated ones in order to determine the conformation around the N? N bond. The first example of a 2J(1H ? N? 15N ) coupling is described. 相似文献
76.
Jean-Marie Webert Denise Cagniant Paul Cagniant Gilbert Kirsch Jean-Victor Weber 《Journal of heterocyclic chemistry》1983,20(1):49-53
The condensation of ethyl sarcosinate on 2- or 3-halogeno 3- or 2-formyl[1]benzofuran. benzothiophene or benzoselenophene, and on the related 2h-[1]-3-benzoheteroyclanones is described. In the last instances the resulting compounds were formylated in teh 2-position with subsequent. After hydrolysis and decarboxylation, the I1methy][1]benzothieno-, benzoseleno [2,3-b]pyrroles were were thus obtained. 相似文献
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