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101.
A new convenient preparation of samarium dibromide in THF is reported. Pinacol coupling reactions using SmBr2 in catalytic amounts together with mischmetall as a coreductant have been performed with a variety of carbonyl compounds. 相似文献
102.
103.
A.L. Florence 《International Journal of Solids and Structures》1977,13(11):1091-1102
An analysis is presented for the response of a clamped circular plate subjected to a rectangular pulse uniformly distributed over a central circular area. The plate is rigid-perfectly plastic with yielding according to the Johansen criterion and the associated flow rule. Bending is assumed to be the predominant response. Simple formulas are obtained for the permanent central deflection for all pressures and loaded areas. 相似文献
104.
A simple direct method is presented for the spectrophotometric determination of calcium in hydrochloric acid soil extracts. The chromugenic agent used is Calciehrome (self-coupled diazotized H-acid), and the method covers the range 4 to 175 μg of calcium. A comprehensive study of interferences has been carried out. and a cation-exchange procedure described for the preliminary separation of large amounts of phosphate. 相似文献
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Florence Scalas 《Proceedings of the American Mathematical Society》2005,133(6):1713-1720
In this paper we study the boundary behavior of Poisson integrals associated to Dunkl differential-difference operators for dihedral groups and the boundary integral representations for functions on the unit disc of annihilated by the Laplace operator corresponding to these differential-difference operators.
109.
Florence Bally Christophe A. Serra Cyril Brochon Georges Hadziioannou 《Macromolecular rapid communications》2011,32(22):1820-1825
Polymerization reactions can benefit from continuous‐flow microprocess in terms of kinetics control, reactants mixing or simply efficiency when high‐throughput screening experiments are carried out. In this work, we perform for the first time the synthesis of branched macromolecular architecture through a controlled/‘living' polymerization technique, in tubular microreactor. Just by tuning process parameters, such as flow rates of the reactants, we manage to generate a library of polymers with various macromolecular characteristics. Compared to conventional batch process, polymerization kinetics shows a faster initiation step and more interestingly an improved branching efficiency. Due to reduced diffusion pathway, a characteristic of microsystems, it is thus possible to reach branched polymers exhibiting a denser architecture, and potentially a higher functionality for later applications. 相似文献
110.