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Robert M. Adlington Jack E. Baldwin William MC Coull Gareth J. Pritchard Christopher J. Schofield Nicholas J. Westwood 《合成通讯》2013,43(21):3803-3813
N-Arylsulfonylation of 2-azetidinones can lead to the diastereoselective formation of oligomerization products. However, a simple increase of arylsulfonyl chloride concentration minimized oligomerization and allowed preparation of 1-arylsulfonyl-2-azetidinones in good yield. 相似文献
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Hudson SR Monticello DA Reiman AH Boozer AH Strickler DJ Hirshman SP Zarnstorff MC 《Physical review letters》2002,89(27):275003
Magnetic islands in free-boundary stellarator equilibria are suppressed using a procedure that iterates the plasma equilibrium equations and, at each iteration, adjusts the coil geometry to cancel resonant fields produced by the plasma. The coils are constrained to satisfy certain measures of engineering acceptability and the plasma is constrained to ensure kink stability. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible. The method is applied with success to a candidate plasma and coil design for the National Compact Stellarator Experiment [Phys. Plasmas 8, 2083 (2001)]]. 相似文献
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The behaviour of the total energy for a semi-infinite piezoelectricbeam, with uniform or variable cross-section, in dynamical conditionsis investigated. Precisely, we obtain some estimates in termsof the data for the energy of the portion of the body at distancegreater than z from the base and for its norm in L1(0,t) (wheret is an arbitrary positive time). We obtain some estimates whichdepend on the initial data if t z/V (where V is a computablepositive material constant); if t > z/V, by using also theKorn inequality, we show that the bounds depend on all the data.Under mild hypotheses on the initial data we derive the asymptoticbehaviour of the energy as z +. All possible combinations ofboundary conditions are examined and the kind of the estimateis formally the same for all the problems whether the beam isa cylinder or not. 相似文献
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Bush CE Goldston RJ Scott SD Fredrickson ED McGuire K Schivell J Taylor G Barnes CW Bell MG Boivin RL Bretz N Budny RV Cavallo A Efthimion PC Grek B Hawryluk R Hill K Hulse RA Janos A Johnson DW Kilpatrick S Manos DM Mansfield DK Meade DM Park H Ramsey AT Stratton B Synakowski EJ Towner HH Wieland RM Zarnstorff MC Zweben S 《Physical review letters》1990,65(4):424-427