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Trifluoroacetamide is easily monoalkylated in a K2 CO3-organic solvent solid-liquid two-phase system affording in good to excellent yields N-alkyltrifluoroacetamides. Under the same conditions, the latter, in turn, react with alkylating agents giving N, N-dialkyltrifluoroacetamides in high yields. 相似文献
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Vito Dario Camiola Giovanni Mascali Vittorio Romano 《Continuum Mechanics and Thermodynamics》2012,24(4-6):417-436
A nanoscale double-gate MOSFET is simulated with an energy-transport subband model for semiconductors formulated starting from the moment system derived from the Schr?dinger–Poisson–Boltzmann equations. The system is closed on the basis of the maximum entropy principle and includes scattering of electrons with acoustic and non-polar optical phonons. The proposed expression of the entropy combines quantum effects and semiclassical transport by weighting the contribution of each subband with the square modulus of the envelope functions arising from the Schr?dinger–Poisson subsystem. The simulations show that the model is able to capture the relevant confining and transport features and assess the robustness of the numerical scheme. 相似文献
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Ricerche di Matematica - This paper provides an account of results and methods from the theory of infinite groups admitting only finitely many normalizers of subgroups with a given property. Some... 相似文献
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Nicholas Favalli Gabriele Bassi Tania Zanetti Jrg Scheuermann Dario Neri 《Helvetica chimica acta》2019,102(4)
The construction of DNA‐encoded chemical libraries (DECLs) crucially relies on the availability of chemical reactions, which are DNA‐compatible and which exhibit high conversion rates for a large number of diverse substrates. In this work, we present our optimization and validation procedures for three copper and palladium‐catalyzed reactions (Suzuki cross‐coupling, Sonogashira cross‐coupling, and copper(I)‐catalyzed alkyne‐azide cycloaddition (CuAAC)), which have been successfully used by our group for the construction of large encoded libraries. 相似文献
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Camille Descour Tibor Macko Dario Cavallo Matthew Parkinson Gerhard Hubner Anne Spoelstra Maurizio Villani Robbert Duchateau 《Journal of polymer science. Part A, Polymer chemistry》2014,52(10):1422-1434
Stereoblock polypropylenes comprising of iPP and sPP segments are synthesized by polymerization of the following binary system of metallocenes: the Cs‐symmetric [2,7‐t‐Bu2(Flu)2Ph2C(Cp)ZrCl2] and the C2‐symmetric rac‐Me2Si(2‐Me‐4‐Ph‐Ind)2ZrCl2. Blends of samples made either by each catalyst individually (solution blend) with materials obtained with the mixed catalyst system (reactor blend) are compared. The simultaneous presence of MAO and DEZ, enhancing fast and reversible transfer of the growing chains between the two active centers, leads to the formation of a stereoblock microstructure. In this case, low molecular weight polymers are obtained. The junction between the blocks is qualitatively observed in 13C NMR. When made in toluene, the stereoblock material consists of a majority of syndiotactic sequences, whereas the ratio is more equilibrated when the polymerization was conducted in the more polar chlorobenzene. This is confirmed by the results obtained with 13C NMR, CRYSTAF, HT HPLC, DSC, SSA, WAXD, and optical microscopy. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1422–1434 相似文献
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Braga Renata M. Melo Dulce M. A. Melo Marcus A. F. Freitas Julio C. O. Boateng Akwasi A. 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6655-6663
Journal of Thermal Analysis and Calorimetry - Elephant grass (Pennisetum purpureum Schum.) is one such resource with a great amount of carbohydrate and lignin polymers that together represent high... 相似文献