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991.
Henri Pottevin 《Fresenius' Journal of Analytical Chemistry》1901,40(10):670
Ohne Zusammenfassung 相似文献
992.
993.
994.
Henri Cartan 《Mathematische Annalen》1932,106(1):540-573
Sans résumé 相似文献
995.
Ludger A. Wessjohann Harry Wild Leonildo A. Ferreira Henri S. Schrekker 《应用有机金属化学》2016,30(8):674-679
The regioselective and diastereoselective chromium(II)‐mediated reactions of 4‐bromocrotonic acid or amides with aldehydes and ketones can proceed without the need to protect protic sites to generate the respective α‐alkenyl‐β‐hydroxy adducts, i.e. formally the addition of the α‐anion of a carboxylic acid or amide to an oxo‐compound is featured. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
996.
Bresme Fernando Vesovic Velisa Bataller Henri Croccolo Fabrizio 《The European physical journal. E, Soft matter》2019,42(11):1-6
The European Physical Journal E - The transmission and the reflection of a shock wave by one or several impurities in viscoelastic bead chains is studied in the present paper. There is only one... 相似文献
997.
Mauro Dalla Palma Davide Gaule Antonio Pimazzoni Roberto Pasqualotto Gianluigi Serianni Bernd Böswirth Henri Greuner 《Journal of Thermal Analysis and Calorimetry》2018,132(1):143-154
Carbothermic reduction of chromite in the presence of nickel as the alloying element was investigated in a wide temperature range up to 1500 °C using thermogravimetric analysis coupled with continuous off-gas analysis (TG-DSC-MS). Both isothermal and non-isothermal linear heating tests were performed for the kinetic study with the calculation of activation energies. In order to further elucidate the reduction mechanism, the reduced products were characterized by SEM–EDS and XRD. It was concluded that the reduction sequence followed a multi-stage mechanism, reflected partly by the dependency of the activation energy on the extent of reduction. With the progress of reduction, refractory oxide layers gradually formed on/close to the surface of each chromite particle, causing the shift of the rate-limiting factor from chemical control to diffusion control. The promoting effect from the addition of Ni was evident at temperatures higher than 1300 °C due to the formation of alloys of lower melting point. 相似文献
998.
Isabelle Dchamps-Olivier Jean-Pierre Barbier Michel Aplincourt Nicolas Oget Franoise Chuburu Henri Handel 《Helvetica chimica acta》1999,82(5):790-795
The acid-base behavior of cyclenphosphine sulfide (cyclenPS) is appreciably different from that of cyclamphosphine sulfide (cyclamPS). The cyclenPS shows five acid functionalities compared to four for cyclamPS. The fifth acidic group in cyclenPS corresponds to the formation of a stable amidure in aqueous solution (pK=12.3). This behavior is due to the strong transannular N→P interaction. The deprotonation sequences were established by 31P-NMR and confirmed by modelling of cyclenPS. 相似文献
999.
Henri Cramail Alain Deffieux Jean-Noêl Pédeutour Karunakaran Radhakrishnan 《Macromolecular Symposia》2002,183(1):113-120
In this paper, we investigate different routes to lower drastically the amount of methylaluminoxane (MAO) required to activate racEt(Ind)2ZrX2 catalysts towards olefin polymerization. A first approach consists in replacing Cl ligands by more easily extractable X groups such as Me, CH2Ph or NMe2 groups. A second method focuses on the preparation of TMA-depleted MAO either by pumping off TMA from commercial MAO or by exploring new synthetic source to MAO via non-hydrolytic processes such as the reaction of TMA with benzophenone. Both methods allowed us to produce polyolefins with a maximal catalytic activity for Al/Zr ratios not exceeding 150, i.e. ratio 20 times lower than those required in the presence of commercial MAO. 相似文献
1000.