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991.
Ornelas C Méry D Blais JC Cloutet E Ruiz Aranzaes J Astruc D 《Angewandte Chemie (International ed. in English)》2005,44(45):7399-7404
992.
Zins EL Pepe C Rondeau D Rochut S Galland N Tabet JC 《Journal of mass spectrometry : JMS》2009,44(1):12-17
Fragmentation pathways of unsubstituted and substituted benzylpyridinium compounds were investigated using mass-analysed kinetic energy (MIKE) technique in combination with high level of quantum chemical calculations in the gas phase. Fast atom bombardment (FAB) source was used for ionisation of the studied compounds. The formation of both benzylium and tropylium species were investigated. Hybrid Hartree-Fock/Density Functional Theory calculations have been performed to assess the geometries and the energies of the transition states and intermediates. For each cases, different reaction pathways were investigated, and particularly in the case of the formation of tropylium species, the formation of the seven-membered ring before or after the loss of pyridine were studied. The effect of para-methyl and para-methoxy substituents on the activation energy of the rearrangement process to form thermodynamically stable tropylium compounds has been studied. Theoretical calculations showed competition between direct bond cleavage and rearrangement reactions to form benzylium and tropylium compounds, respectively. Experimental results also suggested that the rearrangement process takes place to yield stable tropylium under \"soft ionisation techniques\", such as FAB. 相似文献
993.
Eric Soulier Jean-Jacques Yaouanc Pascale Laurent Hervé des Abbayes Jean-Claude Clément 《European journal of organic chemistry》2000,2000(20):3497-3503
The Boyd−Regan methodology allowed for access to various cyclic or benzylic mono- and bis(phosphinic acids) 1−6 . The reduction of monophosphinic acids to secondary phosphanes 7−9 was achieved with silanes. On the other hand, reduction of the bis(phosphinic acids) with LiAlH4 led to bis(phosphanes) 12−13 . Various cyclic phosphanes and bis(phosphanes) were obtained by the alkylation of these secondary phosphanes (as their borane adducts). The Michael addition of the same borane adducts to vinylic phosphonates led to phosphane−phosphonates which could be hydrolysed to new hydrosoluble phosphanes. 相似文献
994.
Jean-Claude Bradley Zhongming Ma 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》1999,111(11):1768-1771
995.
Laurent Heinrich Yun Li Jacqueline Vaissermann Jean-Claude Chottard 《欧洲无机化学杂志》2001,2001(6):1407-1409
A square-planar cobalt(III) complex with an N2S2 bis(carboxamido-N)dithiolato tetradentate ligand was oxygenated by H2O2·urea, after axial coordination of tert-butyl isocyanide, to the first bis(carboxamido-N)bis(sulfenato-S)cobalt(III) complex. 相似文献
996.
Yves Felix Steve Halperin Jean-Claude Thomas 《Proceedings of the American Mathematical Society》2007,135(5):1575-1578
Let be a connected finite type graded Lie algebra. If dim and gldim , then log index . If, moreover, , then for some , dim where log index as
997.
肖辉 孙丽萍 赵辉 霍丽华 Jean-Marc Bassat Aline Rougier S&#;bastien Fourcade Jean-Claude Grenier 《无机化学学报》2015,31(6):1139-1144
采用固相法合成了中温固体氧化物燃料电池(IT-SOFCs)阴极材料LaBiMn2O6,并利用X射线衍射(XRD)和电化学阻抗谱(EIS)进行表征。结果表明该材料与电解质Ce0.7Bi0.3O1.85(CBO)在1000℃烧结12h不发生反应。交流阻抗和直流极化测试结果发现,阴极极化电阻随测试温度的增加而逐渐减小,700℃空气中的极化电阻为0.71Ω·cm2;氧分压测试结果显示,在600~700℃范围内,电极反应的速率控制步骤为电极上发生的电荷转移反应。电极过电位为85mV时,700℃的阴极电流密度达到216mA·cm-2,表明LaBiMn2O6是一种潜在的中温固体氧化物燃料电池(IT-SOFCs)阴极材料。 相似文献
998.
Ciprian Foias Luan Hoang Jean-Claude Saut 《Journal of Applied Analysis & Computation》2018,8(3):727-763
This paper surveys various precise (long-time) asymptotic results for the solutions of the Navier-Stokes equations with potential forces in bounded domains. It turns out that the asymptotic expansion leads surprisingly to a kind of Poincare-Dulac normal form of the Navier-Stokes equations. We will also discuss some related results and a few open issues. 相似文献
999.
We derive quantitative bounds for eigenvalues of complex perturbations of the indefinite Laplacian on the real line. Our results substantially improve existing results even for real potentials. For -potentials, we obtain optimal spectral enclosures which accommodate also embedded eigenvalues, while our result for -potentials yield sharp spectral bounds on the imaginary parts of eigenvalues of the perturbed operator for all . The sharpness of the results are demonstrated by means of explicit examples. 相似文献
1000.