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91.
It has been found that unsolvated bis (diorganoamino) magnesium compounds react smoothly with carboxylic acids to give the corresponding carboxamides directly in good to excellent yields. 相似文献
92.
D.-X. Chen E. Pardo A. Sanchez 《Physica C: Superconductivity and its Applications》2010,470(9-10):444-450
The driving force on an Abrikosov vortex is calculated numerically from the London equation and involved energies for a vortex perpendicular to the screening current near the surface of a superconductor. Compared with previous analytical derivation of the total force, the partial magnetic, kinematic, and external forces are also obtained so that the nature of the driving force may be deeply discussed. It is shown that the force is neither a Lorentz force nor a Magnus force as often believed and that in order to get a correct result, the image effects and the work done by the applied field must be taken into account. A name of London force is suggested for the driving force. A deep understanding of the nature of the driving force on Abrikosov vortices may also be important in the study of vortex pinning and dynamics in type-II superconductors. 相似文献
93.
J. A. Sanchez H. D. Murray W. Minajew K. Swetljakow S. Frolow P. P. Ssasanow W. A. Blinow H. H. Evers N. Strafford D. O. Jones H. R. Lee Erich Müller E. Dachselt L. Desvergnes S. Palkin K. Lehmstedt O. Zumstein K. Heller und Z. Fleischhaus 《Fresenius' Journal of Analytical Chemistry》1931,86(5-6):262-267
Ohne Zusammenfassung 相似文献
94.
95.
A. Z. Hrynkiewicz R. Kmieć K. Tomala J. P. Sanchez J. M. Friedt 《Hyperfine Interactions》1986,28(1-4):1047-1050
Isomer shifts for119Sn and121Sb impurities in different metallic hosts are compared. In the frame of the Miedema and van der Woude model three contributions to the isomer shifts due to the charge transfer, electron density mismatch and volume adjustment are calculated. 相似文献
96.
Zusammenfassung Zum Nachweis des Thoriums bewährte sich als Reagens eine wäßrige, perhydrol- und ammomumnitrathaltige Alizarin S-Lösung. Da Alizarin kein spezifisches Reagens für Thorium ist, wird ein Analysengang beschrieben, der sich zur Entfernung störender Substanzen aus Mineralen eignet. Das dabei erhaltene Thoriumnitrat kann am Ringofen quantitativ bestimmt werden.
Wir danken an dieser Stelle dem Conselho Nacional de Pesquisas von Brasilien, der uns die Durchführung dieser Arbeiten ermöglicht hat. 相似文献
Summary Aqueous alizarin S solution along with perliydrol and ammonium nitrate was found suitable for the detection of thorium. Since alizarin is not a specific reagent for thorium, an analytical procedure is described, which is suitable for the removal of interfering substances from minerals. The thorium nitrate obtained in this way can be determined quantitatively on the ring oven.
Résumé On a utilisé pour la recherche du thorium, une solution aqueuse d'alizarine S avec le perhydrol et le nitrate d'ammonium. Comme l'alizarine n'est pas un réactif spécifique du thorium, on a décrit un procédé d'analyse qui permet l'élimination des substances gênantes à partir des minéraux. On peut doser quantitativement le nitrate de thorium alors obtenu, à l'aide du four annulaire.
Wir danken an dieser Stelle dem Conselho Nacional de Pesquisas von Brasilien, der uns die Durchführung dieser Arbeiten ermöglicht hat. 相似文献
97.
The title reaction was studied in different water–cosolvent (methanol) mixtures. The results have been rationalized employing the Marcus–Hush treatment. To apply this treatment, the true, unimolecular, electron‐transfer rate constants (ket) were obtained from the experimentally measured rate constants after calculation of the equilibrium constant for the processes of formation of the encounter complex. This calculation was carried out using Eigen–Fuoss (EF) and exponential mean spherical (EMSA) approaches employing effective values of the solvent dielectric constant. These effective values were obtained from the measured association constants corresponding to other ion pairs. The results reveal that in these media there is an additional component of reorganization energy, absent in neat solvents. An explanation of the origin of this component is given. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 658–666, 2009 相似文献
98.
R. Arvai F. Toulgoat M. Médebielle B. Langlois F. Alloin J.Y. Sanchez 《Journal of fluorine chemistry》2008,129(10):1029-1035
Several aryl-containing ammonium sulfonates have been prepared either by cationic metathesis from the corresponding lithium sulfonates or from the corresponding sulfonic acids. The latter have been obtained by elution of an Amberlite resin with alcoholic solutions of the lithium sulfonates. These ammonium sulfonates exhibit interesting conductivities and thermal properties which allow them to be promising candidates as electrolytes for electricity storage. 相似文献
99.
100.
J. Betzabe Gonzlez‐campos Evgen Prokhorov Gabriel Luna‐Brcenas A. Mendoza Galvn Isaac C. Sanchez Sergio M. Nuo Donlucas B. Garcia‐Gaitan Yuriy Kovalenko 《Journal of Polymer Science.Polymer Physics》2009,47(9):932-943
Relaxations in chitin have been investigated in the temperature range 298–523 K using impedance spectroscopy in the frequency range 10−1–108 Hz. The objective was to detect a glass‐transition temperature for this naturally occurring, semicrystalline polysaccharide. The impedance study was complemented with X‐ray diffraction, thermogravimetric, and differential scanning calorimetry measurements. Preliminary impedance data treatment includes the subtraction of the dc conductivity contribution, the exclusion of contact and interfacial polarization effects, and obtaining a condition of minimum moisture content for further analysis. When all these aspects are taken into account, two relaxations are clearly revealed in the impedance data. For the first time, evidence is presented for a relaxation process, which exhibits a non‐Arrhenius temperature dependence, in dry α‐chitin (∼0.1% moisture content), and likely represents the primary α‐relaxation. This evidence suggests a glass transition temperature for chitin of 335 ± 10 K estimated on the basis of the temperature dependence of the conductivity and of the relaxation time. A second relaxation in dry α‐chitin, not previously reported in the literature, is observed from 353 K to the onset of thermal degradation (∼483 K) and is identified as the σ‐relaxation often associated with proton mobility. It exhibits a normal Arrhenius‐type temperature dependence with activation energy of 113 ± 3 kJ/mol. The latter has not been previously reported in the literature. A high frequency secondary β‐relaxation is also observed with Arrhenius activation energy of 45 ± 1 kJ/mol. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 932–943, 2009 相似文献