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Gans und Goldschmidt Elektrizitäts-Ges. m. b. H. Berlin W. A. Roth J. Shukow A. Gerassimov Tödt Rossée v Morgenstern E. E. Weibel A. L. Thuras H. T. Stern F. Scheminzky R. Lorenz H. Klauer R. E. Hall L. H. Adams und O. Pfundt 《Fresenius' Journal of Analytical Chemistry》1928,75(3-4):120-123
Ohne Zusammenfassung 相似文献
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Determination of the Li/Nb ratio in lithium niobate by means of birefringence and Raman measurements
U. Schlarb S. Klauer M. Wesselmann K. Betzler M. Wöhlecke 《Applied Physics A: Materials Science & Processing》1993,56(4):311-315
Two optical methods for the determination of the Li/Nb ratio in lithium niobate (LiNbO3) are discussed. Data for the optical birefringence method are presented, they cover the entire composition range in which LiNbO3 can be fabricated and a wide spectral region. The line-widths of lattice modes have been measured by means of Raman scattering as a function of the Li/Nb ratio for single crystals with polished and rough surfaces. 相似文献
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Abstract The electrical DC conductivity [sgrave] of LiNbO3 :H, D was studied as a function of temperature, electric field and proton/deuteron dopant concentration. The conductivity follows linearly the hydrogen content over two orders of magnitude. Independent holographic measurements on the same samples confirm these results in the temperature range 75 – 150 °C. The activation energy for protonic and deuteronic migration turns out to be equal, Eact, H = Eact, D = 1.23 ± 0.04eV. The isotope effect of the pre-exponential factor reflects the mass dependence of the attempt frequency and shows the protons to be the migrating species rather than hydroxyl ions. 相似文献
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Malovichko G. I. Grachev V. G. Kokanyan E. P. Schirmer O. F. Betzler K. Gather B. Jermann F. Klauer S. Schlarb U. Wöhlecke M. 《Applied Physics A: Materials Science & Processing》1993,56(2):103-108
The growth of LiNbO3 single crystals from a melt with the Li/Nb ratio of 0.946, to which 6 wt.% K2O has been added, leads to stoichiometric specimens, essentially free of potassium, with (50±0.15) mol% Li2O in the crystal. This is established by studying the composition dependence of the following properties: linewidths of the electron paramagnetic resonance (EPR) of Fe3+, energy of the fundamental absorption edge, Raman linewidths of phonon modes, and dispersion of the optical birefringence. Comparison of the results with relevant calibration scales leads to the above composition. In all cases the Li2O content was found to be closer to 50% than that of a LiNbO3 crystal vapor-phase equilibrated to 49.9mol% Li2O. The photorefractive effect at light intensities I107 W/m2 is suppressed in this stoichiometric material. The features of the ternary system K2O-Li2O-Nb2O5, which are possibly responsible for the unexpected growth of stoichiometric LiNbO3 from the indicated melts, are discussed. 相似文献
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Wind M Spickermann J Schleimer M Donzelli M Gebhardt K Sturm-Haurany R Klauer D Fullhardt P Schmitt-Hoffmann A 《Journal of mass spectrometry : JMS》2006,41(7):903-910
The metabolic profile of BAL4815, an antifungal azole drug, was determined using in vitro rat hepatocyte incubations and subsequent analysis by capillary LC-qTof-MS and MS/MS including accurate mass determination. For the detection of the metabolites, a mixture of the drug and its deuterium-labelled analogue was used for incubations. Metabolic stability of BAL4815 was high in cultured rat hepatocytes. However, several low-abundant metabolites were detected by the use of capillary LC-qTof-MS and manual investigation of the data. The peak intensity of the most abundant metabolite was close to the limit of detection. Except for an apparent oxidation product, the masses of the other detected metabolites could not be assigned to a single and frequently occurring biotransformation. Accurate mass determination and possible elemental compositions suggested that metabolism occurred through a combination of glutathionylation and defluorination. This was verified using accurate mass MS/MS. The use of accurate mass measurements and the derived suggestions for the elemental compositions were essential to elucidate this atypical metabolic pathway. A mass accuracy better than 8 ppm could be achieved for most assigned MS and MS/MS signals with intensities less than 6 cps in the spectra. 相似文献
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