1,721,473 research outputs found
OH incorporation in synthetic diopside
No full textSingle crystals of diopside doped with different amounts of Fe, Cr, Al and Na were synthesized under silica- and water-saturated conditions at 20 kbar. The OH-incorporation was studied by FTIR-spectroscopy and secondary ion mass spectrometry. Pure diopside exhibits one OH-absorption band at 3357 cm(-1), whereas additional absorption bands appear for Al-, Fe- and Cr-doped diopsides at 3462, 3443 and 3432 cm(-1), respectively. The observed absorption bands are interpreted to be associated with M-site vacancies, and the absence of high wavenumber absorption bands is suggested to be diagnostic for a high silica activity. Incorporation of Na in a Cr-doped diopside caused a decrease of OH-defects, consistent with a simple increase of the kosmochlor component
A new method to eliminate the influence of in situ contamination in SIMS analysis of hydrogen
No full textA new method has been developed that allows us to eliminate the influence of hydrogen contamination/background in SIMS analyses. The method is based on a number of measurements with different primary beam currents and a simple model for the sputtering of adsorbed hydrogen stemming from in situ contamination. Applying the contamination model to the data yields information about the degree of in situ contamination and about the relative intensity of H ions originating from the sample (e. g., H: Si ratio). The new method's advantage is that no other timeconsuming (such as special sample preparation and storage) or complicated and expensive (e. g., machine vacuum) measures to eliminate surface contamination are needed
Uwe Ludwig & Thomas Schilp (Ed.), Nomen et Fraternitas. Festschrift für Dieter Geuenich zum 65. Geburtstag, 2008
No full textRaepsaet-Charlier Marie-Thérèse. Uwe Ludwig & Thomas Schilp (Ed.), Nomen et Fraternitas. Festschrift für Dieter Geuenich zum 65. Geburtstag, 2008. In: L'antiquité classique, Tome 78, 2009. pp. 455-456
Ludwig (Thomas). Die Urkunden der Bischöfe von Meißen. Diplomatische Untersuchungen zum 10.-13. Jahrhundert.
No full textTock Benoît-Michel. Ludwig (Thomas). Die Urkunden der Bischöfe von Meißen. Diplomatische Untersuchungen zum 10.-13. Jahrhundert.. In: Revue belge de philologie et d'histoire, tome 86, fasc. 3-4, 2008. pp. 915-916
Ludwig (Thomas). Die Urkunden der Bischöfe von Meißen. Diplomatische Untersuchungen zum 10.-13. Jahrhundert.
No full textTock Benoît-Michel. Ludwig (Thomas). Die Urkunden der Bischöfe von Meißen. Diplomatische Untersuchungen zum 10.-13. Jahrhundert.. In: Revue belge de philologie et d'histoire, tome 86, fasc. 3-4, 2008. pp. 915-916
Ralph-Johannes Lilie, Claudia Ludwig, Thomas Pratsch, Ilse Rochow, Prosopographie der mittelbyzantinischen Zeit. Erste Abteilung (641-867). Prolegomena.
No full textCheynet Jean-Claude. Ralph-Johannes Lilie, Claudia Ludwig, Thomas Pratsch, Ilse Rochow, Prosopographie der mittelbyzantinischen Zeit. Erste Abteilung (641-867). Prolegomena. . In: Revue des études byzantines, tome 57, 1999. pp. 312-313
Ralph-Johannes Lilie, Claudia Ludwig, Thomas Pratsch, Ilse Rochow, Prosopographie der mittelbyzantinischen Zeit. Erste Abteilung (641-867). Prolegomena.
No full textCheynet Jean-Claude. Ralph-Johannes Lilie, Claudia Ludwig, Thomas Pratsch, Ilse Rochow, Prosopographie der mittelbyzantinischen Zeit. Erste Abteilung (641-867). Prolegomena. . In: Revue des études byzantines, tome 57, 1999. pp. 312-313
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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