1,720,975 research outputs found
Luminescence study of mixed valence Eu-doped nanocrystalline glass-ceramics
No full textEu-doped nanocrystalline NaAlSiO4/NaY9Si 6O26 glass-ceramics have been prepared by controlled crystallization of melt quenched bulk glasses. XRD, SEM and FTIR spectroscopy techniques were employed to characterize the crystallization process and the structural properties of the precursor glass and corresponding glass-ceramics. The formation of divalent europium (Eu2+) from Eu3+ ions during high temperature synthesis under ambient atmosphere was analyzed by photoluminescence spectroscopy and is discussed using the optical basicity model. The observed luminescence properties of Eu: NaY9Si 6O26 are compared with that of Eu: β-PbF2 nanocrystals and their marked differences are discussed. © 2013 Elsevier B.V. All rights reserved
CVV AUGER LINE-SHAPES IN ALUMINUM
No full textIn absence of structural or electronic transitions, the temperature dependence of the inelastic energy losses of escaping electrons is proved to account for most of the temperature dependence of the raw LXX Auger spectrum in vanadium. This effect is expected to be true in general
ON THE RESTORATION OF AUGER LINE-SHAPES
No full textA simple and efficient method to deduce the true Auger spectrum from the raw data is presented. This method is an application to Auger spectroscopy derived from signal processing procedures employed in different fields. It appears particularly promising when complex spectra are analyzed as it avoids spurious information to be introduced. The method is also compared with the more-standard van Cittert's approach. An experimental check of the common assumption that an Auger electron experiences almost the same energy-loss mechanisms as a nearly elastically reflected primary electron at the same energy is given
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Failure of resistive breathing training to improve pulmonary function tests in patients with chronic obstructive pulmonary disease.
No full textHydrogen sorption properties of MgH2/NaBH4 composites
No full textThe hydrogen sorption properties of magnesium hydride-sodium borohydride composites prepared by means of high-energy ball milling under Ar atmosphere were investigated. Mutual influence of milling time and the content of NaBH 4 were studied. Microstructural and morphological analyses were carried out using X-ray Diffraction (XRD), laser scattering measurements and Scanning Electron Microscopy (SEM), while kinetic analysis and cycling were performed in a Sievert's volumetric apparatus. It has been shown that low content of NaBH4 and short milling time are beneficial for hydrogen sorption kinetics. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
AUGER-ELECTRON SPECTROSCOPY STUDY OF THE INTERFACE BETWEEN BULK ALUMINUM AND BULK ALUMINUM-OXIDE
No full textAn extensive Auger electron spectroscopy study of the aluminum-aluminum oxide interface is presented, with the aim of identifying the behaviour of the contact zone between bulk metal and bulk oxide. Restored oxygen KLL and aluminum LW spectra have been derived and analysed as a function of the depth of a thick aluminum sample evaporated onto an aluminum oxide crystal. The capability of the Auger electron spectroscopy to derive rather unique information on the nature of the contact zone is used to infer that the metal and oxide form small isles or domains in the interface region, so that the transition from the metal to the oxide is not characterized by a sharp surface
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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