1,721,096 research outputs found
THERMAL EVOLUTION FROM A PRECURSOR TO THE Y-BA-CU-O SUPERCONDUCTOR - X-RAY ABSORPTION-SPECTROSCOPY STUDY AND APPLICATION TO THICK-FILM TECHNOLOGY
No full textThe local structure around Cu and Y atoms in a Y-Ba-Cu-O precursor prepared by spray pyrolysis was investigated by x-ray absorption spectroscopy. Near-edge and extended x-ray absorption fine structure analysis, together with powder diffraction measurements, give detailed information about structure and morphology of the precursor, as well as a clear picture of its thermal evolution towards the superconducting phase. Thick films prepared starting from this precursor are characterized. Their excellent properties exemplify possible applications of this material
Magnetic dichroism in the angular distribution of Fe 2p and 3p photoelectrons: Empirical support to Zeeman-like analysis
No full textWe report on the measurements and analysis of Fe 2p magnetic dichroism in the angular distribution of the photoelectrons from remanently magnetized Fe(100) surfaces with unpolarized, monochromatized, x rays of 1486 eV energy, and with linearly polarized synchrotron radiation of 800 eV energy. The analysis of the dichroic photoemission intensity in the two experiments verifies the applicability of the atomic photoionization model which provides a consistent understanding of the differences between photoemission experiments with unpolarized and linearly polarized radiation. A comparison of the Fe 2p and Fe 3p dichroism spectra allows us to discuss, on an empirical basis, the validity of a Zeeman-like interpretation of Fe 3p hole sublevels connected to the observed magnetic dichroism in photoemission
NICKEL-BASED AIR-FIRABLE THICK-FILM CONDUCTORS
No full textThe evolution of microstructure/composition of Ni-based thick films prepd. from air-firable pastes was investigated. The pastes contain elemental and/or a B-rich component which effectively competes with the oxidation of Ni grains. The evolution of the electrical properties of the film was studied. Even when the films are not made on sintered Ni grains, relatively high conductivities and high temperature coefficients of resistance are observe
L2L3V Coster-Kronig decay in Fe: the near-edge region RID G-7348-2011
No full textWe have investigated the Auger emission in Fe for photon energies varying across the 2p edges. The probability of the L2L3V Coster-Kronig (CK) decay process has been measured by photoemission spectroscopy using synchrotron radiation. The branching ratio between the process L-2 --> L-3'VV (CK preceded) and the direct Auger decay of the L-2 hole has been determined as a function of the photon energy near the 2p(1/2)-edge (717-735 eV): this branching ratio is found to rapidly converge to an asymptotic value of about 0.83, which favorably compares with the Auger-photoemission coincidence spectroscopy results. (C) 2002 Elsevier Science B.V. All rights reserved
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
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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
LEAD-FREE RUTHENIUM-BASED THICK-FILM RESISTORS - A STUDY OF MODEL SYSTEMS
No full textA model system of thick-film resistor (TFR) was prepared starting from RuO2 powders and a lead-free glass. The microstructural development was investigated by scanning and transmission electron microscopies, energy dispersive X-ray fluorescence, X-ray diffraction, thermogravimetry and other complementary techniques. The electrical properties of the resistors were analysed with particular attention to sheet resistance, temperature coefficient of resistance, size effects and piezoresistive properties. It was found that these simple systems are interesting with respect to their stability in ageing tests at relatively high temperatures but they are not promising for high-temperature piezoresistive gauges because of low strain sensitivity. Some samples were also prepared with a Bi2Ru2O7; a notable exchange reaction occurs between the conductive grains and the glass matrix which prevents the formation of pyrochlore-type based resistors with this glassy matrix
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