1,721,009 research outputs found
Image states on Pb/Ge(111) observed through electron scattering
No full textResonant inelastic electron scattering is a new method that allows to detect image resonances with an energy resolution that makes line-shape analysis possible at an energy far above the vacuum level. For a better understanding of image states on Pb/Ge(111) and of the scattering mechanism, the two symmetry directions of the surface Γ̄M̄ and Γ̄K̄, and the dependence of the image resonances on the surface phases, the sample doping and the Pb coverage have been investigated. The maximum intensity of the image resonances is found for coverages ≥1 ML
Dispersion and intrinsic width of image resonances measured by resonant inelastic electron scattering: the alpha phase of Pb/Ge(111)
No full textHigh-temperature phase transitions at the Ge(110) surface
No full textThe Ge(110) surface has been investigated by core-level and valence band (VB) photoemission spectroscopy as a function of the temperature starting from the room temperature c(8×10) reconstructed surface up to 1196 K. Evidence of a phase transition is found at about 750±50 K from core-level and VB data analysis. VB photoemission shows that above 750 K the Ge(110) surface acquires an increasing metallic character up to 1110 K where a sudden, intense jump of the emission intensity at the Fermi level is observed. At higher temperatures up to 1196 K, a finite and constant density of states is observed, indicating the presence of a metallic surface layer
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
Temperature dependence of the photoemission spectra of Si(110) between 300 and 1630 K
No full textThe valence band (VB) and the 2p core level of the Si(1 1 0) surface have been investigated as a function of the temperature starting from the “16×2” reconstruction at room temperature up to 1630 K which is close to the Si melting point (1683 K). The “16×2”→(1×1) phase transition at about 1000 K causes a sudden shift of the Si 2p core level spectra. It is associated to a change of the surface band bending and to a change of the surface Si 2p components. The transition is also observed in the VB spectra as a change of their shape and of the emission intensity at the Fermi level. Other changes in the surface structure are detected at about 1320 K. No evidence for a sudden surface melting has been found
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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