1,720,964 research outputs found
Insulator-metal phase transitions of alkali atoms on GaAs(001)
No full textThe electronic properties of alkali metals (Cs and Na) deposited on the gallium-rich GaAs(001 surface), have been investigated using synchrotron-radiation photoemission spectroscopy, at liquid nitrogen temperature. From the analysis of the alkali core-level spectra and using usual criteria for metallicity (namely: appearance of the Fermi-level edge, presence of plasmon losses in core-level spectra, and disappearance of surface photovoltage) we find evidence of a surface metallic phase, both for Cs and Na. In agreement with previous determinations of the phase diagram for Such system, we find that the metallic phase coexists with an insulating phase. We also observe a precursor of the surface metallic phase, for which only one of the above criteria is satisfied (plasmon losses). The formation of a Cs metallic phase leads mainly to the rising in the Cs4d core-level spectrum of a narrow component at higher binding energy. In contrast, for Na adsorption, the metallic-related component in the Na2p core-level spectrum lies at lower binding energy. These findings are discussed and tentatively explained in terms of the classical Born-Haber cycle as well as with a tight-binding description of alkali metal adsorption. The core-level photoemission results suggest a morphological model in which part of alkali atoms are bonded to the substrate (first layer; insulating phase) and part are bonded to alkali atoms (either second layer or clusters; metallic phase). (c) 2005 Elsevier B.V. All rights reserved
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
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
Chemically prepared well-ordered InP(001) surfaces
No full textIn the present work HCl-isopropanol treated and vacuum annealed InP(001) surfaces were studied by means of low-energy electron diffraction (LEED), soft X-ray photoemission (SXPS), and reflectance anisotropy (RAS) spectroscopies. The treatment removes the natural oxide and leaves on the surface a physisorbed overlayer containing InClx and phosphorus. Annealing at 230 C induces desorption of InClx overlayer and reveals a P-rich (2 x 1) surface. Subsequent annealing at higher temperature induces In-rich (2 x 4) surface. The structural properties of chemically prepared InP(001) surfaces were found to be similar to those obtained by decapping of As/P-capped epitaxial layers. (c) 2006 Elsevier B.V. All rights reserved
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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