1,720,974 research outputs found
Disorder-order evolution of InSb(110) studied by He scattering
No full textThe evolution of surface defects created by low energy ion bombardment on InSb(110) is studied by He beam scattering experiments. At surface temperatures above 500 K the ion erosion is found to proceed layer-by-layer without changing the stoichiometric composition of the surface. This indicates that the nucleation of surface islands driven by vacancy diffusion is faster than the ion erosion. After different doses of Ar+ ion bombardment, the surface is left in a non-equilibrium state whose time evolution is monitored by measuring the profiles of the He diffraction peaks. It is seen that the coalescence of islands proceeds with anisotropic island size distributions
K3C60: a strongly correlated metal with molecular disorder
No full textThis paper reports an ultra-violet photoemmision spectroscopy study on K3C60 in the temperature range 30-600 K. The experiment shows that the temperature dependence of the conduction band is consistent with the behaviour of a strongly correlated metal. In addition, the photoemission intensity near the Fermi edge decreases as the temperature is increased. This trend is similar to the vanishing behaviour of the quasi-particle weight predicted for strongly correlated metals with increasing disorder. The experimental evidence that the shoulder visible in the highest occupied molecular orbital region. unexpected on the basis of conventional band calculations, is coupled with the sharp peak at the Fermi level is also provided
Interaction of He and Ne with Cu surfaces
No full texthe extensive data available for He and Ne beam elastic scattering from Cu surfaces are analysed by full quantum mechanical calculations and by describing the atom-surface interaction potential according to the present knowledge on van der Waals pair potentials. It is shown that Ne penetrates the surface electron cloud much deeper than He and that the ratio of Ne-to-He adsorption energies exceeds the ratio of the atomic polarizabilities
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
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