1,720,966 research outputs found
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
Enhanced reactivity of NiO/Pd(100) ultrathin films toward H2: Experimental and theoretical evidence for the role of polar borders
No full textNiO layers in the ultrathin regime exhibit an enhanced reactivity toward hydrogen with respect to the typical chemical inertness of bulk-like thicker samples. Such a behavior has been studied by means of photoemission (from both core and valence band levels) and quantum mechanical calculations. It is found that after H2 dosing in mild conditions (from PH2 = 6.5 × 10-7 Pa and T = 330 K) ultrathin films (thickness ≤6MLE, MLE = monolayer equivalent) quickly react forming metal nickel and water. The kinetic of the reaction has been followed in situ recording the intensity of the O 1s and Ni 2p photoemission spectra under different reaction conditions (PH2 ranging from 5 × 10-7 to 2 × 10-5 Pa and T from 330 up to 453 K), and a first-order dependence of the reaction rate on the PH2 and the activation energy of the rate determining step (0.16 ± 0.02 eV) have been determined. A 8 MLE thick film recovers the behavior of bulk-like NiO(100) surfaces, where more drastic reduction conditions are needed, and the kinetic implies an induction period followed by autocatalysis. The enhanced reactivity has been explained assuming the presence of NiO(100) islands exposing polar borders, whose existence was evidenced by previous scanning tunneling microscopy investigations. Such a scenario is confirmed by ab initio quantum mechanical calculations carried out employing polar and nonpolar terminated stepped surface epitaxially strained in order to account for the presence of the metal support which has not been explicitly included. Reported calculations indicate that the polar border can easily dissociate H2 without any activation barrier. The rate determining step of the reaction has been associated to the stage of the reaction where the previously formed hydroxyl groups react with a second hydrogen molecule (an Eley−Rideal-like mechanism) to form metal Ni islands and water, which readily desorbs
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
3D BAROLO: a new 3D algorithm to derive rotation curves of galaxies
Full text linkWe present ^{3{D}}BAROLO,† a new code that derives rotation curves of galaxies from emission-line observations. This software fits 3D tilted-ring models to spectroscopic data cubes and can be used with a variety of observations: from H I and molecular lines to optical/IR recombination lines. We describe the structure of the main algorithm and show that it performs much better than the standard 2D approach on velocity fields. A number of successful applications, from high to very low spatial resolution data are presented and discussed. ^{3D}BAROLO can recover the true rotation curve and estimate the intrinsic velocity dispersion even in barely resolved galaxies (˜2 resolution elements) provided that the signal to noise of the data is larger than 2-3. It can also be run automatically thanks to its source-detection and first-estimate modules, which make it suitable for the analysis of large 3D data sets. These features make ^{3D}BAROLO a uniquely useful tool to derive reliable kinematics for both local and high-redshift galaxies from a variety of different instruments including the new generation Integral Field Units, ALMA and the SKA pathfinders
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
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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