1,720,982 research outputs found
Supramolecular cobalt cages and coordination polymers templated by anion guests: Self-assembly, structures, and magnetic properties
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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
Mass Spectrometric Study of the Laser Vaporisations of Graphite and Uranium Dioxide up to 4000 K
No full textUne nouvelle méthode de spectrométrie de masse (TOF MS) haute température a été développée. La surface de l’échantillon y est chauffée par laser pendant environ 20 ms, et température et spectres de masse sont mesurés en fonction du temps. Chaque expérience couvre tout un intervalle de température. Cette méthode a été appliquée au graphite pyrolytique et au dioxyde d’uranium. L’étude du graphite a clairement montré que la sublimation est de type Langmuir (ou surface libre), malgré les très hautes températures et pressions. Les pressions partielles relatives de C1, C2, C3, C4 et C5 ont été mesurées jusqu’à 4100K, ainsi que les enthalpies de sublimation des trois espèces principales de la vapeur. Les coefficients d’évaporation relatifs de C1-C5 ont été estimés par comparaison des pressions partielles obtenues ici à 4000K avec celles à l’équilibre thermodynamique de la littérature. La courbe de pression de vapeur de UO2 au-dessus du dioxyde d’uranium a été mesurée entre 2800 et 3400 K. Des enthalpies de sublimation et de vaporisation sont proposées pour UO2, ainsi qu’une première valeur expérimentale de l’enthalpie de vaporisation de UO3. Les rapports de pressions partielles p(UO2)/p(UO), p(UO3)/p(UO2) et p(UO+2 )/p(UO+) ont été mesurés aux alentours de 3300K et indiquent que l’évaporation se fait dans des conditions proches de l’équilibre thermodynamique. La méthode développée ici est adaptée à l’étude par spectrométrie de masse jusqu’à de très hautes températures de la vaporisation de matériaux réfractaires, et pourrait être utilisée pour l’étude de matériaux chimiquement instables comme le dioxyde d’uranium hyperstoechiométrique ou des carbures et nitrures.A new method of high-temperature mass spectrometry (TOF MS) was developed, where the specimen surface is heated by a laser pulse of approx. 20 ms. During it, timeresolved measurements of mass spectra and of the temperature are performed. Each experiment covers an entire temperature interval. The method was applied to pyrolytic graphite and uranium dioxide. In graphite study, it was clearly shown that the sublimation occurs in a Langmuir-like mode (free surface vaporisation), despite the very high temperatures and thus pressures. Relative partial pressures of C1, C2, C3, C4 and C5 were measured up to 4100K. Obtained sublimation enthalpies of the main three vapour species are in a good agreement with literature values. Relative vaporisation coefficients of C1-C5 were estimated by comparison of the present partial pressures at 4000K with equilibrium ones given in the literature. The vapour pressure curve of UO2 over stoichiometric uranium dioxide was measured between 2800 and 3400 K. Obtained sublimation and vaporisation enthalpies are in agreement with the literature. The vaporisation enthalpy of UO3 was measured for the first time. Relative partial pressure ratios p(UO2)/p(UO), p(UO3)/p(UO2) and p(UO+2 )/p(UO+) were measured at around 3300K and indicate that the vaporisation occurs in a regime close to thermodynamic equilibrium. This method is suitable for the fast and time-resolved mass spectrometric measurements of refractory materials up to very high temperatures, and could now be applied to the study of chemically unstable materials such as hyperstoichiometric urania and some carbides and nitrides
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
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