1,720,962 research outputs found
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
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
(Flash)A joint experimental and computational study on the influence of packing on organic compounds luminescence and singlet oxygen generation in the condensed phase
No full textInternational audienc
Understanding the Aggregation Induced Emission (AIE) in a heterocyclic tetraphenylethylene analog
No full textInternational audienc
Étude conjointe expérimentale et théorique de la luminescence de composés ditriazolostilbènes en phase condensée
No full textWhile nowadays ubiquitous in a variety of optoelectronic applications, the development and the characterization of new organic solid state luminophores remains a challenge. In this context, the tetraphenylethylene (TPE), which fluorescence is enhanced in the solid state (Aggregation induced emission, AIE), even upon most functionalization, has become a widely popular moiety for solid state luminescent devices.By substituting two of the phenyl rings of the TPE by two azide rings, we developed a new heterocyclic ditriazolostilbene (DTS) core analog of TPE. This DTS core who unlike the TPE can be synthetized as a pure diastereoisomer, also shows AIE properties. Through a combined set of spectroscopic experiments, crystal structure resolution and quantum chemistry, we also show that the photophysical basis of these AIE properties is due to the flexibility at the excited state around the central C=C bond, allowing fast relaxation to the ground state via a conical intersection in solution, which is blocked in the solid.Double alkylation of this molecule to triazolium induces a large red-shift in emission, thanks to increased donor-acceptor character. Owing to counterion exchange, luminescence properties can be further tuned to reach a solid state emission maxima of 700 nm. The solid state properties of these bicationic compounds open possibilities for multiple applications in optoelectronics and bioimaging.The potential energy landscapes of those compounds in the excited state were also further studied by a combination of femtosecond transient spectroscopy and TD-DFT energy scan, allowing a rationalization of the excited state dynamics of this new family of compounds.Malgré de multiples applications potentielles notamment en optoélectronique, le développement et la caractérisation de nouveaux composés organiques émissifs à l'état solide reste difficile. Dans ce contexte, la molécule tétraphényléthylène (TPE), dont la fluorescence augmente lors du passage à l'état solide (émission induite par agrégation, AIE), et ce même après fonctionnalisation, est devenue une molécule plateforme très utilisée pour la réalisation de dispositifs luminescents à l'état solide.En substituant deux groupements phényles par deux azides, nous avons développé un nouveau coeur hétérocyclique ditriazolostilbène (DTS) analogue du TPE. Ce nouveau coeur DTS, qui, contrairement au TPE, peut être synthétisé sous forme diastéroéopure, présente aussi des propriétés d'AIE. En combinant de études spectroscopiques et computationnelles, en solution ainsi qu'à l'état solide, nous avons pu montrer que le phénomène photophysique à l'origine des propriétés d'AIE de la molécule est une rotation autour de la liaison centrale. Celle-ci permet une relaxation rapide vers l'état fondamental via une intersection conique en solution, mais dont l'accès est bloqué à l'état solide.La double alkylation de la molécule vers sa forme triazolium conduit à un grand déplacement bathochrome de l'émission grâce à une augmentation du caractère de transfert de charge. L'émission de ces composés peut être encore modulée par changement du contre-ion jusqu'à attendre un maximum d'émission à 700 nm. Les propriétés d'émission à l'état solide de ces composés bicationiques ouvrent des possibilités d'applications nombreuses en optoélectronique et en imagerie in vivo.La cartographie des surfaces d'énergie potentielle des états excités de ces composés a enfin pu être établie par une combinaison de spectroscopies ultrarapides et de scans d'énergie en TD-DFT, permettant une rationalisation des dynamiques à l'état excité de cette nouvelle famille de composés
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