1,720,987 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
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
Carbon Shell on Active Nanocatalyst for Stable Electrocatalysis
No full text© 2022 American Chemical Society.ConspectusElectrocatalysis is a key process for renewable energy conversion and fuel production in future energy systems. Various nanostructures have been investigated to optimize the electrocatalytic activity and realize efficient energy use. However, the long-term stability of electrocatalysts is also crucial for the sustainable and reliable operation of energy devices. Nanocatalysts are degraded by various processes during electrocatalysis, which causes critical performance loss. Recent operando analyses have revealed the mechanisms of electrocatalyst failure, and specific structures have been identified as robust against degradation. Nevertheless, achieving both high activity and robust stability with the same nanostructure is challenging because the structure-property relationships that affect activity and stability are different. The optimization of electrocatalysis is often limited by a large trade-off between activity and stability in catalyst structures. Therefore, it is essential to introduce functional structural units into catalyst design to achieve electrochemical stability while preserving high activity.In this Account, we highlight the strategic use of carbon shells on catalyst surfaces to improve the stability during electrocatalysis. For this purpose, we cover three issues in the use of carbon-shell-encapsulated nanoparticles (CSENPs) as robust and active electrocatalysts: the origin of the improved stability, the identification of active sites, and synthetic routes. Carbon shells can shield catalyst surfaces from both (electro)chemical oxidation and physical agglomeration. By limiting the exposure of the catalyst surface to an oxidizing (electro)chemical environment, carbon shells can preserve the initial active site structure during electrocatalysis. In addition, by providing a physical barrier between nanoparticles, carbon shells can maintain the high surface area of CSENPs by reducing particle agglomeration during electrocatalysis. This barrier effect is also useful for constructing more active or durable structures by annealing without surface area loss. Compared to the clear stabilizing effect, however, the effect of the shell on active sites on the CSENP surface can be puzzling. Even when they are covered by a carbon shell that can block molecular adsorption on active sites, CSENP catalysts remain active and even exhibit unique catalytic behavior. Thus, we briefly cover recent efforts to identify major active sites on CSENPs using molecular probes. Furthermore, considering the membranelike role of the carbon shell, we suggest several remaining issues that should be resolved to obtain a fundamental understanding of CSENP design. Finally, we describe two synthetic approaches for the successful carbon shell encapsulation of nanoparticles: two-step and one-step syntheses. Both the postmortem coating of nanocatalysts (two-step) and the in situ formation via precursor ligands (one step) are shown to produce a durable carbon layer on nanocatalysts in a controlled manner. The strengths and limitations of each approach are also presented to promote the further investigation of advanced synthesis methods.The hybrid structure of CSENPs, that is, the active catalyst surface and the durable carbon shell, provides an interesting opportunity in electrocatalysis. However, our understanding of CSENPs is still highly limited, and further investigation is needed to answer fundamental questions regarding both active site identification and the mechanisms of stability improvement. Only when we start to comprehend the fundamental mechanisms underlying electrocatalysis on CSENPs will electrocatalysts be further improved for sustainable long-term device operation.N
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
Functional link between surface low-coordination sites and the electrochemical durability of Pt nanoparticles
No full textA promising strategy for achieving enhanced catalytic activity involves the use of nanoscale electro-catalysts; however, their low stability remains a major challenge. Among the various performance degradation mechanisms, atomic dissolution is known to cause severe nanoparticle deactivation. To date, the factors influencing these catalysts' durability are not understood. Herein, we assess the role of low-coordination surface sites, focusing on the atomic dissolution of Pt nanoparticles. The density of low coordination sites was finely controlled, and no significant size change occurred. Based on our findings, we suggest that the initial low-coordination sites trigger metal dissolution, which subsequently accelerates Pt dissolution. We believe that controlling the surface coordination number can open new routes for the design of highly durable nanoscale electrocatalysts. (C) 2016 Elsevier B.V. All rights reserved.N
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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