1,720,954 research outputs found
Single Layers of WS2 Nanoplates Embedded in Nitrogen-Doped Carbon Nanofibers as Anode Materials for Lithium Ion Batteries
No full textSingle Layers of WS2 Nanoplates Anchored to Hollow N-doped Carbon Nanofibers as Efficient Electrocatalysts for Hydrogen Evolution
No full textSince hydrogen is considered as one of the most promising energy carriers, alternative to finite fossil fuels, intensive research efforts have been devoted to developing noble metal-free electrocatalysts for hydrogen evolution reaction (HER). In particular, transition metal dichalcogenides (TMDs) such as MoS2 and WS2 have drawn tremendous attention due to their fascinating electrocatalytic activities for HER when they are single-layered or few-layered with numerous catalytically active sites. Unfortunately, their poor intrinsic conductivities hamper their use as electrocatalysts for HER. In this regard, it is an efficient strategy to make a composite, combining single-layered TMDs with highly conductive materials. Herein, single-layered WS2 nanoplates are randomly oriented and uniformly anchored to hollow N-doped carbon nanofibers (WS2@HNCNFs) via coaxial electrospinning and a subsequent two-step thermal treatment. For the coaxial electrospinning, styrene-acrylonitrile (SAN) was used for the core as a sacrificial template while polyacrylonitrile (PAN) and (NH4)2WS4 for the sheath as a robust carbon matrix and single layers of WS2, respectively. The two-step thermal treatment was conducted for the crystallization of WS2 nanoplates, and for the carbonization of the PAN with in situ N-doping. The growth of WS2 nanoplates along the c-axis direction was hindered by the surrounding amorphous carbon matrix, preventing stacking of the WS2 nanoplates. In situ N-doping in the hollow carbon nanofibers was achieved by generated ammonia gas (NH3) as by-product gas during the thermal decomposition of (NH4)2WS4. For comparison, bulk WS2 powder and single layers of WS2 embedded in nitrogen-doped carbon nanofibers were synthesized and electrochemically tested. The distinctive design of the WS2@HNCNFs enables remarkable electrochemical performances. The catalyst electrode exhibited superior electrocatalytic performance with a low overpotential with reduced charge transfer resistance to obtain significant hydrogen evolution, a small Tafel slope of approximately 45 mV/dec, a high exchange current density, and excellent durability. The extraordinary catalytic performance can be attributable to numerous exposed edges of single-layered WS2 and facile electron path ways provided by the hollow N-doped carbon network. In addition, the hollow structure showed increased the Brunauer-Emmett-Teller (BET) surface area, offering easy accessibility for electrolyte to catalytically active sites
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
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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