1,721,296 research outputs found

    Impact of oxidation morphology on reduced graphene oxides upon thermal annealing

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    Thermal reduction of graphene oxide (GO) is an essential technique to produce low-cost and higher quality graphene-based materials and composites used today in a plethora of applications. However, despite a demonstrated efficiency of high-temperature annealing in reducing the oxygen content of GO, the impact of the morphology of the initially oxidized samples on the restored sp graphene plane versus remaining sp imperfections remains unclear and out-of-control. Here using classical molecular dynamics, we simulate the process of thermal reduction on several GO samples for a variety of initial conditions and elucidate how both the concentration of oxygen functional groups and their spatial distribution jeopardize the reduction process efficiency. Our simulations suggest thermal annealing strategies to further optimize the crystallinity of reduced GO, enhancing their transport properties and hence making the resulting composites even more performant for electronic applications

    Optimization of the sensitivity of a double-dot magnetic detector

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    Altres ajuts: ICN2 is funded by the CERCA Programme/Generalitat de Catalunya.We investigate, by means of numerical simulations, the lowest magnetic field level that can be detected with a given relative accuracy with a sensor based on a double-dot device fabricated in a high-mobility two-dimensional electron gas. The double dot consists of a cavity delimited by an input and an output constriction, with a potential barrier exactly in the middle. In conditions of perfect symmetry, a strong conductance enhancement effect appears as a consequence of the constructive interference between symmetric trajectories. When the symmetry is broken, for example by the presence of an applied magnetic field, this enhancement effect is suppressed. We explore the design parameter space and assess the minimum magnetic field value that can be measured with a given accuracy in the presence of flicker noise

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Scaling of the integrated quantum metric in disordered topological phases

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    We report a study of a disorder-dependent real-space representation of the quantum geometry in topological systems. Thanks to the development of an efficient linear-scaling numerical methodology based on the kernel polynomial method, we can explore nontrivial behavior of the integrated quantum metric and Chern number in disordered systems with sizes reaching the experimental scale. We illustrate this approach in the disordered Haldane model, examining the impact of Anderson disorder and vacancies on the trivial and topological phases captured by this model.J.M.R. acknowledges P. A. Guerrero and L. M. Canonico for fruitful discussions. We acknowledge Grant PID2022-138283NB-I00 funded by MICIU/AEI/10.13039/501100011033 and by ERDF/EU, and European Union NextGenerationEU/PRTR under Grant No. PCI2021-122035-2A-2a. ICN2 is funded by the CERCA Programme/Generalitat de Catalunya and supported by the Severo Ochoa Centres of Excellence programme, Grant No. CEX2021-001214-S, funded by MCIN/AEI/10.13039.501100011033. This work is also supported by MICIN with European funds NextGenerationEU (PRTRC17.I1) and by 2021 SGR 00997, funded by Generalitat de Catalunya.With funding from the Spanish government through the "Severo Ochoa Centre of Excelence" accreditation (CEX2021-001214-S)Peer reviewe

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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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