1,721,721 research outputs found

    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

    Special Smarandache Curves in the Euclidean Space

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    In this work, we introduce some special Smarandache curves in the Euclidean space. We study Frenet-Serret invariants of a special case. Besides, we illustrate examples of our main results

    Synthesis and lithium-storage properties of MnO/reduced graphene oxide composites derived from graphene oxide plus the transformation of Mn(vi) to Mn(ii) by the reducing power of graphene oxide

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    The authors acknowledge the financial support from the National Natural Science Foundation of China (21272236, 21225730, 21207136 and 91326202), the Ministry of Science and Technology of China (2011CB933700), the Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection and the Priority Academic Program Development of Jiangsu Higher Education Institutions.In this report, a novel method is proposed to prepare MnO/reduced graphene oxide (rGO) composites via calcining the precursors (i.e. δ-MnO2/graphene oxide composites) at 500 °C in Ar using no external reducing gas, in which graphene oxide (GO) successfully serves as a reductant by releasing CO during its thermolysis for the first time. By controlling the initial ratios of GO to KMnO4, differently composed precursors can be obtained via the redox reaction between GO and KMnO4, then leading to the formation of composites with different MnO/rGO ratios and dispersion of MnO on the rGO surface (denoted as MGC1 and MGC2). When applied as an active material in lithium ion batteries, MGC1 shows excellent cycling performance and capacity retention. Under 100 and 200 mA g−1, MGC1 could deliver reversible capacities as high as 900 and 750 mA h g−1, respectively, after more than 100 cycles. Considering the simple operation and low energy consumption in the whole material synthesis processes, the present strategy is feasible and effective for practical application. Even more importantly, the reductibility of graphene oxide upon thermolysis is utilized for the first time, which is meaningful for its extension in synthesis of functional nanomaterials.Peer reviewe

    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

    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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    On the electrokinetic characterization of charged polymeric membranes by transversal streaming potential

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    Financial support of this work by Banco de Santander and Universidad Complutense de Madrid within the framework of Project PR75/18-21589 is gratefully acknowledged.The effect of a transmembrane pressure on the electrokinetic properties of different polymeric charged membranes is analysed. Electrokinetic characterization can involve the application of increasing or decreasing pressure differences over a membrane sample. The aim of this work is to study whether the transmembrane pressure application during the measurement process to determine the zeta potential and the intrinsic permeability of polymeric membranes causes a membrane irreversible change. It is a relevant issue in membrane technology, because electrokinetic properties are used to analyse the viability and performance of ion-exchange membranes processes in practical applications. We show that polymeric membranes can be affected by a transmembrane pressure application. This influence does not affect surface char ge distribution of the polymeric membranes, but it can strongly affect the membrane structure. (c) 2021 Elsevier Ltd. All rights reserved.Universidad Complutense de Madrid/Banco de SantanderDepto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEpu
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