1,721,038 research outputs found

    A new kind of vertically aligned field emission transistor with a cylindrical vacuum channel

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    This study investigated a vertically aligned field emission transistor with a cylindrical vacuum channel. The channel length of this proposed transistor can be precisely controlled and easily fabricated to be comparable to the mean free path of electrons in air so that the device can operate in the air without performance degradation. In the study, this vacuum transistor showed a low threshold voltage (1.2 V, 2.2 V, and 3.3 V) with a gate dielectric thickness of 10 nm, 15 nm, and 20 nm and a subthreshold slope of 1.1 V/dec. It was found that the vacuum channel radius should be no less than 20 nm, otherwise, severe performance degradation will appear due to the effect of the gate shield (leading to reduction of the anode current) and electron collision events with the dielectric layer (presenting reliability issues). This kind of vacuum transistor may have wide applications in extreme conditions such as high temperature and intense irradiation. (C) 2017 Elsevier Ltd. All rights reserved.</p

    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

    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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    Numerical analysis of the surface-conduction electron-emitter with a new configuration

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    A new kind of surface -conduction electron -emitter (SCE) with a triangular dielectric layer under the conductive film is proposed. The influences of the vertex angle (theta) of the triangular dielectric layer and the anode voltage (U-a) on the electron emission efficiency and the focusing capability have been investigated with the finite integration technique (FIT). The numerical simulation results show that SCE with a small vertex angle guarantees higher electron emission efficiency even with a low anode voltage. But the focusing capability of the electron emitter will get worse when the theta or U-a becomes too small. Take both the electron emission efficiency and focusing capability into consideration, the structure with a vertex angle (theta) between 60 degrees-100 degrees and the anode voltage of 1500 V is suggested.</p

    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

    Analysis of the influence of nanofissure morphology on the performance of surface-conduction electron emitters

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    A simulation model was built to numerically investigate the electron emission property of a new surface-conduction electron emitter (SCE) with a raised emitter structure. The model calculated the electric field distribution, the electron emission characteristics, and the electron trajectories, which were useful for analyzing and understanding the microscopic mechanism of the electron emissions of the new SCE structure. It was found that the new structure increased the probability of electrons being collected by the anode which led to an increase of the anode current despite of the decrease of field emission current. This study benefits the advanced design of emitter structures in nanoscale technology for new types of electron sources
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