1,720,957 research outputs found
Controlling semiconductor/metal junction barriers by incomplete, nonideal molecular monolayers
No full textWe study how partial monolayers of molecular dipoles at semiconductor/metal interfaces can affect electrical transport across these interfaces, using a series of molecules with systematically varying dipole moment, adsorbed on n-GaAs, prior to Au or Pd metal contact deposition, by indirect evaporation or as "ready-made" pads. From analyses of the molecularly modified surfaces, we find that molecular coverage is poorer on low-than on high-doped n-GaAs. Electrical charge transport across the resulting interfaces was studied by current-voltage-temperature, internal photoemission, and capacitance-voltage measurements. The data were analyzed and compared with numerical simulations of interfaces that present inhomogeneous barriers for electron transport across them. For high-doped GaAs, we confirm that only the former, molecular dipole-dependent barrier is found. Although no clear molecular effects appear to exist with low-doped n-GaAs, those data are well explained by two coexisting barriers for electron transport, one with clear systematic dependence on molecular dipole (molecule-controlled regions) and a constant one (molecule-free regions, pinholes). This explains why directly observable molecular control over the barrier height is found with high-doped GaAs: there, the monolayer pinholes are small enough for their electronic effect not to be felt (they are "pinched off"). We conclude that molecules can control and tailor electronic devices need not form high-quality monolayers, bind chemically to both electrodes, or form multilayers to achieve complete surface coverage. Furthermore, the problem of stability during electron transport is significantly alleviated with molecular control via partial molecule coverage, as most current flows now between, rather than via, the molecules
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
Controlling Au/n-GaAs junctions by partial molecular monolayers
No full textA dipole-layer approach is adapted to describe the electrostatic potential and electronic transport through metal/semiconductor junctions with a discontinuous monolayer of polar molecules at the metal/semiconductor interface. The effective barrier height of those junctions, which have small pinholes, embedded in a molecular layer, which introduces a negative {positive} dipole (i.e., a dipole whose negative {positive} pole is the one that is closest to the semiconductor surface) on an n-type {p-type} semiconductor, is often "tunable" by the magnitude and density of the dipoles. If the lateral dimensions of a molecule-free pinhole at the interface exceed the semiconductor depletion width, carrier transport is not influenced by the molecular layer and the "effective" barrier height is the nominal metal/semiconductor barrier height. If the molecular layer introduces a positive {negative) dipole on an n-type {p-type) semiconductor, enhanced field emission at edges of small pinholes might lead to a leakage- and/or an edge-current component resulting in an effective barrier height lower than the nominal one. We support these conclusions by direct measurements of the nm-scale electronic behaviour of a Au/n-GaAs diode with a discontinuous monolayer of dicarboxylic acids at the interface, using Ballistic Electron Emission Microscopy (BEEM). (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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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