1,720,956 research outputs found
Simultaneous reduction of multi-dimensional defects in Sn-excess BaSnO3 epitaxial films induced by surface chemical reconstruction
No full textMulti-dimensional defects created by thermodynamic and mechanical condition strongly limit electron mobility by the scattering of charged carriers in semiconducting BaSnO3 (BSO) epitaxial films. Here, we demonstrate that the density of both extended and point defects in heteroepitaxial BSO films can be decreased simultaneously by exploiting surface phase instability and a subsequent redistribution of cations at thermal treatment under different oxygen chemical potentials. By delicately controlling both cation ratio and ambient oxygen partial pressure p(O-2), distinct surface topography and cation redistribution (i.e., BaO segregation or SnO evaporation) were observed along with effective healing of extended defects. Simultaneous control of extended and point defects in La-doped BaSnO3 (LBSO) films during treatment under reducing atmosphere decreased their scattering of charged carriers and yielded an increase in room-temperature electron mobility mu(e) by similar to 104% (55-112 cm(2) V-1 s(-1)) in initially Sn-excess LBSO films as a result of a complex interplay with the removal of Sn-related species at the surface. Our finding suggests a versatile strategy to further enhance electron transport of perovskite-type stannate films by exploiting chemical heterogeneity on the surface interfacing with the p(O-2)-controlled ambient.11Nsciescopu
Non-volatile ferroelectric control of room-temperature electrical transport in perovskite oxide semiconductor La:BaSnO3
No full textComplex oxide heterostructures composed of oxide semiconductor thin films and ferroelectric single crystals have attracted substantial interest due to the electrically switchable channel resistance by the polarization reversal of ferroelectrics. Here we achieve reversible and non-volatile modulation of room-temperature (RT) resistance in epitaxial La-doped BaSnO3 (LBSO) transparent oxide layers by exploiting the ferroelectric field effect of (001)-oriented Pb(Mg1/3Nb2/3)O3PbTiO3 (PMNPT) single-crystal substrates. Using "all-perovskite" heterostructures, the sheet resistance of the LBSO thin films could be reversibly modified upon polarization switching; as a result, the non-volatile sheet resistance was modulated by up to similar to 70% at RT. Such heterostructures that combine materials with dissimilar functionality provide scientific insights into the charge-mediated physics of perovskite stannate systems coupled to ferroelectric polarization, and show technological potential for non-volatile electronic devices based on new transparent oxide semiconductors.11sciescopu
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
- …
