1,721,012 research outputs found
All-optical control of a single plasmonic nanoantenna–ITO hybrid
Get PDFWe demonstrate experimentally picosecond all-optical control of a single plasmonic nanoantenna embedded in indium tin oxide (ITO). We identify a picosecond response of the antenna–ITO hybrid system, which is distinctly different from transient bleaching observed for gold antennas on a nonconducting SiO2 substrate. Our experimental results can be explained by the large free-carrier nonlinearity of ITO, which is enhanced by plasmon-induced hot-electron injection from the gold nanoantenna into the conductive oxide. The combination of tunable antenna–ITO hybrids with nanoscale plasmonic energy transfer mechanisms, as demonstrated here, opens a path for new ultrafast devices to produce nanoplasmonic switching and control.<br/
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
Dielectric nanostructures for control of electromagnetic waves
Get PDFHigh refractive index dielectric nanoantennas have emerged as a promising unit for improving optical nanodevices by compensating the drawbacks of plasmonic nanoantennas, which have played a key role in nanophotonics to date. The features of high refractive index dielectric nanoantennas, such as low energy losses, excitation of strong magnetic resonances and enhancement of electric field inside and outside the particle, are expected to provide novel methods to manipulate electromagnetic waves in the nanometer scale.
In this thesis, we theoretically explore and experimentally demonstrate a variety of nanostructures based on high refractive index dielectric nanoantennas to aim at the efficient and tuneable control of electromagnetic waves in linear and nonlinear manners. Firstly, asymmetric Si dimers are investigated to achieve unidirectional forward scattering with high efficiency. An electric or magnetic dipole mode is excited in each particle constituting the asymmetric dimer at the same wavelength. The interference between these two dipolar modes can direct the scattered field selectively into the forward direction with high scattering efficiency. Secondly, we investigate metasurfaces built of array of Si nanodimers to obtain switching from high transmission to reflection depending on the incident polarization. The different linear polarization direction of the incident light can alter the hybridization modes of the constituent Si dimers and, hence, the effective permittivity and permeability of the metasurface. The resulted overlap and separation of the electric and magnetic dipolar resonances facilitates the control over the switching between high transmission and reflection. Thirdly, asymmetric Si dimers are explored to obtain tuneable control of directional scattering either in the left or right direction from the incident axis. Our theoretical analysis reveals that the electric or magnetic dipoles excited perpendicular to the dimer axis are mainly responsible for the tuneable scattering. Experimental demonstration of the scattering tuneability is carried out along the substrate by using back focal plane techniques combined with a prism coupling setup. Fourthly, we show that the third harmonic generation from a high refractive index dielectric nanoantenna can be significantly improved by adding a metallic component to build a metal-dielectric hybrid nanostructure. In this way, the plasmonic resonance of a Au nanoring can boost the anapole mode excited in a Si nanodisk, strongly enhancing the electric field inside the Si nanodisk. As a result, high third harmonic intensity and conversion efficiency can be achieved even in nanometer scale. Our findings on how we can attain the efficient and tuneable control of electromagnetic waves using high refractive index dielectric nanostructures will contribute to opening the new paths towards the realization of novel optical nanodevices.Open Acces
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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