1,721,001 research outputs found
A new quasiparticle in carbon nanotubes
No full textTrions—one electron bound to two holes via Coulomb forces—can be observed in the optical spectra of doped carbon nanotube
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
Orbital Angular Momentum and Energy Loss Characterization of Plasmonic Excitations in Metallic Nanostructures in TEM
No full textRecently, a new device to measure the orbital angular momentum (OAM) electronic spectrum after elastic/inelastic scattering in a transmission electron microscope has been introduced. We modified the theoretical framework needed to describe conventional low-loss electron energy loss spectroscopy (EELS) experiments in transmission electron microscopes (TEM) to study surface plasmons in metallic nanostructures, to allow for an OAM post selection and devise new experiments for the analysis of these excitations in nanostructures. We found that unprecedented information on the symmetries and on the chirality of the plasmonic modes can be retrieved even with limited OAM and energy resolutions
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
Semianalytical approach to simulations in nanophotonics
No full textNumerické simulace se staly nedílnou součástí procesu navrhování v nanofotonice, což nevyhnutelně vedlo k vývoji softwaru specializovaného pro tento úkol. Ačkoli je zde celá řada komerčně dostupných produktů, mnohé aplikace vyžadují datovou analýzu, která překračuje standardní výbavu těchto nástrojů. Zpracování výsledků simulací je těžištěm této práce, kdy důraz je kladen zejména na vývoj semianalytických modelů ušitých na míru jednotlivým experimentům. Spolu s lepší shodou mezi teorií a měřeními tyto modely poskytují také cenný vhled do studovaných fyzikálních procesů. Hlavní část této práce je věnována plazmonicky zesílené elektronové paramagnetické rezonanci (PE EPR), nové metodě využívající kovové antény pro zesílení interakce mezi zářením a materiály s magnetickými přechody mezi spinovými stavy. Jsou zde objasněny základní principy řídící tento jev a představen model umožňující rychlou optimalizaci polí antén pro PE EPR spektroskopii tenkých vrstev. Zvláštní pozornost je pak věnována roli indukovaného proudu a možnostem, které nabízí při projekcích do dalekého pole nebo počítání elektromagnetické interakce mezi objekty. Toto je dále demonstrováno na několika aplikacích, jmenovitě fázovém zobrazování metapovrchů pomocí koherencí řízeného holografického mikroskopu, designu optického prvku pro generování pole svazků na bázi metapovrchu a multipólové analýze elektromagnetických vln emitovaných objekty nacházejícími se uvnitř multivrstvy.Numerical simulations have become an indispensable part of the design process in nanophotonics, which inevitably led to the development of specialized software dedicated to this task. Although there is a number of capable and commercially available options that can serve that purpose, many applications require data analysis that goes beyond the standardly offered analysis tools. The data post-processing lies at the focus of this thesis, with emphasis on the development of semianalytical models that are tailored specifically to each type of experiment, providing better insight into its physical background and improved agreement between theory and measurements. A major part of the thesis is dedicated to the plasmon enhanced electron paramagnetic resonance (PE EPR), a novel technique employing metallic antennas for enhancing the interaction between light and materials exhibiting magnetic spin transitions. Fundamental principles of this effect are laid down and a model facilitating rapid optimization of antenna arrays for thin film PE EPR spectroscopy is presented. Particular attention is paid to the current distribution and to advantages it offers when dealing with far-field projections and electromagnetic interaction between objects. This is further demonstrated on several applications, namely the phase imaging of metasurfaces using coherence controlled holographic microscope, the design of a metasurface-based fan-out element, and the multipolar analysis of far-fields generated by objects embedded within stratified media.
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
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