1,721,073 research outputs found
Surface-enhanced chiroptical spectroscopy with superchiral surface waves
Full text linkWe study the chiroptical properties of one-dimensional photonic crystals supporting superchiral surface waves by introducing a simple formalism based on the Fresnel reflection matrix. We show that the proposed framework provides useful insights on the behavior of all the relevant chiroptical quantities, allowing for a deeper understanding of surface-enhanced chiral sensing platforms based on one-dimensional photonic crystals. Finally, we analyze and discuss the limitations of such platforms as the surface concentration of the target chiral analytes is gradually increased
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
EXPERIMENTAL AND THEORETICAL SURFACE COMPONENT OF THE PL2,3VV AUGER LINESHAPE IN GAP(110) - THE USE OF ORDERED (1X1) SB OVERLAYERS
No full textAn analysis of the theoretical and experimental surface contribution of the PL2,3VV Auger lineshape in GaP(110) is performed. From the theoretical point of view the lineshapes are calculated within a single-particle framework from a slab-by-slab tight-binding calculation of the ideal and real relaxed surfaces. The experimental information is extracted by comparing the Auger feature of as-cleaved GaP(110) and of the GaP(110) interfaced with one ordered monolayer of Sb. This allows the LVV surface component to be isolated. A comparison with theory, showing strong similarities in the position of the surface-related features is discussed
RESOLVING THE SURFACE CONTRIBUTION OF THE P L2, 3 VV AUGER LINESHAPE OF GAP(110) VIA USE OF (1 X-1) SB OVERLAYERS
No full textAn experimental and theoretical study of the band-like P L2,3VV Auger lineshape for GaP(110) is reported (kinetic energy almost-equal-to 120eV). By deposition of one monolayer of Sb (isoelectronic to P) we determine the surface-related Auger lineshape as the difference between the two spectra measured from the as-cleaved surface and the GaP/Sb interface. Theoretical calculations based on a single particle approach including different structural coordination models (i.e. ideally truncated surface, real relaxed surface, ordered Sb overlayer) are performed, which allows to isolate the surface contribution of the L2,3VV Auger profile from the bulk related lineshape. Moreover the results of the joint analysis are discussed giving excellent agreement between calculations and measurements and pointing toward an interpretation of the P LVV lineshape in terms of surface structural probe
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
Chiral surface waves for enhanced circular dichroism
No full textWe present a novel chiral sensing platform that combines a one-dimensional photonic crystal design with a birefringent surface defect. The platform sustains simultaneous transverse electric and transverse magnetic surface modes, which are exploited to generate chiral surface waves. The present design provides homogeneous and superchiral fields of both handednesses over arbitrarily large areas in a wide spectral range, resulting in the enhancement of the circular dichroism signal by more than two orders of magnitude, thus paving the road toward the successful combination of surface-enhanced spectroscopies and electromagnetic superchirality
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
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