1,721,035 research outputs found
Editorial: Nanobiophotonics and Related Novel Materials Aimed at Biosciences and Biomedicine
Full text linkEditorial on the Research Topic
Nanobiophotonics and Related Novel Materials Aimed at Biosciences and Biomedicin
Dynamical medium depletion in high-order above-threshold ionization with few-cycle laser pulses
No full textThe influence of dynamical medium depletion in high-order above-threshold ionization (ATI) in left/right asymmetry of photoelectron energy spectra is analyzed. Based on a classical analysis of high-order ATI electrons produced by few-cycle laser pulses, calculated asymmetry maps of electron spectra reproduce very well the experimental results reported in Lindner [Phys. Rev. Lett. 92, 113001 (2004)], utilized for determining the Guoy phase shift of few-cycle laser pulses. The anomalous behavior of the high-energy part of the ATI electron spectra is, then, fully understood in terms of earlier medium depletion occurring in the leading edge of the laser pulse. In order to correctly reproduce the experimental findings a physical temporal envelope of the laser pulse, which only vanishes at the infinity, plays a crucial role.The authors (C.H.N and V.T.) acknowledge the support of
the Science and Technology Ministry of Korea through the
Creative Research Initiative Progra
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
Thermal and nonthermal ion emission during high-fluence femtosecond laser ablation of metallic targets
No full textWe have investigated the emission of positive ions from metallic targets irradiated with intense, ultrashort laser pulses (approximate to 120 fs) at 780 nm, in both S and P polarized states. The measured energy spectra show the presence of a nonthermal, high-energy (several keV) ion component accompanying low-energy ions (tens of eV) produced by a thermal mechanism. The yield of the high-energy component shows a strong dependence on both laser fluence and light polarization. For the low-energy component a higher ablation efficiency was observed for P polarization, and ascribed to a more effective absorption mechanism active during the laser-target interaction. (C) 2000 American Institute of Physics. [S0003-6951(00)02549-3]
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
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