1,720,991 research outputs found
Vibron propagation and localization determined from infrared combination bands of molecular crystals
No full textTRANSLATIONAL AND ROTATIONAL SPECTRA IN THE FUNDAMENTAL INFRARED BAND OF LIQUID AND SOLID PARAHYDROGEN
No full textThe Q1(0) and Q1(0)+S0(0) infrared bands have been studied in liquid and solid para-H-2 with particular regard to their translational sidebands. In the liquid, their line shapes are well fitted by a model in which the excited particle is encapsulated. In the solid, the phonon sidebands reproduce the main features of the density of states (DOS), as extracted from neutron scattering. The S1(0)+S0(0) band shows a pure rotonic line shape which is well described by recent DOS calculations
FAR-INFRARED SPECTRA OF N2-AR ALLOYS
No full textThe far-infrared spectra of (N2)1-xArx solid mixtures have been studied at 18 K and p=0 for 0<x<0.25. At x=0, in addition to the phonon peaks Tu(1) and Tu(2), the combination bands recently observed at high pressure have been detected. In the alloy, the width of Tu(1) increases with x while its central frequency slowly decreases. In the phase (x=0.25) a translational mode still exists, which can be derived from the Tu(1) mode of the phase. Tu(2) is nearly insensitive to the concentration of impurities, but it disappears at the - transition. A concentration x=0.05 of Kr atoms is found to enhance the intensity of absorption in solid N2 by a factor of 5. © 1989 The American Physical Society
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
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
The near-infrared spectrum of solid CH4
No full textThe infrared absorption spectrum of CH4 from 4000 to 12 000 cm−1 has been first studied in the solid phases I and II. More than forty overtone and combination bands, up to the sixth order, have been observed. Some of them are weaker by a factor of ≊105 than the infrared fundamentals. The bands have been assigned on the basis of their frequency, structure, and intensity. Features that can be attributed to propagating vibrons have been observed. The rotovibrational lines of molecules at Oh sites of phase II have been resolved in a few bands, and their relative intensities are in excellent agreement with the predictions of the extended James and Keenan model. The results reported here may help to analyze more complicated spectra, as those of CH4 in planetary atmospheres
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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