1,721,023 research outputs found
Pressure weakens coupling strength in In and Sn elemental superconductors
Full text linkThe pressure dependence of the thermodynamic critical field Bc in elemental indium (In) and tin (Sn)
superconductors was studied by means of muon-spin rotation/relaxation. Pressure enhances the deviation of
Bc(T) from the parabolic behavior expected for a typical type-I superconductor, suggesting a weakening of the
coupling strength α = kbTc ( is the average value of the superconducting energy gap, Tc is the transition
temperature, and kB is the Boltzmann constant). As pressure increases from 0.0 to = 3.0 GPa, alfa decreases linearly,
approaching the limiting weak-coupling Bardeen-Cooper-Schrieffer (BCS) value alfaBCS =1.764. Analysis
of the data within the framework of Eliashberg theory reveals that only part of the pressure effect on alfa can
be attributed to the hardening of the phonon spectra, reflected by a decrease in the electron-phonon coupling
constant. Nearly 40% of the effect is caused by an increased anisotropy of the superconducting energy gap
Perspective on the muon-spin rotation/relaxation under hydrostatic pressure
Full text linkPressure, together with temperature, electric and magnetic fields, alters the
system and allows to investigate the fundamental properties of the matter.
Under applied pressure the interatomic distances shrink, which modify
interactions between atoms and may lead to appearance of a new (sometime
exotic) physical properties as, e.g., pressure induced phase transition(s);
quantum critical points(s), new structural, magnetic and/or superconducting
states; changes of the temperature evolution and the symmetry of the order
parameter(s) etc. The muon-spin rotation/relaxation (SR) appears to be a
commonly used powerful technique allowing to study the magnetic and
superconducting responses of various materials under extreme conditions. At
present, SR experiments might be performed under the high magnetic field
up to T, temperatures down to mK and hydrostatic
pressure up to GPa. In the following Perspective paper the
requirements to the SR under pressure experiments, the existing
high-pressure muon facility at the Paul Scherrer Institute (Switzerland), and
selected experimental results obtained by using the SR under pressure
technique are discussed.Comment: 14 pages, 14 figure
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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