1,720,963 research outputs found
Accelerated search for thermoelectric and topological materials using first-principles and machine learning
No full textIn summary, we have performed first-principles calculations to study the topological phase transitions
in chalcopyrite compounds as a function of hydrostatic pressure. These compounds are
topological insulators in the native phase with an inverted band order around BZ center. Upon
hydrostatic compression, there is a transition from nontrivial TI phase to a Dirac semimetallic
state at a critical pressure. Further increase in pressure drives the materials into a trivial semiconductors
along with normal ordering of bands. Different quantum phases are characterized
by topological invariants as well as surface states. These quantum phase transitions are further
validated by model calculations based on L¨uttinger Hamiltonian, which unravels the critical
role played by pressure-induced anisotropy of frontier bands in driving the phase transitions.
Such a manoeuvre between various topological phases by hydrostatic pressure can stimulate
the search for TQPTs in future experiment
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Rattling-Induced Ultralow Thermal Conductivity Leading to Exceptional Thermoelectric Performance in AgIn5S8
No full textRattling has emerged as one of the most significant phenomenon for notably reducing the thermal conductivity in complex crystal systems. In this work, using first-principles density functional theory, we found that rattlers can be hosted in simpler crystal systems such as AgIn(5)S(8 )and CuIn5S8. Rattlers Ag and Cu exhibit weak and anisotropic bonding with the neighboring In and S and reside in a very shallow anharmonic potential well. The phonon spectra of these compounds have multiple avoided crossing of optical and acoustic modes, which are a signature of rattling motion. This leads to ultralow thermal conductivity, which is inversely proportional to mass and frequency span of rattling modes. Even though Ag atoms contribute to the valence band states, the rattler modes of Ag do not scatter carriers significantly, leaving the electronic transport virtually unaffected. Moreover, AgIn5S8 possesses a combination of heavy and light valence bands resulting in a very high power factor. A combination of favorable thermal and electronic transport results in a very high figure of merit of 2.2 in p-doped AgIn5S8 at 1000 K. The proposed idea of having rattlers in simpler systems can be extended to a wider class of materials, which would accelerate the development of thermoelectric modules for waste energy harvesting
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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