1,721,049 research outputs found
Data for "Rotation of gap nodes in the topological superconductor Cux(PbSe)5(Bi2Se3)6"
No full text<p>Raw data files for all figures presented in the paper.</p>
Field dependence of the magnetic spectrum in anisotropic and Dzyaloshinskii-Moriya antiferromagnets. II. Raman spectroscopy
No full textWe compare the theoretical predictions of the previous paper on the field dependence of the magnetic spectrum in anisotropic two-dimensional and Dzyaloshinskii-Moriya layered antiferromagnets [L. Benfatto and M. B. Silva Neto, Phys. Rev. B 74, 024415 (2006)], with Raman spectroscopy experiments in Sr2CuO2Cl2 and untwinned La2CuO4 single crystals. We start by discussing the crystal structure and constructing the magnetic point group for the magnetically ordered phase of the two compounds, Sr2CuO2Cl2 and La2CuO4. We find that the magnetic point group in the ordered phase is the m_mm_ orthorhombic group, in both cases. Furthermore, we classify all the Raman active one-magnon excitations according to the irreducible co-representations for the associated magnetic point group. We find that the in-plane (or Dzyaloshinskii-Moriya) mode belongs to the DA(g) co-representation while the out-of-plane (XY) mode belongs to the DBg co-representation. We then measure and fully characterize the evolution of the one-magnon Raman energies and intensities for low and moderate magnetic fields along the three crystallographic directions. In the case of La2CuO4, a weak-ferromagnetic transition is observed for a magnetic field perpendicular to the CuO2 layers. We demonstrate that from the jump of the Dzyaloshinskii-Moriya gap at the critical magnetic field H-c similar or equal to 6.6 T one can determine the value of the interlayer coupling J(perpendicular to)/J similar or equal to 3.2x10(-5), in good agreement with previous estimates. We furthermore determine the components of the anisotropic gyromagnetic tensor as g(s)(a)=2.0, g(s)(b)=2.08, and the upper bound g(s)(c)=2.65, also in very good agreement with earlier estimates from magnetic susceptibility. For the case of Sr2CuO2Cl2, we compare the Raman data obtained in an in-plane magnetic field with previous magnon-gap measurements done by electron spin resonance (ESR). Using the very low magnon gap estimated by ESR (similar to 0.05 meV), the data for the one-magnon Raman energies agree reasonably well with the theoretical predictions for the case of a transverse field (only hardening of the gap). On the other hand, an independent fit of the Raman data provides an estimate for g(s)similar or equal to 1.98 and gives a value for the in-plane gap larger than the one measured by ESR. Finally, because of the absence of the Dzyaloshinskii-Moriya interaction in Sr2CuO2Cl2, no field-induced modes are observed for magnetic fields parallel to the CuO2 layers in the Raman geometries used, in contrast to the situation in La2CuO4. (c) 2006 American Institute of Physics
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
Brain-grounded theory of temporal and spatial design: in architecture and the environment
No full textIn this book, brain-grounded theory of temporal and spatial design in architecture and the environment is discussed. The author believes that it is a key to solving such global problems as environmental disorders and severe climate change as well as conflicts that are caused by the ill-conceived notion of “time is money”. There are three phases or aspects of a person’s life: the physical life, the spiritual or mental life, and the third stage of life, when a person moves from middle age into old age and can choose what he or she wishes to do instead of simply what must be done. This book describes the temporal design of the environment based on the theory of subjective preference, which could make it possible for an individual to realize a healthy life in all three phases. In his previously published work, the present author wrote that the theory of subjective preference has been established for the sound and visual fields based on neural evidence, and that subjective preference is an overall response of cooperating temporal and spatial factors, associated with the brain’s left and right hemispheres, respectively. In this book, based on that theory, some examples are shown for the temporal design of architecture and the environment, which may play important roles in the development of personality, thus inducing creativity. Also discussed is how all individuals may find their own personality and develop it according to the preferred direction of their individual lives
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