1,720,965 research outputs found
Engineering the magnetic properties of hybrid organic-ferromagnetic interfaces by molecular chemical functionalization
Get PDFWe have performed systematic first-principles calculations to tailor the magnetic properties at a hybrid organic-ferromagnetic interface by adsorbing organic molecules containing π(p[subscript z]) electrons onto a magnetic substrate. For such hybrid systems, magnetic properties such as molecular magnetic moments and their spatial orientation can be specifically tuned by substituting the H atoms with more electronegative atoms such as Cl and F. This chemical functionalization process surprisingly reveals the importance of the spin-orbit coupling present at the magnetic surface–molecule interface. As a key result, our simulations indicate a direct connection between substituent electronegativity and these magnetic properties which can be exploited to design more efficient organic spintronic devices.Deutsche Forschungsgemeinschaft (DFG
Prediction of solid-aqueous equilibria: Scheme to combine first-principles calculations of solids with experimental aqueous states
Get PDFWe present an efficient scheme for combining ab initio calculated solid states with experimental aqueous states through a framework of consistent reference energies. Our work enables accurate prediction of phase stability and dissolution in equilibrium with water, which has many important application areas. We formally outline the thermodynamic principles of the scheme and show examples of successful applications of the proposed framework on (1) the evaluation of the water-splitting photocatalyst material Ta3N5 for aqueous stability, (2) the stability of small nanoparticle Pt in acid water, and (3) the prediction of particle morphology and facet stabilization of olivine LiFePO[subscript 4] as a function of aqueous conditions.United States. Dept. of Energy. (Contract number DEAC02- 05CH11231)United States. Dept. of Energy. (Grant No. DE-FG02-96ER45571
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
First principles high throughput screening of oxynitrides for water-splitting photocatalysts
No full textIn this paper, we present a first principles high throughput screening system to search for new water-splitting photocatalysts. We use the approach to screen through nitrides and oxynitrides. Most of the known photocatalytic materials in the screened chemical space are reproduced. In addition, sixteen new materials are suggested by the screening approach as promising photocatalysts, including three binary nitrides, two ternary oxynitrides and eleven quaternary oxynitrides.United States. Dept. of Energy (contract DE-FG02-96ER4557)National Science Foundation (U.S.) (TeraGrid resources under Grant No. TG-DMR970008S)Pittsburgh Supercomputing CenterUniversity of Texas at Austin. Texas Advanced Computing CenterEni-MIT Solar Frontiers Cente
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
SOLVING FOR MICRO- AND MACRO-SCALE ELECTROSTATIC CONFIGURATIONS USING THE ROBIN HOOD ALGORITHM
No full textWe present a novel technique by which highly-segmented electrostatic configurations can be solved. The Robin Hood method is a matrix-inversion algorithm optimized for solving high density boundary element method (BEM) problems. We illustrate the capabilities of this solver by studying two distinct geometry scales: (a) the electrostatic potential of a large volume beta-detector and (b) the field enhancement present at surface of electrode nano-structures. Geometries with elements numbering in the O(105) are easily modeled and solved without loss of accuracy. The technique has recently been expanded so as to include dielectrics and magnetic materials.United States. Dept. of Energy (Grant No. DE-FG02-06ER-41420)Germany. Federal Ministry of Education and Research ((BMBF) under contract Nr. 05CK5VKA/5
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
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