1,721,046 research outputs found
Cr, Sn and Ag/SnO2 interface formation studied by synchrotron radiation induced UPS
No full textThe room temperature (RT) formation of the interface between metals (Cr, Sn, Ag) and the SnO2 surface was studied by Synchrotron Radiation induced UPS. The Sn4d core level and the Valence Band were monitored as a function of metal growth starting from submonolayer regime. At low monolayer coverages a redox reaction with different rate and evolution depending on metal reactivity, arises between the Cr and Sn atoms and the SnO2 surface, oxidizing the overlayer and reducing the Sn cation at the interface. Deposition of less reactive Ag film leaves the stoichiometry of the substrate unchanged. However, in this case as well as for Cr, at high metal coverage the metallic tin segregation is observed
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
A spectroscopic and ab initio study of the formation of graphite and carbon nanotubes from thermal decomposition of silicon carbide
No full textOn the hydrophilic/hydrophobic character of carbonaceous nanoparticles formed in laminar premixed flames
No full textCarbon nanoparticles in laminar premixed flames are broadly divided into two classes based on the bimodal shape of the particle size distribution and on the different chemical and physical properties that these particles present depending on the combustion conditions, such as residence time, equivalence ratio, and fuel chemical composition. The chemical and structural characteristics of carbon nanoparticles have been the subject of numerous works because these properties might be of relevance for particle reactivity and optical properties. Few information are available on their hydrophilic properties although these are of relevance for the human health, the climate change, in addition to the technological implementation of condensation nuclei particle counters in aerosol science, water scrubbers and electrostatic precipitators. The aim of this work is to investigate the hydrophilic/hydrophobic behavior of carbon nanoparticles formed in different flame conditions. Static contact angle measurements in addition to chemical and physical characterization of the carbon nanoparticles have been implemented. Results show that nanoparticles formed in richer flame conditions, are the most hydrophobic, whereas nanoparticles of organic carbon, formed in relatively leaner flame condition, appeared to be the most hydrophilic. The reason for a different water affinity of particles, and especially of the smaller organic carbon nanoparticles, has been discussed by analyzing the different material in terms of their chemical/structural composition and in terms of surface functionalities. While no significant differences have been found by Raman spectroscopy in terms of their carbon structure, the different hydrophilicity is explained in terms of the different amount of surface oxygen detected by X-ray photoelectron spectroscopy (XPS). Combustion conditions are therefore very important in outlining the hydrophilic/hydrophobic tendency of the carbon particles
Photoelectron Diffraction Study of the Low-Temperature, Low-coverage Oxygen Layer on Rh(110)
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