1,720,960 research outputs found
The growth of ultrathin films of vanadium oxide on TiO2(110)
Full text linkThe growth morphology of ultrathin (up to 5 ML) vanadium oxide films on TiO2(1 1 0) has been investigated by scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED). It has been found that the reactive evaporation technique produces more uniform and better-ordered vanadia layers than the post-oxidation method. At low coverages V-oxide clusters adsorb on top of the fivefold-coordinated Ti rows of the substrate. With increasing coverage the clusters agglomerate and form strands, which are oriented along the [0 0 1] titania direction. For oxide coverage >2 ML the strands cover uniformly the titania substrate, forming a texture along the [0 0 1] direction, and give rise to a (1 · 1) LEED pattern. The latter is consistent with the growth of an epitaxial rutile-type VO2 phase
Vanadium on TiO2(110): adsorption site and sub-surface migration
No full textThe initial stages of the growth of vanadium overlayers on TiO2(1 1 0) at room temperature have been investigated with scanning tunneling microscopy. At very low coverages both individual vanadium adatoms and small vanadium clusters have been imaged with good resolution. The V adatoms adsorb preferentially on the so-called “upper threefold hollow” sites, as revealed by atomically resolved STM images: they are thus bonded to two bridging oxygen atoms and one threefold coordinated basal oxygen atom. At higher coverages the vanadium adlayers grow in form of poorly ordered three-dimensional islands. The number of V clusters at low coverages decreases by gentle annealing or with time even at room temperature. This kinetic effect has been interpreted in terms of sub-surface migration of V adatom
Strain relaxation and surface morphology of nickel oxide nanolayers
No full textThe surface morphology and the lattice constants of NiO overlayers in the thickness range of 1–20 monolayers (NiO nanolayers) on Pd(1 0 0) have been investigated by high-resolution spot profile low-energy electron diffraction (SPA-LEED) and scanning tunneling microscopy (STM). NiO islands grow epitaxially on Pd(1 0 0) on top of a c(4 × 2) Ni3O4 monolayer with a compressed strained lattice, which relaxes gradually attaining the bulk lattice constant at 10–12 monolayers. The strain relaxation is accompanied by the formation of small angle mosaic defect regions at the surface, which have been characterised quantitatively by following the behaviour of the satellites to the main Bragg diffraction rods. The analysis of the diffuse scattering intensity around the (0 0) diffraction spot reveals anisotropic NiO island shapes, whose orientation depends on the growth conditions. An incommensurate superlattice in LEED and STM at intermediate NiO coverages (∼2–6 monolayers) is observed and its origin is discussed
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
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