1,721,116 research outputs found
Catalysis, God's Algorithm, and the Green Demon
Get PDFWaarom gooide God Adam en Eva uit het paradijs? Wilde hij voorkomen dat het tweetal toegang kreeg tot zijn algoritme? Kan een verkleinde, menselijke versie van dit algoritme het grootste chemische bedrijf ter wereld helpen om een goede katalysator te vinden voor de reactie dat het meedraagt in zijn naam? Gadi Rothenberg behandelt deze vragen in zijn oratie en bespreekt bovendien of Newtons wetten van de zwaartekracht in het geheim worden gecontroleerd door 'de groene duivel'. De voertaal van oratie is Engels
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
Highly Selective Oxidation of Ethyl Lactate to Ethyl Pyruvate Catalyzed by Mesoporous Vanadia–Titania
Get PDFThe
direct oxidative dehydrogenation of lactates with molecular
oxygen is a “greener” alternative for producing pyruvates.
Here we report a one-pot synthesis of mesoporous vanadia–titania
(VTN), acting as highly efficient and recyclable catalysts for the
conversion of ethyl lactate to ethyl pyruvate. These VTN materials
feature high surface areas, large pore volumes, and high densities
of isolated vanadium species, which can expose the active sites and
facilitate the mass transport. In comparison to homogeneous vanadium
complexes and VOx/TiO2 prepared
by impregnation, the meso-VTN catalysts showed superior activity,
selectivity, and stability in the aerobic oxidation of ethyl lactate
to ethyl pyruvate. We also studied the effect of various vanadium
precursors, which revealed that the vanadium-induced phase transition
of meso-VTN from anatase to rutile depends strongly on the vanadium
precursor. NH4VO3 was found to be the optimal
vanadium precursor, forming more monomeric vanadium species. V4+ as the major valence state was incorporated into the lattice
of the NH4VO3-derived VTN material, yielding
more V4+–O–Ti bonds in the anatase-dominant
structure. In situ DRIFT spectroscopy and density functional theory
calculations show that V4+–O–Ti bonds are
responsible for the dissociation of ethyl lactate over VTN catalysts
and for further activation of the deprotonation of β-hydrogen.
Molecular oxygen can replenish the surface oxygen to regenerate the
V4+–O–Ti bonds
Book Review: Catalysis and Electrocatalysis at Nanoparticle Surfaces. Editors A. Wieckowski, E. R. Savinova and C. G. Vayenas
No full textDispelling 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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