1,720,975 research outputs found
CuCl-catalyzed radical cyclisation of N-a-pechloroacyl-ketene-N,S-acetals: a new way to prepare disubstituted maleic anhydrides
No full textThe discovery that cycloalkanes can form thermomorphic systems with typical polar organic solvents has
led to the development of less-polar electrolyte solutions. Their mixing and separation can be regulated
reversibly at a moderate temperature range. The phase switching temperature can be controlled by
changing the solvent compositions. While biphasic conditions are maintained below the phase switching
temperature, conductive monophasic conditions as less-polar electrolyte solutions are obtained above
the phase switching temperature. After the electrochemical transformations, biphasic conditions are
reconstructed below the phase switching temperature, facilitating the separation of cycloalkane where
hydrophobic products or designed hydrophobic platforms are selectively partitioned. Several polar organic
solvents, including acetonitrile, methanol, and pyridine, can be used in this system according to the
requirement of the reactions
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
Poly(ethylene glycol)-supported copper(II) triazacyclononane: an efficient, recoverable, and recyclable catalyst for the cleavage of a phosphodiester
No full text1,3,5-Triazacyclononane macrocycle has been linked to the soluble polymer monomethoxy poly(ethyleneglycol) and its copper(II) complex efficiently catalyzes the hydrolysis of a model phosphodiester. The catalyst, easily recovered from the water solution, shows no appreciable loss of activity when recycled up to three times
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
Breakthrough in the alfa-perchlorination of acyl chlorides
No full textThe preparation of -perchloroacyl chlorides, from reaction of the corresponding unfunctionalized acyl halides with chlorine, was efficiently achieved under base-catalysis, using a tetraalkylammonium chloride as catalyst. The process is solvent-free and the procedure is easy, inexpensive, and suitable for scale-up
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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