1,720,978 research outputs found
Inhibitive action of some dibenzofuran derivatives on corrosion of iron in sulphuric acid media.
No full text
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
Synthesis and cyclization reactions of platinum(Il)-coordinated arsonium-substituted phenyl isocyanides, o-(I-R3As+-CH2)C6H4N C
No full textThe arsonium-substituted isocyanides, o-(I-R3As+CH2)C6H4NC (AsR3 = AsPh3, L-1; AsMePh2, L-2; AsMe2Ph, L-3), were prepared by reaction of o-(chloromethyl)phenyl isocyanide, o-(CH2Cl)C6H4NC, with a slight molar stoichiometric amount of the arsine in the presence of a Mold excess of NaI in acetone at room temperature. The isocyanides L-1-L-3 coordinate to some Pt(II) complexes such as trans-[PtX{o-(I-R3As+CH2)C6H4NC}(PPh3)2] [BF4] (AsR3 = AsPh3, 1; AsMePh2, 2; AsMe2Ph, 3; X = Cl, I) and [PtX {o-(I-R3As+CH2)C6H4NC}(Ph2PCH=CHPPh2)] [BF4] (AsR3 = AsMePh2, 4; X = Cl, I). Complexes 2-4 are converted in CH2Cl2 at room temperature in the presence of NEt3 to the corresponding indolidin-2-ylidene derivatives trans-[PtX{CN(H)-o-C6H4C(AsR3)}(PPh3)2]BF4] (AsR3 =AsPh3, 5; AsMePh2, 6; AsMe2Ph, 7) and [PtX{CN(H)-o-C6H4(AsMePh2)}(Ph2PCH=CHPPh2)][BF4] (8). (C) 2004 Elsevier B.V. All rights reserved
Azione inibitrice di alcuni derivati del dibenzofurano nella corrosione del ferro in acido solforico
No full textN-heterocyclic carbenes from transition metal coordinated functional isocyanides of the type o-(CH2Y)C6H4N C (Y=OSiMe3, OH; N-3; AsR3+)
No full textThe synthesis, transition metal coordination and reactivity of the functional isocyanides o-(CH2Y)C6H4-N&3bond; C (Y = OSiMe3, OH; N-3; AsR3+) to afford N-heterocyclic carbenes is shortly reviewed
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
Baeyer-Villiger Oxidation of Ketones Catalyzed by Platinum(II) Lewis Acid Complexes Containing Coordinated Electron-poor Fluorinated Diphosphines
No full textNew hydroxo-bridged platinum(II) complexes of the type [P(μ-OH)(P-P)]2[BF4]2, containing fluorinated diphosphines, are used in the Baeyer−Villiger oxidation of 2-methylcyclohexanone using 35% hydrogen peroxide as oxidant. IR data of the isocyanide group in complexes of the type [PtCl(CN-2,6-(CH3)2C6H3)(P-P)][BF4] have allowed us to investigate the Lewis acidity of the complexes. A correlation is found between the electrophilicity of the metal center and the catalytic activity of complexes in the Baeyer−Villiger oxidation of ketones
- …
