1,720,965 research outputs found
Effects of Zr addition on the phase stability of L1(2)-based Al-Ti-Cr alloys
No full textZr was added to the Al-21Ti-23Cr (L1(2)+Cr2Al) alloy to improve the L1(2) phase stability at temperatures around 800 degrees C. It was found that the addition of Zr effectively reduced and delayed the decomposition of the L1(2) matrix into L1(2) and Ti(Cr,Al)(2) phases in the Al-21Ti-23Cr alloy. Furthermore, the temperature range of the L1(2) matrix decomposition was narrowed when Zr was added to. the Al-21Ti-23Cr alloy. It is suggested that improvement of L1(2) phase stability by the addition of Zr could be the result of two factors. First, the movement of the L1(2) single-phase field could be reduced by the addition of Zr, possible decreasing the fraction of L1(2) matrix decomposition. Second, atomic diffusion could be suppressed by the addition of Zr, possible delaying the precipitation of the Ti(Cr,Al)(2) phase in the L1(2) matrix. (C) 2005 Elsevier B.V. All rights reserved
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
Catalytic properties of intermetallic compound Ni3Al foils for hydrogen production by methanol decomposition
No full text
Catalytic properties of Ni3Al foils for methanol decomposition
No full textHydrogen was produced by methanol decomposition over cold-rolled foils of intermetallic compound Ni3Al which is known as an excellent high-temperature structural material. We found high catalytic activity and selectivity for methanol decomposition in flat cold-rolled Ni3Al foils. The catalytic activity was enhanced above 713 K by the spontaneous formation of fine Ni particles dispersed on carbon nanofibers during the reaction, resulting in high catalytic performance. The results demonstrate that the Ni3Al foils can be used both as catalyst precursors and as structural materials of microreactors for hydrogen production
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