1,721,035 research outputs found
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
Coupled qubits as a quantum heat switch
No full textWe present a quantum heat switch based on coupled superconducting qubits, connected to two LC resonators that are terminated by resistors providing two heat baths. To describe the system, we use a standard second order master equation with respect to coupling to the baths. We find that this system can act as an efficient heat switch controlled by the applied magnetic flux. The flux influences the energy level separations of the system, and under some conditions, the finite coupling of the qubits enhances the transmitted power between the two baths, by an order of magnitude under realistic conditions. At the same time, the bandwidth at maximum power of the switch formed of the coupled qubits is narrowed
Remote meta-selective C-H bromination of arenes using a recyclable Ru-based aminopropyl bifunctional PMO with robust imidazolium bridges
No full textThis systematic study delves into the synthesis and characterization of robust bi-functional aminopropyl-tagged periodic mesoporous organosilica with a high loading of small imidazolium bridges in its framework (PrNH2@R-PMO-IL, ∼2 mmol g−1 of IL). The materials proved to be a reliable and enduring support for the immobilization of Ru species, demonstrating strong performance and excellent selectivity in the meta-bromination of various derivatives of 2-phenylpyridine compounds and other heterocycles, showcasing its effectiveness and robust nature. The synthesized materials were thoroughly characterized to determine their structural properties, such as pore size distribution, loading of organic groups, and surface area, using various analytical techniques. The research aims to improve the catalytic activity of supported ruthenium species in meta-selective bromination reactions through a systematic approach that emphasizes the synergistic effects of the mesoporous structure, concentration of imidazolium incorporated, and aminopropyl functionalization for enhancing the catalytic performance of the supported Ru species in these reactions. Our findings indicate that the developed catalyst system exhibits promise as a recyclable catalyst for meta-C-H activation, offering the potential for multiple reaction cycles and reduced waste production. This study highlights the enhanced catalytic performance and versatility of Ru@PrNH2@R-PMO-IL in comparison with previously documented homogeneous and heterogeneous catalyst systems, even when using lower loading levels. This is particularly evident in meta-C-H bromination of challenging substrates, such as 1-phenylpyrazole for the first time under the described catalytic chemical reaction
Chemical constraints on the genesis and geodynamic setting of Late Cretaceous magmatism in northeast of Tehran, Central Alborz
No full textThe Alborz range is part of Alpine- Himalayan orogenic system which preserved important magmatic features related to the evolution of Gondwana-Eurasia junction realm. Several well-developed sub-marine Cretaceous volcanic units are exposed in Central to Northern Alborz e.g. in Marzan-Abad and Lahijan areas. The volcanics display mainly basaltic composition. Study of chemical signatures of these rocks is a key issue to constrain the tectonomagmatic environment of melt formation and paleogeographic reconstructions. In this research we aim to study the volcanic outcrops located to the northeast of Tehran (south of Amol), Central Alborz. Stratigraphic relationships show that the volcanics are interlayered with marly limestone, limestone and marls of Late Cretaceous. Here, we present new geochemical data on these rocks to identify the origin and condition of magma genesis which helps to infer paleotectonic setting of Alborz magmatism during Late Cretaceous. The major and trace element contents of whole rock samples have been obtained by XRF and ICP-MS at Ferrara University, Italy. Using recalculated anhydrous major elements, the samples display wide range of variation in SiO2 (42-68 wt.%), TiO2 (0.45- 4.7 wt.%), Al2O3 (12.6-18.8 wt.%), Mg# (17.8-49) and Na2O + K2O (2.9-11.7 wt.%), likely reflecting various mineralogy and different degrees of fractionation. Based on Nb/Y (1.8-3.4) and Zr/Ti (0.01-0.29) ratios the rocks plot within alkali basalt, trachy-andesite and trachyte fields. High Zr (83-738 ppm) and Nb (43-111 ppm) contents is also consistent with alkaline nature of the samples. Other incompatible element values shown by normalized multi-element patterns are enriched as well, which is similar to typical within-plate alkaline basalts, such as ocean island basalts (OIB). Furthermore, no negative Nb and Ta relative depletion can be observed in these patterns. In chondrite- normalized REE patterns, the rocks display elevated LREE enrichment with respect to HREE, exemplified by high (La/Yb)N ratio (15-33). Overall, the REE enrichment of the rock suites is 155- 375 and 8.5- 17 times chondrite value for La and Yb, respectively. Using trace element abundances such as Zr, Y, Nb and Ti contents and also the ratios of Zr/P2O5, Nb/Y, Zr/Y, Ti/Y, Th/Yb and Ta/Yb, the basaltic rocks plot in the fields of alkaline and subduction-unrelated OIB-like magmas. Moreover, theoretical modeling using REE ratios e.g. Sm/Yb and La/Yb displays that the parental melt originated from partial melting of deep garnet-bearing enriched mantle with low (<15%) partial melting. Therefore, we conclude that the tectonic environment of melt formation is unrelated to subduction process and mostly corresponds to within-plate magmatism in an extensional setting. This conditions is more probably consistent with hot spot/mantle plume activity and continental rift-related events
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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