1,721,012 research outputs found
Dynamically enhanced magnetodielectric effect and magnetic-field-controlled electric relaxations in La-doped BiMnO3
No full textBi ions of multiferroic BiMnO3 were replaced with La ions in order to induce an overlap of the ferroelectric and ferromagnetic transitions in temperature and thus enhance the interproperty coupling. Twenty percent La-doped BiMnO3 in thin-film form shows a broad ferroelectric transition below 150 K; spontaneous magnetization also develops in the transition region. The saturation magnetization and polarization reach 1.6 mu(B)/Mn and 12 mu C/cm(2) at 5 K, respectively. This new magnetic ferroelectric shows a greatly enhanced magnetodielectric effect in the transition region with maximum 45% at 9 T, which is a 70-fold increase compared to that of the pure bulk compound. It is demonstrated that the magnetodielectric effect is dynamically enhanced due to a phenomenon of magnetic-field controlled electric relaxations
Control of multiferroic phase in Tb1-x(Bi,La,Y)(x)MnO3
No full textThe effects of Bi-substitution in TbMnO3 on structural, magnetic, ferroelectric, and thermal properties were studied. Exotic enhancement of magnetism in Bi3+ substitution is distinguished from the simple dilution effect of magnetic Tb3+ ion with nonmagnetic Y3+ and La3+ replacement. From both structural and magnetic characterizations, we conjectured that the strong local anisotropic distortion around Bi3+ ion due to its 6s(2) tone pair modified neighboring Mn3+ spin configuration, from modulated antiferromagnetic to a ferromagnetic one and induced the formation of fierromagnetic cluster. Both the b-lattice parameter to which the modulation wave vector is parallel and the ferroelectric transition temperature turned out to be very susceptible to Bi-substitution. Controllability of both magnetic and ferroelectric phases suggests a possible route to the simultaneous occurrence of two phase transitions of different origins at the same temperature for the enhanced coupling between magnetism and ferroelectricity. (c) 2006 Elsevier B.V. All rights reserved
New materials search for spintronics applications: Synthesis of BiMn1-xFexO3 films via combinatorial chemistry
No full textThe combinatorial chemistry method that employs multiple metal-masks and shutters in the pulsed laser deposition of thin films was used to synthesize a series of BiMn1-xFexO3 (x = 0-0.4) films on single SrTiO3(001) substrates. The films showed a systematic variation of c-axis x-ray diffraction peaks with a discontinuity at x similar to 0.15. They also possessed narrow full-width-at-half-maximum in the rocking curves. From the temperature dependence of magnetization, we were able to conclude that as substitution of Fe for Mn is increased, antiferromagnetic interaction becomes enhanced with consequent suppression of the ferromagnetic ordering and eventually antiferromagnetic states prevail below 45 K for x > 0.15. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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
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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