1,720,974 research outputs found
New method for designing narrow-band reflecting filters with application in optical integration
No full textGraphene/Cu composites: Electronic and mechanical properties by first-principles calculation
No full textGraphene characterized with ultrahigh intrinsic strength and excellent electronic properties is an ideal material to reinforce metals without despairing their thermal and electrical properties. Here, the electronic and mechanical properties of graphene intercalated copper (graphene/Cu) composites are investigated using density functional theory calculations. Graphene/Cu systems present an excellent electrical conductivity and increasing Debye temperature from 335 K for pure Cu to over 535 K in regardless of stacking models. In addition to greatly enhanced Young's modulus (149%), shear modulus (156%) and bulk modulus (108%) compared to copper, the ultimate strength of graphene/Cu composites are enhanced by 174% and 162%, in x and y directions, respectively. The strengthening and toughening effects of graphene in the composites is originated from strain strengthening and load transfer, which is consistent with the experimental results. Based on this calculation, the strengthening mechanism can be understood, which explains many experimental observations and also provides us a guide to improve graphene/metal composites quality
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
Twin density gradient induces enhanced yield strength-and-ductility synergy in a S31254 super austenitic stainless steel
No full textGradient structure (GS), as a typical heterostructure, is arousing great interest for an improved synergy between the strength and ductility which are mutually conflicting. Recently, a novel design of GS is proposed by taking the density of twins in grains, instead of common grain size, as a gradient variable, showing the key role in strain hardening by the nano-scale twin boundaries. Following this idea, here, a deformation twin-density GS was produced by means of the technique of surface mechanical attrition treatment in a S31254 super austenitic stainless steel. To be specific, the GS consisted of a central coarse-grained (CG) core, with two sides sandwiched by the gradient-structured layer (GL), where the density of deformation twins appears gradient in grains along the depth towards the CG core. The tensile tests show that as compared to CG counterpart, yield strength in GS increases 80% to 0.5 GPa, along with comparable ductility of 36%. The interrupted tensile tests show the presence of mechanical hysteresis loops during each unload-reload cycle, indicative of the generation of heterodeformation-induced (HDI) stress during tensile deformation. Furthermore, both the HDI stress and HDI strain hardening account for a large proportion of global flow stress and forest hardening. The deformation twins and their evolutions, with the emphasis on their interaction with the dislocations, are investigated in detail by means of EBSD and TEM observations to correlate the mechanical properties. The present results shed light on the crucial role of deformation twins in the twin-density gradient for the synergistic enhancement of both strength and ductility
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
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
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
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
- …
