1,721,159 research outputs found
Metallorganic chemical vapor deposition of metallic Ru thin films on biaxially textured Ni substrates using a Ru(EtCp)2 precursor
No full textRuthenium (Ru) films on rolling-assisted biaxially textured Ni substrates (RABiTs) were deposited by liquid source chemical vapor deposition using bis-(ethyl-π-cyclopentadienyl)ruthenium (Ru(C2H5C 5H4)2). The thermal decomposition process of the precursor was investigated by Fourier transform infrared spectroscopy (FTIR), mass spectroscopy, and differential scanning calorimetry/ thermogravimetric analyses (DSC/TGA). The crystalline structure and resistivity of Ru thin films were investigated. The Ru films were polycrystalline and had a grainy structure. Although the thermal decomposition of the precursor required a sufficient amount of oxygen, the experimental results showed that up to a certain concentration of oxygen (i.e. O2/Ar ∼ 30/10), Ru metal film was deposited without any detectable RuO2 impurities. A higher deposition temperature and a higher ratio of O2/Ar will be beneficial to the growth of (0 0 2) orientation. They showed a low resistivity of about 10-20 μΩ cm, which is sufficiently low for them to be used as a buffer layer in superconductor tapes or electrode materials in dielectric capacitors.Department of Applied Physic
Study of solid-state reaction of CaCO3 and RuO2 and fabrication of pseudocubic epitaxial thin films by e-beam evaporation
No full textPure CaRuO3 powders were prepared from solid-state reaction using stoichiometric RuO2 (99.9%) and CaCO3 (99.99%) powders. The process of the reaction was investigated employing thermogravimetry analysis and differential scanning calorimetry (TGA and DSC). The solid-state reaction rate increased when the compounds were heated in flowing air/oxygen, as it acted as a catalyst. The phase variations in samples heated at different temperatures were analyzed by X-ray diffraction (XRD) and the alignments of the films studied by XRD-rocking curves and pole-figures. The microstructures of powders were measured by scanning electron microscopy. Biaxially textured CaRuO3 thin films were formed at 700°C by e-beam evaporation, and they showed strong (0 0 1) orientation on SrTiO 3 (1 0 0) substrates.Department of Applied Physic
Structural and electrical characteristics of highly textured oxidation-free Ru thin films by DC magnetron sputtering
No full textTextured Ru thin films (∼120 nm) were deposited on Si and rolling-assisted biaxially textured Ni substrates by a DC magnetron sputtering technique with a two-step process. The biaxially textured pure Ni substrates with a thickness of 80 μm were fabricated by rolling followed by recrystallization. The alignments and the crystallinity of Ru films were analyzed by pole figures, as well as X-ray diffraction (θ - 2θ) analysis. The highly (0 0 2) oriented Ru films were fabricated on Si substrates, and four-fold symmetric Ru films on Ni(2 0 0) substrates. The resistivities of pure metallic Ru films were 20-80 μΩ cm for Ru on Si and 16-40 μΩ cm on Ni, respectively, which is sufficiently low to be used as a buffer layer in superconductor tapes or electrode materials in capacitor dielectrics.Department of Applied Physic
Fatigue fracture-behavior of carbon-fiber-reinforced modified bismaleimide composites
No full textThe fracture toughness and fatigue fracture behaviour of carbon-fiber-reinforced modified bismaleimide (BMI) composites have been studied. These composites were found to have higher fracture toughnes, better damage tolerance and longer fatigue life than carbon-fiber composites with epoxy matrices. Delamination is the major mode of failure in fatigue and it is controlled by the properties of the matrix and interface. The improved performance is dire to the presence of thermoplastic particles in the modified BMI matrix which gives rise to enhanced fiber/matrix adhesion and more extensive plastic deformation. The fatigue behaviour also depends on the stacking sequence, with the multidirectional [45/90/-45/0] fiber-reinforced modified BMI composite having a lower crack propagation rate and longer fatigue life than the unidirectional laminate. This arises because of the constraint on the damage processes due to the different fiber orientation in the plies
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
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