1,720,991 research outputs found
Comparative study of Li(Li1/3Ti5/3)O-4 and Li(Ni1/2-xLi2x/3Tix/3)Ti3/2O4 (x=1/3) anodes for Li rechargeable batteries
No full textA solid solution of spinel (2/3)Li(Li1/3Ti5/3)O-4-(1/3)Li(Ni1/2Ti3/2)O-4 was prepared, and its structural/electrochemical properties were compared with Li(Li1/3Ti5/3)O-4 to identify the effect of doping to the structural invariance of Li(Li1/3Ti5/3)O-4. The solid solution retained the zero strain characteristic of Li(Li1/3Ti5/3)O-4 during discharge/charge with an excellent cycle stability, while the rate capability was notably improved. However, a reversible broadening of the XRD peak was observed at the end of discharge, indicating some structural changes. XANES measurements showed that the oxidation state of Ti was +4 and that of Ni was +2 in the solid solution. (C) 2009 Elsevier Ltd. All rights reserved.N
Flexible quasi-solid-state lithium-ion capacitors employing amorphous SiO2 nanospheres encapsulated in nitrogen-doped carbon shell as a high energy anode
No full textLithium-ion hybrid capacitors (LICs) take the advantage of simultaneous high energy – power output, and become increasingly important for next generation applications. Developing a high performing LICs with high energy-power-cycle combination remains a significant challenge due to low capacity intercalation electrodes, and kinetically sluggish alloying type electrodes. A strategy employing fast pseudocapacitive lithium ion storage in high-capacity alloying type anode, rather than a bulk storage, can output kinetically superior LICs with high energy even at high power conditions. Herein, we demonstrate a highly interconnected 3-dimensional (3D) SiO2 nanospheres embedded Nitrogen-doped carbon shell with fast lithium ion storage kinetics as high performing anode for LICs. As a result, LIC with a high energy (139 Wh kg−1), high power density (42 kW kg−1), and super stability (20,000 cycles) is obtained, outperforming previously studied alloying type metal oxide and sulfide anodes. A flexible LICs is further demonstrated which shows good stability under different bending conditions. The current research promotes the practical utilization of earth-abundant material as a high capacity and high rate electrode for the next-generation flexible and wearable devices. © 20201
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
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
Electrochemical Performance and ex situ Analysis of ZnMn2O4 Nanowires as Anode Materials for Lithium Rechargeable Batteries
No full textOne-dimensional ZnMn2O4 nanowires have been prepared and investigated as anode materials in Li rechargeable batteries. The highly crystalline ZnMn2O4 nanowires about 15 nm in width and 500 nm in length showed a high specific capacity of about 650 mAh.g(-1) at a current rate of 100 mA.g(-1) after 40 cycles. They also exhibited high power capability at elevated current rates, i.e., 450 and 350 mAh.g(-1) at current rates of 500 and 1000 mA.g(-1), respectively. Formation of Mn3O4 and ZnO phases was identified by ex situ X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies after the initial discharge-charge cycle, which indicates that the ZnMn2O4 phase was converted to a nanocomposite of Mn3O4 and ZnO phases immediately after the electrochemical conversion reaction.close687
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