1,721,039 research outputs found
CVD of Copper Oxides from a beta-Diketonate Diamine Precursor: Tailoring the Nano-Organization
No full textA copper(II) hexafluoroacetylacetonate (1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, hfa) adduct with N,N,N′,N′-
tetramethylethylenediamine (TMEDA) [Cu(hfa)2 ·TMEDA] is used for the first time as precursor for the chemical vapor deposition
(CVD) of copper oxide nanosystems. The syntheses are carried out under both O2 and O2+H2O reaction atmospheres on Si(100)
substrates, at temperatures ranging between 250 and 550 °C. Subsequently, the interrelations between the preparative conditions and
the system composition, nanostructure, and morphology are elucidated by means of complementary analytical techniques [Fourier
transform infrared spectroscopy (FT-IR), X-ray photoelectron and X-ray excited auger electron spectroscopies (XPS and XE-AES),
glancing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FESEM), transmission electron
microscopy (TEM)]. The obtained data revealed a gradual transformation from Cu2O, to Cu2O + CuO, to CuO nanosystems upon
increasing the deposition temperature from 250 to 550 °C under both growth atmospheres. Such a phenomenon was accompanied
by a progressive morphological evolution from continuous films to 1D hyperbranched nanostructures. Water vapor introduction in
the deposition environment enabled to lower the deposition temperature and resulted in a higher aggregate interconnection, attributed
to a higher density of nucleation centers
Dynamics of nanoclustering in Te+ implanted Si after application of high frequency electromagnetic field and thermal annealing
No full textTellurium nanoclusters were synthesized in (100) Si by ion implantation followed by annealing for 60 min with a 0.45 MHz high-frequency electromagnetic field. The results were compared with previous ones for a 30 min treatment. Structural studies were done by cross-sectional high resolution transmission electron microscopy and fast Fourier transformation of the images. The results show that for the 60 min treatment, the dynamics of nanocluster formation change, larger clusters are observed, some of which crystallized and were separated by high-resistive areas of amorphous Si. The structural changes are correlated with the electrical resistance as measured by ac impedance spectroscopy. The conductance of the samples after the 60 min treatment, compared to as implanted samples, dropped by seven orders of magnitude in the range of low frequencies and about three orders of magnitude at higher frequencies. This drastic change of the electrophysical behaviour of the field treated nanomaterial is discussed in terms of potential barriers at the interface of different phases
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
Ion beam synthesis of Te and Bi nanoclusters in silicon: The effect of post-implantation high frequency electromagnetic field
No full textThe post-implantation effect of high frequency electromagnetic field (HFEMF) on the microstructure and electrical properties of high dose Te+ and Bi+ implanted (100) Si was investigated by cross-sectional high resolution transmission electron microscopy and fourpoint probe electrical measurements. Te and Bi nanoclusters (NCs) embedded in amorphized Si have been formed by ion implantation. Post-implantation treatment with HFEMF reorganizes the cluster shape and distribution by stimulation of spinodal decomposition and ordering of Te NCs to a percolation system. The effect of HFEMF on Bi NCs is assumed to be connected with the formation of electrical microcurrents causing local heating of their interfaces with the a-Si matrix. The results of electrical measurements show that the HFEMF application reduces the sheet resistance by a factor of about 6 for Te+ and about 3 for Bi+ irradiation
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
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