104,754 research outputs found
Author Correction: Kondo-like transport and magnetic field effect of charge carrier fluctuations in granular aluminum oxide thin films
No full textCorrection to: Scientific Reports https://doi.org/10.1038/s41598-018-32298-1, published online 17 September 2018
Unconventional magnetic field effect on noise properties of AlOx thin films in Kondo-like transport regime
No full textGranular aluminum oxide is an interesting material for application in quantum circuits. However, several issues regarding its normal state transport properties are still open. Here, detailed DC and noise transport measurements have been performed on thin films of granular Al oxide. The results evidence the presence of a Kondo-type resistivity increase at low temperatures, where specific excess 1/f noise is observed. The magnetic dependence of the excess noise further strengthens its connection with the Kondo mechanism
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Current-Resistance Effects Inducing Nonlinear Fluctuation Mechanisms in Granular Aluminum Oxide Nanowires
No full textThe unusual superconducting properties of granular aluminum oxide have been recently investigated for application in quantum circuits. However, the intrinsic irregular structure of this material requires a good understanding of the transport mechanisms and, in particular, the effect of disorder, especially when patterned at the nanoscale level. In view of these aspects, electric transport and voltage fluctuations have been investigated on thin-film based granular aluminum oxide nanowires, in the normal state and at temperatures between 8 and 300 K. The nonlinear resistivity and two-level tunneling fluctuators have been observed. Regarding the nature of the noise processes, the experimental findings give a clear indication in favor of a dynamic random resistor network model, rather than the possible existence of a local ordering of magnetic origin. The identification of the charge carrier fluctuations in the normal state of granular aluminum oxide nanowires is very useful for improving the fabrication process and, therefore, reducing the possible sources of decoherence in the superconducting state, where quantum technologies that are based on these nanostructures should work
Structure and Properties of Precursor/Successor Complex and Transition State of the FeCl2+/Fe2+ Electron Self-Exchange Reaction via the Inner-Sphere Pathway
No full textThe electron self-exchange reaction FeCl(OH2)(5)(2+) + Fe(OH2)(6)(2+) -> Fe(OH2)(6)(2+) + FeCl(OH2)(5)(2+), proceeding via the inner-sphere pathway, was investigated with quantum chemical methods. Geometry and vibrational frequencies of the precursor/successor complex, (H2O)(5)(FeClFeII)-Cl-III(OH2)(5)(4+)/(H2O)(5)(FeClFeIII)-Cl-II(OH2)(5)(4+) (P/S), and the transition state, (H2O)(5)FeClFe(OH2)(5)(4+) (TS), were computed with the LC-BOP functional and CPCM hydration. Bent and linear structures were computed for the TS and P/S. The electronic coupling matrix element (H-ab) and the electronic energies were calculated with multistate extended general multiconfiguration quasi-degenerate second-order perturbation theory (XGMC-QDPT2) and spin-orbit configuration interaction (SO-CI). Since the Fe Fe distance changes considerably along the electron transfer step, the transformation P -> TS -> S, equations based on the hypothesis of a fixed donor-acceptor distance cannot be applied. Hence, the rate constant for the electron transfer step (k(et)) was calculated as described previously (Rotzinger, F. P. Inorg. Chem. 2014, 53, 9923). k(et) is very fast, similar to 9.4 x 10(8-)6.6 x 10(9) s(-1) at 0 degrees C. The experimental rate constant of the title reaction (k) is much slower and controlled by the formation of the precursor complex. The substitution of a water ligand by FeCl(OH2)(5)(2+) at Fe(OH2)(6)(2+) is rate-determining.LP
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Kondo-like transport and magnetic field effect of charge carrier fluctuations in granular aluminum oxide thin films
No full textGranular aluminum oxide is an attractive material for superconducting quantum electronics. However, its low-temperature normal state transport properties are still not fully understood, while they could be related to the unconventional phenomenon of the superconductivity in this material. In order to obtain useful information on this aspect, a detailed study of charge carrier fluctuations has been performed in granular aluminum oxide films. The results of electric noise measurements indicate the presence of a Kondo-type spin-flip scattering mechanism for the conducting electrons in the normal state, at low temperatures. Moreover, the magnetic field dependence of the noise amplitude suggests that interface magnetic moments are the main source of fluctuations. The identification of the nature of fluctuation processes is a mandatory requirement for the improvement of quality and performance of quantum devices
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Structure and Properties of Precursor/Successor Complex and Transition State of the FeCl<sup>2+</sup>/Fe<sup>2+</sup> Electron Self-Exchange Reaction via the Inner-Sphere Pathway
No full textThe electron self-exchange reaction <b>Fe</b>Cl(OH<sub>2</sub>)<sub>5</sub><sup>2+</sup> + Fe(OH<sub>2</sub>)<sub>6</sub><sup>2+</sup> → <b>Fe</b>(OH<sub>2</sub>)<sub>6</sub><sup>2+</sup> + FeCl(OH<sub>2</sub>)<sub>5</sub><sup>2+</sup>, proceeding via the inner-sphere pathway, was investigated
with quantum chemical methods. Geometry and vibrational frequencies
of the precursor/successor complex, (H<sub>2</sub>O)<sub>5</sub>Fe<sup>III</sup>ClFe<sup>II</sup>(OH<sub>2</sub>)<sub>5</sub><sup>4+</sup>/(H<sub>2</sub>O)<sub>5</sub>Fe<sup>II</sup>ClFe<sup>III</sup>(OH<sub>2</sub>)<sub>5</sub><sup>4+</sup> (P/S), and the transition state,
(H<sub>2</sub>O)<sub>5</sub>FeClFe(OH<sub>2</sub>)<sub>5</sub><sup>4+⧧</sup> (TS), were computed with the LC-BOP functional and
CPCM hydration. Bent and linear structures were computed for the TS
and P/S. The electronic coupling matrix element (<i>H</i><sub>ab</sub>) and the electronic energies were calculated with multistate
extended general multiconfiguration quasi-degenerate second-order
perturbation theory (XGMC-QDPT2) and spin–orbit configuration
interaction (SO-CI). Since the Fe···Fe distance changes
considerably along the electron transfer step, the transformation
P → TS → S, equations based on the hypothesis of a fixed
donor–acceptor distance cannot be applied. Hence, the rate
constant for the electron transfer step (<i>k</i><sub>et</sub>) was calculated as described previously (Rotzinger, F. P. <i>Inorg. Chem.</i> <b>2014</b>, <i>53</i>, 9923). <i>k</i><sub>et</sub> is very fast, ∼9.4 × 10<sup>8</sup>–6.6 × 10<sup>9</sup> s<sup>–1</sup> at 0 °C.
The experimental rate constant of the title reaction (<i>k</i>) is much slower and controlled by the formation of the precursor
complex. The substitution of a water ligand by FeCl(OH<sub>2</sub>)<sub>5</sub><sup>2+</sup> at Fe(OH<sub>2</sub>)<sub>6</sub><sup>2+</sup> is rate-determining
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
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