1,721,806 research outputs found
Iзінгівська поведінка критичних властивостей слабкого сегнетоелектрика Li₂Ge₇O₁₅
Full text linkThe dielectric constant ε and electron spin resonance spectra of Mn²⁺
ions have been studied in the range of the ferroelectric phase transition in
Li₂Ge₇O₁₅ single crystals. Analysis of the experimental data permits one
to estimate the critical exponents of dielectric susceptibility γ ≅ 1.25, order parameter β ≅ 0.32 and correlation length ν ≅ 0.63. The values of the
critical exponents determined in a fairly broad temperature interval around
Tc, are consistent with the theoretical predictions of the Ising model with a
one-component non-polar ordering coordinate.Дiелектрична проникнiсть ε та спектри ЕПР iонiв Mn²⁺ дослiдженi в
околi сегнетоелектричного фазового переходу у кристалах
Li₂Ge₇O₁₅. Аналiз експериментальних даних дозволив оцiнити критичнi iндекси дiелектричної сприйнятливостi γ ≅ 1.25, параметра порядку β ≅ 0.32 i кореляцiйної довжини ν ≅ 0.63. Величини критичних
iндексiв, обчисленi у досить широкому iнтервалi температур поблизу Tc, узгоджуються з теоретичними показниками моделi Iзiнга для
однокомпонентного неполярного параметра порядку
Elastic properties of crystalline Li–Ge phases with increasing Li concentration: A first-principles study
No full textTo obtain a better understanding of the failure mechanism of Ge anode during the charging and discharging process, in this paper, we systematically studied the mechanical properties of Li–Ge alloys based on density functional theory. The results show that the bulk, shear, and Young’s moduli of Li–Ge alloys decrease almost linearly with increasing Li concentration. In addition, based on the analysis of shear to bulk modulus and Poisson’s ratios, Li−Ge alloys demonstrate enhanced brittleness during the lithiation process which would make electrode materials fragile to cracks and failure. The weakened elastic moduli and enhanced brittleness would lead to the poor cycle performance and crushing failure of Ge anode materials during charging and discharging process
Li-Ge data for: Machine Learning of Ab-initio Energy Landscapes for Crystal Structure Predictions
No full textEvolutionary algorithm structure search for Li-Ge crystal structures.
W. W. Tipton, C. A. Mathulis, and R. G. Hennig. Ab-initio prediction of the Li5Ge2 Zintl compound. Comp. Mater. Sci. 93, 133 (2014
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
The electrical resistivities of liquid Li-Ge alloys
No full textResistivities of liquid Li-Ge alloys have been measured in the composition range from 17 to 70 at% Ge. Plotted as a function of composition the resistivity exhibits a sharp peak at 80 at% Li. This is considered as an indication for the formation of a liquid octet compound. Around that composition the values of the resistivity indicate a diffusive motion of electrons and the temperature derivative of the resistivity has a sharp negative minimum. This behaviour is compared with that of liquid Li-Si, Li-Sn and Li-Pb. The results are also related to earlier NMR data
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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