1,721,324 research outputs found
Self-assembly of hydrogen-bonded polymeric rods based on the cyanuric acid center dot melamine lattice
No full textThis paper describes the self-assembly of hydrogen-bonded polymeric rods based on the lattice of cyanuric acid and melamine (CA . M). Data from H-1 NMR spectroscopy, IR spectroscopy, gel permeation chromatography (GPC), and transmission electron microscopy (TEM) are interpreted as indicating that the self-assembly of a bisisocyanuric acid (bisCA) and a bismelamine (bisM) formed polymeric nanorods [(bisCA)(n)(bisM)(n)] composed of parallel CA . M rosettes. The TEM results suggest that these rods aggregate as bundles. The length of the bundles ranged from 100 to 1500 nm, and their diameter was in the range from 15 to 500 nm
Ar-40-Ar-39 plateau ages of biotite and amphibole from tonalite of Huangling granitoids and their cooling curve.
No full textEstimating magic numbers larger than 126 by Fermi-Yang Liming method
No full textThe Fermi-Yang Liming method is followed and developed to estimate new magic numbers in nuclei with a Woods-Saxon density function. The calculated results predict that the magic number next to 126 should be around 184 and 258.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)0ARTICLE4447-4503
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
Geochemical characteristics of Cretaceous mafic dikes from northern guangdong, SE China: Age, origin and tectonic significance
No full textSystematic radiometric, geochemical and Sr -Nd isotopic analyses are reported here for the Cretaceous mafic dikes from Northern Guangdong, SE China in order to provide a better understanding of the origin of magma and its tectonic significance. The mafic dikes were emplaced in three principal episodes: at similar to 140 Ma, similar to 105 Ma and similar to 90 Ma. With the chemical characteristics of tholeiitic basalts, they were derived from a moderate time-integrated LREE depleted mantle source with epsilon Nd(T) values of 5. The trace element chemistry of the dikes shows general similarities to within-plate basalts. However, some of the 140 Ma dike samples exhibit are signatures with Th-enrichment and Zr- and Hf-depletion. Thus, the mafic dikes are interpreted as having been magmatism produced during a lithospheric extension from a mantle source influenced by earlier subduction processes. This mantle source shows an EM2 signature in incompatible trace element ratios, such as La/Nb approximate to 1.12, Ba/Nb approximate to 9.1, Ba/La approximate to 8.2, Th/Nb approximate to 0.16 and Th/La approximate to 0.146, together with a high Th/U ratio of 4.7 similar to the EM1 component. The combined geochemical and geochronological constraints on the origin of the mafic dikes, together with results from previous studies of late Mesozoic granites, volcanic rocks, rifting systems and extensional or rifted basins indicate that SE China was dominated by an extensional tectonic regime during the Cretaceous, with four major episodes of extensional activities taking place at similar to 140 Ma, similar to 124 Ma, similar to 105 Ma and similar to 90 Ma
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
Cryopreserved oocytes of infertile couples undergoing assisted reproductive technology could be an important source of oocyte donation: A clinical report of successful
No full textZircon and whole-rock Hf isotope constraints on the petrogenesis of Transhimalayan plutonic rocks
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