1,721,052 research outputs found
Molecular nickel poly-carbide carbonyl nanoclusters: The octa-carbide [HNi42C8(CO)44(CuCl)]7- and the deca-carbide [Ni45C10(CO)46]6-
No full textThe reaction of [Ni10(C2) (CO)16]2- with CuCl in thf affords [Ni45C10(CO)46]6- as the major product. This represents the first deca-carbide carbonyl cluster and this is the highest number of C-atoms found in a molecular cluster. Besides, the new octa-carbide [HNi42C8(CO)44(CuCl)]7- and the previously reported tetra-carbide [Ni34+xC4(CO)38+x]6- (x = 0,1) have been obtained as side-products. Whilst studying the reactions of miscellaneous Ni carbide clusters with Cu(I) salts in the search for a better synthesis of [HNi42C8(CO)44(CuCl)]7-, the homoleptic [Ni32+xC6(CO)36+x]6- (x = 0-2) and the heteroleptic [Ni38C6(CO)36(MeCN)6(CuMeCN)2x]2- clusters have been isolated in low yields. By analysing the Ni carbide clusters herein reported as well as those previously described in the literature, it results that they are built-up starting from four fundamental building blocks: octahedral Oh-Ni6C, trigonal prismatic TP-Ni6C, capped trigonal prismatic cTP-Ni7C and square anti-prismatic SA-Ni8C. These may be joined into larger NixCy metal-carbide frameworks by sharing vertices, edges or faces. Even though infinite combinations are possible, some NixCy motives are common to two or more clusters, envisioning a possible rationale behind their building-up
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
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
Globular molecular platinum carbonyl nanoclusters: Synthesis and molecular structures of the [Pt26(CO)32]- and [Pt14+x(CO)18+x]4- anions and their comparison to related platinum "browns"
No full textThe thermal decomposition of [Pt3n(CO)6n]2- (n=2-10) Chini clusters results in the formation of globular molecular platinum carbonyl clusters, whose nature depends of the nuclearity of the parent cluster as well as the counter-ion and solvent employed. Among these, the new [Pt14+x(CO)18+x]4- (x=0,1) and [Pt44(CO)45] n-, as well as the previously reported [Pt15(CO)19]4-, [Pt19(CO)22]4-, [Pt24(CO)30]2-, [Pt26(CO)32]2-, [Pt33(CO)38]2- and [Pt38(CO)44]2- have been identified. Oxidation of [Pt14+x(CO)18+x]4- (x=0,1) with HBF4·Et2O affords [Pt26(CO)32]2-, which is further oxidized to the related [Pt26(CO)32]- mono-anion. Oxidation of [Pt19(CO)22]4-, under similar conditions, affords the unstable [Pt19(CO)22]2- di-anion, that rearranges during crystallization into the new [Pt36(CO)44]2-. Conversely, the reduction of [Pt19(CO)22]4- with Na/naphthalene results in the [Pt19(CO)22]5- penta-anion which, after work-up, is transformed into the new [Pt23(CO)27]2-. The new clusters [Pt14+x(CO)18+x]4- (x=0,1) and [Pt26(CO)32]- have been fully characterized by means of single crystal X-ray diffractometry as their [NEt4]4[Pt14+x(CO)18+x]·MeCN (x=0.18) and [NEt4][Pt26(CO)32]·2.12thf·0.38C6H14 salts. Conversely, in the case of the new [Pt23(CO)27]2-, [Pt36(CO)44]2- and [Pt44(CO)45] n-, due to the poor quality of their crystals, only a partial structural determination has been possible. [Pt14+x(CO)18+x]4- (x=0,1) displays a distorted bcc structure, [Pt26(CO)32]- and [Pt23(CO)27]2- adopt hcp structures, [Pt36(CO)44]2- presents a distorted ccp metal core, whereas [Pt44(CO)45] n- possesses a twinned hcp/ccp ABCBA structure. The structures of the metal cores of these clusters is compared to previously reported globular platinum carbonyl nanoclusters ("platinum browns")
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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