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Structure des phases binaires V6Si5 et Ti6Ge5
No full textThe crystals of V₆Si₅ and Ti₆Ge₅ belong to the orthorhombic system, space group Ibam , with Z = 4 in a unit cell of dimensions :
V₆Si₅ a = 15.966 Å b = 7.501 Å c = 4.858 Å
Ti₆Ge₅ a = 16.915 Å b = 7.954 Å c = 5.233 Å
The structure were determined by Patterson syntheses. The positions of the atoms were refined by means of a least-squares method. There is a very great structural analogy between the V₆Si₅ and Ti₆Ge₅ phases on the one hand, and the hexagonal form of V₅Si₃, the tetragonal forms of the V₅Si₃ and V₃Si compounds on the other hand. These structures are characterised by very short metal-metal bonds, making up metallic chains.Les cristaux de V₆Si₅ et de Ti₆Ge₅ appartiennent au système orthorhombique, groupe spatial Ibam. Leur maille de paramètres :
V₆Si₅ a = 15,966 Å b = 7,501 Å c = 4,858 Å
Ti₆Ge₅ a = 16,915 Å b = 7,954 Å c = 5,233 Å
contient quatre groupements formulaires.
La structure cristalline a été déterminée par déconvolution de la fonction de Patterson. Les positions des atomes ont été affinées à l'aide d'un programme de moindre carrés. Il existe une très grande analogie structurale entre les phases V₆Si₅ et Ti₆Ge₅ d'une part, et les composés du type V₅Si₃ forme hexagonale, V₅Si₃ forme quadratique et V₃Si d'autre part. Ces structures sont caractérisées par des liaisons métal-métal très courtes, formant des chaînes métalliques.Spinat Pierre, Fruchart Robert, Herpin Paulette. Structure des phases binaires V6Si5 et Ti6Ge5. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 93, 1, 1970. pp. 23-36
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
Structure de Mn5 Si C
No full textCrystals of Mn₅ Si C belong to the orthrhombic system, space group Cmc2₁, with Z = 8 in a unit cell of dimensions a = 10.198 Å, b = 8.035 Å, c = 7.630 Å.
The stuctural hypothesis stablished from isomorphous compound Mo Mn₄ Si C by Patterson and Fourier syntheses, was completed on Mn₅ Si C by electron density maps. A least-squares refinement gave R = 0.06 using 565 observed structure factors.
The structure consists of a succession of perpendicular plans to [100]. Carbon atoms may be located in the center of right prisms, bases of which are triangular.Les cristaux de Mn₅ Si C appartiennent au système orthorhombique, groupe spatial Cmc2₁. La maille, de paramètre a = 10,198 Å, b = 8,035 Å, c = 7,630 Å, contient huit groupements formulaires.
L'hypothèse de structure, établie à partir du composé isomorphe Mo Mn₄ Si C par des méthodes de Patterson et synthèses de Fourier, a été précisée sur Mn₅ Si C , à l'aide de sections de densité électronique. Un affinement par moindres carrés conduit à un R final de 0,06 pour 565 facteurs de structure observés.
La structure peut être décrite comme étant formé d'une succession de plans perpendiculaires à [100]. Le carbone se situe probablement au centre d'un prisme droit à base triangulaire.Spinat Pierre, Fruchart Robert, Kabbani Mayer, Herpin Paulette. Structure de Mn5 Si C. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 93, 2, 1970. pp. 171-184
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
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
Influence des écarts à la composition sur les propriétés magnétiques des phases Mn3 Ga C1˗x et Mn5 Si3 Cx
No full textIt has been shown that Mn₅Si₃ type silicides dissolve amounts of small non metals. When the octaedral holes of Mn5Si3 are partially filled with carbon, this compound has magnetic properties under 152° K. The ferromagnetic and dilatometric properties are very sensitive to non stoichiometry.
Mn₃GaC₁₋ₓ, is a perowskite type carbide. It presents an antiferro-ferromagnetic transition at 150° K. This transformation is strongly dependent of non stoichiometry.
When the formula has a value betwen Mn₃GaC₀,₉₈ and MnGaC₀,₉₅ a new type of magnetic transformation appears. There is no magnetic transformation when the formula has a value between Mn₃GaC₀,₉₅ and Mn₃GaC₀,₅₅. This work includes dilatometric study of the transitions, and the effect of various magnetic fields on the thermomagnetic curves.Le remplissage partiel des sites octaédriques de Mn₅Si₃ par des atomes de carbone fait apparaître des propriétés ferromagnétiques à basses températures. Les propriétés, magnétiques ainsi que les propriétés dilatométriques sont très sensibles aux écarts de composition.
Mn₃GaC présente une transition antiferro-ferromagnétique à 150° K. Cette transition est modifiée profondément par de faibles écarts à la composition en carbone. Entre Mn₃GaC₀,₉₈ et Mn₃GaC₀,₉₅, un nouveau type de transition magnétique apparaît. Lorsque la formule est comprise entreMn₃GaC₀,₉₅ et Mn₃GaC₀,₅₅, le composé ne présente plus de transition. Les deux types de transition sont étudiés sous différentes valeurs du champ magnétique appliqué, l'étude dilatométrique montre également la différence fondamentale entre les deux types de transition.Sénateur J.-P., Bouchaud J.-P., Fruchart Robert. Influence des écarts à la composition sur les propriétés magnétiques des phases Mn3 Ga C1˗x et Mn5 Si3 Cx. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 90, 4, 1967. Réunion annuelle de l'Association Française de Cristallographie, Lyon, 13-15 avril 1967
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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