1,720,979 research outputs found
Synthèse de nouveaux assemblages à base de porphyrines organiques et organométalliques pour l’optique
No full textDuring this thesis, we have worked on the synthesis and characterization of new compounds using the porphyrin macrocycle as a starting material. The aim, after synthesis, is to study the photophysical properties of these new molecules. A general bibliographic study was presented followed by introducing the synthetic methods of porphyrins and characterization means. Then, fluorene was considered to be an attracting unit due to its interesting photophysical properties: acting as efficient antennae for collecting light. First, we have presented the synthesis of porphyrin dendrimers having fluorenyl arms of different generations. That is to test the effect of number of fluorenes on the photophysical properties. Another way is to connect the fluorenes directly to the porphyrin core by synthesizing porphyrin dimer and trimer. We have also detailed the synthesis and characterization of a new family of porphyrin organometallic assemblies possessing ruthenium and iron moieties. In addition, a new organometallic porphyrin dendrimer bearing twelve ruthenium species was reported as well. These organometallic porphyrins are of interest in the third order of Nonlinear Optics (NLO). In the last chapter of this thesis we showed an example of application of porphyrin chemistry. We reported the elaboration of a new organic light emitting Diode (OLED) using these new porphyrins that emits in the red region.Au cours de cette thèse, nous avons synthétisé et caractérisé de nouveaux composés en utilisant le macrocycle porphyrinique comme brique moléculaire de départ. Le but de ce travail étant l’étude des propriétés optiques de ces nouveaux composés obtenus. Après avoir effectué l’étude bibliographique sur les porphyrines, nous avons fait une présentation générale des porphyrines symétriques et non symétriques, de leurs propriétés et de leurs synthèses. D’autre part, nous avons aussi considéré l’unité fluorène qui possède des propriétés photophysiques très intéressantes comme antenne collectrice de lumière. Puis, nous avons abordé des méthodes de synthèse permettant d’associer le macrocycle porphyrinique avec de nombreuses unités fluorènes. Cette association a pu être réalisée de différentes manières : soit de façon dendritique ou par connexion directe sur la porphyrine (dimère et trimère). Nous avons également décrit l’obtention d’une nouvelle famille de porphyrines substituées par des groupements organométalliques de type acétylure de ruthénium et de fer pour l’optique non linéaire de troisième ordre (ONL TO). Lors de la dernière partie de mes travaux de thèse, comme application de ces composés luminescents dans le rouge, nous avons reporté l’élaboration de différents dispositifs de diodes électroluminescentes (OLED) émettant dans le rouge
Synthesis of new organic and organometallic Porphyrin Assemblies for Optics
No full textAu cours de cette thèse, nous avons synthétisé et caractérisé de nouveaux composés en utilisant le macrocycle porphyrinique comme brique moléculaire de départ. Le but de ce travail étant l’étude des propriétés optiques de ces nouveaux composés obtenus. Après avoir effectué l’étude bibliographique sur les porphyrines, nous avons fait une présentation générale des porphyrines symétriques et non symétriques, de leurs propriétés et de leurs synthèses. D’autre part, nous avons aussi considéré l’unité fluorène qui possède des propriétés photophysiques très intéressantes comme antenne collectrice de lumière. Puis, nous avons abordé des méthodes de synthèse permettant d’associer le macrocycle porphyrinique avec de nombreuses unités fluorènes. Cette association a pu être réalisée de différentes manières : soit de façon dendritique ou par connexion directe sur la porphyrine (dimère et trimère). Nous avons également décrit l’obtention d’une nouvelle famille de porphyrines substituées par des groupements organométalliques de type acétylure de ruthénium et de fer pour l’optique non linéaire de troisième ordre (ONL TO). Lors de la dernière partie de mes travaux de thèse, comme application de ces composés luminescents dans le rouge, nous avons reporté l’élaboration de différents dispositifs de diodes électroluminescentes (OLED) émettant dans le rouge.During this thesis, we have worked on the synthesis and characterization of new compounds using the porphyrin macrocycle as a starting material. The aim, after synthesis, is to study the photophysical properties of these new molecules. A general bibliographic study was presented followed by introducing the synthetic methods of porphyrins and characterization means. Then, fluorene was considered to be an attracting unit due to its interesting photophysical properties: acting as efficient antennae for collecting light. First, we have presented the synthesis of porphyrin dendrimers having fluorenyl arms of different generations. That is to test the effect of number of fluorenes on the photophysical properties. Another way is to connect the fluorenes directly to the porphyrin core by synthesizing porphyrin dimer and trimer. We have also detailed the synthesis and characterization of a new family of porphyrin organometallic assemblies possessing ruthenium and iron moieties. In addition, a new organometallic porphyrin dendrimer bearing twelve ruthenium species was reported as well. These organometallic porphyrins are of interest in the third order of Nonlinear Optics (NLO). In the last chapter of this thesis we showed an example of application of porphyrin chemistry. We reported the elaboration of a new organic light emitting Diode (OLED) using these new porphyrins that emits in the red region
Synthèse de nouveaux assemblages à base de porphyrines organiques et organométalliques pour l’optique
No full textDuring this thesis, we have worked on the synthesis and characterization of new compounds using the porphyrin macrocycle as a starting material. The aim, after synthesis, is to study the photophysical properties of these new molecules. A general bibliographic study was presented followed by introducing the synthetic methods of porphyrins and characterization means. Then, fluorene was considered to be an attracting unit due to its interesting photophysical properties: acting as efficient antennae for collecting light. First, we have presented the synthesis of porphyrin dendrimers having fluorenyl arms of different generations. That is to test the effect of number of fluorenes on the photophysical properties. Another way is to connect the fluorenes directly to the porphyrin core by synthesizing porphyrin dimer and trimer. We have also detailed the synthesis and characterization of a new family of porphyrin organometallic assemblies possessing ruthenium and iron moieties. In addition, a new organometallic porphyrin dendrimer bearing twelve ruthenium species was reported as well. These organometallic porphyrins are of interest in the third order of Nonlinear Optics (NLO). In the last chapter of this thesis we showed an example of application of porphyrin chemistry. We reported the elaboration of a new organic light emitting Diode (OLED) using these new porphyrins that emits in the red region.Au cours de cette thèse, nous avons synthétisé et caractérisé de nouveaux composés en utilisant le macrocycle porphyrinique comme brique moléculaire de départ. Le but de ce travail étant l’étude des propriétés optiques de ces nouveaux composés obtenus. Après avoir effectué l’étude bibliographique sur les porphyrines, nous avons fait une présentation générale des porphyrines symétriques et non symétriques, de leurs propriétés et de leurs synthèses. D’autre part, nous avons aussi considéré l’unité fluorène qui possède des propriétés photophysiques très intéressantes comme antenne collectrice de lumière. Puis, nous avons abordé des méthodes de synthèse permettant d’associer le macrocycle porphyrinique avec de nombreuses unités fluorènes. Cette association a pu être réalisée de différentes manières : soit de façon dendritique ou par connexion directe sur la porphyrine (dimère et trimère). Nous avons également décrit l’obtention d’une nouvelle famille de porphyrines substituées par des groupements organométalliques de type acétylure de ruthénium et de fer pour l’optique non linéaire de troisième ordre (ONL TO). Lors de la dernière partie de mes travaux de thèse, comme application de ces composés luminescents dans le rouge, nous avons reporté l’élaboration de différents dispositifs de diodes électroluminescentes (OLED) émettant dans le rouge
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
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
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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