1,721,027 research outputs found
Synthesis of indolo[3,2-b]carbazole-based random copolymers for polymer solar cell applications
No full text[[abstract]]In addition to preparing two indolocarbazole-based random copolymers (named as r-PICTBT1 and r-PICTBT2), this work investigated their feasibility for bulk heterojunction polymer solar cells (PSCs). These copolymers consisted of commercially available 3,9-dibromo-5,11-dioctyl-5,11-dihydroindole[3,2-b]carbazole, 2,5-bis(trimethylstannyl) thiophene and dibromobenzo[c][1,2,5]thiadiazole by varying the feed in ratios via Stille cross-coupling reactions. The photophysical and electrochemical properties of the resulting copolymers could be fine-modulated easily by adjusting the feed ratios of monomers. Both copolymers in the thin film state exhibited two obvious peaks and a vibronic shoulder in the absorption spectra. Electrochemical experiments indicated that the highest occupied molecular orbital energy levels were -4.95, -5.00 eV; meanwhile, the lowest unoccupied molecular orbital energy levels were -3.38, -3.54 eV for r-PICTBT1 and r-PICTBT2, respectively. Bulk heterojunction PSCs composed of anelectron-donor copolymer blended with an electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) or [6,6]-phenyl-C71-butyric acidmethyl ester (PC71BM) at a weight ratio of 1: 1 or 1: 3 were investigated. Moreover, the r-PICTBT2/PC71BM-based (w/w = 1: 1) PSC performed the best with an open-circuit voltage of 0.54 V, short-circuit current of 6.83 mA/cm(2), fill factor of 0.44, and power conversion efficiency of 1.63%. (C) 2013 Elsevier B. V. All rights reserved.[[note]]SC
Increased nucleolar organizer regions in bronchial epithelium nearby bronchogenic carcinomas.
No full text
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
D-sJ(+)(2632): An excellent candidate of tetraquarks
No full textWe analyze various possible interpretations of the narrow state D-sJ(2632) which lies 100 MeV above threshold. This interesting state decays mainly into D(s)eta instead of (DK+)-K-0. If this relative branching ratio is further confirmed by other experimental groups, we point out that the identification of D-sJ(2632) either as a c (s) over bar state or more generally as a (3) over bar state in the SU(3)(F) representation is probably problematic. Instead, such an anomalous decay pattern strongly indicates D-sJ(2632) is a four-quark state in the SU(3)(F) 15 representation with the quark content 1/2root2 (ds (d) over bar +sd (d) over bar +su (u) over bar -2ss (s) over bar)(c) over bar. We discuss its partners in the same multiplet and the similar four-quark states composed of a bottom quark B-sJ(0)(5832). Experimental searches of other members especially those exotic ones are strongly called for.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)22ARTICLE9null7
Pentaquark magnetic moments in different models
No full textWe calculate the magnetic moments of the pentaquark states from different models and compare our results with predictions of other groups.Physics, NuclearSCI(E)25ARTICLE3null6
Nuclear Area and DNA Content Analysis of Tumor and Non-Tumor Portions of Hepatocellular Carcinoma
No full textVariations 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
- …
