1,721,215 research outputs found
Enhancement of microbicidal activity in the tiger shrimp Penaeus monodon via immunostimulation.
No full textBlue-light-emitting and anodically electrochromic materials of new wholly aromatic polyamides derived from the high-efficiency chromophore 4,4 '-dicarboxy-5 ''-methyltriphenylamine
No full text[[abstract]]A series of organosoluble, aromatic polyamides were synthesized from a 4-methyl-substituted, triphenylamine-containing, aromatic diacid monomer, 4,4'-dicarboxy-4"-methyltriphenylamine, which is a blue-light (454-nm) emitter with a fluorescence quantum efficiency of 46%. These triphenylamine-based, high-performance polymers had strong fluorescence emissions in the blue region with high quantum yields up to 64% and one reversible oxidation redox couple around 1.20 V versus Ag/AgCl in acetonitrile solutions. They exhibited good thermal stability, with 10% weight loss temperatures above 480 degrees C under a nitrogen atmosphere and with relatively high glass-transition temperatures (252-309 degrees C). All the polyamides revealed excellent stability of electrochromic characteristics, changing color from the original pale yellow to blue. (c) 2006 Wiley Periodicals, Inc.[[note]]SC
Synthesis and evaluation of photoluminescent and electrochemical properties of new aromatic polyamides and polyimides with a kink 1,2-phenylenediamine moiety
No full text[[abstract]]A series of novel triphenylamine-containing aromatic polyamides and polyimides having a crank and twisted noncoplanar structures were synthesized in inherent viscosities of 0.14-0.64 dL/g and 0.11-0.67 dL/g, respectively. These polymers had useful levels of thermal stability associated with relatively high glass-transition temperatures (174-311 degrees C). They exhibited strong UV-Vis absorption bands at around 300 nm in NMP solutions. The PL spectra of these polymers in NMP solutions (I x 10(-5) M) showed maximum peaks around 396-479 nm. The bole-transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammetry (CV) of the polymer films cast onto an indium-tin oxide (ITO)-coated glass substrate exhibited two reversible oxidation redox couples at potentials of 0.70-1.01 V and 1.10-1.46 V, respectively, vs. Ag/AgCl in acetonitrile solution. The polymer films revealed electrochromic characteristics, with a color change from neutral pale yellowish to green and then to a blue oxidized form at applied potentials ranging from 0.00 to 1.75 V. (c) 2006 Wiley Periodicals, Inc.[[note]]SC
A study of complex slow-release oral delivery system using alginate-polysaccharide beads
No full textSynthesis, photoluminescent and electrochromic properties of new aromatic poly(amine-hydrazide)s and poly(amine-1,3,4-oxadiazole)s derived from 4,4 '-dicarboxy-5 ''-methyltriphenylamine
No full text[[abstract]]A series of new poly(amine-hydrazide)s I were prepared from the dicarboxylic acid 4,4'-dicarboxy-4"-methyltriphenyl-amine with terephthalic dihydrazide (TPH) and isophthalic dihydrazide (IPH), respectively, via the Yamazaki phosphorylation reaction. Polymers I were readily soluble in many common organic solvents, and could be solution cast into transparent, tough, and flexible films with good mechanical properties. Differential scanning calorimetry (DSC) indicated that the hydrazide polymers had T-g's in the range of 222-223 degrees C and could be thermally cyclodehydrated into the corresponding oxadiazole polymers in the range of 300-400 degrees C. The resulting poly(amine-1,3,4-oxadiazole)s II exhibited T-g's in the range of 269-283 degrees C, 10% weight-loss temperatures in excess of 511 degrees C, and char yield at 800 degrees C in nitrogen higher than 63%. These poly(amine-hydrazide)s I exhibited strong UV-Vis absorption bands at 351-355 nm in NMP solution. Their photoluminescence spectra in NMP solution and film showed maximum bands around 459-461 nm in the blue region for I series. The hole-transporting and electrochromic properties are examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine-hydrazide)s I prepared by casting polymer solution onto an indium-tin oxide (ITO)-coated glass substrate exhibited one reversible oxidation redox couples at 1.32-1.33 V vs. Ag/AgCl in acetonitrile solution. All obtained poly(amine-hydrazide)s I revealed excellent stability of electrochromic characteristics, changing color from original pale yellowish to blue. (c) 2006 Elsevier Ltd. All rights reserved.[[note]]SC
Thermally stable, light-emitting, triphenylamine-containing poly(amine hydrazide)s and poly(amine-1,3,4-oxadiazole)s bearing pendent carbazolyl groups
No full text[[abstract]]A series of new organosoluble poly(amine hydrazide)s were synthesized via the Yamazaki phosphorylation reaction and were solution-cast into transparent films. Differential scanning calorimetry indicated that the hydrazide polymers could be thermally cyclodehydrated into the corresponding oxadiazole polymers in the range of 300-400 degrees C. The resulting poly(amine-1,3,4-oxadiazole)s exhibited glasstransition temperatures in the range of 276-297 degrees C, 10% weight loss temperatures in excess of 520 degrees C, and char yields at 800 degrees C in nitrogen higher than 67%. The holetransporting and electrochromic properties were examined with electrochemical and spectroelectrochemical methods. Cyclic voltammograms of these polymers prepared by the casting of polymer solutions onto an indium tin oxide coated glass substrate exhibited two reversible oxidative redox couples at 1.10-1.19 and 1.35-1.60 V versus Ag/AgCl in an acetonitrile solution, respectively. The poly(amine hydrazide)s revealed excellent stability of the electrochromic characteristics, changing color from the original pale yellow to green and then to blue. (c) 2006 Wiley Periodicals, Inc.[[note]]SC
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
New soluble triphenylamine-based amorphous aromatic polyamides for high performance blue-emitting hole-transporting and anodically electrochromic materials
No full text[[abstract]]A newly 4-methoxy-substituted triphenylamine-containing aromatic diacid monomer, 4,4'-dicarboxy-4"-methoxytriphenylamine 2, with blue light (454 nm) fluorescence quantum efficiency 45% was successfully synthesized by the sodium hydride-mediated condensation of 4-methoxyaniline with 4-fluorobenzonitrile, followed by alkaline hydrolysis of the intermediate dicyano compound. A series of novel aromatic polyamides having strong fluorescence emissions in the blue region with high quantum yields up to 40% and one reversible oxidation redox couples at 1.08 V vs. Ag/AgCl in acetonitrile solution have been synthesized and characterized. They exhibited good thermal stability with 10% weight-loss temperatures above 460 degrees C under a nitrogen atmosphere with relatively high glass-transition temperatures (267-307 degrees C). All obtained polyamides revealed excellent stability of electrochromic characteristics, changing color from original pale yellowish to blue. (c) 2006 Elsevier Ltd. All rights reserved.[[note]]SC
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
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