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Okaya, Japan

Kyushu International University is a private university in Yahata Higashi, Kitakyushu, Fukuoka, Japan.The roots of the university can be found in the "Kyushu Law School", which was founded in 1930. The direct predecessor to the school, "Yahata University", was established in 1950, and it adopted the present name in 1989. Wikipedia.

Ishimatsu R.,Kyushu University | Edura T.,Kyushu University | Adachi C.,Kyushu International University | Nakano K.,Kyushu University | Imato T.,Kyushu University
Chemistry - A European Journal

The photophysical properties and electrogenerated chemiluminescence (ECL) of three donor-acceptor molecules composed of dicyanobenzene and methyl-, tert-butyl-, and phenyl-substituted carbazolyl groups, 1,2,3,5-tetrakis(3,6-disubstituted-carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN-Me, 4CzIPN-tBu, and 4CzIPN-Ph, respectively) are described. These molecules show delayed fluorescence as a result of thermal spin upconversion from the lowest triplet state to the lowest singlet state at room temperature. The three molecules showed yellow to yellowish-red ECL. Remarkably, the ECL efficiencies of 4CzIPN-tBu in dichloromethane reached almost 40%. Moreover, stable ECL was emitted from 4CzIPN-tBu and 4CzIPN-Ph. In case of 4CzIPN-Me, the ECL intensity decreased during voltage cycles because of polymerization. Quantum chemical calculations revealed that polymerization was inhibited by the steric hindrance of the bulky tert-butyl and phenyl groups on the carbazolyl moieties and lowered the spin density on the carbazolyl groups through electron conjugation for 4CzIPN-Ph. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Zhang Q.,Kyushu University | Tsang D.,i3 Electronics | Kuwabara H.,Kyushu University | Hatae Y.,Kyushu University | And 5 more authors.
Advanced Materials

The design of efficient and concentration-insensitive metal-free thermally activateddelayed fluorescence (TADF) materials is reported. Blue and green organic light-emitting diodes (OLEDs) containing a hole-transport layer, an undoped TADF emissive layer, and an electron-transport layer achieve maximum external quantum efficiencies of 19%, which is comparable to the best doped OLEDs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Yamamoto K.,Kyushu International University
Science Reports of the Tohoku University, Series 7: Geography

A certain type of cultural industry agglomerates in metropolises. Not only do the characteristics of the production structure influence this phenomenon, but so does the consumption structure of cultural product markets. This article contributes to an understanding of the agglomeration of a cultural industry by describing a segment of the spatial structure of the small theater performance market in Tokyo. In this study, we show the change in the spatial structure of Small Theater Performances from 1980 to 2010 by using the GIS technique, and we also explore the structure of this consumption space based on the results of a questionnaire survey given to audience members of theater performances as cultural consumers in Tokyo. Source

Yoshida M.,Hokkaido University | Kondo M.,Japan Science and Technology Agency | Torii S.,Japan Institute for Molecular Science | Sakai K.,Kyushu International University | Masaoka S.,Japan Institute for Molecular Science
Angewandte Chemie - International Edition

Rational molecular design of catalytic systems capable of smooth O-O bond formation is critical to the development of efficient catalysts for water oxidation. A new ruthenium complex was developed, which bears pendant SO3- groups in the secondary coordination sphere: [Ru(terpy)(bpyms)(OH2)] (terpy=2,2′:6′,2′′-terpyridine, bpyms=2,2′-bipyridine-5,5′-bis(methanesulfonate)). Water oxidation driven by a Ce4+ oxidant is distinctly accelerated upon introduction of the pendant SO3- groups in comparisons to the parent catalyst, [Ru(terpy)(bpy)(OH2)]2+ (bpy=2,2′-bipyridine). Spectroscopic, electrochemical, and crystallographic investigations concluded that the pendant SO3- groups promote the formation of an O-O bond via the secondary coordination sphere on the catalyst, whereas the influence of the pendant SO3- groups on the electronic structure of the [Ru(terpy)(bpy)(OH2)]2+ core is negligible. The results of this work indicate that modification of the secondary coordination sphere is a valuable strategy for the design of water oxidation catalysts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Nakamura H.,Sony Corporation | Noh S.-H.,Sony Corporation | Kuribayashi M.,Sony Corporation | Adachi C.,Kyushu International University
Journal of the Society for Information Display

The influence of organic-organic interfacial contaminants and deterioration in organic light-emitting diodes (OLEDs) was investigated. There was deterioration of the device characteristics when atmospheric contamination was introduced to the emission site. We simultaneously observed a decrease of the maximum capacitance, Cmax, of the OLEDs, implying that there was charge accumulation at the interface. Our study demonstrates that maintaining the interface adjacent to emission site free from contaminants is crucial to protect the device from deterioration. © Copyright 2015 Society for Information Display. Source

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