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991.
Dr. Edlira Suljoti Raul Garcia‐Diez Dr. Sergey I. Bokarev Dr. Kathrin M. Lange Roland Schoch Brian Dierker Marcus Dantz Kenji Yamamoto Nicholas Engel Dr. Kaan Atak Prof. Dr. Oliver Kühn Prof. Dr. Matthias Bauer Prof. Dr. Jan‐Erik Rubensson Prof. Dr. Emad F. Aziz 《Angewandte Chemie (International ed. in English)》2013,52(37):9841-9844
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An enhanced host–guest electro‐optical polymer system using poly(norbornene‐dicarboximides) via ROMP
Feng Yu Andrew M. Spring Lu Li Feng Qiu Kazuhiro Yamamoto Daisuke Maeda Masaaki Ozawa Keisuke Odoi Shiyoshi Yokoyama 《Journal of polymer science. Part A, Polymer chemistry》2013,51(6):1278-1284
High glass transition temperature poly(N‐cyclohexyl‐5‐norbornene‐2,3‐dicarboximide)s (NDI)s prepared by ring opening metathesis polymerization yielded polymers with a narrow polydispersity and well‐controlled molecular weight materials when using the Grubbs first generation initiator. Polymers produced using the Grubbs second generation initiator could not be controlled easily. By initiator selection it was also possible to synthesize polymers with either 98 or 52% trans microstructures. These materials were employed as electro‐optic (EO) polymer hosts for high molecular hyperpolarizability (β) phenyl vinylene thiophene vinylene bridge chromophores. This chromophore was modified by the incorporation of a tert‐butyldiphenylsilane group. The addition was able to further increase its EO coefficient (r33) to reach 93 pm/V in a trans rich poly(NDI) produced by the Grubbs first generation initiator, compared to a benchmark chromophore / polymer combination. We investigated in detail the relationship between polymer microstructure and their absolute molecular weight on forming the best host–guest with the high β chromophore. Our results indicate that by utilizing a very simple host–guest system a high r33 can be realized. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
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Masahiko Suzuki Yukio Yamamoto Masahiro Irie Koichiro Hayashi 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):1607-1622
Photopolymerization of styrene in the presence of pyromellitic dianhydride, an electron acceptor which forms a charge-transfer complex with the monomer, was studied. Polymerization was initiated by illumination with a light of wavelength longer than 350 nm, where only the charge-transfer absorption band exists. It was found that the reaction involves cationic and radical polymerizations and that the reaction course strongly depends on polarity of the system. It was also suggested by the dependence of the rate of polymerization on light intensity and temperature that the cationic polymerization consists of free ion and ion-pair polymerizations. These results were compared with those of the photoinduced cationic polymerization of α-methylstyrene, which has previously been studied. 相似文献
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Nobuyasu Itoh Takamitsu Otake Yoshie Aoyagi Mayumi Matsuo Takashi Yarita 《Chromatographia》2009,70(7-8):1073-1078
We applied liquid chromatography-dopant-assisted atmospheric pressure photoionization-mass spectrometry to quantify four distinct pesticides (isoprothiolane, fenitrothion, fthalide, and ethophenprox) in unpolished rice flour. Although the effect of acetone as a dopant on enhancement of ionization differed among the pesticides, the analytical results by LC-DA-APPI-MS with a dopant flow rate of 50 μL min?1 were not only repeatable (relative SD < 9%, n = 3) but also comparable to those by gas chromatography–mass spectrometry. 相似文献
998.
Y. Miyamoto T. Yamamoto K. Kinoshita S. Koyama Y. Takei H. Nanto Y. Shimotsuma M. Sakakura K. Miura K. Hirao 《Radiation measurements》2010,45(3-6):546-549
The objective of this study is to investigate the emission mechanism of radiophotoluminescence (RPL) in the Ag+-doped phosphate glass (glass dosimeter), which is now used as individual radiation dosimeter, because the emission mechanism of RPL in glass dosimeter was not fully understood. Optical properties such as optical absorption spectrum, RPL spectrum and change of RPL spectrum as a function of X-ray irradiation dose were measured for commercially available glass dosimeter. In this study, we discuss the emission mechanism of two RPL peaks at 460 nm and 560 nm, based on the fact that electrons and holes produced by X-ray irradiation are trapped at Ag+ ions to produce Ag0 and Ag2+ ions, respectively, when the Ag+-doped phosphate glass is exposed to X-ray. We would like to propose the emission mechanism of RPL peaks at 460 nm and 560 nm, concerning with Ag2+ and Ag0 ions. 相似文献
999.
3‐Methacryloxypropylpolysilsesquioxane (MA‐PS) was prepared by acid‐ or base‐catalyzed hydrolytic polycondensation of 3‐methacryloxypropyltrimethoxysilane (MAS). MA‐PS coating film was prepared by dip‐coating on organic, metal and inorganic substrates, including poly(ethylene terephthalate), aluminum, stainless steel, and glass. The coating films on poly(ethylene terephthalate) and glass showed high adhesive strength. The hardness of coating films increased with increasing heat treatment temperature, whereas they decreased with increasing H2O/MAS molar ratio. The refractive index of coating films increased with increasing heat treatment temperature. In addition, flat and transparent free‐standing films (0.24–0.27 mm thickness) were prepared from MA‐PS that were crack‐free after heat treatment at 1000 °C. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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