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141.
Kazunari Nanjo S. M. Abdul Karim Ryoji Nomura Tatsuo Wada Hiroyuki Sasabe Toshio Masuda 《Journal of polymer science. Part A, Polymer chemistry》1999,37(3):277-282
Polymerizations of 1‐naphthylacetylene (1‐NA) and 9‐anthrylacetylene (9‐AA) by various transition metal catalysts were studied, and properties of the polymers were clarified. 1‐NA polymerized with WCl6‐based catalysts to offer dark purple polymers in good yield. Especially, a binary catalyst composed of WCl6 and Ph3Bi gave a polymer with high molecular weight (Mw = 140×103) and sufficient solubility in common solvents. The use of Mo and Rh catalysts, in contrast, resulted in the formation of insoluble red poly(1‐NA)s. 9‐AA gave insoluble polymers by both WCl6‐ and MoCl5‐based catalysts in moderate to good yields. Copolymerization of 9‐AA with 1‐NA by WCl6–Ph3Bi provided a soluble copolymer which exhibited the largest third‐order nonlinear optical susceptibilities (χ(3)(−3ω; ω, ω, ω) = 40×10−12) among all the substituted polyacetylenes synthesized so far. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 277–282, 1999 相似文献
142.
Chiaki Hirose Nobuyuki Watanabe Hiroyoshi Yamamoto Akihide Wada Kazunari Domen T. Ohtake Norihisa Mino 《中国化学会会志》1994,41(3):275-278
The vibrational spectroscopy by way of vibrational sum-frequency generation (VSFG) has been made of formic acid adsorbed on MgO(001) surface and of n-alkyltrichlorosilanes chemisorbed on quartz plates. It was revealed that the species on the MgO surface was formate ion (HCOO+) with CH bonds standing vertical to the surface and that the different adsorption sites showed up on repeated cycles of adsorption-desorption processes. The results of chemisorbed films indicated that the g-t and/or g-t-g′ conformational scquences of n-alkyl chains occurred more frequently by the length of alkyl chain and that the surface hydroxyls, which are the sites of chemisorption, are ripped off by pre-exposure of substrate to oxygen plasma. 相似文献
143.
Kazunari Nanjo Toshio Masuda 《Journal of polymer science. Part A, Polymer chemistry》1996,34(14):2931-2935
1-Chloro-2-β-naphthylacetylene (ClβNA) polymerized in good yields in the presence of MoCl5-based catalysts. The highest weight-average molecular weight of poly(ClβNA) reached about 3 × 105. The polymer was a yellow solid (absorption cutoff in CHCl3 450 nm). It was soluble in toluene, chloroform, etc., and provided a tough film by the solvent casting method. The polymer retained its weight up to 300°C in air; it was thermally less stable than poly(1-chloro-2-phenylacetylene) but more stable than poly(β-naphthylacetylene). The oxygen permeability coefficient (PO2) of this polymer was 19 barrers (25°C), which is fairly small for a substituted polyacetylene. © 1996 John Wiley & Sons, Inc. 相似文献
144.
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147.
Masakazu Anpo Takaiki Nomura Junko Kondo Kazunari Domen Ken-Ichi Maruya Takaharu Onishi 《Research on Chemical Intermediates》1990,13(3):195-202
Photoluminescence and FT-IR studies of the adsorption of H2 on ZrO2 catalysts have been performdd to clarify the true natuee of active surface sites for the activaiion of H2 in connection with the CO — H2 reaction on the catalyst. The results indicate that the coordinatively unsaturated surface sites with different coordination
numbers are generated on the surfaces by evacuation at temperatures higher than 600 K. These surface sites of lower coordination
play a significant role in the reversible and irreversible dissociative adsorption of H2 on the active ZrO2 catalyst. The former seems to act as active hydrogen species for the CO — H2 reaction to form branched hydrocarbons on the ZrO2 catalyst. 相似文献
148.
A newly designed jet-type, water-cooled heat sink (the funryu heat sink, meaning fountain flow in Japanese) yielded 255-W cw laser output at 808 nm from a 1-cm bar made from InGaAsP/InGaP quantum-well active layers with a 67% fill factor [70 quantum-well laser diode (LD) array along the 1-cm bar]. A funryu heat sink measuring 1.1 mm in thickness gave the LD 0.25 degrees C/W thermal resistance, one of the lowest values achieved with a 1-cm LD bar. Over a short period of operation, the device reached a maximum cw power of 255 W. To the best of our knowledge, this is the highest power ever achieved in 808-nm LD operation. In the future, the funryu heat sink may be capable of 80-W cw operation over an extended lifetime of several thousand hours. 相似文献
149.
Mitsunori Asada Takao Fujimori Kenta Fujii Ryo Kanzaki Yasuhiro Umebayashi Shin‐ichi Ishiguro 《Journal of Raman spectroscopy : JRS》2007,38(4):417-426
The solvation structure of magnesium, zinc(II), and alkaline earth metal ions in N,N‐dimethylformamide (DMF) and N,N‐dimethylacetamide (DMA), and their mixtures has been studied by means of Raman spectroscopy and DFT calculations. The solvation number is revealed to be 6, 7, 8, and 8 for Mg2+, Ca2+, Sr2+, and Ba2+, respectively, in both DMF and DMA. The δ (O C N) vibration of DMF shifts to a higher wavenumber upon binding to the metal ions and the shift Δν(= νbound − νfree) becomes larger, when the ionic radius of the metal ion becomes smaller. The ν (N CH3) vibration of DMA also shifts to a higher wavenumber upon binding to the metal ions. However, the shift Δν saturates for small ions, as well as the transition‐metal (II) ions, implying that steric congestion among solvent molecules takes place in the coordination sphere. It is also indicated that, despite the magnesium ion having practically the same ionic radius as the zinc(II) ion of six‐coordination, their solvation numbers in DMA are significantly different. DFT calculations for these metalsolvate clusters of varying solvation numbers revealed that not only solvent–solvent interaction through space but also the bonding nature of the metal ion plays an essential role in the steric congestion. The individual solvation number and the Raman shift Δν in DMF–DMA mixtures indicate that steric congestion is significant for the magnesium ion, but not appreciable for calcium, strontium, and barium ions, despite the solvation number of these metal ions being large. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
150.
Yasumasa Nishiwaki Kazunari Masutani Yoshiharu Kimura Chan-Woo Lee 《Journal of polymer science. Part A, Polymer chemistry》2020,58(6):860-871
Bis-hydroxyl-terminated poly(1,2-propylene succinate) (PPS-diols) with high molecular weight (10–40 kDa) are prepared by two-step melt polycondensation of succinic acid and 1,2-propanediol with Ti(BuO)4 as the catalyst. By using these PPS-diols as macroinitiators, the ring-opening polymerization of d - and l -lactides is readily conducted to obtain enantiomeric ABA triblock copolymers consisting of poly(l -lactide) and PPS (B) (t-l -PPS) as well as those of poly(d -lactide) and PPS (B) (t-d -PPS) which have higher PPS compositions (20–70 wt%) in addition to high molecular weight (20–80 kD). The Tg, Tm, and ΔHm values of the t-l -PPS copolymers as well as the stereo mixtures of t-l -PPS/t-d -PPS are controlled to linearly decrease with increasing the PPS content. The copolymers also exhibit higher elastomeric properties with increasing the PPS content. The tensile properties of the copolymer films having higher PPS contents (both the single block copolymers and stereo mixtures) are comparable to those of the oil-based thermoplastic elastomers. It is therefore concluded that these block copolymers can afford thermoplastic elastomers or flexible plastic materials having a 100% biobased content. 相似文献