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991.
Masato IwatsukiToshiya Ishimori Tsuyoshi YamamotoKeiko Takata Mihoko Mori Kenichi NonakaRokuro Masuma Yoichi HayakawaHideaki Hanaki Kazuro Shiomi Satoshi ōmura 《Tetrahedron》2011,67(35):6644-6648
Biverlactones, new circumventors of arbekacin resistance in methicillin-resistant Staphylococcus aureus (MRSA) were isolated from a culture broth of Penicillium sp. FKI-4429. Their structures were elucidated by spectroscopic studies, including various NMR experiments. Biverlactones A-D had novel skeletons, consisting of a lactone ring conjugated with exo- or endo-olefin, a carboxylic group and a characteristic alkyl side chain in common. 相似文献
992.
993.
994.
Takaaki Sakai Seok-Jun Kim Satoshi Kajitani Jun-ichi Hamagami Hiroyuki Oda Maki Matsuka Tatsumi Ishihara Hiroshige Matsumoto 《Journal of Solid State Electrochemistry》2012,16(6):2055-2059
The proton conduction properties of sulfuric acid-modified nano-titania prepared by impregnation method were investigated. The proton conductivity of sulfuric acid-modified nano-titania was almost the same as that of hydrous sulfated nano-titania investigated in our previous work when the amount of adsorbed sulfate groups was almost the same. The highest conductivity was obtained at an adsorbed sulfate group amount of 0.42?mmol/g, not 0.97?mmol/g. This result indicates that the enhancement of conductivity with increasing amount of adsorbed sulfate groups is limited. This might be attributable to insufficient water molecule adsorption on the Ti4+ site coordinated with a bidentate sulfate group due to the prevention by excess sulfuric acid. 相似文献
995.
996.
997.
Akihiro Oshima Satoshi Okubo Tomoko Gowa Oyama Masakazu Washio Seiichi Tagawa 《Radiation Physics and Chemistry》2012,81(5):584-588
Micro- and nano-fabrications of polystyrene (PS) having the atactic and syndiotactic structures were carried out with direct maskless etching using focused ion beam (FIB). Micro- and nano-scale structures were obtained with selective beam and material conditions avoiding the beam-heating and charge-up effects. The etching rates were different between atactic and syndiotactic PS. The rate of fabrication for syndiotactic PS shows higher than that of atactic one. Moreover, the direct etching was influenced by the molecular weight. The etching rate for the lower molecular weight became the faster. The FIB direct etching proceeds through the two steps (decomposition and desorption (outgas)). Both decomposition and desorption are influenced by both conformation (morphology) and configuration (stereoregularity). Furthermore, the beam profiles and fluence play the important roles to perform the nano-fabrication of PS. 相似文献
998.
999.
Namiko Fukuzaki Kazuhiro Nakabayashi Satoshi Nakazawa Shigeaki Murata Tomoya Higashihara Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2011,49(1):93-100
A novel highly phosphonated poly(N‐phenylacrylamide) ( PDPAA ) with an ion‐exchange capacity (IEC) of 6.72 mequiv/g was synthesized by the radical polymerization of N‐[2,4‐bis(diethoxyphosphinoyl)phenyl]acrylamide ( DEPAA ), followed by the hydrolysis with trimethylsilyl bromide. Then, the crosslinked PDPAA membrane was successfully prepared by the electrophilic substitution reaction between the aromatic rings of PDPAA and the carbocation formed from hexamethoxymethylmelamine (CYMEL) as a crosslinker in the presence of methanesulfonic acid. The crosslinked PDPAA membrane had high oxidative stability against Fenton's reagent at room temperature. The proton conductivity of the crosslinked PDPAA membrane was 8.8 × 10?2 S/cm at 95% relative humidity (RH) and 80 °C, which was comparable to Nafion 112. Under low RH, the crosslinked PDPAA membrane showed the proton conductivity of 1.9 × 10?3 and 4.7 × 10?5 S/cm at 50 and 30% RH, respectively. The proton conductivity of the crosslinked PDPAA membrane lied in the highest class among the reported phosphonated polymers, and, consequently, the very high local concentration of the acids of PDPAA (IEC = 6.72 mequiv/g) achieved high and effective proton conduction under high RH. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
1000.
Toshikazu Takigawa Satoshi Yamasaki Kenji Urayama Masaoki Takahashi Toshiro Masuda 《Rheologica Acta》1996,35(3):288-295
Elastic properties of segmented polyurethaneureas (SPUs) under pure shear deformation were investigated. Data were analyzed by using strain energy density function (W). The values of the derivatives of W with respect to the invariants of the strain tensor (I
i
; i = 1, 2, 3 ) at zero strain limit were also estimated theoretically and were compared with those estimated by experiment. The limiting value of the derivative with respect to I
1 (W/I
1) was shown theoretically to be 5 G/8, while the derivatives with respect to I
2 and I
3 (W/I
2 and W/I
3 were respectively-G/8 and -3G/8. The theoretical prediction could explain the asymptotic behavior of the derivatives of SPUs as well as isoprene rubber (IR) reported by Kawabata et al. at small I
1 limit. 相似文献