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151.
A benign initiating system for cationic polymerization of isobutyl vinyl ether: Silver salt/aryl(alkyl) halide/lewis base 下载免费PDF全文
Li Lin Guangyou Zhang Koichi Kodama Mikio Yasutake Takuji Hirose 《Journal of polymer science. Part A, Polymer chemistry》2015,53(17):2050-2058
Aryl(alkyl) halides and silver salts were studied as environmentally benign initiating systems for cationic polymerization of isobutyl vinyl ether (IBVE). The reactivity of the benzyl cations could be effectively controlled by using dimethyl sulfide (Me2S) as an additive, which was shown to be an effective Lewis base (LB), and diethyl ether as a reaction solvent. Detailed study of various benzyl cations and the order of addition of the reagents revealed that the reaction was controlled by the electronic and steric features of aryl(alkyl) halides, LBs, and IBVE, and a plausible reaction mechanism was presented. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2050–2058 相似文献
152.
1‐Cyano‐1,2‐bis(biphenyl)ethene (CNBE) derivatives with a hexa(ethylene glycol) group as an amphiphilic side chain were synthesized and the self‐assembling character and fluorescence behavior were investigated. The amphiphilic derivatives showed aggregate‐induced enhanced emission (AIEE) in water and in the solid state. The fluorescence quantum yield increased as the rigidity of the aggregates increased (i.e., in ethyl acetate<in water<in the solid state). As determined from measurements of fluorescence spectra, fluorescence quantum yields, and fluorescence lifetimes, a key factor for the enhanced emission is suppression of the nonradiative decay process arising from restricted molecular motion. Additionally, the difference in the emission rate constant is not negligible and can be used to interpret the difference in fluorescence quantum yield in water and in the solid state. 相似文献
153.
Noji T Kamidaki C Kawakami K Shen JR Kajino T Fukushima Y Sekitoh T Itoh S 《Langmuir : the ACS journal of surfaces and colloids》2011,27(2):705-713
An oxygen-evolving photosynthetic reaction center complex (PSII) was adsorbed into nanopores in SBA, a mesoporous silica compound. We purified the dimer of PSII complex from a thermophilic cyanobacterium, Thermosynechococcus vulcanus, which grows optimally at 57 °C. The thermally stable PSII dimeric complex has a diameter of 20 nm and a molecular mass of 756 kDa and binds more than 60 chlorophylls. The SBA particles, with average internal pore diameters of 15 nm (SBA(15)) and 23 nm (SBA(23)), adsorbed 4.7 and 15 mg of PSII/g SBA, respectively. Measurement with a confocal laser-scanning microscope indicated the adsorption of PSII to the surface and the inner space of the SBA(23) particles, indicating the adsorption of PSII into the 23 nm silica nanopores. PSII did not bind to the inner pores of SBA(15). PSII bound to SBA(23) showed the high and stable activity of a photosynthetic oxygen-evolving reaction, indicating the light-driven electron transport from water to the quinone molecules added in the outer medium. The PSII-SBA conjugate can be a new material for photosensors and artificial photosynthetic systems. 相似文献
154.
Kazutoshi Tsuda Yuji Hirose Hironao Ogura Yasufumi Otsubo 《Colloids and surfaces. A, Physicochemical and engineering aspects》2008,324(1-3):228-233
The surface deformation induced in electric fields is studied on the comb pattern electrodes for silica suspensions. On the application of electric fields, a fine pattern with a waveform is developed from the smooth surface. The surface profiles can be approximated by single sinusoidal waves or their superposition depending on the sample thickness. In electric fields, the silica suspensions shows the viscosity decrease in steady shear and yield stress in the limit of zero shear rates. The viscosity decrease can be attributed to electrophoretic migration of particles to one electrode and the development of yield stress to eletrorheological effects due to chain formation of particles between electrodes. In thick liquid films, the dielectric polarization forces are predominant and the sinusoidal profiles with a wavelength of pitch of electrodes are formed. In thin films, the electrophoretic forces are predominant and the wavelength coincides with twice the pitch of electrodes. At intermediate thicknesses, the surface profiles can be expressed by a superposition of two sinusoidal waves. 相似文献
155.
Takada A Imaichi K Kagawa T Takahashi Y 《The journal of physical chemistry. B》2008,112(32):9660-9662
The effect of adding an inorganic salt, lithium chloride, and water on the viscosity of an ionic liquid, 1-n-butyl-3-methylimidazolium chloride (BmimCl), was investigated by shear stress measurements with a rheometer. The shear rate dependence of the viscosity showed shear thinning behavior, which implies that some structure should exist in the liquid and the structure should change at high shear rates. Addition of LiCl enhances the viscosity of BmimCl. The logarithmic value of zero-shear viscosity, eta(0), of BmimCl increases linearly and largely with increasing added salt content. The increasing rate of the viscosity by addition of LiCl was about 10 times larger than that for an aqueous solution of LiCl. When water is added into BmimCl, viscosity decreased. The increasing rate of the viscosity by addition of LiCl for BmimCl with about 5 wt % of water was almost the same as that for BmimCl without addition of water. 相似文献
156.
Prof. Hidemitsu Uno Kota Muramatsu Shogo Hiraoka Hiroyuki Tahara Mako Hirose Eidai Tamura Tatsumi Shiraishi Dr. John Mack Prof. Nagao Kobayashi Dr. Shigeki Mori Dr. Tetsuo Okujima Dr. Masayoshi Takase 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(25):5701-5708
A bicyclo[2.2.2]octadiene(BCOD)-fused bis(dipyrromethane) derivative was reacted with methylal in the presence of trifluoroacetic acid followed by oxidation with chloranil to give a doubly N-confused phlorin derivative, which did not undergo the retro-Diels–Alder reaction extruding an ethylene molecule on heating. In contrast, a 7-tert-butoxybicyclo[2.2.1]heptadiene(7-BuOBCHD)-fused bis(dipyrromethane) yielded benzene-ring-fused doubly N-confused porphyrins by following similar reaction sequences. 相似文献
157.
Z. Homonnay K. Nomura E. Kuzmann A. Vértes Y. Hirose T. Hasegawa 《Hyperfine Interactions》2008,184(1-3):69-74
Rutile-type Co x Ti1???x O2???d laser deposited on alumina substrate was studied after 57Co doping, using emission Mössbauer spectroscopy. It was found that although under certain conditions (i.e., which result in high conductivity) the thin rutile layers showed magnetooptical effect, the Mössbauer probe did not reveal any magnetic splitting, but showed paramagnetic Co3?+? (Fe3?+?) in the films of low electric resistance. This supports that these samples have carrier induced magnetism which is also connected to the defect structure of the rutile films. 相似文献
158.
T. Ohtsuki K. Shikano H. Yuki K. Hirose K. Takamiya 《Czechoslovak Journal of Physics》2006,56(1):D425-D432
In order to achieve a progressive experimental program, a new system for radioisotope production has been developed at one
of the beam-courses of a multipurpose Cyclotron of K=110 MeV. The upgraded beam-course is useful for the study of the nuclear physics and chemistry of heavy elements, radiopharmaceutical
studies, the production of radioactive tracers, activation analysis using charged particles, etc. Several topics are demonstrated
in the field of radioanalytical and nuclear studies. 相似文献
159.
Sohei Okazaki Yasushi Hirose Taro Hitosugi Toshihiro Shimada Tetsuya Hasegawa 《Applied Surface Science》2007,254(3):757-759
We propose a novel method for high-throughput quantitative analysis of thin-film conductivity σ by using a scanning microwave microscope (SμM). We demonstrated that composition spread thin films of Ti1-xNbxO2 can be utilized as a standard reference in a wide σ range. The shift in Q-value measured by SμM along the composition-spread axis showed a single peak, which moved to the lower x side with film thickness. This behavior was confirmed by electrical field simulation using the finite element method. 相似文献
160.