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311.
Imai H Matsumoto M Miyazaki T Kato K Tanida H Uruga T 《Chemical communications (Cambridge, England)》2011,47(12):3538-3540
The dynamical oxidation processes of Pt-skin layers on Pt(3)Co were investigated in situ and in real-time by time-resolved X-ray absorption spectroscopy combined with electrochemical measurements. Growth limit behaviors and the suppression of higher-order formation of surface oxides were observed, and these might explain the highly durable nature of Pt-skin layers. 相似文献
312.
313.
Interactions between proteins and biomaterial surfaces correlate with many important phenomena in biological systems. Such interactions have been used to develop various artificial biomaterials and applications, in which regulation of non-specific protein adsorption has been achieved with bioinert properties. In this research, we investigated the protein adsorption behavior of polymer brushes of dendrimer self-assembled monolayers (SAMs) with other generations. The surface adsorption properties of proteins with different pI values were examined on gold substrates modified with poly(amidoamine) dendrimer SAMs. The amount of fibrinogen adsorption was greater than that of lysozyme, potentially because of the surface electric charge. However, as the generations increased, protein adsorption decreased regardless of the surface charge, suggesting that protein adsorption was also affected by density of terminal group. 相似文献
314.
The lipase-catalyzed transesterifications of various substituted diphenyl 1,2-ketals of glycerol have been investigated. Efficient modification of the substrate structure with bis(4-bromophenyl) ketal was found to enhance the enantioselectivity up to E=57 at 0 °C. 相似文献
315.
Maki Sachiko Eiji Nishibori Shinobu Aoyagi Makoto Sakata Masaki Takata Mio Kondo Masaki Murata Ryota Sakamoto Hiroshi Nishihara 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(7):696-703
The title compound, [Fe2(C5H5)2(C40H22O2)] or 1,4‐(FcPh)2Aq [where FcPh is 2‐(4‐ferrocenylphenyl)ethynyl and Aq is anthraquinone], was synthesized in an attempt to obtain a new solvent‐incorporating porous material with a large void space. Thermodynamic data for 1,4‐(FcPh)2Aq show a phase transition at approximately 430 K. The crystal structure of solvent‐free 1,4‐(FcPh)2Aq was determined at temperatures of 90, 300 and 500 K using synchrotron powder diffraction data. A direct‐space method using a genetic algorithm was employed for structure solution. Charge densities calculated from observed structure factors by the maximum entropy method were employed for model improvement. The final models were obtained through multistage Rietveld refinements. In both phases, the structures of which differ only subtly, the planar Aq fragments are stacked alternately in opposite orientations, forming a one‐dimensional column. The FcPh arms lie between the stacks and fill the remaining space, leaving no voids. C—H...π interactions between the Ph and Fc fragments mediate crystal packing and stabilization. 相似文献
316.
Takeshi Takeda Shuichi Kuroi Makoto Ozaki Akira Tsubouchi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5-6):1291-1296
Abstract Trialkylsilyl group-directed regioselective transformations of alkynyl thioacetals to alkynylcyclopropanes and enynes are described. 相似文献
317.
Daisuke Kobayashi Yuko Endo Tadaaki Sakamoto Tomoki Takahashi Hideyuki Matsumoto Chiaki Kuroda Katsuto Otake Atsushi Shono 《Macromolecular Symposia》2013,324(1):55-61
Summary: Polypyrrole conducting polymers have been investigated widely for various applications because of their thermal and environmental stability and good electrical conductivity. Using chemical oxidative polymerization for the synthesis of polypyrrole particles, the reaction rate is very fast. In this study, we designed two new reaction fields for the synthesis of spherical polypyrrole nanoparticles. In the first system, oxidative polymerization of monomer droplets infused in a water/oil (W/O) emulsion reaction field was investigated. The second system employed dispersed monomer in an aqueous solution with a low concentration of oxidant in which polymerization was augmented by ultrasonic irradiation. Effective control of the reaction rate was important for enabling the synthesis of fine spherical polypyrrole particles. 相似文献
318.
Atsushi Ikeda Masaru Kawaguchi Yoshio Suzuki Tsukasa Hatano Munenori Numata Seiji Shinkai Akio Ohta Makoto Ohta 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):163-170
The calixarene-fullerene interaction,which causes only a slight change in the absorptionspectra, has been substantiated by calorimetricmeasurements: the H° values arecomparable with those obtained from the associationconstants estimated by a spectroscopic method. Furthermore, we determined the association constantbetween homooxacalix[3]arene and [60]fullerenederivatives with a porphyrin moiety by fluorescencespectra. 相似文献
319.
Tetsuji Yano Makoto Ebizuka Hiroyuki Yamamoto Shuichi Shibata Masayuki Yamane 《Journal of Sol-Gel Science and Technology》2000,19(1-3):845-849
Na2O-B2O3-SiO2 (NBS) gels containing a large amount of CdS quantum-dots (10 wt%) were densified using the hot press (HP) sintering method. By HP treatment, full-densification temperature could be lowered by about 40°C than that of the normal non-pressing (NP) heat treatment. Exciton absorption of CdS quantum-dots in HP-sample showed a large blue shift compared with that in the NP sample, and the size-distribution of CdS dots remained very sharp, with a mean particle diameter d = 3.66 nm and a standard deviation of = 0.72. HP pressure had a large effect on the reduction of sintering temperature and time, resulting in the suppression of the aggregation and growth of CdS quantum-dots in NBS glasses. 相似文献
320.
A convenient method for determination of sodium azide in beverages using ion chromatography is described. This method combines the specificity for azide with a simple sample preparation using a bubble and trap apparatus that removes any interferences. Sodium azide in a sample was acidified, and the azide was converted to the volatile hydrazoic acid, which was trapped in 2.5 mM sodium hydroxide solution. Determination was performed by isocratic ion chromatography using suppressed conductivity detection. Calibration curves were linear for 0.5 to 20 microg/mL sodium azide and the detection limit was 0.05 microg/mL. Recoveries of sodium azide from spiked samples (10.0 microg/g) were more than 82.6%. The method was then used to analyze various beverages. 相似文献