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排序方式: 共有895条查询结果,搜索用时 15 毫秒
111.
Characterization of Cu Nanoparticles on TiO2 Photocatalysts Fabricated by Electroless Plating Method
Zheng Wang Kentaro Teramura Tetsuya Shishido Tsunehiro Tanaka 《Topics in Catalysis》2014,57(10-13):975-983
Cu-modified TiO2 photocatalysts (Cu/TiO2) were fabricated by electroless plating and wet impregnation methods. Photocatalytic activity for H2 production over Cu/TiO2 by electroless plating method was higher than that over Cu/TiO2 by impregnation method. Characterization of Cu nanoparticles by HRTEM, STEM-EDX, XRD and XAFS was studied. As compared to the wet impregnation method, the electroless plating method resulted in the formation of Cu nanoparticles with small size and uniform distribution on the TiO2 surface, which caused the enhancement of H2 production. XAFS measurement provided the evidences for the chemical state change of Cu species during the photocatalytic reaction. The process that Cu species varied from Cu2+ into Cu0 via Cu1+ as the intermediate under photoirradiation is very important for the H2 production, which indicates that the metallic Cu nanoparticles acted as the active sites and restrained the photogenerated charges recombination. 相似文献
112.
Koyama D Isago R Nakamura K 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(3):596-602
A liquid lens is proposed that uses acoustic radiation force with no mechanical moving parts. It consists of a cylindrical acrylic cell filled with two immiscible liquids (degassed water and silicone oil) and a concave ultrasound transducer. The focal point of the transducer is located on the oil-water interface, which functions as a lens. The acoustic radiation force is generated when there is a difference in the acoustic energy densities of different media. An acoustic standing wave was generated in the axial direction of the lens and the variation of the shape of the oil-water interface was observed by optical coherence tomography (OCT). The lens profile can be rapidly changed by varying the acoustic radiation force from the transducer. The kinematic viscosity of silicone oil was optimized to minimize the response times of the lens. Response times of 40 and 80 ms when switching ultrasonic radiation on and off were obtained with a kinematic viscosity of 200 cSt. The path of a laser beam transmitted through the lens was calculated by ray-tracing simulations based on the experimental results obtained by OCT. The transmitted laser beam could be focused by applying an input voltage. The liquid lens could be operated as a variable-focus lens by varying the input voltage. 相似文献
113.
Hibi Y Asai K Arafuka H Hamajima M Iwama T Kawai K 《Journal of Bioscience and Bioengineering》2011,111(5):547-549
La(3+) and not Ca(2+) increases methanol dehydrogenase (MDH) activity in Methylobacterium radiotolerans NBRC15690. La(3+)- and Ca(2+)-MDH-like proteins were found to be homodimeric (α(2)) and heterotetrameric (α(2)β(2)), respectively. N-terminal amino acid sequences of these proteins revealed that La(3+)- and Ca(2+)-MDH-like proteins were encoded by xoxF and mxaFI, respectively. 相似文献
114.
115.
Two Al2O3 powders with different particle sizes were sintered by pulse electric current sintering method at different heating rates. Rapid heating reduced grain growth rate, and the level of reduction depended on the initial powder size and sintering temperature. Under certain conditions, rapid heating could enhance densification. 相似文献
116.
F Suzuki N Toshida H Nawata N Yamamoto K Hirao N Miyasaka T Kawara K Hiejima T Harada 《Canadian Metallurgical Quarterly》1998,31(4):345-361
INTRODUCTION: Rapid atrial pacing in sinus rhythm may directly induce atrial flutter without provoking intervening atrial fibrillation, or initiate atrial flutter indirectly, by a conversion from an episode of transient atrial fibrillation provoked by rapid atrial pacing. The present study was performed to examine whether or not the direct induction of clockwise or counterclockwise atrial flutter was pacing-site (right or left atrium) dependent. METHODS AND RESULTS: We analyzed the mode of direct induction of atrial flutter by rapid atrial pacing. In 46 patients with a history of atrial flutter, rapid atrial pacing with 3 to 20 stimuli (cycle length = 500 - 170 ms) was performed in sinus rhythm to induce atrial flutter from 3 atrial sites, including the high right atrium, the low lateral right atrium, and the proximal coronary sinus, while recording multiple intracardiac electrograms of the atria. Direct induction of atrial flutter by rapid atrial pacing was a rare phenomenon and was documented only 22 times in 15 patients: 3, 11, and 8 times during stimulation, respectively, from the high right atrium, low lateral right atrium, and the proximal coronary sinus. Counterclockwise atrial flutter (12 times) was more frequently induced with stimulation from the proximal coronary sinus than from the low lateral right atrium (8 vs 1, P = .0001); clockwise atrial flutter (10 times) was induced exclusively from the low lateral right atrium (P = .0001 for low lateral right atrium vs proximal coronary sinus, P = .011 for low lateral right atrium vs high right atrium). CONCLUSIONS: Direct induction of either counterclockwise or clockwise atrial flutter was definitively pacing-site dependent; low lateral right atrial pacing induced clockwise, while proximal coronary sinus pacing induced counterclockwise atrial flutter. Anatomic correlation between the flutter circuit and the atrial pacing site may play an important role in the inducibility of counterclockwise or clockwise atrial flutter. 相似文献
117.
Yibin Zhang Toshimi Yamane Keiichi Hirao Yoritoshi Minamino 《Journal of Materials Science》1991,26(21):5799-5805
Al-Cu alloys near the Al-Al2Cu equilibrium eutectic composition were rapidly solidified by the single-roller method. Two-zone structures were observed in transverse sections of Al-24.8, 30.0, 32.7, 33.2, 37.0 and 40.3 mass % Cu alloy ribbons, which were interpreted on the basis of the difference in cooling rates and of the temperature gradients between the chilled and free-surface sides of the ribbons. Non-equilibrium eutectic structures, cellular and irregular lamellar, were seen at the chilled side because the alloy liquids were directionally solidified with coupled eutectic growth. The coupled zone of the Al-Cu alloy expanded over the composition range 24.8–40.3 mass % Cu by rapid solidification. Dendritic structures were formed at the unchilled side of Al-24.8, 30.0, 37.0 and 40.3 mass % Cu alloys. Vickers hardness values at the chilled side differed from those at the unchilled side due to the difference in the microstructure. 相似文献
118.
119.
Kentaro Kuratani Masayasu Uemura Minoru Mizuhata Akihiko Kajinami Shigehito Deki 《Journal of the American Ceramic Society》2005,88(10):2923-2927
We report on the direct deposition of high-quality ZrO2 thin films on various kinds of substrates by the liquid phase deposition method. After reaction for 24 h, thin films formed on various kinds of substrates, and the obtained thin film was comprised of densely packed nano-sized particles. The film annealed at 500°C showed a tetragonal phase at room temperature and this phenomenon has been discussed from the viewpoint of crystallite size effect. The result of optical transmittance measurement revealed that high transparency, more than 70% transmittance, has been achieved for the film after annealing at 900°C. 相似文献
120.
N Ide Y Hata K Hirao M Irie M Deguchi I Yao A Satoh M Wada K Takahashi H Nakanishi Y Takai 《Canadian Metallurgical Quarterly》1998,244(1):258-262
We have recently isolated a rat homologue of the Caenorrhabditis elegans lin-10 product. Although rat lin-10 is expressed in the cytosol and membrane fractions of various tissues, it is distributed only in the membrane fraction in brain where it is enriched in the synaptic plasma membrane and postsynaptic density fractions. We have isolated here a rat lin-10-interacting protein from rat brain and identified it to be neurabin-II/spinophilin, which has recently been isolated as a protein interacting with protein phosphatase I and F-actin. Neurabin-II/spinophilin is ubiquitously expressed but enriched in brain, especially in the synaptic plasma membrane and postsynaptic density fractions. We discuss the physiological significance of the interaction of rat lin-10 with neurabin-II/spinophilin. 相似文献