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71.
Sea urchin gonads are highly priced sushi foodstuff “Uni” in Japanese traditional food, but after removal of them the residual shells with spines are dumped as waste. However, sea urchin shells contain naphthoquinone pigments with several phenolic hydroxyl groups, which were expected to act as potent antioxidant substances by donating hydrogens. Our previous study has evaluated their antioxidant ability to depress lipid peroxidation. This study examined other antioxidant property of the pigments from purple sea urchin shells, which possess larger amount of pigments than those of red and green sea urchins. The pigments as well as known antioxidant, α-tocopherol, exhibited 1,1-diphenyl 2-picryhydrazyl (DPPH) radical scavenging ability. Superoxide anion radical and hydrogen peroxide were also scavenged while hydroxyl radical, one of the most reactive oxygen species, was not significantly inhibited. However, because the pigments had significant activity to scavenge hydrogen peroxide and superoxide anion radical that could be in vivo precursors of hydroxyl radical, sea urchin pigments would be able to depress the generation of its related active oxygen radical species. These results suggested that sea urchin shells, which are still regarded as food waste, would be a new bio-resource for obtaining natural antioxidant. 相似文献
72.
73.
Palladium-platinum nanoalloys with a core-shell and nano-network structure were successfully synthesized by a hydrogen sacrificial protective method in an aqueous solution directly using a perfluorinated sulfonic acid (PFSA) ionomer as a protecting agent. The structure, local composition and electrocatalytic activity for the oxygen reduction reaction of the Pd/Pt/PFSA nanoalloys were investigated by transmission electron microscopy (TEM), aberration corrected scanning transmission electron microscopy (Cs-STEM), energy-dispersive X-ray spectrometry (EDS) and voltammetry. The core-shell structure was completed without contaminating reducing agents, organic solvents, useless protecting agents and a mediator. The Pd/Pt/PFSA core-shell nanoalloys realized a high electrochemical surface area and better electrocatalytic mass-activity for the oxygen reduction reaction than the Pt/PFSA nanoparticles. 相似文献
74.
Koji Sugano Yuki Uchida Osamu Ichihashi Hideo Yamada Toshiyuki Tsuchiya Osamu Tabata 《Microfluidics and nanofluidics》2010,9(6):1165-1174
Gold nanoparticles with diameters of a few tens of nanometer and a narrow size distribution were synthesized using a pulsed
mixing method with a microfluidic system which consists of a Y-shaped mixing microchannel and two piezoelectric valveless
micropumps. This mixing method enables control of the mixing speed of gold salts and reducing agent by changing the switching
frequency of the micropumps, which was our focus to improve the particle size distribution, which is an essential parameter
in gold nanoparticle synthesis. In the proposed method, the mixing time was inversely proportional to the switching frequency
and the minimum mixing time was 95 ms at a switching frequency of 200 Hz. During synthesis experiments, the mean diameter
of the synthesized gold nanoparticles was found to increase, and the coefficient of variation of particle size was found to
decrease with decreasing mixing time. We successfully improved the coefficient of variation to less than 10% for a mean diameter
of around 40 nm. 相似文献
75.
Takanori Isobe Taku Takaku Tadayuki Kitahara Hideo Sumitani Ryuichi Shimada 《Electrical Engineering in Japan》2009,169(4):65-74
This paper proposes a power supply suitable for driving linear induction motors. The power supply consists of a voltage source inverter (VSI) and a magnetic energy recovery switch (MERS). Circuit configuration and operation principles of the power supply are described. Power factor correction by MERS can increase the output power. Technical advantages of using MERS compared with increasing the rated voltage of VSI are discussed. Some experiments with a linear induction motor were conducted. The results confirm that MERS can reduce the capacity of the VSI or increase the output with the same VSI capacity. The number of devices and magnitude of losses are evaluated on a large‐scale drive system. A half‐bridge type of MERS is provided and discussed. The half‐bridge MERS mitigates disadvantages of using MERS. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(4): 65–74, 2009; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20832 相似文献
76.
The block copolymers consisting of 2,7-dimethoxycarbazole- and oxadiazole-containing segments as hole and electron transporting units, respectively, were synthesized by NMRP manner. OLED devices were fabricated using block copolymer, random copolymer, and polymer blend for matrix of the emitting layer with Ir(ppy)3 as a phosphorescent dopant in order to investigate morphological effect on the performance. From the finding that the block copolymer system overwhelmed the others in EQE, we assumed that a morphology with dimethoxycarbazole units assembled to the surface of PEDOT:PSS played a considerable role for effective recombination of charges as well as sufficient charge injection into the emitting layer. 相似文献
77.
Akihito Takeuchi Kazuhiro Hosono Gen Tatara 《Journal of Superconductivity and Novel Magnetism》2010,23(1):31-32
We show theoretically that charge and spin currents arise from spin dynamics in the presence of the spin–orbit interaction.
The dominant calculation is the inverse spin Hall effect, namely the spin current pumped from precession of local spins is
converted into the charge current by the spin–orbit interaction. The conversion mechanism is explained based on the conservation
laws of charge and spin. 相似文献
78.
Hidenori Hiramatsu Yoichi Kamihara Hiroshi Yanagi Kazushige Ueda Toshio Kamiya Masahiro Hirano Hideo Hosono 《Journal of the European Ceramic Society》2009,29(2):245-253
Optoelectronic properties and device applications of layered mixed-anion compounds such as oxychalcogenide LaCuOCh (Ch = chalcogen) and oxypnictide LaTMOPn (TM = 3d transition metal, Pn = pnicogen) are reviewed. Several distinctive functions have been found in these materials based on our original material exploration concept. Fabrication of high-quality epitaxial films of LaCuOCh leads to clarifying the excellent electrical and optical properties such as high hole mobility of 8 cm2/(V s) and heavy hole doping at >1021 cm?3 in LaCuOSe, and sharp and tunable-wavelength photoluminescence in the solid–solution systems in LaCuOCh. In addition, a room temperature operation of a light-emitting diode is demonstrated using LaCuOSe as a light-emitting layer. These results suggest that the layered oxychalcogenides have potential for light-emitting layers as well as transparent hole-injection layers in organic/inorganic light-emitting diodes. Furthermore, by extending the material system from the copper-based oxychalcogenides to isostructural compounds, transition metal-based oxypnictides LaTMOP (TM = Fe, Ni), we have found novel superconductors, LaFeOP and LaNiOP. 相似文献
79.
Shin-ichi Morita Yasutaka Hayamizu Akihiko Horibe Naoto Haruki Hideo Inaba 《热科学学报(英文版)》2013,22(2):145-151
Recently, much attention has been paid to investigate the latent heat storage system. Using of ice heat storage system brings an equalization of electric power demand, because it will solved the electric -power-demand-concentration on day-time of summer by the air conditioning. The flowable latent heat storage material, Oil/Water type emulsion, microencapsulated latent heat material-water mixture or ice slurry, etc., is enable to transport the latent heat in a pipe. The flowable latent heat storage material can realize the pipe size reduction and system efficiency improvement. Supercooling phenomenon of the dispersed latent heat storage material in continuous phase brings the obstruction of latent heat storage. The latent heat storage rates of dispersed water drops in W/O (Water/Oil) emulsion are investigated experimentally in this study. The water drops in emulsion has the diameter within 3 ~ 25μm, the averaged water drop diameter is 7.3μm and the standard deviation is 2.9μm. The direct contact heat exchange method is chosen as the phase change rate evaluation of water drops in W/O emulsion. The supercooled temperature and the cooling rate are set as parameters of this study. The evaluation is performed by comparison between the results of this study and the past research. The obtained experimental result is shown that the 35K or more degree from melting point brings 100% latent heat storage rate of W/O emulsion. It was clarified that the supercooling rate of dispersed water particles in emulsion shows the larger value than that of the bulk water. 相似文献
80.
Experimental values of the thermal conductivity and the thermal diffusivity of six pure liquid n-alkanes (C
n
H2n+2; n=5 to 10) and toluene are presented in the temperature range of –20 to 70°C under atmospheric or saturation pressure. Measurements were made with the transient hot-wire method, and in the analysis, the temperatures T
and T
(associated with both and ) were used. In the present work, the values of thermal diffusivity were corrected by the factors k
f (=1.0076 to 0.9892) for data sets obtained with different configurations of the experiment, in which the factors were determined by reference to the thermal diffusivity of n-heptane [=
s/(c
p
)s] at 298.15 K calculated from the volumic heat capacity (c
p
)s as a reference material for heat capacity and the experimentally obtained thermal conductivity
s. The uncertainty of the data is estimated to be 0.48% for the thermal conductivity (absolutely measured) and about 1.8% for the thermal diffusivity (with a coverage factor of k
p
=2; p=95%). 相似文献