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991.
Yutaka Fujimoto Takayuki Yanagida Yuui Yokota Noriaki Kawaguchi Kentaro Fukuda Daisuke Totsuka Kenichi Watanabe Atsushi Yamazaki Akira Yoshikawa 《Optical Materials》2011,34(2):444-447
The undoped and 0.5% Ce3+-doped strontium metaborate SrB2O4 single crystals has been grown successfully by micro-pulling down method with radio frequency (RF) heating system, and scintillation characteristics including optical properties and radiation response were studied for these crystals. The Ce3+-doped SrB2O4 crystal showed absorption band around 240–320 nm, which is corresponding to the 4f-5d transition of Ce3+. Intense emission band at 375 nm due to the Ce3+ 5d–4f transition was observed under 241Am 5.5 MeV α-ray excitation. The scintillation decay time showed fast (50 ns) and slow (1430 ns) components ascribed to the Ce3+ 5d–4f transition and lattice defect in the crystal, respectively. The scintillation light yield of Ce3+-doped SrB2O4 was calculated to be about 1000 ph/n under 252Cf irradiation. 相似文献
992.
Impact-damage visualization in CFRP by resistive heating: Development of a new detection method for indentations caused by impact loads 总被引:1,自引:0,他引:1
Yoshiro Suzuki Akira TodorokiRyosuke Matsuzaki Yoshihiro Mizutani 《Composites Part A》2012,43(1):53-64
Rapid and automatic inspection of composite aircraft after every flight would reduce the safety factor and allow for more flights. Although, an electrical resistance change method (ERCM) has been proposed, there are many problems with its practical application. In this study, a new diagnostic method, impact-damage visualization, was developed. Indentation damage increases fiber-fiber contact at the interlaminar interface and electrical conductivity. Consequently, electrical current applied to the material will concentrate around the damaged area, and lead to selective and intense resistive heating. This temperature increase can be observed by thermography or detected as a change in electrical resistance caused by the temperature difference. The proposed method had sufficient reliability and sensitivity for practical application as a damage inspection method. 相似文献
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996.
A study of internal face finishing of the cooling channel in injection mold with free abrasive grains 总被引:1,自引:0,他引:1
Tatsuaki Furumoto Takashi UedaToru Amino Akira Hosokawa 《Journal of Materials Processing Technology》2011,211(11):1742-1748
This paper deals with a finishing method for the internal face of a cooling channel located in an injection mold that makes use of free abrasive grains. The injection mold is fabricated by layered manufacturing equipment using a ferrous based metal powder. When the internal pressure is loaded to the hydraulic cylinder, the solution containing the free abrasive grains is passed through the cooling channel. The internal face is then finished by the free abrasive grains. The effects of various conditions on finishing characteristics are investigated experimentally. The results showed that the internal face roughness of the cooling channel improved significantly during the first 1000s of finishing. The significant improvement achieved during the initial stages of finishing is due to the removal of the aforementioned unstable powders. Free abrasive grains are employed to remove the unstable powder on the internal face rather than to polish the alloyed face. The high-speed flow of the free abrasive grains results in an increase in their kinetic energy, thereby increasing the force with which they collide with the internal face and resulting in an improvement of the surface roughness. The internal face finishing was effective for the improvement of the thermophysical properties in the cooling channel. 相似文献
997.
Masao?KanekoEmail author Rie?Saito Hirohito?Ueno Junichi?Nemoto Akira?Izuoka 《Catalysis Letters》2011,141(8):1199-1206
Abstract
UV light-activated highly efficient photocatalytic decomposition of aqueous glucose and polysaccharides (starch and cellulose) to CO2 was successfully achieved by using a mesoporous TiO2 thin film coated on a fluorine-doped transparent conductive glass (FTO). The external quantum efficiency (η) of 0.08 (=8%) was obtained for glucose photodecomposition at neutral pH based on the total incident UV light, and the internal quantum efficiency (η′) was 8 (=800%) based on the photon that was effective for activating the reactant, demonstrating that the major decomposition mechanism is dark auto-oxidation of the activated reactant by O2. Glucose gave η′ values of 19 at pH 12 and 25 at pH 2 demonstrating that when a glucose molecule was once activated by one photon, the molecule can undergo auto-oxidative decomposition to CO2 at these pH under dark. Water-soluble starch was also photodecomposed completely to CO2 with estimated η′ value of 8.6. Water-soluble carboxymethyl cellulose (CMC) also underwent decomposition to CO2 with similar efficiency of η′ = 5. Solid state cellulose powders could be photodecomposed to CO2 by sandwiching them between FTO-coated TiO2 thin films. 相似文献998.
999.
Akira Taniike Yasutomo KidaYuichi Furuyama Akira Kitamura 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(24):3237-3241
The graft polymerization method is one of the most effective techniques to produce a new polymer with unique function. To produce the polymer, we conducted experiments on radiation graft polymerization using ion beams of several hundred keV energy. A high density polyethylene (PE) film was irradiated with H+ beams, then, graft polymerization with monomer solution such as acrylic acid or acrylonitrile was conducted. Radicals generated by the interaction between the beam ions and the PE molecules become the starting point of the graft polymerization. Since the range in PE depends on ion energy, the density distribution of the graft chain can be controlled by the ion energy. Using a mask which restricts the ion beam incidence, PE sheets containing graft chains only in the unmasked area were obtained. Multiple ion beam graft polymerization can produce a polymer which has some functional bases at specified position. We have demonstrated the production of a polymer film with a three-dimensional structure. 相似文献
1000.
Kentaro Fukuda Sumito IshizuNoriaki Kawaguchi Toshihisa SuyamaTakayuki Yanagida Yuui YokotaMartin Nikl Akira Yoshikawa 《Optical Materials》2011,33(8):1143-1146
Thirty millimeter diameter single crystal of Nd3+ doped LuF3 was grown using LiF as solvent. The single phase crystallization was confirmed by the powder X-ray diffraction, and high structural perfection was demonstrated by X-ray rocking curve (XRC) measurements. FWHM of XRC for 220 reflection was 32 arcsec. No remarkable absorption due to unfavorable impurities was observed from optical absorption measurements in the VUV spectral region. The crystal showed the VUV luminescence peaking around 178 nm that is consistent with the 4f25d-4f3 transition of Nd3+ ion. The luminescence intensity of Nd:LuF3 under X-ray irradiation was significantly higher than that of reported VUV scintillators such as Nd:LaF3 or Nd:LiLuF4. 相似文献