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61.
62.
Akihiro Ishimi Kozo Katsuyama Koji Maeda Tsuyoshi Nagamine Takeo Asaga Hirotaka Furuya 《Journal of Nuclear Science and Technology》2013,50(12):1144-1155
The X-ray CT technology previously developed by JAEA was upgraded. The shape of the X-ray source beam was changed from a circular shape to an elliptical one and the collimator slit width was decreased from 0.3 to 0.1 mm. The X-ray detector was improved by changing a CdWO4 scintillator to a highly sensitive silicon semiconductor detector. The analysis code of X-ray CT image was revised with respect to the number of points by using two kinds of experimental results and taking into account the effects of crack existence and deviation of the central void position from the radial center of a fuel pellet. As a result, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assemblies. The error of the dimensional measurement was improved from ±0.1 to ±0.03 mm by upgrading the instrument and revising the analysis code of X-ray CT image. The discriminating accuracy of density difference could be increased, and the low density region (undisturbed region) and high density region (equi-axial and columnar regions) in the X-ray CT image on the cross section of irradiated fuel could be discriminated from each other. The reliability of fuel performance analysis improves because a large number of PIE data can be collected, compared with the conventional destructive PIE. 相似文献
63.
The mechanism of the suppression of vapor explosions by adding inversely soluble polymers in water is studied. Vapor explosion experiments and quench experiment are conducted using a silver test piece. Polymetric solution (polyethylene oxide), of concentrations from 0 to 500 wppm, whose normalized viscosity (by water) varies from 1.00 to 2.00, is used. No vapor explosion is observed in the aqueous polymer solution at a concentration higher than 200 wppm. Quench experiments using the silver test piece submerged in the polymer solution and water are performed in order to examine the stability of film boiling. The suppression of the vapor film collapse is attributed to the precipitation of polyethylene as a gel around the vapor film. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(4): 297–306, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10037 相似文献
64.
Printed Electronics: Room‐Temperature Printing of Organic Thin‐Film Transistors with π‐Junction Gold Nanoparticles (Adv. Funct. Mater. 31/2014) 下载免费PDF全文
65.
The mechanical properties of styrene‐butadiene rubber (SBR) vulcanizates prepared using various plasticizers including liquid polybutadiene and styrene‐butadiene copolymers were investigated. The effect of the liquid polymers as the plasticizers on the mechanical properties of the polymers, such as the hardness, tensile storage modulus, tanδ, and the modulus at 100% elongation values, were determined before and after the thermal aging. As a result, it was revealed that the use of these liquid polymers gave less amount of change in the measurement values for the mechanical properties during the aging. The crosslinking density and the amount of free polymers were also determined on the basis of the swelling and extraction data, respectively, using several organic solvents. These results support the fact that the added liquid polymers are fixed to the SBR networks. We revealed the superiority of the liquid styrene‐butadiene copolymers as the plasticizer, which provides sufficient mechanical properties after vulcanization and the excellent maintenance of the properties during the thermal aging process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
66.
67.
Masaaki Takehisa Hiromasa Watanabe Hirondo Kurihara Kouichi Yamaguchi Hayato Nakajima Toshiaki Yagi Terutaka Watanabe Takanobu Sugo Takeshi Suwa Shinsaku Maruyama Atsuro Kodama Takeo Shimada Yoshio Maruyama Masamichi Tohei Takeshi Wada Sueo Machi 《应用聚合物科学杂志》1979,24(8):1831-1844
Radiation-induced polymerization of ethylene using aqueous tert-butyl alcohol as medium was carried out in a large-scale pilot plant with a 50-liter central source-type reactor at a pressure of 105 to 395 kg/cm2, temperature of 30° to 80°C, mean dose rate of 4.5 × 104 to 1.9 × 105 rads/hr, ethylene feed rate of 5.5 to 23.5 kg/hr, and medium feed rate of 21 to 102 l./hr. The space–time yield and molecular weight of the polymer were in the range of 4.7 to 16.8 g/l.-hr and 1.3 × 104 to 8.9 × 104, respectively. The space–time yield and molecular weight increased with mean residence time at 30°C, whereas at 80°C they became almost independent of the time. The space–time yield increased with pressure and dose rate, slightly decreased with temperature, and was maximum at ethylene molar fraction of 0.5. The polymer molecular weight increased with pressure and ethylene molar fraction, and decreased with dose rate and temperature. The total amount of deposited polymer on the reactor wall, source case wall, and scraping blades was usually less than 1 kg, which was negligibly small for the analysis of polymerization. Continuous discharge of the polymer slurry and production of fine-powder polyethylene were successfully carried out. In the central source-type reactor, a dose rate of 1.9 × 105 rads/hr was obtained with a 60Co source of ca. 12 kCi. 相似文献
68.
Keiichi Tomishige Tomohisa Miyazawa Takeo Kimura Kimio Kunimori Naoto Koizumi Muneyoshi Yamada 《Applied catalysis. B, Environmental》2005,60(3-4):299-307
In the partial oxidation of tar derived from the pyrolysis of cedar wood, the effect of H2S addition was investigated over non-catalyst, steam reforming Ni catalyst, and Rh/CeO2/SiO2 using a fluidized bed reactor. In the non-catalytic gasification, the product distribution was not influenced by the presence of H2S. Steam reforming Ni catalyst was effective for the tar removal without H2S addition, however, the addition of H2S deactivated drastically. In contrast, Rh/CeO2/SiO2 exhibited higher and more stable activity than the Ni catalyst even under the presence of high concentration of H2S (280 ppm). On the Ni catalyst, the adsorption of sulfur was observed by XPS and Ni species was oxidized during the partial oxidation of tar. In the case of Rh/CeO2/SiO2, the adsorption of sulfur was below the detection limit of XPS. This can be related to the self-cleaning of catalyst surface during the circulation in the fluidized bed reactor for the partial oxidation of tar derived from cedar pyrolysis. 相似文献
69.
70.
In estimating motions of multi-centered optical systems using the generalized camera model, one can use the linear seventeen-point
algorithm for obtaining a generalized essential matrix, the counterpart of the eight-point algorithm for the essential matrix
of a pair of cameras. Like the eight-point algorithm, the seventeen-point algorithm has degenerate cases. However, mechanisms
of the degeneracy of this algorithm have not been investigated. We propose a method to find degenerate cases of the algorithm
by decomposing a measurement matrix that is used in the algorithm into two matrices about ray directions and centers of projections.
This decomposition method allows us not only to prove degeneracy of the previously known degenerate cases, but also to find
a new degenerate configuration. 相似文献