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71.
Hideo Mori Takenobu Kaida Masaki Ohno Suguru Yoshida Yoshinori Hamamoto 《Journal of Nuclear Science and Technology》2013,50(4):373-383
Supercritical pressure water cooled reactor (SCWR) has been regarded as an innovative nuclear reactor. For the design and development of the SCWR, heat transfer performance under supercritical pressure is one of the most important indicators. In this paper, experimental data are presented on the heat transfer to a supercritical pressure fluid flowing vertically upward and downward in a small diameter heated tube and two sub-bundle channels with three heater rods and seven heater rods, using HCFC22 as the test fluid. Downstream of grid spacer for the sub-bundles, heat transfer enhancement was observed in the upward flow, but not in the downward flow. The enhancement was remarkable especially when the heat transfer deterioration occurs in the fully developed region unaffected by the spacer. The heat transfer correlation for the downstream region of the spacer was developed in the normal heat transfer of sub-bundles. In the fully developed region for the sub-bundle, occurrence of the heat transfer deterioration was suppressed or degree of the deterioration was moderated. At high mass velocity for downward flow in the seven rod sub-bundle, oscillation of heat transfer was observed in the region of the enthalpy over the pseudocritical point. 相似文献
72.
The drying process of durum wheat semolina dough was measured by thermogravimetry in the temperature and relative humidity ranges of 30–90 °C and 0–80%, respectively, in order to predict the drying process of pasta under any drying conditions. About 20% of the water was evaporated during the constant drying-rate period which has been ignored in previous studies. It is demonstrated that the constant drying-rate period should be taken into account in order to predict the drying curve with a high accuracy. The drying rate during the constant drying-rate period and the mass transfer coefficient estimated by the thermogravimetric analysis were expressed as functions of the temperature and relative humidity, and they were useful for predicting the drying processes of pasta under any drying conditions including the programmed ones. 相似文献
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High-durability lead zirconate titanate (PZT) ceramics were developed in the present study to prevent time-dependent deterioration of displacement, as well as failure under operation. Current leakage in PZT was decreased by adding elemental manganese, changing the zirconium content from 54.0 to 54.2 mol%, and decreasing the antimony content. Displacement was improved by adding both manganese and indium to the PZT. The present investigation resulted in the development of PZT compositions with high displacement and low time-dependent displacement degradation. These results were confirmed by analyzing stack actuators made from enhanced PZT compositions. 相似文献
76.
Microflaps: Magnetically Responsive Microflaps Reveal Cell Membrane Boundaries from Multiple Angles (Adv. Mater. 18/2014)
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77.
Li Z Qin Y Mu Y Chen T Xu C He L Wan J Song F Zhou J Han M Wang G 《Journal of nanoscience and nanotechnology》2011,11(8):7042-7046
Thin Bi2Te3 flakes, with as few as 3 quintuple layers, are optically visualized on the SiO2-capped Si substrates. Their optical contrasts vary with the illumination wavelength, flake thickness and capping layers. The maximum contrast appears at the optimized light with the 570 nm wavelength. The contrast turns reversed when the flake is reduced to less than 20 quintuple layers. A calculation based on the Fresnel law describes the above observation with the constructions of the layer number-wave length-contrast three-dimensional (3D) diagram and the cap thickness-wavelength-contrast 3D diagram, applicative in the current studies of topological insulating flakes. 相似文献
78.
Takenobu Suzuki Shin-ichiro Masaki Kento Mizuno Yasutake Ohishi 《Optical Materials》2011,33(12):1943-1947
Transparent glass–ceramics containing YLiF4 nano-crystals were synthesized by controlled heat-treatments of LiFYF3Al2O3SiO2 glass. The crystallite size estimated to be about 8 nm was much less than the wavelength of the visible light. The transmittance of the glass–ceramic with a thickness of 2 mm was more than 85% at 400 nm and as high as 95% in the infrared region. The fluorescence centered around 1000 nm was hardly observed from Er3+-doped precursor glass under 800 nm excitation, while the emission with the Stark spitting was clearly observed for the Er3+-doped glass–ceramic. The phonon sideband of the 7F0 → 5D2 excitation spectra of Eu3+ reveals that Eu3+ doped in precursor glass is in silicate network while Eu3+ doped in the glass–ceramic is in not only silicate framework but also fluoride framework. These results indicate that rare-earth ions such as Er3+ and Eu3+ could be successfully incorporated into YLiF4 nano-crystals in the glass–ceramics. 相似文献
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Ryoichi Kurose Takenobu Michioka Naoki Kohno Satoru Komori Yuya Baba 《American Institute of Chemical Engineers》2011,57(4):911-917
Large‐eddy simulations using the flamelet models are applied to turbulent reacting liquid flows and validated by comparing with the experiments. The computations are performed for two reaction conditions, namely a rapid reaction and a moderately fast reaction in a grid‐generated turbulent flow. For the flamelet models, both the steady flamelet model and the unsteady Lagrangian flamelet model are tested. A second‐order, irreversible, and isothermal reaction is considered. The results show that the flamelet models inherently developed for turbulent combustion are applicable to turbulent reacting liquid flows, provided that the model coefficient in evaluating the subgrid scale variance of mixture fraction in the scale‐similarity model is set to be 5.0. The rapid reaction can be adequately predicted by both the steady and unsteady Lagrangian flamelet models, whereas the moderately fast reaction can be predicted only by the unsteady Lagrangian flamelet model which is capable to take slow chemical processes into account. © 2010 American Institute of Chemical Engineers AIChE J,, 2011 相似文献