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91.
Okuda T Kato J Mori J Tenmoku M Suda Y Tanaka S He K Ma Y Yang F Yu X Duan F Lei Y 《The Science of the total environment》2004,330(1-3):145-158
This paper describes the daily concentrations of trace metals and ionic constituents in the aerosol of Beijing, China from March 2001 to August 2003. Daily PM10 concentrations were also measured from September 2001 to August 2003. The daily average PM10 concentration at Beijing, China from September 2001 to August 2003 was 171+/-117 microg m(-3) (n = 673), which is 5-fold higher than at Yokohama, Japan. Trace metal concentrations were analyzed by using inductively coupled plasma mass spectrometry equipped with a laser ablation sample introduction (LA/ICP-MS), which is a rapid and simultaneous method for multi-element analysis. The daily average metal concentrations in TSP in Beijing from March 2001 to August 2003 were: Al: 3.5+/-2.4 (n = 727), Ti: 0.47+/-0.35 (n = 720), V: 0.013+/-0.010 (n = 716), Cr: 0.019+/-0.015 (n = 618), Mn: 0.24+/-0.16 (n = 730), Fe: 5.5+/-3.9 (n = 728), Co: 0.0046+/-0.0055 (n = 629), Ni: 0.022+/-0.024 (n = 680), Cu: 0.11+/-0.11 (n = 660), Zn: 0.77+/-0.60 (n = 726), As: 0.048+/-0.047 (n = 731), Se: 0.010+/-0.010 (n = 550), Cd: 0.0068+/-0.0082 (n = 709), Sb: 0.033+/-0.036 (n = 687), and Pb: 0.43+/-0.50 (n = 728) (unit, microg m(-3)). All the metal concentrations in TSP in Beijing, China were 1.7-21.8 times higher than those in TSP in the center of Tokyo, Japan. Notably, As concentrations in TSP in Beijing were 20-fold higher than those in Tokyo. Source identification of aerosols in Beijing was carried out by using the chemical mass balance (CMB) receptor model, with the daily concentration of metals in the aerosol. The major primary sources of the aerosol of Beijing were considered to be soil dust and coal combustion. Vehicle exhaust contribution tended to increase. 相似文献
92.
To evaluate the oxidation behavior of high-burnup advanced fuel cladding tubes in high-temperature steam, laboratory-scale isothermal oxidation tests were conducted using the following advanced fuel cladding tubes with burnups of up to 85 GWd/t: M-MDATM, low-tin ZIRLOTM, M5®, and Zircaloy-2 (LK3). These oxidation tests were performed in steam-flowing conditions at temperatures ranging from 1173 to 1473 K for durations between 120 and 4000 s, and the oxidation kinetics was evaluated. The oxidation kinetics of the high-burnup advanced fuel cladding tube specimens estimated by assuming the parabolic rate law was comparable to or slower than that of the unirradiated Zircaloy-4 cladding tube specimens reported in a previous study. It is considered that the protective e?ect of the corrosion layer hindered oxidation. Furthermore, no increase in the oxidation kinetics because of the pre-hydriding was observed. The onset times of the breakaway oxidations of these cladding tube specimens were comparable to those of the unirradiated Zircaloy-4 cladding tubes reported in previous studies. Therefore, it is considered that the burnup extension up to 85 GWd/t and the use of the advanced fuel cladding tubes do not significantly increase the oxidation kinetics and do not significantly reduce the onset time of the breakaway oxidation. 相似文献
93.
Shoji Eita Takahashi Ryuji Isogai Shosei Ito Naoto Kubo Masaki Tsukada Takao Fukuyama Hiroyuki 《Metallurgical and Materials Transactions B》2019,50(5):2454-2458
Metallurgical and Materials Transactions B - Normal spectral emissivity of molten Cu-Fe alloy with different compositions was measured at the wavelength of 807 nm using an electromagnetic... 相似文献
94.
Takeyuki Gotoh Fuyuki Abe Takenori Ishizu Masaki Yoshio 《Journal of power sources》1996,60(2):193-196
A study of the pyrolysis of an aqueous solution of manganese nitrate in the presence of silver compounds has been carried out. Thermal analysis showed that the MnO2 formation temperature and the transformation temperature from MnO2 to Mn2O3 shifted towards a lower temperature in the presence of silver acetate. A large particle-size and high crystallinity MnO2 was formed; this may be a useful method of making an excellent tantalum capacitor with high capacitance. 相似文献
95.
Hashimoto A Mitsuishi K Shimojo M Zhu Y Takeguchi M 《Journal of electron microscopy》2011,60(3):227-234
We experimentally examined the characteristics of bright-field (BF) scanning confocal electron microscopy (SCEM) images by changing the observation conditions and comparing the images with those obtained by BF transmission electron microscopy (TEM) and BF scanning TEM (STEM) modes. The observation of 5-nm-diameter Au nanoparticles demonstrated that BF-SCEM produces object elongation of more than 2000?nm along the optical axis, as do BF-TEM and BF-STEM. We demonstrated the relationship between elongation length and geometric effects such as convergence and collection angles of a probe and the lateral size of an object; the relationship is consistent with previous theoretical prediction. Further, we observed interesting features that are seen only in the BF-SCEM images; the film contrast was strongly enhanced, compared with that of BF-STEM. In addition, a bright contrast appeared around the object position in the elongated images. Using this characteristic, we could determine the object position and structure. 相似文献
96.
M. Tanaka K. Ozaki H. Nishino H. Ebe Y. Miyamoto 《Journal of Electronic Materials》1998,27(6):579-582
We employed AgNO3 solutions for doping Ag in liquid phase epitaxy (LPE) grown Hg0.78Cd0.22Te epilayers and found that the minority carrier lifetimes became longer so that the diode properties improved. After annealing
LPE grown Hg(1-x)Cd(x)Te layers (x=0.22) in Hg atmosphere, the epilayers were immersed in an AgNO3 solution at room temperature. The typical carrier concentrations of holes was 3 × 1016 cm−3 at 77K. These values were almost the same as for the nondoped wafers. Also, its acceptor level was 3 to 4 meV. This shows
that the Ag was activated. The doped crystals have lifetimes several times longer than those of the nondoped crystals. Numerical
fitting showed the lifetime was limited mostly by the Auger 7 process. The Shockley-Read-Hall recombination process was not
effective. To examine the Ag-doped wafer, we fabricated photodiodes using standard planar technology. The diodes have an average
zero-bias resistance of several MΩ and a shunt resistance of about 1 GΩ for a 10 μm cutoff wavelength at 78K. These values
are about four times higher than those of nondoped diodes. The photo current is also two times higher at the same pixel size.
This shows that the quantum efficiency is increased. The extension of the lifetime contributes to the high resistance and
the high quantum efficiency of the photodiode. 相似文献
97.
Shoya Ueno Yuki Nakamura Ken-Ichi Sugioka Masaki Kubo Takao Tsukada Masahito Uchikoshi Hiroyuki Fukuyama 《International Journal of Thermophysics》2017,38(2):16
The normal spectral emissivity of molten Cu–Co alloy with different compositions was measured in the wavelength range of 780 nm to 920 nm and in the temperature range of 1430 K to 1770 K including the undercooled condition by an electromagnetic levitator superimposed with a static magnetic field. The emissivity was determined as the ratio of the radiance from a levitated molten Cu–Co droplet measured by a spectrometer to the radiance from a blackbody calculated by Planck’s law at a given temperature, where a static magnetic field of 2.5 T to 4.5 T was applied to the levitated droplet to suppress the surface oscillation and translational motion of the sample. We found little temperature dependence of the normal spectral emissivity of molten Cu–Co alloy. Concerning the composition dependence, the emissivity decreased markedly above 80 at%Cu and reached that of pure Cu, although its dependence was low between 20 at%Cu and 80 at%Cu. In addition, this composition dependence of the emissivity of molten Cu–Co alloy can be explained well by the Drude free-electron model. 相似文献
98.
Motoyuki Ozaki Toshimitsu Higashi Taiki Ogata Tatsunori Hara Jose Ildefonso Udang Rubrico 《Advanced Robotics》2016,30(22):1446-1457
Distribution centers, which are essential to our society, are becoming increasingly important. Although the efficiency of an AVS/RS (Autonomous vehicle storage and retrieval system) makes it a promising system, there is still much to be studied regarding its effective use and design. This paper proposes a method of designing AVS/RSs through a quantitative consideration of group constraint by utilizing probability theory. The proposed algorithm also deals with the problem of designing the sizes of several buffers, and considers the effect of load fluctuations, which are important for real-world operation, by use of queuing network theory. Effectiveness of the proposed algorithm is shown with simulations of various number of groups, those of various safety factors for fluctuations, and those of various evasion rates for buffer overflow. The design results are shown to be much different from those which do not consider those factors. The results prove that the proposed method provides an accurate quantitative assessment of the AVS/RS’s constraints. 相似文献
99.
Toshiki Tsubota Masaki Morita Sunao Kamimura Teruhisa Ohno 《Journal of Porous Materials》2016,23(2):349-355
Unconventional pretreatment, that is, delignification and the addition of guanidine phosphate, was performed for the synthesis of activated carbon having a high specific surface area from bamboo by physical activation. The values of the specific surface area, total pore volume, and average pore size depended on the amount of added guanidine phosphate and the CO2 activation time. The amount of the added guanidine phosphate under the optimum conditions for the highest specific surface area was much lower than that of the phosphorous acid chemical activator under conventional conditions. The N2 adsorption isotherms of all the samples were type I, which means that micropores were dominant. The pore sizes of the samples in this study were similar to that of the physically-activated carbon. Therefore, the activation process was presumed to be essentially not chemical, but physical. The relation between the yield and the specific surface area improved with the addition of guanidine phosphate. The reason for the improvement may be the change in the reactivity of the carbon material generated during the heating process. The maximum specific surface area was ca. 2000 m2 g?1, which is a high value for a physically-activated carbon. 相似文献