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排序方式: 共有1930条查询结果,搜索用时 15 毫秒
51.
Ninomiya Yuma Sasaki Hideaki Yoshikawa Takeshi Maeda Masafumi 《Metallurgical and Materials Transactions B》2019,50(1):407-415
Metallurgical and Materials Transactions B - The dissolution and passivation of pure Cu and Cu-5 wt pct Ag anodes in H2SO4-CuSO4 electrolyte were investigated by a direct... 相似文献
52.
Miwa N Kashiwagi M Kawamori F Masuda T Sano Y Hiroi M Kurashige H 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2006,47(2):41-45
The incidence and levels of Vibrio parahaemolyticus and thermostable direct hemolysin gene (tdh)-positive organisms in retail seafood were determined. The most probable number-polymerase chain reaction (MPN-PCR) method using a PCR procedure targeting the species-specific thermolabile hemolysin gene (tlh) and tdh was used to determine the levels of V. parahaemolyticus and tdh-positive organisms, respectively. In seafood for raw consumption, V. parahaemolyticus was found in four (13.3%) of 30 fish samples, 11 (55.0%) of 20 crustacean samples, and 29 (96.7%) of 30 mollusc samples. Levels of V. parahaemolyticus were below 10(4) MPN/100 g in all fish and crustacean samples tested. However, they were above 10(4) MPN/100 g in 11 (36.7%) of the 30 mollusc samples. In all seafood for raw consumption, the level of tdh-positive organisms was below the limit of detection (< 30 MPN/100 g). In seafood for cooking, V. parahaemolyticus was found in 15 (75.0%) of 20 fish samples, nine (45.0%) of 20 crustacean sample, and 20 (100%) of 20 mollusc samples. Levels of V. parahaemolyticus were above 10(4) MPN/100 g in only three (15.0%) and one (5.0%) of the 20 fish and 20 crustacean samples, respectively. However, they were above 10(4) MPN/100 g in 18 (90.0%) of the 20 mollusc samples. In seven (35.0%) of the 20 mollusc samples, tdh-positive organisms were found and their levels ranged from 3.6x10 to 1.1 x 103 MPN/100 g. From four of seven tdhpositive samples, tdh-positive V. parahaemolyticus was isolated. 相似文献
53.
Koichiro Oishi Genki Saito Kiyoshi Ebina Masanori Nagahashi Kazuo Jimbo Win Shwe Maw Hironori Katagiri Makoto Yamazaki Hideaki Araki Akiko Takeuchi 《Thin solid films》2008,517(4):1449-1452
Cu2ZnSnS4 films were grown on Si (100) by vacuum evaporation using elemental Cu, Sn, S and binary ZnS as sources. X-ray diffraction patterns of films grown at different substrate temperatures indicated that polycrystalline growth was suppressed and the orientational growths were relatively induced in a film grown at higher temperatures. Tetragonal structure of Cu2ZnSnS4 films was confirmed by studying RHEED patterns. The existence of c-axis ([001] direction) growth, two kinds of a-axis (〈100〉 direction) growth and four kinds of {112} twins which can be classified as two symmetrical pairs is proposed. Broad emissions at around 1.45 eV and 1.31 eV were observed in the photoluminescence spectrum measured at 13 K. 相似文献
54.
Hideaki Ohkubo Z. Tang Y. Nagai M. Hasegawa T. Tawara M. Kiritani 《Materials Science and Engineering: A》2003,350(1-2):95-101
Vacancies and vacancy clusters in Ni, Cu, and Fe induced by high- and low-speed deformations are studied systematically by positron annihilation techniques and are compared with those induced by the conventional-rolling. To clarify the nature of the defects, the experimental results are compared with our superimposed-atomic-charge calculations of the positron lifetimes in the vacancy clusters as a function of their size. It is found that the deformation-induced defects in the fcc and bcc metals are significantly distinct. In the fcc metals of Ni and Cu, monovacancies with high number densities are induced by the high- and low-speed deformations and by heavy conventional-rolling (>10% in Ni and >40% in Cu). Vacancy clusters are observed after the high- and low-speed deformation for Ni and after the conventional-rolling for Cu. On the contrary, dislocations and vacancy clusters are introduced in bcc Fe regardless of the type or degree of deformation. 相似文献
55.
An accurate nonlinearity compensation technique for voltage source inverter (VSI) inverters is presented in this paper. Because of the nonlinearity introduced by the dead time, turn-on/off delay, snubber circuit and voltage drop across power devices, the output voltage of VSI inverters is distorted seriously in the low output voltage region. This distortion influences the output torque of IM motors for constant V/f drives. The nonlinearity of the inverter also causes 5th and 7th harmonic distortion in the line current when the distributed energy system operates in the grid-connected mode, i.e., when the distributed energy system is parallel to a large power system through the VSI inverter. Therefore, the exact compensation of this nonlinearity in the VSI inverter over the entire range of output voltage is desirable. In this paper, the nonlinearity of VSI inverter output voltage and the harmonic distortion in the line current are analyzed based on an open-loop system and a L-R load. By minimizing the harmonic component of the current in a d-axis and q-axis synchronous rotating reference frame, the exact compensation factor was obtained. Simulations and experimental results in the low frequency and low output voltage region are presented. 相似文献
56.
Yoshimasa A. Ono Jun'ichiro Hara Katsuhiko Nagai Kiyoshi Kawamura 《Journal of Low Temperature Physics》1977,27(3-4):513-536
The shear viscosity (T) in the Balian-Werthamer (BW) state of superfluid
3
He is calculated variationally throughout the region 0t 1(t=T/T
c) from the transport equation for Bogoliubov quasiparticles. Coherence factors are treated exactly in the calculation of the collision integral. The numerical result for
=s= s(T)/n(Tc) agree very well with experiment in the range 0.8t1.0. Analytic expressions
= 0.577 (1–1.0008t) and
=1–(23/64) [=(T)/k
B
T] are obtained in the low-temperature region and in the vicinity ofT
c, respectively. From the numerical analysis it is shown that the latter equation is valid only in the temperature range 0.9997t1.0.Supported by the Research Institute for Fundamental Physics, Kyoto University. 相似文献
57.
Spatial and Temporal Analysis of Hydrological Provision Ecosystem Services for Watershed Conservation Planning of Water Resources 总被引:1,自引:0,他引:1
Spatial planning for sustainable water resources development requires precise information on the local potential for providing water yield in a watershed. For water resource conservation, we analyzed spatial and temporal patterns of hydrological provision ecosystem services in the upper Teshio watershed of northernmost Japan. The Soil and Water Assessment Tool (SWAT) was applied to simulate hydrologic processes and determine parameters affecting the water cycle. The spatial increase of water yield at flat area near river channel in winter was explained by low field capacity of soil water, absence of water uptake by crops and gentle topography. The spatial patterns of snowmelt and rainfall were important drivers of the spatial pattern in water yield during other periods. The zonation model was applied to investigate dynamic changes in spatial conservation prioritization of hydrological provision ecosystem services, according to simulated water yields in February, April and October. The results showed that the conservation priority ranking dynamically changed spatially and temporally. Our economic assessment of hydrological provisioning services (irrigation, electricity production and household usage) indicated that the spatial pattern of the priority for water resources was different from that of economic value of the provisioning services. Our results indicated that a combination of hydrologic and cost zonation models would improve sustainable management planning of water resources and their hydrological ecosystem services have great spatiotemporal fluctuation. 相似文献
58.
Lead recovery from lead zirconate (PbZrO(3)) ceramics was investigated using a wet ball-mill treatment in H(2)SO(4) aqueous solution. Subsequently crystalline alpha-zirconium phosphate (alpha-Zr(HPO(4))(2).H(2)O) was synthesized using a hydrothermal technique in order for the resource recovery of zirconium in the wastewater after the wet ball-mill treatment. A wet ball-mill treatment in 4.5M H(2)SO(4) aqueous solution for 24h was capable of converting more than 99.9% of the Pb initially included in the PbZrO(3) to solid state PbSO(4) with a purity of 98%. On the other hand, the Zr in the PbZrO(3) was dissolved into the acidic solution during the treatment. The Pb and Zr metal elements coexisting in PbZrO(3) were successfully separated by the wet ball-mill technique. Then, resource recovery of zirconium in the wastewater was examined. Crystalline alpha-Zr(HPO(4))(2).H(2)O was synthesized by hydrothermal treatments in 3.1-12.5M H(3)PO(4) aqueous solutions at temperatures of 120-240 degrees C for a duration of 70h. The hydrothermally prepared powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and then they were also evaluated in terms of cation exchange capacity (CEC) measurement and thermogravimetric (TG) analysis. 相似文献
59.
Wakita K. Kawamura Y. Yoshikuni Y. Asahi H. Uehara S. 《Quantum Electronics, IEEE Journal of》1986,22(9):1831-1836
The first measurements to be made of large anistropic electroabsorption and modulation of long-wavelength light propagating along the plane of InGaAs/InAlAs multiple quantum well (MQW) structures grown by molecular beam epitaxy (MBE) are reported. Photocurrent response of waveguide p-i-n diodes is studied for incident light polarization parallel and perpendicular to the MQW layers. Photocurrent increase with reverse bias throughout the entire photoresponse spectrum is observed for both polarizations. The MQW p-in optical modulator shows a capacitance-limited pulse response of 250 ps and the modulation depth is 14 percent. 相似文献
60.
Allan Abraham B. Padama Bhume Chantaramolee Hiroshi Nakanishi Hideaki Kasai 《International Journal of Hydrogen Energy》2014
The absorption of H atom in H-covered Pd(110) (1 × 2) missing-row surface is investigated using density functional theory based calculations. For 1.5 monolayer H coverage, interaction among the adsorbed H atoms is found to be negligible and was verified by analyzing the electronic structure of the system and by comparing the calculated binding energies with low H coverage case. Neither the monoatomic absorption of H nor the assistance from the initially adsorbed H atom explains the experimentally observed presence of subsurface H in Pd(110) at high H coverage. Instead, H absorption is realized through the assistance of incoming H atoms from vacuum. The absorption of H in the H-covered surface is non-activated while the dissociation of H2 is the rate-limiting process. Dissociation on ridge site is energetically more preferred than on trough site and the difference in the activation barrier is elucidated by investigating the electronic structures of the system. 相似文献