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991.
992.
Acetone-dried cells of aRhizopus species, immobilized on biomass support particles were applied to the transesterification between phosphatidylcholine and
heptadecanoic acid. All eight species ofRhizopus tested exhibited good transesterification performance, with the immobilized cells ofR. niveus, R. delemar, andR. javanicus showing particularly high reaction rates which were equal to or exceeded that of a commercially available immobilized lipase
preparation, Lipozyme IM60. 相似文献
993.
994.
Ding W. Hayashi R. Suehiro J. Zhou G. Imasaka K. Hara M. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2006,13(2):353-361
The authors proposed a new type of gas sensor for high sensitive detection of decomposition products generated by partial discharge (PD) in SF/sub 6/ gas. The sensor employed carbon nanotubes (CNTs) as gas sensing transducer and was fabricated by electrokinetic manipulation of CNTs using dielectrophoresis. Due to complicated gas decomposition process of SF/sub 6/ gas, calibration of the CNT gas sensor is an essential and challenging subject in order to realize reliable and stable detection of PD under practical conditions. In this paper, two methods for the CNT gas sensor calibration were proposed and tested. The first method was based on initial conductance dependence of the CNT gas sensor response. The CNT gas sensor response to PD increased almost linearly with the amount of CNT trapped onto the sensor electrode, which could be quantified by the initial conductance of the sensor. However, the calibration accuracy of this method was about 50 % and was not high enough for practical use. The second method employed NO/sub 2/ (nitrogen dioxide) as calibration gas because of the similarity in the CNT sensor response to PD decomposition products and NO2. It was found that the accuracy of the NO/sub 2/ calibration was about 10 % and far better than the first method. Finally, effectiveness of the NO/sub 2/ calibration was demonstrated by a PD monitoring test in which two CNT sensors were simultaneously exposed to SF/sub 6/ decomposition products with identical concentration. 相似文献
995.
Hideyuki Hara Yasuhisa Sano Hidekazu Mimura Kenta Arima Akihisa Kubota Keita Yagi Junji Murata Kazuto Yamauch 《Journal of Electronic Materials》2006,35(8):L11-L14
A new abrasive-free planarization method for silicon carbide (SiC) wafers was proposed using the catalytic nature of platinum
(Pt). We named it catalyst-referred etching (CARE). The setup equipped with a polishing pad made of Pt is almost the same
as the lapping setup. However, CARE chemically removes SiC with an etching agent activated by a catalyst in contrast to mechanical
removal by the lapping process. Hydrofluoric acid which is well known as an etchant of silicon dioxide (SiO2) that cannot etch SiC, was used as the source of the etching agent to SiC. The processed surfaces were observed by Nomarski
differential interference contrast (NDIC) microscopy, atomic force microscopy (AFM), and optical interferometry. Those observations
presented a marked reduction in surface roughness. Moreover, low-energy electron diffraction (LEED) images showed that a crystallographically
well-ordered surface was realized. 相似文献
996.
Observation of Antiferromagnetic Spin-Flop Transition in λ-type BETS Salts Using AFM Microcantilever
H. Tanaka S. Hara M. Tokumoto H-B. Cui H. Kobayashi A. Kobayashi 《Journal of Low Temperature Physics》2006,142(3-4):609-612
Antiferromagnetic spin-flop transitions in a series of λ- (BETS)2FeBr
x
Cl4-x
are observed using piezoresistive AFM microcantilever. The measurements are carried out on a tiny single crystal using a
sample rotator and the easy axis changes with increasing the bromine content x. The Néel temperature and spin-flop transition
field also rise with increasing the bromine content x, suggesting an enhancement of π-d interactions by replacement of chlorine
with bromine atoms in this mixed-halide anion system. 相似文献
997.
Sakai K.-I. Abella D.L. Khan Y. Suehiro J. Hara M. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2003,10(3):404-417
This paper deals with free-conducting particle motion and particle-triggered breakdown in AC electric fields between nonparallel plane electrodes in atmospheric air. Spherical particle motion was investigated theoretically and experimentally under AC voltages with various frequencies, considering the effect of the electrical gradient force and the dependence of the Coulomb force magnitude on the distance between a particle and an electrode. The result shows that when the Coulomb force acting on a bouncing particle changes its direction periodically under AC voltage whose frequency is around commercial power frequency, the electrical gradient force can become effective in initiating particle motion toward decreasing electrode gap regions, causing the particle to trigger breakdown. Moreover, it was found that the direction in which a particle advances horizontally is greatly influenced by microdischarge occurrence when the particle bounces very near to the grounded electrode under high-frequency AC voltage, and that when a particle bounces on an electrode, particle-triggered breakdown voltage is decreased by the effect of microdischarge. 相似文献
998.
Sakai K.-I. Abella D.L. Khan Y. Suehiro J. Hara M. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2003,10(3):418-424
When a spherical conducting particle exists in an electrode system where electrical gradient force acts along the electrode surface, the particle tends to move towards the high field region. The possibility of appearance of this phenomenon is experimentally investigated with wire particles, which can easily produce the corona discharge on their ends resulting the action of a reactive force on the particle by a corona wind. The results show that a hovering particle travels deeper into the high electric field regions regardless of the corona discharge. Moreover, it is found that wire particle with corona discharge hovers near the negative electrode under DC voltage in atmospheric air due to different characteristics of corona discharge by the polarity. But under the AC voltage, the particle hovers near the bottom electrode only and invades in the high field region deeper than under the DC voltage. 相似文献
999.
Crystal structure and optical property of TiO2 gels and films prepared from Ti-edta complexes as titania precursors 总被引:3,自引:0,他引:3
Titania gel and films were prepared from Ti-edta complex solutions as new ceramic precursors, and their crystal structures and optical properties were investigated. Anatase appeared in the gel at firing temperatures between 450 and 500°C, and was transformed to rutile at temperatures between 550 and 600°C. This low transformation temperature is presumed to be due to the small crystalline size and micro pores in the gel. Refractive indices of the films were higher than those of the films prepared by a sol-gel process at firing temperatures above 700°C. These high values were caused by the rutile phase in the TiO2 films. 相似文献
1000.
A series of undrained tests were performed on granular soils consisting of sand and gravel with different particle gradations and different relative densities reconstituted in laboratory. Despite large differences in grading, only a small difference was observed in undrained cyclic shear strength or liquefaction strength defined as the cyclic stress causing 5% double amplitude axial strain for specimens having the same relative density. In a good contrast, undrained monotonic shear strength defined at larger strains after undrained cyclic loading was at least eight times larger for well-graded soils than poorly graded sand despite the same relative density. This indicates that devastating failures with large postliquefaction soil strain are less likely to develop in well-graded granular soils compared to poorly graded sands with the same relative density, although they are almost equally liquefiable. However, if gravelly particles of well-graded materials are crushable such as decomposed granite soils, undrained monotonic strengths are considerably small and almost identical to or lower than that of poorly graded sands. 相似文献