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排序方式: 共有265条查询结果,搜索用时 31 毫秒
51.
The selective production of lactic acid by anaerobic acidogenesis with low pH control was examined using a chemostat culture. By decreasing culture pH to 3.5 in a chemostat culture containing mixed microbial populations for anaerobic acidogenesis, heterolactic fermentation became dominant, resulting in the selective production of lactic acid and ethanol. This phenomenon was reversible between the acidic and neutral conditions, and was not affected by the dilution rate. The extremely low pH operation was effective for selective lactic acid production in anaerobic acidogenesis. 相似文献
52.
Characterization of electrical properties and photosensitivity of SnS thin films prepared by the electrochemical deposition method 总被引:2,自引:0,他引:2
Naoya Sato Masaya Ichimura Eisuke Arai Yoshihisa Yamazaki 《Solar Energy Materials & Solar Cells》2005,85(2):153-165
Using the electrochemical deposition (ECD) method, we prepared tin sulfide thin films, which are suitable for the absorption layer in solar cells because of its bandgap energy (1 eV). We first optimized pulse-form biasing for ECD by characterizing deposited samples with scanning electron microscope, Auger electron spectroscopy and X-ray diffraction measurements. Then, we investigated the electrical properties of deposited SnS thin films and the properties of contacts with several different metals. Furthermore, we observed the photoconductivity of the films by means of photoelectrochemical measurements. From these results, we confirmed that the SnS thin films show p-type conduction. 相似文献
53.
Yoshikatsu Ichimura Katsumi Kishino Masaru Kuramoto Mitsunari Satake Atsushi Yoshida 《Journal of Electronic Materials》1995,24(3):171-176
Thermal annealing effects on optical and electrical characteristics for p-type and n-type II–VI compound layers (ZnSe, ZnSSe,
and MgZnSSe) and on the emission efficiency of ZnCdSe/Zn(S)Se 6 quantum well (QW) light emitting diodes (LEDs) grown by molecular
beam epitaxy were investigated. It was clarified that serious degradation of optical and electrical characteristics was not
observed up to an annealing temperature of 400°C. In the case of p-MgZnSSe, the maximum permitted annealing temperature was
lower than that of Zn(S)Se. The light output of the ZnCdSe/Zn(S)Se multi QW LEDs was enhanced by a factor of three at optimum
thermal annealing conditions. The study suggests that this thermal effect for LEDs was produced by the improved crystal quality
of ZnCdSe QWs by thermal annealing. 相似文献
54.
Jun-Ichi Anzai Yasuhiro Suzuki Akihiko Ueno Tetsuo Osa 《Israel journal of chemistry》1985,26(1):60-64
Photoreactivities and cation transporting properties of monomeric, dimeric, and polymeric crown ethers which contain cinnamoyl residues were investigated. Photochemical cycloaddition reaction of the cinnamoyl moieties was accelerated by NaCl or KCl for the dimeric and polymeric derivatives but not for the monomeric one. The dimeric and polymeric crown ethers after irradiation in the presence of KCl showed a significant enhancement in the transport rates for Rb+ cation. 相似文献
55.
Transport behavior of several aromatic compounds through a poly(vinyl chloride)membrane and poly(vinyl alcohol)-poly(ethylenimine) composite membranes was studied in the presence of cyclodextrin in the aqueous solution. o-Isomers of nitrophenol, nitroaniline, and iodophenol were effectively separated from their mixture of regio isomers based on the preferential complexation between cyclodextrin and the m- and p-isomers over the o-isomers. Pumping of p-nitroaniline across the membrane was also observed by addition of cyclodextrin. The results were explained as a consequence of the selective complex formation between cyclodexarin and substrate and the low membrane permeability of the complexes. 相似文献
56.
57.
Takenori Tanno Ken Suto Yutaka Oyama Jun-Ichi Nishizawa 《Journal of Electronic Materials》2003,32(3):172-175
The effects of substrate pre-annealing on deep level density in Mg-doped GaP liquid-phase epitaxy (LPE) layers were investigated
by photocapacitance measurement. With annealing under optimum phosphorus-vapor pressure, concentration of deep donor at EC — 1.9–2.1 eV increased in undoped GaP substrate. Deep level densities in Mg-doped layers were also affected by pre-annealing
of the substrates. Densities of dominant deep levels at EV + 0.85 eV and EV + 1.5 eV were an order of magnitude reduced and, in contrast, the level at EC − 2.1 eV in Mg-doped layer increased with long pre-annealing. This level at EC − 2.1 eV is supposed to be involved with P-rich-type nonstoichiometric defects, such as phosphorus interstitial atoms diffused
from the surface of the substrate. 相似文献
58.
Kiyoshi Oku Osamu Nakamura Jun-Ichi Inoue Masakasu Kohata 《Electrical Engineering in Japan》1996,117(1):60-70
Voltage distortion of 6.6-kV distribution systems has been increasing recently especially in commercial areas. Harmonic currents of certain orders are amplified and voltage distortions are generated by the resonance between system impedance and static capacitor under the leading power factor condition. This paper describes the results of a test on suppression effects on model systems and an actual system. The effect of the use of an active power filter on the resonant harmonics of the system including capacitor was verified. 相似文献
59.
S Ozaki T Ichimura T Isobe K Nagashima H Sugano S Omata 《Canadian Metallurgical Quarterly》1993,67(4):268-276
A small amount of a glycoprotein species (21-kDa glycoprotein) with high affinity for methylmercury (MeHg) was detected in the post-nuclear or post-mitochondrial supernatant fraction of the homogenate of rat sciatic nerve on electrophoresis and autoradiography after binding of Me203Hg to the fraction. The 21-kDa glycoprotein was also found in the subcellular fractions of mouse, hamster, guinea pig, rabbit and human peripheral nervous tissues. Experiments with the cellular fractions of the tissues revealed that the 21-kDa glycoprotein is localized mainly in the myelin fraction, whereas it was not found in the cellular fractions of brain, spinal cord and nonneural tissues, such as kidney and liver. The specific binding activity of the 21-kDa glycoprotein with MeHg was 12-15 fold that of the major myelin protein, Po. It was shown that the interaction of the 21-kDa glycoprotein with MeHg was mediated through sulfhydryl groups in experiments with iodoacetamide and dithiothreitol. The amino acid compositions of the rat and human 21-kDa glycoproteins were similar but very different from that of a typical metallothionein. The N-terminal amino acid sequences of the two components of the rat 21-kDa glycoprotein were identical to those of P0 and PMP-22, respectively. The in vitro binding of MeHg was also observed in the myelin fraction obtained from the sciatic nerves of MeHg-dosed rats. 相似文献
60.
Hiroshi Watanabe Mitsutake Motozawa Ken Suto Jun-Ichi Nishizawa 《Journal of Electronic Materials》1998,27(8):979-984
Photocapacitance (PHCAP) and photoluminescence (PL) measurements were applied to unintentionally doped p-type Al0.38Ga0.62As grown by liquid phase epitaxy using the temperature difference method under controlled vapor pressure. PHCAP spectra revealed
three dominant deep levels at Ev+0.9, Ev + 1.45, and Ev+1.96 eV, and a deep level at Ev+0.9−1.5 eV which was not neutralized by forward bias injection. These level densities increase with increasing arsenic vapor
pressure and net shallow acceptor density. Furthermore, PL spectra reveal a deep level at 1.6–1.7 eV. The PL intensity of
this deep level increases with increasing arsenic vapor pressure. These deep levels are thought to be associated with excess
As. 相似文献