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71.
Miyanishi N Hamada N Kobayashi T Imada C Watanabe E 《Journal of Bioscience and Bioengineering》2003,95(1):45-51
A novel extracellular alkaline stable beta-1,3-glucanase produced by Bacillus clausii NM-1 isolated from the ezo abalone Haliotis discus hannai was purified by ammonium sulfate precipitation, DEAE-Sepharose FF ion exchange chromatography and Sephacryl S-200HR gel filtration. The molecular weight of the purified enzyme was estimated to be 71 kDa from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was very stable at pH 5.3 to 11.5 but unstable at pH 4.0 to 4.5. The optimum temperature and thermostability of the enzyme increased in the presence of CaC1, The enzyme hydrolyzed R-1,3-glucan from marine organisms, but did not show activity against any other beta-1,3-glucans. The major hydrolysis products of beta-1,3-glucan from Laminaria digitata and Eisenia bicyclis were laminaritriose and laminaritetraose, respectively. The N-terminal amino acid sequence of the purified enzyme was similar to that of several beta-1,3-glucanases in the glycoside hydrolase family 16. 相似文献
72.
Shinji Munetoh Makoto Saisho Takuya Oka Toshiko Osada Hideshi Miura Osamu Furukimi 《Journal of Electronic Materials》2014,43(6):2430-2434
We have synthesized n- and p-type clathrates Ba8?d Au x Si46?x?y with various Au contents (4.6 < x < 6.0) by arc-melting, annealing at 1173 K, and spark plasma sintering at 1073 K. The Au compositions found by wavelength-dispersive x-ray spectrometry for the synthesized samples were slightly lower than the nominal compositions. Ba7.8Au4.6Si41.4 and Ba7.7Au4.9Si41.1 samples showed n- and p-type conduction, respectively. According to the electron count (Ba2+)8Au(3?)5.33Si40.67, the clathrate composition with x = 5.33 is expected to be an intrinsic semiconductor. Our experimental results show that increase of the Au composition causes a transition from n-type to p-type conduction between x = 4.6 and 4.9. We have also calculated the band structures of the Ba8Au x Si46?x clathrate including a vacancy by ab initio calculation based on density functional theory with structure optimization. It was found that the vacancy behaves like an electron acceptor and the numbers of vacancies at 24k sites for the synthesized Ba8Au x Si46?x?y clathrates can be estimated as ~0.4 in a unit cell. 相似文献
73.
Kazuo Murakawa Hideshi Oohashi Hiroshi Yamane Mitsuo Hattori Shoichi Kuramoto Masanobu Machida Hitoshi Kijima 《Electrical Engineering in Japan》2006,154(3):16-26
This paper proposes an earthing resistance measurement method for a simple earthing electrode without two auxiliary electrodes. The proposed method can measure the earthing resistance by evaluating loop impedance of an earth return circuit composed of an earth electrode of the under test and a lead wire, a return wire, and the earth soil. The return wire is placed on the soil surface without any terminations. The earthing resistance of the electrode of the under test can be given by the earth return circuit impedance at a resonant frequency design between 100 kHz and 1 MHz. The measurement conditions for the proposed method are determined by numerical calculations. Earthing resistance deviations between the proposed method and the existing method are ?13% to +22% for earthing resistance values with 50, 100, or 300Ω. It is found that the proposed method can be used to evaluate an earthing resistance around 100Ω for a simple earthing electrode. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(3): 16–26, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20196 相似文献
74.
Yusuke Onizuka Takuya Oka Toshiko Osada Hideshi Miura Shinji Munetoh Osamu Furukimi 《Journal of Electronic Materials》2014,43(6):2059-2063
Single-crystalline Ba8Al x Ga y Si46?x?y clathrates were synthesized by the arc melting method and Czochralski method without subsequent treatment, and their thermoelectric properties were compared with those of Ba8Al x Ga y Si46?x?y and Ba8Al x Si46?x clathrates with almost the same carrier concentration as estimated from the similar Seebeck coefficient and the Zintl concept. The resistivity of Ba7.8Al5.3Ga7.4Si33.3 was lower than that of Ba7.9Al12.6Si33.4. The specific electrical resistance of Ba7.9Al12.6Si33.4 and Ba7.8Al5.3Ga7.4Si33.3 was 0.573 mΩ cm and 0.282 mΩ cm at 750 K, respectively. The band structure of Ba8Al8Ga8Si30 and Ba8Al16Si30 was estimated by first-principle calculations using density functional theory with the local density approximation. Based on these calculations, it was found that the shape of the bottom of the conduction band for Ba8Al x Si46?x clathrate changed slightly on Ga doping and the radius of curvature of the bottom of the conduction band for Ba8Al8Ga8Si30 clathrate was lower than that for Ba8Al16Si30 clathrate. These results indicate that the mobility was enhanced by Ga doping of Ba8Al x Si46?x clathrate. We also synthesized single-crystalline Ga-doped Ba8Al x Si46?x clathrate. The electrical resistivity decreased dramatically due to the single-crystallization because of reduced electron scattering on grain boundaries. These results suggest that Ga doping and single-crystallization are effective for improvement of the thermoelectric properties of Ba8Al x Si46?x clathrate. 相似文献
75.
Hydrogen adsorption was studied for Pt/SO4
2--ZrO2 samples modified with Na addition, pyridine preadsorption, and water preadsorption to elucidate the relation between the rate and capacity of hydrogen adsorption and the surface state. The surface states were monitored by XRD, IR, ammonia TPD, and measurement of catalytic activity for cyclohexane isomerization. All the modifications suppressed the hydrogen uptake. It was suggested that Lewis acid sites promote the hydrogen uptake by stabilizing spiltover hydrogen atoms. 相似文献
76.
Hirohito Matsui Hiroshi Matsumoto Hideshi Kuzumoto Masaarki Sekino Yasuo Nimura Tetsuo Ukai 《Desalination》1981
Two types of new “HOLLOSEP” have been developed for single-pass desalination of high salinity seawater. One is a high pressure and high temperature module, type “HPT”. The performance of this new type HOLLOSEP is analyzed in the case of desalination of high salinity seawater under a high pressure Of 75Kg/cm2 G at high temperature of 40°C. It has been found that the operation costs can be reduced by this high pressure and high temperature operation system.The other is a large size module containing five elements of 12 inches diameter, type “JM-12”. This module has been developed to reduce the water cost by enlarging the diameter and the length of a vessel coupled with the improvement in water flux rate of the hollow fiber membranes. The fresh water productivity of this module is 150m3/day under the conditions of 3.5% NaCl feed water, 30% product water recovery at 55kg/cm2G. 相似文献
77.
Both Asian dust (kosa) transported from the East Asian continent and locally suspended dust near monitoring sites contribute to the observed atmospheric deposition of (137)Cs in Japan. To estimate the relative contribution of these dust phenomena to the total (137)Cs deposition, we monitored weekly deposition of mineral particles and (137)Cs in spring. Deposition of (137)Cs from a single Asian dust event was 62.3 mBq m(-2) and accounted for 67% of the total (137)Cs deposition during the entire monitoring period. Furthermore, we found high (137)Cs specific activity in the Asian dust deposition sample. Although local dust events contributed to (137)Cs deposition, their contribution was considerably smaller than that of Asian dust. We conclude that the primary source of atmospheric (137)Cs in Japan is dust transported from the East Asian continent. 相似文献
78.
Cyanoethylation of alcohols with acrylonitrile to form 3-alkoxypropanenitriles proceeds effectively over solid base catalysts such as alkaline metal oxides and hydroxides, lanthanum oxide, and alumina supported potassium fluoride and hydroxide at a reaction temperature below 323 K. The order of the reactivity of alcohols varied with the types of catalyst. With magnesium hydroxide and calcium hydroxide, the reactivity of alcohol decreased: methanol>ethanol>2-propanol, while with the alkaline earth oxides, lanthanum oxide, and alumina supported KOH and KF, the reactivity order was opposite. The reactivity orders are interpreted by the acidity of alcohol combined with the basic strength of the catalysts. The catalytic activity of solid base catalysts were scarcely affected by exposure of the catalyst to air before use for the reaction. 相似文献
79.
Yasuaki Okamoto Satoshi Umeno Yusaku Arima Kazuyuki Nakai Takeshige Takahashi Kei Uchikawa Kazuhiro Inamura Yoshio Akai Osamu Chiyoda Naonobu Katada Tetsuya Shishido Hideshi Hattori Sadao Hasegawa Hisao Yoshida Koichi Segawa Naoto Koizumi Muneyoshi Yamada Akio Nishijima Toshiaki Kabe Atsushi Ishihara Takaaki Isoda Isao Mochida Hideyuki Matsumoto Miki Niwa Toshio Uchijima 《Applied Catalysis A: General》1998,170(2):211-357
In the present part of the group study on the preparation of 13 wt% MoO3/Al2O3, the effects of drying processes were investigated on the physicochemical and catalytic properties. Two series of catalysts were prepared by a conventional impregnation technique and by an equilibrium adsorption method using a common extrudate support. XPS and EPMA results demonstrated that the distribution of Mo oxide species in extrudates was strongly affected by drying processes. A rapid drying, in particular at a reduced pressure, was found to induce a strong segregation of Mo oxides on the outer surface of the extrudates, forming a sharp egg shell type distribution of Mo. On the other hand, drying under static conditions produced a moderate egg shell type distribution, suggesting that a slow drying rate is favorable for a homogeneous distribution of Mo. The equilibrium adsorption technique was found to provide considerably flat Mo profiles inside the extrudates except for the utmost surfaces where Mo concentrations increased steeply. 相似文献
80.
Sakai F Ihara H Aoyama K Igarashi H Yanahira S Ohkubo T Asao T Kozaki S 《Journal of food protection》2008,71(9):1855-1860
Staphylococcal enterotoxin H (SEH) is predicted to be involved in staphylococcal food poisoning. To characterize SEH-producing Staphylococcus aureus isolates from staphylococcal food poisoning cases in Japan, we investigated the relationship between SEH production and coagulase serotype, which is an epidemiological marker, and compared the properties of SEH production with those of staphylococcal enterotoxins A (SEA) and B (SEB). SEH production was determined by a newly developed sandwich enzyme-linked immunosorbent assay. Eighty-six (59.7%) of 144 isolates from staphylococcal food poisoning cases produced SEH. Seventy-one of the SEH-producing isolates simultaneously produced SEA, SEB, or both. All SEH-producing isolates belonged to coagulase type VII, which was the predominant type, representing 99 (68.8%) of 144 isolates. The amount of SEH produced in brain heart infusion was almost the same as the amount of SEA and approximately 10-fold lower than that of SEB. SEH and SEA were produced mainly during the late exponential phase of growth, whereas SEB was produced mostly during the stationary phase. The production levels of SEH and SEA were gradually affected by decreases in water activity, but the production of SEB was greatly reduced under conditions of low water activity. These findings indicate that SEH-producing S. aureus isolates are of high prevalence in staphylococcal food poisoning cases. Given the unique epidemiological characteristic of these isolates, SEH and SEA probably are responsible for food poisoning. 相似文献