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排序方式: 共有434条查询结果,搜索用时 187 毫秒
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Sutrisno A Ueda M Inui H Kawaguchi T Nakano Y Arai M Miyatake K 《Journal of Bioscience and Bioengineering》2001,91(6):599-602
A gene encoding chitinase from Aeromonas sp. no. 10S-24 was expressed using pTrc99A in Escherichia coli JM 105 which yielded a 5-fold higher activity than when pUC19 was used. Three different truncated enzymes (SA-1, SA-2 and SA-3) were obtained after purification. Their isoelectric points were 7.0, 6.9, and 6.7, respectively. The enzymes showed two optimum pHs, 4.0 and 7.0, when incubated with ethylene glycol chitin as the substrate, and were stable over a wide pH range (3.0-9.0). The optimum temperature was 60 degrees C and the enzymes were stable up to 50 degrees C. The chitinases exhibited wide substrate specificities for chitin-related compounds. 相似文献
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The removal of paint on the surface of waste plastics is difficult by the conventional process; in this research, a new cleaning mechanism using atmospheric plasmas was examined through optical emission spectroscopy, electron spectroscopy for chemical analysis, and scanning electron microscopy. Results indicate that an increase of pulse frequency enables for a short processing time for the removal of the paint film, signifying that the production of radicals in plasma, especially oxygen radicals, can be controlled by pulse frequency.Plasma jets were generated under the experimental conditions of an input power of 250 W to 400 W, a pulse frequency of 2 kHz to 12 kHz, and a plasma gas flow rate of 30 L/min. Examination of the intensity ratio of the reactive species, as measured by emission spectroscopy, showed that the O/N value increased with an increase in pulse frequency. Results of analysis with electron spectroscopy for chemical analysis show that nitrogen atoms and molybdenum in only the paint film decreased through plasma processing. 相似文献
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Preparation of one-dimensional photonic crystals by sol-gel process for magneto-optical materials 总被引:1,自引:0,他引:1
Chie Inui 《Thin solid films》2008,516(9):2454-2459
One-dimensional photonic crystal (PC) of periodically alternating low (SiO2) and high (TiO2) refractive index materials was prepared by sol-gel dip coating method that controls the thickness of each layer with nanometer level. The photonic band gap of high reflectivity was verified at wavelengths between 590 nm and 820 nm, which became significant with increasing the number of bilayer. The UV-vis spectra, SEM image and glow discharge optical emission spectroscopy indicate the periodic structure of SiO2/TiO2 multilayer. The magnetic layer of CoFe2O4 was also prepared by a sol-gel dip coating method. After the annealing at 700 °C, the single phase of CoFe2O4 film with spinel structure, without any preferred crystalline orientation, was obtained. In addition, the one-dimensional magnetophotonic crystal (MPC), in which the magnetic defect layer of CoFe2O4 is introduced into the periodic structure, was prepared. The light was localized at the magnetic defect due to the interference of the multilayer film, and the localized transmittance was observed around 530 nm. The Faraday rotation of MPC shows a peak at ∼ 570 nm which is close to the localized peak of transmittance. This may correspond to the enhancement of Faraday rotation due to the localization of light. 相似文献
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New catalytic technologies in Japan 总被引:9,自引:0,他引:9
Recent trends in R&D of catalytic technology in Japan (cleaner and more efficient production, environmental catalysts, and recycling processes) are overviewed and examples of recent achievements are listed. Examples are then described as zeolite-catalyzed organic reactions recently commercialized and expected to be commercialized: hydration of cyclohexene, synthesis of pyridine derivatives and gas-phase Beckmann rearrangement of cyclohexanone oxime. Finally, as an example of environmental catalysts, the NOx storage–reduction type three-way automobile catalyst, is introduced. 相似文献
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AlthoughT
c cannot be found for a liquid-quenched Bi1.6Pb0.4Sr2Ca2Cu3Ox glassy sample, a highT
c is found after annealing for 24 h at 1100 K. The maximum offset temperature of the superconducting transition is 113.3 K at 2.2 × 10–2mAmm–2. The maximumT
c
off is larger than that (the maximumT
c
off is 103.4 K at 2.0 × 10–2 mAmm–2) of sintered specimens before liquid quenching. 相似文献