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排序方式: 共有670条查询结果,搜索用时 11 毫秒
71.
Y. Nakashima K. Yatsu K. Tsuchiya K. Ohtoshi M. Shoji N. Yamaguchi M. Ichimura M. Inutake T. Tamano S. Miyoshi 《Journal of Nuclear Materials》1993,200(3):351-354
A method for evaluating wall condition by using plasma impact desorption (PID) technique has been developed and successfully applied to the tandem mirror GAMMA 10 as a monitor for wall conditioning. A magnetically shielded quadrupole mass spectrometer was installed in the vacuum chamber of the GAMMA 10 central cell. The behaviour of the partial pressure of various gas molecules desorbed by ICRF-heated plasma discharges were analyzed. The predominant increase of the partial pressure due to PID (ΔPPID) was hydrogen (M = 2) and a small amount of impurity as CO (M = 28), CH3 (M = 15), H2O (M = 18) and CO2 (M = 44) was observed in the wall-conditioning discharges. The reduction of hydrogen pressure as well as ΔPPID of the above impurities was observed with the progress of wall conditioning. This behavior has a good correlation with the increase of partial pressures due to electron-impact desorption measured at the same period. The relation between ΔPPID and the charge-exchange flux was investigated. 相似文献
72.
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74.
Kagawa Y Mitani Y Yun HY Nakashima N Tamura N Tamura T 《Journal of Bioscience and Bioengineering》2012,113(5):596-603
The genus Rhodococcus exhibits a broad range of catalytic activity and is tolerant to various kinds of organic solvents. This property makes rhodococci suitable for use as a whole-cell catalyst. Various tools for genetic engineering have been developed to use Rhodococcus erythropolis as a host for bioconversion. In this study, we investigated the protein expression responses of R. erythropolis strains and found that isocitrate lyase production in R. erythropolis PR4 (ICL(Re)) was induced by methanol. By analyzing the regulation mechanisms of icl(Re) expression, the ~200-bp upstream region from the first nucleotide of the translation initiation codon of icl(Re) was shown to be sufficient for the methanol-inducible expression. Also, the ~100-bp upstream region exhibited strong constitutive promoter activity by an unknown mechanism(s). By investigating proteins that bound to the upstream region of icl(Re)in vitro, a RamB homologue of R. erythropolis PR4 (RamB(Re)) was identified. Moreover, 2 putative RamB(Re) binding sites were identified in the upstream region of icl(Re) through pull-down assays. A ramB(Re) knockout experiment suggested that RamB(Re) negatively controlled the expression of icl(Re) and that RamB(Re) regulation was dependent on the availability of a carbon source. On the basis of these findings, we were able to create novel methanol-inducible and strong constitutive expression vectors. 相似文献
75.
The practical details for the direct measurement of structural phases and magnitudes from centrosymmetric crystals using three-beam convergent beam electron diffraction patterns are given. These details are presented as a step-by-step guide for easy implementation. Each step is illustrated with worked examples from alpha-Al(2)O(3). Twenty-nine measurements of 6 independent three-phase invariants and 87 measurements of 10 independent structure magnitudes have been made. 相似文献
76.
Mohamed Mahmoud Nasef Tsuyohiko Fujigaya Ebrahim Abouzari-Lotf Naotoshi Nakashima 《国际聚合物材料杂志》2017,66(6):289-298
Nanosized ZrO2 clusters were prepared by electrospinning a poly(vinylpyrrodine) (PVP)/ZrO2 mixture for calcination to remove PVP template and sizing. The morphological, chemical, structural, and thermal resistance changes during preparation stages were investigated using scanning electron microscope, energy-dispersive X-ray spectroscopy, transmission electron microscope, X-ray diffraction, and thermogravimetric analysis. The obtained ZrO2 clusters were used for preparation of nanocomposite membranes by dispersion in 2,6-pyridine polybenzimidazole (2,6-Py-PBI) matrix at 5?wt% content followed by phosphoric acid (PA) doping. The ZrO2 nanoclusters were found to be uniformly distributed in 2,6-Py-PBI/PA matrix leading to a remarkable increase in the PA doping level and proton conductivity of the obtained composite membrane. 相似文献
77.
In this article, I present a software architecture for intelligent agents. The essence of AI is complex information processing. It is impossible, in principle, to process complex information as a whole. We need some partial processing strategy that is still somehow connected to the whole. We also need flexible processing that can adapt to changes in the environment. One of the candidates for both of these is situated reasoning, which makes use of the fact that an agent is in a situation, so it only processes some of the information – the part that is relevant to that situation. The combination of situated reasoning and context reflection leads to the idea of organic programming, which introduces a new building block of programs called a cell. Cells contain situated programs and the combination of cells is controlled by those programs. 相似文献
78.
79.
C. Gaire Y. Ou H. Arao M. Egami A. Nakashima R. C. Picu G.-C. Wang T.-M. Lu 《Journal of Porous Materials》2010,17(1):11-18
Mechanical properties of porous methyl silsesquioxane samples with dielectric constant 2.4 and 2.0 and a recently developed
nanoclustering silica film samples with dielectric constants 2.3 and 2.0 were evaluated using an atomic force microscope based
nanoindentation. It was found that the Young’s modulus and the hardness decrease while the fracture toughness increases with
a decrease in the dielectric constant in the same type of material. Moreover, the Young’s modulus and the hardness of the
nanoclustering silica films were observed to be at least twice and fracture toughness values ~1.3–1.5 higher than those for
methyl silsesquioxane films with similar dielectric constants. The high resolution topographic imaging capability of atomic
force microscope was shown to be particularly useful in the measurement of cracks generated by the ultra-low indentation loads,
and the evaluation of the fracture toughness of the nanoscale volumes of materials. 相似文献
80.
S. Nakashima Y. Ikeda S. Hirose H. Nakamura T. Ito 《Journal of Materials Engineering and Performance》1992,1(2):211-218
Kawasaki Steel Corporation and Kawatetsu Mining Co., Ltd. have developed a new refining process to extract iron oxide from
iron ore to meet the increase in demand for iron oxide for high- grade hard ferrites. This article discusses the quality of
iron oxides and the characteristics of the hard ferrite magnets produced from them. 相似文献