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排序方式: 共有622条查询结果,搜索用时 125 毫秒
611.
Tohru MIZUUCHI Kazunobu NAGASAKI Hiroyuki OKADA Shinji KOBAYASHI Satoshi YAMAMOTO Takashi MINAMI Shinsuke OHSHIMA Masaki TAKEUCHI Kiyofumi MUKAI Hyunyong LEE Linge ZANG Kohta NOMURA et al. 《等离子体科学和技术》2011,13(1):21-25
Recent progress in plasma control studies on the improvement of plasma performance in Heliotron J is reviewed. The supersonic molecular beam injection (SMBI) fueling is successfully applied to Heliotron J plasma. A supersonic H2-beam is effectively injected to increase fueling efficiency and generate a peaked density profile. Local fueling with a short-pulsed SMBI can increase the core plasma density and avoid the degradation arising from edge cooling. Second harmonic electron cyclotron current drive (ECCD) experiments were conducted by launching a focused Gaussian beam with -0.05 ? N|| ? 0.6. Results show that the EC driven current is determined not only by N|| but also by local magnetic field structure where the EC power is deposited. Detailed analysis of the observed N|| and B dependences is in progress with a ray-tracing simulation using the TRAVIS code. Fast ion velocity distribution was investigated using fast protons generated by ion cyclotron resonant frequency (ICRF) minority heating. For the standard configuration in Heliotron J, charge exchange neutral particle analysis (CX-NPA) measurements show higher effective temperature of fast minority protons in the on-axis resonance case compared to that in the HFS (high field side) off-axis resonance case. However, the increase in bulk ion temperature in the HFS resonance case is larger than that in the on-axis resonance. 相似文献
612.
Shengfang Shi Tomoyo Goto Sunghun Cho Tohru Sekino 《Journal of the American Ceramic Society》2019,102(7):4236-4246
We demonstrated for the first time the room-temperature crack healing in ceramic-based composites. For this purpose, 20 and 30 vol% of fine titanium metal (Ti) were homogeneously dispersed in electrically insulating alumina (Al2O3) ceramic to obtain composites that exhibited excellent electrical conductivity. Electrochemical anodization at room temperature was used to successfully heal cracks induced in the Al2O3/Ti composites and recover their fracture strength and reliability. The bending strength of as-prepared, crack-induced, and electrochemically healed composites was measured to evaluate the crack-healing ability. Moreover, the effects of the anodization current density, crack size (including length and crack open distance), and the conductivity of the composites on their crack-healing behavior were investigated and discussed. The results indicate that the bending strength of crack-induced composites, which was approximately 61% of the crack-free composite strength, was completely recovered after the crack-healing procedure at room temperature under appropriate anodization conditions. The titanium oxides obtained after anodization formed bridges that healed the crack; this was considered to be the main strength recovery mechanism. By anodizing Al2O3/Ti composites, we developed a new and convenient approach to heal cracks and recover the fracture strength of cracked ceramics at room temperature. 相似文献
613.
Novel Mechanism of Fatty Acid Sensing in Enteroendocrine Cells: Specific Structures in Oxo‐Fatty Acids Produced by Gut Bacteria Are Responsible for CCK Secretion in STC‐1 Cells via GPR40 下载免费PDF全文
614.
Satoshi KANECO Hiroaki KITANAGA Hideyuki KATSUMATA Tohru SUZUKI 《Frontiers of Chemical Science and Engineering》2012,6(4):432
In the present work, a new preconcentration method of trace elements by adsorption onto a niobium wire has been developed for electrothermal atomization atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer. Detection limits (pg·mL–1) by this method combined with ETAAS were 45 for bismuth, 7.0 for cadmium, 20 for copper, 1.3 for gold, 36 for lead, 65 for manganese, 9.5 for rhodium and 19 for silver. 相似文献
615.
Tohru Shiga Takeshi Narita Taiji Ikawa Akane Okada 《Polymer Engineering and Science》1998,38(4):693-698
Stress monitoring in thin polymer coatings was monitored using time resolved fluorescence from organic molecules. The decay time of fluorescence from an organic molecule in a uniaxially stretched polymer coating decreases with increasing tensile stress. The substance 9-methylanthracene (9-MeAn) is an effective dye for detecting internal stresses up to 10 MPa. Compared with the traditional bimetallic method, time resolved fluorescence of 9-MeAn gave reliable values for internal stresses in a thin polymer coating. The internal stress in a polymer coating cured on a glass plate was measured during exposure to an outdoor weathering test. The internal stress diminished significantly in three days. The decrease in the internal stress was caused mainly by light irradiation. Because 9-MeAn degraded in sunlight, it was a useful probe for stress monitoring only for periods less than two weeks. 相似文献
616.
A new hybrid phosphine was designed. The phosphine combines two common structural characteristics found among the effective phosphine ligands reported recently, namely, three tert‐alkyl substituents binding to the phosphorus and an aryl group at an appropriate position. A hybrid phospine/palladium system is versatile and effective for the coupling reaction of various aryl halides with primary and secondary amines including carbazole. 相似文献
617.
Prof. Dr. Yoshitsugu Akiyama Kazunori Kimura Dr. Syuuhei Komatsu Dr. Tohru Takarada Prof. Dr. Mizuo Maeda Prof. Dr. Akihiko Kikuchi 《Chembiochem : a European journal of chemical biology》2023,24(1):e202200451
A colorimetric assay of DNA cleavage by bleomycin (BLM) derivatives was developed utilizing high colloidal stability on double-stranded (ds) DNA-modified gold nanoparticles (dsDNA-AuNPs) possessing a cleavage site. The assay was performed using dsDNA-AuNPs treated with inactive BLM or activated BLM (Fe(II)⋅BLM). A 10-min exposure in dsDNA-AuNPs with inactive BLM treatment resulted in a rapid color change from red to purple because of salt-induced non-crosslinking aggregation of dsDNA-AuNPs. In contrast, the addition of active Fe(II)⋅BLM retained the red color, probably because of the formation of protruding structures at the outermost phase of dsDNA-AuNPs caused by BLM-mediated DNA cleavage. Furthermore, the results of our model experiments indicate that oxidative base release and DNA-cleavage pathways could be visually distinguished with color change. The present methodology was also applicable to model screening assays using several drugs with different mechanisms related to antitumor activity. These results strongly suggest that this assay with a rapid color change could lead to simple and efficient screening of potent antitumor agents. 相似文献
618.
619.
620.
Shengfang Shi Hideki Hashimoto Tohru Sekino 《International Journal of Applied Ceramic Technology》2023,20(3):1774-1784
This work investigates the effects of content ratio Co3+/Co2+ on piezoelectric properties of lead-free Ba0.88Ca0.12Zr0.12Ti0.88O3 (BCZT) ceramics. For this purpose, 0.10 wt% Co ions using a CoO powder doped BCZT ceramics were sintered under various atmospheres (ranging from pure nitrogen to 100 vol% oxygen concentration) to vary the ratio value Co3+/Co2+. X-ray photoelectron spectroscopy analysis revealed the coexistence of Co3+ and Co2+ for oxygen concentration below 40 vol% and the single oxidation state of Co3+ for oxygen concentration over 50 vol%. Co2+ substitution could induce more oxygen vacancy to accelerate densification and grain growth, whereas Co3+ substitution usually leads to larger lattice distortion to generate a stable asymmetric structure. When oxygen concentration was 30 vol% and Co3+/Co2+ near to 1.0, the respective superiority of Co3+ and Co2+ is brought into full play, and the ceramic showed the highest piezoelectric constant d33* ∼ 518 pm/V (380 pm/V for undoped BCZT) and the relatively high Curie temperature Tc ∼ 105°C (95°C for undoped BCZT). This study suggests that optimizing sintering atmosphere might be an effective way to enhance the piezoelectric properties for some composition-modified piezoelectric BCZT ceramics. 相似文献