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51.
Kobayashi M. Sawada R. Ueda Y. 《IEEE journal of selected topics in quantum electronics》2003,9(2):142-147
Ultraviolet laser diodes (UV-LD) were used for the excitation source of autofluorescence (AF) measurements and spectroscopic imaging of the AF originating from the human bronchus was obtained. The AF spectra from normal bronchus tissues were measured and a clear AF spectrum was obtained by using a short wavelength (400 nm) laser diode; the overlap of the AF signal and excitation source could be substantially eliminated. In order to study the origin of AF intensity deterioration from bronchus tissue due to the formation of tumor tissues, the fluorescence spectrum was measured for various AF substances under various conditions. The blue AF signal of elastin and NADH solutions, which could not be easily studied by conventional excitation light sources, as well as the green AF became weak by adding lactic acid. The AF spectrum was measured for 512/spl times/512 pixels and the intensity mapping as a function of emission wavelength was obtained. Two-dimensional information of the AF signal intensity distribution for a certain wavelength component was measured. The feature originating from a region as small as about 100 /spl mu/m could be recognized. Numerical calculations of the data were performed and precise features of the AF were revealed. 相似文献
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Suga M Nishiyama H Konyuba Y Iwamatsu S Watanabe Y Yoshiura C Ueda T Sato C 《Ultramicroscopy》2011,111(12):1650-1658
Although conventional electron microscopy (EM) requires samples to be in vacuum, most chemical and physical reactions occur in liquid or gas. The Atmospheric Scanning Electron Microscope (ASEM) can observe dynamic phenomena in liquid or gas under atmospheric pressure in real time. An electron-permeable window made of pressure-resistant 100 nm-thick silicon nitride (SiN) film, set into the bottom of the open ASEM sample dish, allows an electron beam to be projected from underneath the sample. A detector positioned below captures backscattered electrons. Using the ASEM, we observed the radiation-induced self-organization process of particles, as well as phenomena accompanying volume change, including evaporation-induced crystallization. Using the electrochemical ASEM dish, we observed tree-like electrochemical depositions on the cathode. In silver nitrate solution, we observed silver depositions near the cathode forming incidental internal voids. The heated ASEM dish allowed observation of patterns of contrast in melting and solidifying solder. Finally, to demonstrate its applicability for monitoring and control of industrial processes, silver paste and solder paste were examined at high throughput. High resolution, imaging speed, flexibility, adaptability, and ease of use facilitate the observation of previously difficult-to-image phenomena, and make the ASEM applicable to various fields. 相似文献
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Phase transformation and interface segregation behavior in Si3N4 ceramics sintered with La2O3–Lu2O3 mixed additive 下载免费PDF全文
Ryosuke Urakami Yukio Sato Masayoshi Ogushi Takeshi Nishiyama Aoi Goto Kazuhiro Yamada Ryo Teranishi Kenji Kaneko Mikito Kitayama 《Journal of the American Ceramic Society》2017,100(3):1231-1240
Microstructure and mechanical property of silicon nitride (Si3N4) ceramic are strongly dependent on the selection of sintering additives. When rare‐earth (RE) oxide is used as the sintering additive, segregation of RE ions at interface between Si3N4 grain and intergranular glassy film (IGF) is believed to play a critical role. Although the ionic radius of RE ion is known to be an empirical parameter to modify the mechanical property, the correlation between the segregated ions and their ionic radii is still under controversy. In order to address this issue, (i) rate of α‐β phase transformation and (ii) segregation behavior at the interface were studied for Si3N4 ceramics sintered using mixture of La2O3 and Lu2O3 as additives in this study. Specimens of Lu content 30% and higher exhibited lower activation energies for the α‐β phase transformation as compared with those of Lu content 20% and lower. In terms of the segregation behavior, La was preferably segregated at one site and Lu at the other site along β‐Si3N4/IGF interface in the specimens of Lu content 30% and higher. It is understood from these results that Lu segregation site should be more closely related with grain growth. 相似文献
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A Method for Reducing the Dead‐Time Voltage and Impedance Voltage in a Series Voltage Compensator 下载免费PDF全文
Atsushi Nakata Masahiro Nozaki Akihiro Torii Akiteru Ueda 《Electrical Engineering in Japan》2014,186(3):85-93
Many research groups are developing series voltage compensators. In a series converter, since a transformer is used in series in the power system, the power system current flows into the voltage source inverter through the transformer. The inverter current, which is determined by the transformation ratio, gives rise to an error voltage that consists of a dead‐time voltage and an impedance voltage. The error voltage is generated even when the reference voltage is zero. This paper describes the mechanism by which the error voltage occurs and proposes a method for reducing the error voltage. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(3): 85–93, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22333 相似文献
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A chemically amplified molecular glass resist with an ionic photoacid generator and a single protection group 下载免费PDF全文
A molecular glass resist with an ionic photoacid generator and a single protection group (MR‐1) has been developed. MR‐1 exhibited good thermal properties, such as a 5% weight loss temperature (Td5%) of 167°C and a glass transition temperature (Tg) of 80°C. MR‐1 showed the good sensitivity of 80 μC/cm2 and high contrast of 4.9 with e‐beam exposure (50 keV). A relatively high resolution of 50 nm and low Line‐Edge‐Roughness of 3.8 nm were obtained by e‐beam exposure (100 keV). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39769. 相似文献
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Enhanced Light Storage of SrAl2O4 Glass‐Ceramics Controlled by Selective Europium Reduction 下载免费PDF全文
Takayuki Nakanishi Kazune Watanabe Jumpei Ueda Koji Fushimi Setsuhisa Tanabe Yasuchika Hasegawa 《Journal of the American Ceramic Society》2015,98(2):423-429
A luminescent Eu, Dy: SrAl2O4 glass‐ceramics with high transparency in the visible region was successfully synthesized using the frozen sorbet technique with the control of O2 partial pressure () for the oxidation of Eu2+ ions. The glass‐ceramics include Eu2+, Eu3+, and Dy3+ ions, and thus exhibits three characteristic types of emission bands, 4f–5d at around 520 nm (Eu2+ ions), 4f–4f at 610 nm (Eu3+ ions), and 480 nm (Dy3+ ions). The Eu, Dy: SrAl2O4 glass‐ceramics provide remarkable long‐persistent luminescence under dark condition. The glass‐ceramics also exhibits color‐changing luminescence in the visible region based on their remarkable light storage properties. The luminescent Eu, Dy: SrAl2O4 glass‐ceramics using the frozen sorbet technique with control of are promising materials for application in novel photonic and light storage materials. 相似文献