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341.
Motoyuki Yamagami Akihiro Ikeshita Yoshinobu Onizuka Shinjiro Kojima Takashi Yamada 《Spectrochimica Acta Part B: Atomic Spectroscopy》2003,58(12):2079-2084
A total reflection X-ray fluorescence spectrometer integrated with vapor phase decomposition, VPD-TXRF, was newly developed. This instrument was designed to achieve a minimum footprint, to avoid cross contamination during operation, and to protect people and instruments from HF gas. Comparisons between analysis by VPD-TXRF and by atomic absorption spectrometry (AAS) indicated very good agreement in a wide range, from 108 to 1012 atoms/cm2. The lower limits of detection (LLDs) were improved by two orders of magnitude compared with straight TXRF. For 300-mm Si wafers, the LLDs were 5×108 atoms/cm2 and 1×107 atoms/cm2 for Al and Ni, respectively. VPD-TXRF was able to perform ultra-trace analysis at the level of 108 atoms/cm2. 相似文献
342.
Toshiaki Yamaguchi Toshio Suzuki Sota Shimizu Yoshinobu Fujishiro Masanobu Awano 《Journal of membrane science》2007,300(1-2):45-50
Preparation conditions to obtain a dense electrolyte layer on a micro-tubular electrode support were investigated using wet coating and subsequent co-firing techniques. An anode-supported micro-tubular SOFC with 1.5 mm diameter was successfully fabricated by careful control of the co-sintering process of electrolyte/anode support laminates. The densification of the electrolyte layer deposited on the support surface was greatly affected by the shrinkage of tubular support during the co-sintering process. Support shrinkage above 15% was found to produce a fully densified electrolyte layer on the anode support. In contrast, the use of an anode support with shrinkage below 10% constrained gadolinium-doped ceria (GDC) sintering, resulting in a poorly densified GDC microstructure. Finally, we obtained a micro-tubular cell composed of a dense GDC and a porous (La,Sr)(Co,Fe)O3–GDC multi-layered structure on a NiO–GDC micro-tubular anode support. The cell, with a dense and ≈15 μm thick GDC electrolyte layer, was electrochemically evaluated in a temperature range from 450 to 550 °C. This micro-tubular cell with an electrode length of 6.3 mm showed a power density above 0.1, 0.2 and 0.4 W/cm2 at 450, 500 and 550 °C, respectively, in wet H2 fuel flow. 相似文献
343.
Propargyl alcohol reacts with a variety of amines in the presence of zinc acetate and cadmium acetate at reflux temperatures for 8–20 h to give aminopropanones in fairly good yields. o-Phenylenediamine gives 2-methylquinoxaline. 相似文献
344.
H Yamaguchi S Sato M Yasunam T Sato M Yoshinobu 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》1997,53(14):2471-2473
The electronic and fluorescence spectra of banz[a]azulene derivatives have been measured. the fluorescence from the second excited singlet state have been observed for these compounds. The fluorescence quantum yields (φf) is sensitive to the energy difference between the first excited singlet (S1) and the second excited singlet state (S2). 相似文献
345.
Yoshinobu Baba Mitsutomo Tsuhako Shigeru Enomoto A. Michael Chin Robert S. Dubrow 《Journal of separation science》1991,14(3):204-206
High resolution separations of nucleic acids have been performed using high performance capillary electrophoresis (HPCE) and high performance liquid chromatography (HPLC). Electropherograms showing HPCE separations of single and double stranded DNA are presented and compared with HPLC separations. Single base resolution of poly(dA) oligonucleotides in the size range of 12 to 60-mers was achieved in 35 min using HPCE. Plate numbers for HPCE are in the hundreds of thousands and reproducibility is about 1–2 % (RSD). In comparison with HPLC separations, the resolution of nucleic acids obtained using HPCE is much better than that using HPLC, while reproducibility of HPCE is comparable with that of HPLC. 相似文献
346.
We give an overview of recent development of low-viscosity polymer solutions and entropic trapping networks for double-stranded DNA (dsDNA) separations by conventional capillary electrophoresis and microchip electrophoresis. Theoretical models for describing separation mechanisms, commonly used noncross-linked polymer solutions, thermoresponsive (viscosity-adjustable) polymer solutions, and novel entropic trapping networks are included. The thermoresponsive polymer solutions can be loaded at one temperature into microchannels at lower viscosities, and used in separation at another temperature at entanglement threshold concentrations and higher viscosities. The entropic-based separations use only arrays of regular obstacles acting as size-separations and do not need viscous polymer solutions. These progresses have potential in integration to automated capillary and microfluidic chip systems, enabling better reusability of separation microchannels, much shorter DNA separation times, and higher reproducibility due to less matrix degradation. 相似文献
347.
Zhelev Z Jose R Nagase T Ohba H Bakalova R Ishikawa M Baba Y 《Journal of photochemistry and photobiology. B, Biology》2004,75(1-2):99-105
The present study describes an impressive enhancement of the photoluminescence (PL) intensity of low-temperature synthesized CdSe nanocrystals (75 degrees C) during long-term UV-irradiation. The integrated PL-intensity of CdSe core and CdSe/ZnS core/shell nanocrystals, dispersed in chloroform, enhanced about 3 and 6 times, respectively, during 9 h exposure to UV-light, without any significant changes in the characteristic absorbance spectra and shifting of PL-spectra. After termination of the irradiation a comparatively slow photobleaching was detected with tau(1/2) = 6 h for CdSe core and tau(1/2) = 14 h for CdSe/ZnS core/shell nanocrystals. The most impressive was the effect of UV-irradiation on the photoluminescence of water-soluble CdSe nanocrystals. The integrated PL-intensity enhanced about 10 times during 11 h exposure to UV-light and the improved PL-intensity was preserved during 3 days after termination of the irradiation without any significant photobleaching. The results are discussed in the context of application of CdSe nanocrystals as novel fluorophores in life science experiments. 相似文献
348.
In this paper the vibration and the traveling wave in a coupled magneto-elastic beam system are discussed experimentally. The vibration excited by the periodical forcing at the beam system propagates to another as a wave through the coupling elastic beams. Each magneto-elastic beam shows the variety of vibrations caused by the nonlinearity of the potential well and the wave propagation with time delay. The temporal vibration of the magneto-elastic beam is explained with relations to the spatial state transition based on the experimental results. (c) 1997 American Institute of Physics. 相似文献
349.
Urata H Nishioka Y Tobashi T Matsumura Y Tomimori N Ono Y Kiso Y Wada S 《Chemical & pharmaceutical bulletin》2008,56(11):1611-1612
The first chemical synthesis of two metabolites ((1R,2S,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane (SC-1) and (1R,2S,5R,6S)-2,6-bis(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3,3,0]octane (SC-2)) of sesamin was achieved by a simple two-step approach from sesamin. The approach consists of acetoxylation of the methylenedioxy moiety(ies) with lead(IV) tetraacetate and acid hydrolysis of the resulting hemiorthoester to SC-1 and SC-2. 相似文献
350.
Kuramoto H Park YS Kaji N Tokeshi M Kogure K Shinohara Y Harashima H Baba Y 《Analytical and bioanalytical chemistry》2008,391(8):2729-2733
Microfluidic devices may be highly beneficial to the rapid fabrication of small quantities of various nonviral vectors with
different functionalities, which is indispensable for effective order-made gene therapy. We adapted a microfluidic chip-based
approach for fabricating small quantities of nonviral vectors in a short time in preparation for order-made gene therapy applications.
This approach permitted us to fabricate multifunctional envelope-type nanodevices (MENDs), composed of a compacted (or condensed)
DNA core and a lipid bilayer membrane shell, which are considered as promising nonviral vectors for gene therapy applications.
The on-chip fabrication of the MEND was very simple, rapid, convenient, and cost-effective compared with conventional methods.
The size of the MEND showed strong dependence on the concentration and flow rate of the reaction precursors and could be controlled
to be much smaller than that achievable by conventional methods. This, together with abovementioned merits, makes our microfluidic
chip-based approach very attractive for the fabrication of MENDs for effective application to order-made gene therapy. 相似文献