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131.
Hirokazu Masai Ryota Shirai Takamichi Miyazaki Kazuki Yoshida Takumi Fujiwara Yomei Tokuda Toshinobu Yoko 《Journal of the American Ceramic Society》2013,96(11):3576-3583
Transparent (Sr0.5Ba0.5)Nb2O6 (SBN50) nanocrystallite‐precipitated phosphate glass‐ceramics were prepared by a conventional glass‐ceramic process. x(SrO–BaO–2Nb2O5) ? (100–4x)P2O5 (xSBNP) glasses with a refractive index of 1.9–2.0 exhibited high water resistance owing to the presence of Q0 and Q1 phosphate units. Both bulk and surface crystallization of the SBN50 phase were observed in 20SBNP and 21SBNP glass‐ceramics. Although the nominal content of SBN50 crystals in the 21SBNP glass was larger than that in the 20SBNP glass, the latter exhibited better crystallinity of SBN50 and a higher number density of precipitated SBN nanocrystallites. By tuning the two‐step heat‐treatment and the chemical composition, transparent SBN50‐precipitated glass‐ceramics were successfully obtained. Given that no remarkable increase of the relative dielectric constants was observed after crystallization of the SBN50 nanocrystallites, it is postulated that the relative dielectric constant of the bulk is mainly governed by the amorphous phosphate region, and that the contribution of precipitation of the SBN50 nanocrystallites to the dielectric constant is not very significant in this system. 相似文献
132.
Kazuki Akamatsu Takuya Murakami Takashi Sugawara Ryuji Kikuchi Shin‐ichi Nakao 《American Institute of Chemical Engineers》2011,57(7):1882-1888
Equilibrium shifts of methane steam reforming in membrane reactors consisting of either tetramethoxysilane‐derived amorphous hydrogen‐selective silica membrane and rhodium catalysts, or hexamethyldisiloxane‐derived membrane and nickel catalysts is experimentally demonstrated. The hexamethyldisiloxane‐derived silica membrane showed stable permeance as high as 8 × 10?8 mol m?2 s?1 Pa?1 of H2 after exposure to 76 kPa of vapor pressure at 773 K for 60 h, which was a much better performance than that from the tetramethoxysilane‐derived silica membrane. Furthermore, the better silica membrane also maintained selectivity of H2/N2 as high as 103 under the above hydrothermal conditions. The degree of the equilibrium shifts under various feedrate and pressure conditions coincided with the order of H2 permeance. In addition, the equilibrium shift of methane steam reforming was stable for 30 h with an S/C ratio of 2.5 at 773 K using a membrane reactor integrated with hexamethyldisiloxane‐derived membrane and nickel catalyst. © 2010 American Institute of Chemical Engineers AIChE J, 2011 相似文献
133.
Kazuki Kudo Kunio Koyabu Fumikazu Ohira Mitsushi Matsunaga Yasuyuki Inoue 《Precision Engineering》1999,23(1):34
A machine has been developed that can automatically insert a thin-film filter into the narrow groove of an optical wavelength-division-multiplexing (WDM) transceiver module reliably and at low cost. The methods it uses for determining the filter orientation, handling the filter, and inserting the filter utilize the filters characteristics. These methods and an insertion-force control method were shown to be effective by testing an automated machine incorporating these methods. The average time to produce a module was 1 minute, and the average insertion loss for the assembled modules for 1.55–μm wavelength light reflected from the filter was less than 2 dB. Thus, this machine is suitable for mass production of WDM transceiver modules for future fiber-to-the-home networks. 相似文献
134.
A method for profiling arachidonic acid metabolites by radio gas chromatography (GC) is described. The incubation mixture
of rabbit platelets with [14C]arachidonic acid was purified on a Sep-Pak C18 cartridge and derivatized with diazomethane,O-methylhydroxylamine and dimethylisopropylsilylimidazole. The recovery of total14C-radioactivity was 93.1±7.2%. Loss of radioactivity during derivatization was negligible. Baseline separations for [14C]arachidonic acid and its metabolites were obtained in a single run within 45 min by GC using a synchronized accumulating
radioisotope detector (GC/SARD). The recovery of radioactivity from the GC column was virtually 100%. The chemical structures
of the metabolites were confirmed by GC/mass spectrometry; peaks of arachidonic acid metabolites were assigned by comparison
of the methylene unit values with those of radioactive peaks in GC/SARD analyses. The intra-assay coefficients of variation
in GC/SARD analyses were less than 10%. The method was used to map the profile of arachidonic acid metabolites formed by rabbit
platelets in the presence of indomethacin, baicalein or glutathione. 相似文献
135.
136.
Fumihiro Muto Tomoyuki Kakigi Naohiro Mitani Akio Matsuura Kazuki Fujii Yukiko Sato Jingye Li Masakazu Washio 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,265(1):162-167
Polymer electrolyte fuel cell (PEFC) membranes based on thin film of crosslinked perfluorinated polymer-alloys (RX-FA) have been fabricated by soft electron beam (soft-EB) grafting with styrene monomers using soft-EB irradiation under nitrogen atmosphere at room temperature (RT). The characteristic properties of styrene-grafted materials (GRX-FA) and sulfonated materials (SRX-FA) have been measured by differential scanning calorimetry (DSC) and FT-IR spectroscopy, ionic conductivity and so on. The glass transition temperatures (dry state) of all obtained SRX-FA were about 105 ± 1 °C, which are higher than Nafion®. The ion exchange capacities of SRX-FA have been achieved about 3.3 meq/g (dry). The ionic conductivity of obtained SRX-FA has showed about 0.17 S/cm at 60 °C with relative humidity (RH) of ∼95%. The ionic conductivities of the obtained SRX-FA were higher than that of conventional perfluoro-sulfonic acid membranes (PFSA). Fabricated membrane electrode assemblies (MEAs) based on the obtained SRX-FA have shown encouraging performance in the PEFC, compared with the conventional PFSA. The power density of obtained MEAs based on the SRX-FA was about 330-340 mW/cm2 under 500 mA/cm2 at 60 °C operation. Moreover, the maximum power densities of obtained MEAs based on the SRX-FA shows about 630 mW/cm2 at 60 °C. On the other hand, the power density at 500 mA/cm2 and maximum power density of MEA based on Nafion®112 were about 320 and 590 mW/cm2 at 60 °C. Thus, the power density of the obtained SRX-FA was higher than that of conventional PFSA. 相似文献
137.
Combined effects of Cordyceps sinensis and methotrexate on hematogenic lung metastasis in mice 总被引:7,自引:0,他引:7
Nakamura K Konoha K Yamaguchi Y Kagota S Shinozuka K Kunitomo M 《Receptors & channels》2003,9(5):329-334
We investigated antitumor effects of water extracts of Cordyceps sinensis (WECS). WECS (100 microg/ml) induced apoptosis of B16 melanoma cells after 48 h exposure in vitro as determined by both the TUNEL (TdT-mediated dUTP-biotin nick end labeling) method and the detection of a DNA ladder. In vivo, combined treatment with WECS and methotrexate (MTX) in mice intravenously inoculated with B16 melanoma cells was conducted. Although MTX caused a significant and severe decrease in body weight compared with that in control mice starting 16 days after the start of administration, the mice given both MTX and WECS did not show a significant decrease in body weight. The mean survival time (days) of the control mice, MTX-treated mice (15 mg/kg/day, s.c.), and WECS-treated mice (200 mg/kg/day, p.o.) was 25.0 +/- 0.3, 25.6 +/- 1.3, and 25.7 +/- 1.0 (mean +/- S.E.M. of 6-7 mice), respectively. On the other hand, mean survival time (days) of mice given the combination of MTX and WECS was 28.2 +/- 0.7, significantly longer than the control value. WECS might be beneficial in the prevention of tumor metastasis as an adjuvant agent in cancer chemotherapy. 相似文献
138.
The application of a Hadamard transform technique to microchip electrophoresis is described. The sample is electrokinetically injected into a separation channel and is then detected by diode laser-induced fluorometry. The sample and buffer solutions are introduced into the channel by controlling the high voltages applied to the solutions, according to a code determined by a Hadamard matrix. The S/N ratio of the signal in the electropherogram can be improved by a factor of 5 in comparison with that obtained by a conventional single-injection method, although an 8-fold improvement is theoretically predicted when a 255-order matrix is used. 相似文献
139.
We have studied the diffuse reflection properties of ceramics in the presence of dielectric thin films on the surface. A simple optical model was proposed in which interference effects in a thin film were considered for light scattered out of a ceramic in various directions. Measurements were performed on angle-resolved reflection spectra of a thin-film-coated alumina ceramic in the case of normal incidence. They showed that the presence of the thin film on the ceramic's surface modified the angular distributions of scattered radiation from that of a bare ceramic, which suggested a way to tailor the scattering properties of a diffuse reflector as needed. 相似文献
140.
Removal of B from Si by solidification refining with Si-Al melts 总被引:2,自引:0,他引:2
To discuss the removal of B by solidification refining of Si with a Si-Al melt, the segregation of B between solid Si and
the Si-Al melt was investigated by use of the temperature-gradient-zone melting (TGZM) method. The segregation ratio of B
at its infinite dilution was determined to be 0.49 (1473 K), 0.32 (1373 K), and 0.22 (1273 K), respectively. With the obtained
segregation ratio, the activity coefficient of B in solid Si at its infinite dilution relative to pure solid B was determined
by the following equation:
Calculated results of directional solidification of the Si-Al alloy revealed the removal fraction of B to be as much as 90
pct. The effective removal of B by a solidification refining process with a Si-Al melt is clarified. 相似文献