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Tomoki Yabutani Yasuhiro Utsunomiya Yukiko Kado Yuji Tani Hideyuki Kishimoto Akinori Fukuda Junko Motonaka 《Analytical sciences》2006,22(7):1021-1024
We present a new multielement masking method using magnesium hydroxide coprecipitation for the selective determination of Pb by differential pulse anodic stripping voltammetry (DPASV). The recovery of Pb in the masking method was over 95%, while interfering ions (Cd(2+), Co(2+), Cu(2+), Fe(3+), Mn(2+), and Ni(2+)) could be removed at 100% from the analytical sample. A linear regression was obtained in the Pb concentration from 10 to 1000 microg kg(-1) in the existence of 100 microg kg(-1) of the interfering ions. When this method was applied to the determination of Pb in a natural water-standard reference material (NIST 1640), the determined value for Pb in this work (25.4 +/- 4.1 microg kg(-1)) almost agreed with the certified value (27.89 +/- 0.14 microg kg(-1)). 相似文献
486.
Yukiko Furuhashi Yoshiharu Kimura Hideki Yamane 《Journal of Polymer Science.Polymer Physics》2007,45(2):218-228
The higher order structure of stereocomplex‐type poly(lactic acid) melt‐spun fibers of an equimolar blend of poly(L ‐lactic acid) and poly(D ‐lactic acid) was analyzed with wide‐angle X‐ray diffraction (WAXD) and birefringence measurements. Two different crystalline structures were observed in the fibers: α‐form homocrystals and stereocomplex crystals. The weight fractions of the two crystals were estimated with the WAXD integrated intensity data. The crystalline orientation factors were obtained from the WAXD measurements. Well‐oriented homocrystals formed during a drawing process at the crystallization temperature of the homocrystal. Drawing above this temperature caused the stereocomplex crystal to be formed. The crystalline orientation tended to be lower with increasing drawing temperatures. Through the combination of the intrinsic birefringence and the fractions of the α‐form homocrystals and stereocomplex crystals, the birefringence of the amorphous phase was evaluated. The amorphous birefringence stayed positive and decreased with increasing drawing temperature. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 218–228, 2007 相似文献
487.
Daichi Asakawa Takuro Kiyota Yukiko Yanagi Nobuhide Fujitake 《Analytical sciences》2008,24(5):607-613
A method of high-performance size-exclusion chromatography (HPSEC) for a wide variety of soil humic acids (HAs) was developed. Two types of soil HAs (Cambisol and Andosol HAs), which have substantially different chemical properties, showed different effects of salt and organic solvent concentrations in the eluent on chromatograms. A Shodex OHpak SB-805 HQ column with 10 mM sodium phosphate buffer (pH 7.0) containing 25% of acetonitrile (v/v) was found to be applicable for different HAs, and showed high reproducibility and recovery (87.0 - 94.5%). The Cambisol HA was fractionated into five fractions using an ultrafiltration with different molecular-weight cut-offs. The order of the molecular weights of the five fractions calculated from the HPSEC analysis corresponded to that defined by ultrafiltration. This supported the reliability of the method. 相似文献
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This paper describes applications of computed tomography (CT) to combustion phenomena under microgravity conditions. Infrared Thermography (IT) has been considered as a promising method for two-dimensional measurement of flames. We have applied IT to CT for a butane flame under microgravity conditions. The method joining spectroscopy to CT for diffusion flame of hydrogen has also been carried out. Intensity of chemical luminescence, which is originated from combustion-chemical reaction in the flame, can be measured by scanning a spectrometer with collimator. The effectiveness of the CT applications to microgravity combustion has been confirmed from two method. 相似文献
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Akira Iwasaki Mamoru Kubota Akira Fujimori Katsumasa Suzaki Yoshinao Abe Hiroshi Ono Kaoru Nishimura Hideo Yokoyama 《Radiation Physics and Chemistry》2005,72(6):657-661
On the basis of X-ray spectra information for 4, 10 and 15 MV X-rays from a linear accelerator, we propose a method for formulating the attenuation coefficient in water as a function of depth and off-axis distance. It was confirmed by transmission measurement that the formulation provides a good estimation of the attenuation coefficient in water. Using the formulation, we further assessed the effective attenuation coefficient in water as a function of off-axis distance. 相似文献