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51.
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Two flow injection analyses (FIA) methods for the determination of diffusion coefficients in a straight single tube FIA system were developed. Based on the analytical solution of the convection-diffusion equation, linear relationships of the logarithmic values of the dispersion coefficient (D) and the half-peak width (W1/2) with the diffusion coefficient (Dm) were obtained. Experiments were designed to verify these methods. For example, for potassium hexacyanoferrate (III) a Dm value of 0.72 × 105 cm2 s−1 was found versus a literature value of 0.76 × 105 cm2 s−1 (error, 5%). For potassium hexacyanoferrate (II) a Dm value of 0.67 × 105 cm2 s−1 was obtained versus a literature value of 0.63 × 105 cm2 s−1 (error, 6%). The diffusion coefficients of some important biomedical compounds, such as dopamine, epinephrine, norepinephrine and ascorbic acid, were then determined. The values of 105 Dm/cm2 s−1 are 0.60 ± 0.03, 0.44 ± 0.02, 0.60 ± 0.01 and 0.68 ± 0.06, respectively. 相似文献
53.
应用等离子体发射光谱法(ICP-AES)对精神分裂症急性期男病人48例,女病人30例和慢性期男病人50例,女病人30例,检测头发中Zn、Fe、Cu、Ca、Mn5种元素,并与158名男女正常人作对照,发现无论是急性期还是慢性期,男女病人的Cu、Mn两元素的含量,均显著低于正常人(P<0.05~0.001). 相似文献
54.
论述了用激光解吸电离谱法分析富勒烯。因在电离过程中富勒分子不发生裂解,因此这种方法可直接用于富勒烯混合物的分析而勿需任何预分离。还给出了用本法分析较大、较稳定富勒烯分子的质谱图。 相似文献
55.
The γ(HO2) was elevated with increase of Cu(II) concentrations in aqueous (NH4)2SO4 aerosol. The threshold of Cu(II) concentration was 10-3 mol/L for the dramatic increase of γ(HO2) to 0.1, suggesting sensitive γ(HO2) value to concentration of transition metal ions in aerosol. 相似文献
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[structure: see text] Total synthesis of a cyclic depsipeptide with proposed structure of palau'amide is achieved, which features a stereoselective elaboration of its 5,7-dihydroxy-2,6-dimethyldodec-2-en-11-ynoic acid unit. The synthetic compound has potent cytotoxicity against three tumor cell lines but different rotation and NMR data compared to those reported for palau'amide, which implies that its conformation is close to that of palau'amide but that some stereochemistry in palau'amide was misassigned. 相似文献
59.
Jingfei Luan Zhigang Zou Minghui Lu Guoyou Luan Yanfeng Chen 《Research on Chemical Intermediates》2006,32(1):31-42
In2BiTaO7 was synthesized using the solid-state reaction method and its photocatalytic properties were investigated. The results of
powder X-ray diffraction (XRD) indicated that the compound crystallizes in the pyrochlore-type structure, cubic system with
space group Fd-3m. The lattice parameter is 10.6972(1) ?. In addition, the compound shows strong optical absorption in the
visible region (λ > 420 nm) and the band gap of In2BiTaO7 was estimated to be about 2.47 eV. For the photocatalytic reaction, H2 or O2 evolution was observed from CH3OH/H2O or AgNO3 solution respectively with In2BiTaO7 as the photocatalyst under visible light irradiation, indicating that In2BiTaO7 is responsive to visible light for splitting water. Furthermore, the catalyst remained photoactive in the wavelength range
up to 510 nm. Photocatalytic degradation of methylene blue (MB) dye over the compound was further investigated under visible
light irradiation. The results showed that complete removal of aqueous MB could be achieved after irradiation for 135 min
over In2BiTaO7. Furthermore, under visible light irradiation In2BiTaO7 showed markedly higher catalytic activity compared to P-25 for MB photocatalytic degradation. 相似文献