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101.
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X. Wang Y. W. Pan Q. L. Cui J. Zhang W. Gao G. T. Zou 《Journal of solid state chemistry》2001,160(2):307
The in situ behavior of distorted perovskite La0.5−xBixCa0.5MnO3 (x=0.1, 0.15, 0.2) under high pressure has been studied by energy-dispersive X-ray diffraction in a diamond anvil cell. An abnormal change of the 202–040 d-spacing ascribed to the disappearance of the distortion mode Q2 in the MnO6 octahedra is observed at 1.2, 1.4, and 1.6 GPa, respectively, and it results in a reduction of the Jahn–Teller distortion commonly existing in the manganites. Effect of the unique 6s2 long-pair character of the Bi3+ ion on the pressure dependence of the lattice distortion is discussed. 相似文献
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Endophytes: a rich source of functional metabolites 总被引:48,自引:0,他引:48
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An automated nano-LC-MS/MS platform without trap column was established, which only used a 20 cm lauryl methacrylate-ethylene dimethacrylate (LMA-EDMA) monolithic capillary column to allow preconcentration and separation of peptides. The monolithic column had the advantages of good permeability and low backpressure resulting in higher flow rates for capillary columns. Tryptic digests of bovine albumin and yeast protein extract were tested using the monolithic column system. High proteomic coverage using this approach were demonstrated in this study. Furthermore, peptide samples extracted from mouse liver were separated by using the monolithic column system combined with size-exclusion chromatography prefractionation. This monolithic column system might be a promising alternative for the automated system previously using a trap column for routine proteome and peptide profiling analysis. 相似文献
108.
用Cyanex272-Span80-甲苯乳状液膜体系研究了铅的迁移行为,确定了铅迁移的适宜条件。在此条件下,许多常见离子如Cu^2+、Co^2+、Ni^2+、Cd^2+等均不迁移,Hg^2+迁移率很低。因此Pb^2+能与这些离子得到快速且完全的分离。这对分析测定及三废处理等工作具有实际意义。 相似文献
109.
The biotransformation of 2α,5α,10β-triacetoxy-14-oxo-taxa-4(20),11-diene (1) by cultured Gingko cells afforded four products. Their structures were identified on the basis of analyses of the chemical and spectroscopic (IR, MS, 1H- and 13C-NMR) data. Among them, 2, 3 and 5 were three new compounds, and 4 displayed potent multi-drug resistant (MDR) reversal activities to MX-1/T tumor MDR cells. 相似文献
110.
Shan Y Shi X Dou A Zou C He H Yang Q Zhao S Lu X Xu G 《Journal of chromatography. A》2011,1218(13):1743-1748
Microcystins and nodularins are cyclic peptide hepatotoxins and tumour promoters from cyanobacteria. The present study describes the development, validation and practical application of a fully automated analytical method based on on-line micro solid-phase extraction-capillary liquid chromatography-tandem mass spectrometry for the simultaneous determination of seven microcystins and nodularin-R in tap water and lake water. Aliquots of just 100 μL of water samples are sufficient for the detection and quantification of all eight toxins. Selected reaction monitoring was used to obtain the highest sensitivity. Good linear calibrations were obtained for microcystins (50-2000ng/L) and nodularin-R (25-1000 ng/L) in spiked tap water and lake water samples. Excellent interday and intraday repeatability were achieved for eight toxins with relative standard deviation less than 15.7% in three different concentrations. Acceptable recoveries were achieved in the three concentrations with both tap water matrix and lake water matrix and no significant matrix effect was found in tap water and lake water except for microcystin-RR. The limits of detection (signal to noise ratio=3) of toxins were lower than 56.6 ng/L which is far below the 1 μg/L defined by the World Health Organization provisional guideline for microcystin-LR. Finally, this method was successfully applied to lake water samples from Tai lake and proved to be useful for water quality monitoring. 相似文献