Mn2O3 nanowires with diameters of about 130 nm and lengths up to tens of micrometers were synthesized by the thermal decomposition of MnCO3 precursors. It was identified that the growth of the cubic Mn2O nanowires was...Mn2O3 nanowires with diameters of about 130 nm and lengths up to tens of micrometers were synthesized by the thermal decomposition of MnCO3 precursors. It was identified that the growth of the cubic Mn2O nanowires was preferential along the [001] direction. The intermediate stage containing melting state and the particles of manganese oxide played an important role for the formation of Mn2O3 with one-dimensional structure. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to characterize the morphology and crystal structure of the precursors and final products. Thermogravimetry analysis was also carried out to find the mechanism for the formation of Mn2O3 nanowires. The growth of the nanowires was proposed to be dominated by the conventional melt-growth mechanism.展开更多
目的:对草龙Ludwigia hyssopifoLia(G.Don)Exell药材的质量控制进行研究,为草龙质量标准的制定提供科学依据。方法:采用HP L C法定量测定其中2α,3β,19α,6β,24-五羟基-12-烯-18-乌苏酸、2α,3β,19α,23-四羟基-12-烯-28-乌苏酸及乌...目的:对草龙Ludwigia hyssopifoLia(G.Don)Exell药材的质量控制进行研究,为草龙质量标准的制定提供科学依据。方法:采用HP L C法定量测定其中2α,3β,19α,6β,24-五羟基-12-烯-18-乌苏酸、2α,3β,19α,23-四羟基-12-烯-28-乌苏酸及乌发醇的含量,以COSMOSIL 5C18-PAQ(4.6mm×250mm,5μm)为色谱柱;流动相:乙腈(B)-水(A),梯度洗脱(0~18min、29%B;18~45min、53%B);体积流量:1mL/min;检测波长:210nm;柱温:30℃。结果:2α,3β,19α,6β,24-五羟基-12-烯-18-乌苏酸、2α,3β,19α,23-四羟基-12-烯-28-乌苏酸及乌发醇分别0.0499~0.7982μg(r=0.9995)、0.2000~3.1997μg(r=0.9999)、0.5001~8.0019μg(r=0.9997)线性关系良好,平均回收率分别为100.43%(RSD=1.43%)、100.03%(RSD=1.24%)、100.04%(RSD=1.47%)。结论:该方法准确、可靠、重复性好,可用于草龙药材的质量控制。展开更多
基金Supported by the Program for New Century Excellent Talents in University of China(No.NCET-04-0653)
文摘Mn2O3 nanowires with diameters of about 130 nm and lengths up to tens of micrometers were synthesized by the thermal decomposition of MnCO3 precursors. It was identified that the growth of the cubic Mn2O nanowires was preferential along the [001] direction. The intermediate stage containing melting state and the particles of manganese oxide played an important role for the formation of Mn2O3 with one-dimensional structure. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to characterize the morphology and crystal structure of the precursors and final products. Thermogravimetry analysis was also carried out to find the mechanism for the formation of Mn2O3 nanowires. The growth of the nanowires was proposed to be dominated by the conventional melt-growth mechanism.
文摘目的:对草龙Ludwigia hyssopifoLia(G.Don)Exell药材的质量控制进行研究,为草龙质量标准的制定提供科学依据。方法:采用HP L C法定量测定其中2α,3β,19α,6β,24-五羟基-12-烯-18-乌苏酸、2α,3β,19α,23-四羟基-12-烯-28-乌苏酸及乌发醇的含量,以COSMOSIL 5C18-PAQ(4.6mm×250mm,5μm)为色谱柱;流动相:乙腈(B)-水(A),梯度洗脱(0~18min、29%B;18~45min、53%B);体积流量:1mL/min;检测波长:210nm;柱温:30℃。结果:2α,3β,19α,6β,24-五羟基-12-烯-18-乌苏酸、2α,3β,19α,23-四羟基-12-烯-28-乌苏酸及乌发醇分别0.0499~0.7982μg(r=0.9995)、0.2000~3.1997μg(r=0.9999)、0.5001~8.0019μg(r=0.9997)线性关系良好,平均回收率分别为100.43%(RSD=1.43%)、100.03%(RSD=1.24%)、100.04%(RSD=1.47%)。结论:该方法准确、可靠、重复性好,可用于草龙药材的质量控制。
