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采用正交试验设计研究微波辅助提取资兴柑橘皮中总黄酮的工艺条件,并对资兴柑橘皮中总黄酮的抗氧化活性进行探讨。结果表明:资兴柑橘皮中总黄酮的最佳微波提取工艺为乙醇溶液体积分数70%、料液比1∶40(g/mL)、微波提取功率600W、提取温度70℃条件下提取20min,在此条件下,柑橘皮中总黄酮提取量可达21.11mg/g。影响柑橘皮中总黄酮提取效果的主次因素为:料液比>乙醇体积分数>提取温度>微波功率。柑橘皮总黄酮对清除自由基有明显的作用,且黄酮类化合物的添加量在实验范围内与其抗氧化性呈正相关,是一种潜在的具有抗氧化功能食品原料,该工艺技术适用于工业化大批量提取柑橘皮中总黄酮。 相似文献
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稀土复合固体超强酸SO_4~(2-)/ZrO_2-CeO_2催化合成食用香料乳酸乙酯的研究 总被引:1,自引:0,他引:1
研究了以稀土复合固体超强酸SO_4~(2-)-/ZrO_2-CeO_2作催化剂,乳酸和乙醇为原料合成食用香料乳酸乙酯。通过正交实验考察了影响酯化反应的主要因素,确定的最佳合成条件为:乳酸用量为0.1 mol时,乙醇与乳酸物质的量之比为3.0:1,催化剂用量为乳酸质量的2.5%,回流反应3.0 h,带水剂环已烷20 mL/0.1 mol乳酸条件下,酯化率可达90.3%。且该催化剂具有良好的重复性和再生性。 相似文献
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Rare earth sulfides were systematically synthesized via the sulfurization of their commercial oxide powders using CS2 gas to shorten sulfurization time, and their UV-vis absorption spectra were investigated. The appropriate sulfurization conditions were studied. For the rare earth sulfides with the same crystal structure, the sulfurization temperature showed increasing tendency with the decrease of rare earth element atomic radii. The UV-vis absorption spectra of rare earth sulfides did not depend on the crystal structure of rare earth sulfides, but on the 4f electronic structure of rare earth element. The data showed that the optical band gaps of rare earth sulfides were irregular, and the values ranged from 1.65 to 3.75 eV. 相似文献
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无机及分析化学实验课是实施研究性教学,促进大学生培养研究性学习思维、提高科研素质的第一课堂。结合多年来对农科院校不同专业大学生的授课经验,从实验过程的三个阶段:前期、中期和后期,对每个阶段采用不同的教学侧重点,注重对学生的素质教育的培养。 相似文献
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In order to investigate the suitability of ternary rare earth sulfide LaxCe2-xS3 in plastic application as a red pigment,we prepared LaxCe2-xS3 via the sulfurization of the oxide powders using CS2 gas.In the sulfurization of LaxCe2-xS3,β-phase and γ-phase ternary rare earth sulfide LaxCe2-xS3 were synthesized at the sulfurization temperature of 1000 and 1250 oC for 3 h,respectively.The UV-vis absorption spectra of synthesized LaxCe2-xS3 showed that the absorption wavelengths of β-phase and γ-phase LaxCe2-xS3 samples were in the region of 617-670 nm and 607-653 nm,respectively.They were in red absorption region.Furthermore,the scanning electron microscopy(SEM)results of the synthesized LaxCe2-xS3 samples were investigated.The typical SEM micrographs indicated that the particle sizes of synthesized LaxCe2-xS3 were in the range of 0.5-6 μm. 相似文献
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