排序方式: 共有104条查询结果,搜索用时 15 毫秒
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采用反相高效液相色谱法测定了生孢乳杆菌发酵液中的乳酸.在EclipseXDB-C8,(4.6 mm i.d.×150 mm,5 μm)色谱柱上,以0.005 mol/L硫酸(pH值2.5)溶液作流动相,流速为1 mL/min,以示差折光检测器检测信号,峰面积(Y)与乳酸的质量浓度(X,g/L)的线性相关方程为Y=292.08x+4.6967,线性相关系数r为0.999 9,线性范围为0.75~9.0g/L,检测限为0.2μg(3倍信噪比).结果表明,实验方法简便、快速、可靠,精密度为0.22%(n=5),回收率99%以上. 相似文献
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对云南某黄磷厂尾气综合利用生产二甲醚的可行性进行了研究,并对该项目的适宜工艺路线和技术经济进行了评价。 相似文献
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竖井SVE修复有机污染土壤的数值模拟分析 总被引:3,自引:2,他引:3
采用Galerkin三角形有限单元法对复合地表边界的竖井土壤气相抽提(SVE)稳态流动问题进行了数值模拟分析,模拟结果显示:气相压力沿径向梯度迅速下降,抽提流量与土壤通透系数及真空度呈现高度相关的正比例关系,且地表隔绝覆盖层对流场影响很大.通过与野外实测真空度数据的对比验证,表明该二维轴径向流动模型能较好应用于现场条件,明显优于一维模型.再采用一个稳定的交替方向有限差分(ADI)解出传质微分方程,从而实现多维情况下竖井SVE修复的完整模拟过程.4组不同条件下为期60d的SVE修复过程的计算机模拟显示,土壤通透系数是决定修复效果的关键因素.在流场及传质方面建立的数值模拟分析对SVE的工程设计及预测可提供初步指导. 相似文献
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Octacosanol is purified by agitated short-path distillation (SPD). Effects of evaporation temperature,number of SPD steps in series and other distillation method on the octacosanol recovery and decomposition are studied. Although the experimental results indicate some decomposition when the mixture of higher primary aliphatic alcohols is distillated by SPD, SPD is still an effective method to purify octacosanol. It is concluded that evaporation temperature affects greatly on the purity and recovery of octacosanol. 相似文献
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1 INTRODUCTION Further scientific and technological investigations aimed at optimizing design and operation of tray- columns, which are widely used in industry, are of great interests. Accurate prediction of efficiency for large plate is important for commercial design. The ef- fects of liquid mal-distribution on plate efficiency have been noted for a long time[1]. The flow regions are re- sulted from the complex interactions of operational, constructional and material parameters. On a la… 相似文献
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