Concentration of docosahexaenoic acid in glyceride by hydrolysis of fish oil withcandida cylindracea lipase

In an attempt to concentrate the content of DHA (docosahexaenoic acid) in a glyceride mixture containing triglyceride, diglyceride and monoglyceride, fish oil was hydrolyzed with six kinds of microbial lipase. After the hydrolysis, free fatty acid was removed and fatty acid components of the glyceride mixtures were analyzed. When the hydrolysis withCandida cylindracea lipase was 70% complete, the DHA content in the glyceride mixture was three times more than that in the original fish oil. The EPA (eicosapentaenoic acid) content became almost 70% of the original fish oil. Hydrolysis with other lipases did not result in an increase in the DHA content in the glyceride mixtures. Hydrolysis of DHA-rich tuna oil (DHA content is about 25%) withCandida cylindracea lipase resulted in 53% DHA in the glyceride mixture. The EPA content, however, remained close to that of the original tuna oil. In this report, the acyl chain specificity of lipases is evaluated in terms of hydrolysis resistant value (HRV). HRV is the ratio between the DHA contents in the glyceride mixture of hydrolyzed oil and original oil. HRV clearly indicates differences in hydrolysis between DHA and other fatty acids (e.g., saturated and monoenoic acids).     

Optical and thermal properties of poly(ethylene oxide) doped with MnCl2 salt

The optical and thermal properties of prepared poly(ethylene oxide)/MnCl₂ films were studied as a function of MnCl₂ concentration at room temperature. The observed optical energy gap (E_opt) and energy gap tail (ΔE) were determined from the measured absorption spectra. It was found that the optical energy gap decreases with MnCl₂ concentration, and the absorption coefficient reduces sharply at concentration of 5 wt% MnCl₂ compared with the neat PEO. Differential scanning calorimetry (DSC) measurement shows that the heat of fusion increases with the MnCl₂ concentration, while the melting point decreases. Correlation between the observed optical energy gap and heat of fusion is presented.     

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本文在肯定聚合物泥浆提高钻井速度的同时,也指出了该种泥浆在井内使用较长时间以后将会出现网架结构强、包被抑制性能减弱的弊病。为此,文中强调推出新的聚合物材料,研究泥浆中聚合物剩余浓度的测定方法及控制浓度的要领,提高固控效率净化泥浆等措施以解决之。     

硫化钠在黑白钨加温精选中的应用研究

介绍了柿竹园黑白钨混合粗精矿加温精选中 ,添加硫化钠与水玻璃混合剂比单一添加水玻璃能更有效地使白钨矿与萤石等含钙矿物及脉石矿物分离。论述了硫化钠在加温精选中的作用效果并探讨了其作用机理     

明渠湍流床面附近跃移层面颗粒浓度垂线分布

本文以动理学理论的Boltzmann方程为基础，考虑明渠湍流床面附近猝发喷射和清扫运动对跃移层内运动颗粒的不同作用，分析了明渠中泥沙颗粒浓度垂线分布问题，得到了适用于包括跃移层、悬移层在内的统一浓度垂线分布公式。文中着重研究了跃移层内运动颗粒的浓度垂线分布，并将本文结果与实测跃移层内浓度垂线分布及实测跃移层顶部浓度进行了对比，结果表明理论与实验两者符合较好。     

EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF HIGH CONCENTRATION JET FLOW IN NEAR REGION

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅｓｅａｒｃｈｏｆｊｅｔｉｓａｎｉｍｐｏｒｔａｎｔｆｉｅｌｄｉｎｆｌｕｉｄｍｅｃｈａｎｉｃｓ.Ｉｔａｌｓｏｈａｓｍａｎｙａｐｐｌｉｃａｔｉｏｎｓｉｎｅｎｇｉｎｅｅｒｉｎｇ ,ｆｏｒｅｘａｍｐｌｅ ,ｔｈｅｄｉｓｃｈａｒｇｅｏｆｐｏｌｌｕｔａｎｔａｎｄｃｏｏｌｉｎｇｗａｔｅｒｉｎｉｎｄｕｓｔｒｉｅｓ .Ｗｈｅｎｔｈｅｉｎｉｔｉａｌｄｅｎｓｉｔｙｏｆｔｈｅｊｅｔｉｓｄｉｆｆｅｒｅｎｔｆｒｏｍｔｈａｔｏｆｔｈｅａｍｂｉｅｎｔｗａｔｅｒｂｏｄｙ ,ｔｈｅｊｅｔｗｉｌｌｂｅａｆ…     

水性聚氨酯电导率与聚沉值的研究

研究了软（硬）段含羧基的水性阴离子纳米聚氨酯体系的n(NCO)/n(OH)比值，COOH的质量分类，反离子各类，合成方法与电导率关系及产生的原因；探讨了该体系的n(NCO)/n(OH)值，COOH的质量分数，合成方法与临界聚沉值（Cc.c)的关系和规律。并分析，比较了软（硬）段含羧基的水性阴离子聚氨酯体系电导率与Cc.c二者关系，得出了随COOH的质量分数升高，二者变化相同，随n(NCO)/n(OH)比值升高,二者变化相反的结论。     

水平浓缩燃烧器在65t/h煤粉炉上的应用

介绍65t/h煤粉炉的基本概况和存在的问题，详细阐述了采用水平浓缩煤粉燃烧技术对原燃烧器的改造过程，对改造前后运行参数及经济效益进行了对比。