In this study, production of ct-linoleic acid concentrated from crude perilla oil by gradient cooling urea inclusion was optimized. The fatty acid composition was determined after ethyl esterification by gas chromatog...In this study, production of ct-linoleic acid concentrated from crude perilla oil by gradient cooling urea inclusion was optimized. The fatty acid composition was determined after ethyl esterification by gas chromatography (GC). In this process, orthogonal experiment was carried out. Under optimum conditions, the maximum amount of α-linoleic acid (91.5%) was obtained at a urea to fatty acid ratio of 3, a solvent to fatty acids ratio of 7, a reaction temperature of 348 K and a crystallization time of 690 min. A simple method of gradient cooling urea inclusion was used to purify α-linolenic acid by using urea to form inclusion complexes with the saturated and the less unsaturated fatty acids, which enhanced the purity of α-linoleic acid ethyl ester by above 90%.展开更多
研究了一类定义在由3个节点和两条边构成的星图上的非线性Caputo类型的序列分数阶微分方程边值问题(boundary value problem,BVP)解的存在性。通过变量变换,将所研究的带混合边界条件具有不同定义域的分数阶微分方程组转化为等价的具有...研究了一类定义在由3个节点和两条边构成的星图上的非线性Caputo类型的序列分数阶微分方程边值问题(boundary value problem,BVP)解的存在性。通过变量变换,将所研究的带混合边界条件具有不同定义域的分数阶微分方程组转化为等价的具有相同定义域的带同等边界条件的微分方程组。然后借助Schaefer和Schauder不动点定理得到了边值问题解存在的充分条件,借助Banach不动点定理得到了边值问题解存在且唯一的充分条件。展开更多
基金the National Natural Science Foundation of China (20871061)the National 973 Program of China (2008CB617512) for the financial support
文摘In this study, production of ct-linoleic acid concentrated from crude perilla oil by gradient cooling urea inclusion was optimized. The fatty acid composition was determined after ethyl esterification by gas chromatography (GC). In this process, orthogonal experiment was carried out. Under optimum conditions, the maximum amount of α-linoleic acid (91.5%) was obtained at a urea to fatty acid ratio of 3, a solvent to fatty acids ratio of 7, a reaction temperature of 348 K and a crystallization time of 690 min. A simple method of gradient cooling urea inclusion was used to purify α-linolenic acid by using urea to form inclusion complexes with the saturated and the less unsaturated fatty acids, which enhanced the purity of α-linoleic acid ethyl ester by above 90%.
文摘研究了一类定义在由3个节点和两条边构成的星图上的非线性Caputo类型的序列分数阶微分方程边值问题(boundary value problem,BVP)解的存在性。通过变量变换,将所研究的带混合边界条件具有不同定义域的分数阶微分方程组转化为等价的具有相同定义域的带同等边界条件的微分方程组。然后借助Schaefer和Schauder不动点定理得到了边值问题解存在的充分条件,借助Banach不动点定理得到了边值问题解存在且唯一的充分条件。