Abstract:用高压液相色谱法从果品加工食品中分离和测定了一种引起果品霉烂,主要引起苹果霉烂的真菌代谢有毒产物棒曲霉素。样品经乙酸乙酯萃取后,对果汁用碳酸钠溶液纯化,对果酱用甲苯-水作洗脱剂,硅胶往层析处理,分离出棒曲霉素。文章提出了分离棒曲霉素的最佳分离条件。在C_(18) Micropak MC-H柱或μ-Bondapak柱上,用四氢呋喃-水溶液作流动相,用276nm或254nm紫外吸收波长,以反相液相色谱法测定棒曲霉素。棒曲霉素浓度与峰面积间具有良好的线性关系,回收率达90%,变异系数小于10%,最小检测约1.5—2μg/1。

Abstract:The molecular matter nature of konjac glucomannan(KGM) isolated from konjac flour, the molecular weight(M_w), the mean square of radius of gyration (1/2)and molecular expansion coefficient(a_s), was measured by using Ubbelodhe type viscosimeter in th

Abstract:L-Threonine enlarge-up fermentative experiment processes on a scale of 500 l and 6000 l tanks using Brevibacterium lactofermentum ZT-1 strain. It can accumulate L-threonine above 20g/1, the maximum up to 24.8 g/1 in the medium containing industrial glucos

Abstract:首次从油茶叶中分离得到了三种黄酮体化合物,经UV,IR,~1HNMR,~(13)CNMR,EI-MS及FAB-MS等仪器分析,鉴定为槲皮素(1),槲皮素-3-0-鼠李吡喃糖甙(2)和槲皮素-3-0-葡萄吡喃糖-(6→1)鼠李吡喃糖甙(3)。在Metrohm Rancimat中测定了它们的诱导时间,显示这些化合物对于猪油及菜籽色拉油都是良好的抗氧剂,尤其是槲皮素对于猪油的抗氧性在相同添加量时比BHT高得多。此外还对这类化合物的抗氧活性与其结构的关系作了初步探讨。

Abstract:In this paper, the feature of the band width-varying servosystem with positive velocity feedback is discussed. Trecisionand high speed of the system close with a regenerative feedback system. Not only it has reliability and simple structure, but also it i

Abstract:This paper discusses a Dynamics Combined method in Pneumatic transmission for a piston on defined moving pattern.

Abstract:This paper seeks after the analytics of designing conjugate camprofile for warp-weaving machines. Due to complex number methods applied, a set of simple expressions for similar angular velocity and acceleration of mechanisms is derived and two new quation

Abstract:A new thought to represent dynamic state of rotating drapers has been expressed in this paper. Based on it, a test system was set up. The paper also explained the test result on both drape shapes and physics with a dynamic analysis of drapers in theory.

Abstract:We prove existence and approximation theorems of positive solutions in the space L[0,1] of integral equation of Chandrasekhar with perturbation. The results presented in this paper improve and extent some recent results in [1-6]