以碳酸二甲酯为有机相,柠檬酸钠为盐相,采用三相分配体系(three-phase partitioning,TPP)对螺旋藻多糖(polysaccharides of Spirulina platensis,PSP)进行萃取分离。结果表明,在碳酸二甲酯与多糖粗提液体积比为0.6∶1.0、柠檬酸钠质量...以碳酸二甲酯为有机相,柠檬酸钠为盐相,采用三相分配体系(three-phase partitioning,TPP)对螺旋藻多糖(polysaccharides of Spirulina platensis,PSP)进行萃取分离。结果表明,在碳酸二甲酯与多糖粗提液体积比为0.6∶1.0、柠檬酸钠质量浓度为0.18 g/mL、温度为30℃、pH值为6.0的条件下,制备的螺旋藻多糖(PSP-D)的最大得率为(11.90±0.12)%。PSP-D比叔丁醇和硫酸铵形成TPP制备的多糖(PSP-T)具有更高的多糖含量,PSP-D和PSP-T具有不同的化学组成和分子质量,但其化学结构基本保持不变。PSP-D具有较强的自由基清除能力和总抗氧化能力,因此,碳酸二甲酯作为叔丁醇替代溶剂的TPP体系对天然生物分子的高效分配具有很大的潜力。展开更多
For classifying unknown 3-D objects into a set of predetermined object classes, a part-level object classification method based on the improved interpretation tree is presented. The part-level representation is implem...For classifying unknown 3-D objects into a set of predetermined object classes, a part-level object classification method based on the improved interpretation tree is presented. The part-level representation is implemented, which enables a more compact shape description of 3-D objects. The proposed classification method consists of two key processing stages： the improved constrained search on an interpretation tree and the following shape similarity measure computation. By the classification method, both whole match and partial match with shape similarity ranks are achieved; especially, focus match can be accomplished, where different key parts may be labeled and all the matched models containing corresponding key parts may be obtained. A series of experiments show the effectiveness of the presented 3-D object classification method.展开更多
This paper presents practical distribution system equipment models such as various distributed generators, voltage regulators, and loads for fast three phase unbalanced load flow calculation in distribution systems. T...This paper presents practical distribution system equipment models such as various distributed generators, voltage regulators, and loads for fast three phase unbalanced load flow calculation in distribution systems. The method can calculate voltage and current of distribution systems, in which distributed generators are introduced. The calculation time of the proposed method is about 40 times faster than that of the Newton-Raphson method. Moreover, an introduction effect evaluation tool for distributed generators using the proposed three phase unbalanced load flow calculation is presented. It provides various functions such as a power system network diagram creation function and a voltage profile chart display function. Therefore, the introduction effect evaluation of distributed generators in distribution systems can be evaluated quite easily.展开更多
基金The National Basic Research Program of China(973Program)(No2006CB303105)the Research Foundation of Bei-jing Jiaotong University (NoK06J0170)
文摘For classifying unknown 3-D objects into a set of predetermined object classes, a part-level object classification method based on the improved interpretation tree is presented. The part-level representation is implemented, which enables a more compact shape description of 3-D objects. The proposed classification method consists of two key processing stages： the improved constrained search on an interpretation tree and the following shape similarity measure computation. By the classification method, both whole match and partial match with shape similarity ranks are achieved; especially, focus match can be accomplished, where different key parts may be labeled and all the matched models containing corresponding key parts may be obtained. A series of experiments show the effectiveness of the presented 3-D object classification method.
文摘This paper presents practical distribution system equipment models such as various distributed generators, voltage regulators, and loads for fast three phase unbalanced load flow calculation in distribution systems. The method can calculate voltage and current of distribution systems, in which distributed generators are introduced. The calculation time of the proposed method is about 40 times faster than that of the Newton-Raphson method. Moreover, an introduction effect evaluation tool for distributed generators using the proposed three phase unbalanced load flow calculation is presented. It provides various functions such as a power system network diagram creation function and a voltage profile chart display function. Therefore, the introduction effect evaluation of distributed generators in distribution systems can be evaluated quite easily.
