三相交流电机的受控源等效电路及其分析

根据动态磁耦合电路的观点分析三相隐极型电机定子绕组、转子绕组以及它们之间的关系,得到了电机定、转子分离的受控源电路模型,并通过该电路模型分析电机的各种工作状态.     

长株潭传统产业集群的核心竞争力

以产业价值链为主线,结合长沙-株洲-湘潭三市传统产业的竞争优势及其变化趋势思考,探讨了全球生产体系下的国际分工格局及其变化趋势,认为产业竞争力并不必然决定于产业层次,而更主要决定于创造附加价值的能力.最后,提出提升传统产业竞争优势的思路.     

跳跃扩散型离散几何平均亚式期权的定价

在股票市场有重大信息公布时,股票价格会发生跳跃.在股票价格服从Ito-Skorohod跳跃扩散过程的条件下,运用概率论的方法研究离散几何平均亚式期权的定价,并得出其定价公式.     

扩增引进限制性酶切位点技术检测CYP2C9基因的多态性

建立了一种简便、快速、准确的检测CYP2C9基因Arg144Cys位点和Ile359Leu位点多态性的新方法.该方法采用与模板具有1个碱基错配的引物通过PCR在扩增产物中引进限制性酶切位点,即扩增引进限制性酶切位点(amp lification-created restriction sites,ACRS),其中通过上游引物在扩增Arg144Cys位点的片断中引入AvaⅡ切点,使得野生型基因CYP2C9*1和突变型基因CYP2C9*2的PCR产物中分别含有2个和1个AvaⅡ切点;通过下游引物在扩增Ile359Leu位点的片断中引入MvaⅠ切点,使得野生型基因CYP2C9*1和突变型基因CYP2C9*3的PCR产物中分别含有1个和2个MvaⅠ切点.将来自Arg144Cys位点和Ile359Leu位点的PCR产物各取一份测序,表明错配碱基成功引入PCR产物中.将包含Arg144Cys位点的PCR产物用AvaⅡ消化,将包含Ile359Leu位点的PCR产物用MvaⅠ消化,然后通过聚丙烯酰胺凝胶电泳-银染进行基因分型.由于野生型基因和突变型基因的PCR产物中都至少含有1个酶切位点,能完全避免因限制性核酸内切酶失活或酶切不完全而导致的基因分型错误.     

基于颜色分块全局直方图的图像检索方法及系统实现

通过比较全局颜色直方图和分块颜色直方图, 提出一种分块全局直方图的检索方法. 该方法以分块直方图的特征为基础, 在检索时, 由用户为含有重要空间信息的分块设置权值, 并将不注重空间信息的分块权值设为零. 系统将权值为零的分块重新合并为部分全局直方图, 计算所有权值非零分块的距离及部分全局直方图的距离, 再按照用户给出的权值进行加权累加作为两幅图像之间的最终距离. 结果表明, 两幅图像间 的距离越小, 则视觉差异也越小. 同时, 引入相关反馈技术以改善检索效果.     

铝酸钠溶液中苛性碱、碳酸碱和氧化铝含量的连续测定

利用自动电位滴定法, 选择葡萄糖酸钠配合铝酸钠溶液中的铝, 在滴定碱总量时保持氢氧化铝稳定而不沉淀析出, 不干扰测定. 再以氟化钾置换配合铝酸钠溶液中的铝, 同时放出与铝等化学计量的OH-, 通过酸碱滴定, 实现了在铝酸钠溶液中对苛性碱、 碳酸碱和氧化铝含量的连续测定. 此方法操作简便、 快速, 数据准确可靠.     

Multiple Needle Electrospinning for Fabricating Composite Nanofibers with Hierarchical Structure

Electrospinning is a powerful method for fabricating micro/nano fibers that can be applied to various fields. Composite materials with nanoscale structure can show more excellent properties than their conventional partners. Here, we reported hierarchical structured nanofibers with beads and spheres by double needle electrospinning with an auxiliary airflow. Two different spinning solutions with different concentrations were placed into different syringes. The action of airflow was able to make the two differently morphological nanofibers mixed together evenly. The results showed that the obtained nanofiber membrane has a good hierarchical structure with different morphologies.     

具有光活性含偶氮苯基团的新型表面活性剂的合成和性质

把具有光反应性的偶氮苯引入到表面活性剂2-(2-乙基己基)琥珀酸酯磺酸盐(AOT)中,合成了一种具有光活性的含偶氮苯基团的表面活性剂(azo-AOT).采用紫外-可见光谱对其进行了分析,结果表明化合物结构中的偶氮苯基团的顺反式异构化易于通过光的辐射来控制.     

B-Rep模型重构中切割点和内点问题

基于投影理论讨论了匹配投影边组特性,以及对应的空间边包含空间顶点为内点(因与其他空间边重叠,所以该边是无效的)或隐含了切割点(常规方法无法求得的形体顶点)的条件,以此为基础提出了防止生成重叠边、求切割点的新方法.     

Reactive scheduling of multiple EOSs under cloud uncertainties: model and algorithms

Most earth observation satellites(EOSs)are low-orbit satellites equipped with optical sensors that cannot see through clouds.Hence,cloud coverage,high dynamics,and cloud uncertainties are important issues in the scheduling of EOSs.The proactive-reactive scheduling framework has been proven to be effective and efficient for the uncertain scheduling problem and has been extensively employed.Numerous studies have been conducted on methods for the proactive scheduling of EOSs,including expectation,chance-constrained,and robust optimization models and the relevant solution algorithms.This study focuses on the reactive scheduling of EOSs under cloud uncertainties.First,using an example,we describe the reactive scheduling problem in detail,clarifying its significance and key issues.Considering the two key objectives of observation profits and scheduling stability,we construct a multi-objective optimization mathematical model.Then,we obtain the possible disruptions of EOS scheduling during execution under cloud uncertainties,adopting an event-driven policy for the reactive scheduling.For the different disruptions,different reactive scheduling algorithms are designed.Finally,numerous simulation experiments are conducted to verify the feasibility and effectiveness of the proposed reactive scheduling algorithms.The experimental results show that the reactive scheduling algorithms can both improve observation profits and reduce system perturbations.