一种新型故障限流器的设计和仿真

采用短路电流限制器(FCL)快速限制短路电流是提高系统稳定性和断路器开断能力的有效方法之一.文中提出一种新型的具有串联补偿功能的故障电流限流器,它由补偿电容和旁路电感并联后与限流电感串联而成;和旁路电感相串联的可关断晶闸管(GTO)控制正常时的补偿度和故障时的限流程度.用MATLAB对传输线路短路的仿真分析证明此装置效果良好,是电力系统中有用的保护设备.     

中国云南地区3个少数民族DXS6799位点的遗传多态性

目的采用分子克隆技术制备DXS6799位点等位基因分型标准物,并应用于傈僳、普米、德昂族群体的遗传多态性研究,实现短串联重复序列(STR)分型的准确性和标准化。方法用PCR扩增和变性聚丙烯酰胺凝胶电泳技术分离各等位基因片段,回收纯化后再次进行扩增,分别插入到pGEM(-T Easy质粒载体中,DNA测序证实插入片段的大小和结构,等位基因片段按国际标准进行命名后,经转化、扩大培养、扩增及再鉴定后制备出该位点的等位基因分型标准物,进行群体遗传学研究。结果应用此分型标准物调查了中国傈僳、普米、德昂族人群DXS6799位点的基因型分布频率。结论此法制备的STR位点等位基因分型标准物在法科学实践中有较高的应用价值,DXS6799位点是一个适合我国群体分析和法科学应用的遗传标记。     

潜艇舵机液压复合控制技术分析

从液压复合控制技术出发,对阀泵并联控制舵机、阀泵串联控制舵机以及电液复合控制舵机进行了分析。     

FPSO与油轮串靠外输时的系泊时域分析

Problems experienced during Floating Production, Storage and Offloading (FPSO) tandem offloading operations were investigated. The aim of this research was to improve the reliability of such systems, and it needed a means to assess them. Time-domain simulation and analysis of offloading systems was performed using the multi-body mooring software ARIANE 7.0. Hydrodynamic interaction between the vessels was considered. The responses of the offloading system in different loading cases, different parameters of offloading hawsers and the effects of challenging environmental conditions were calculated. There was a focus on the problems of relative motion between the two bodies and its effects on the intensity of hawser forces. Minimum relative distance, maximum relative headings and maximum tension in the hawsers of offloading systems were obtained by time-domain analysis. The time-domain analysis was effective and comparative study can be used to optimize parameters of the system and extend operating limits.     

串联式混合动力电动汽车先导车的研究开发

在对串联混合动力电动汽车的结构,原理、特性进行探讨的基础上,研究了电机功率,APU功率等参数的选择方法及控制策略,并选以神龙富康988－EX车型进行了串联式混合动力先导车的研究开发。     

基于IVCBC涡方法高雷诺数下串联双圆柱的数值计算模型及其尾流特征研究

针对串联双圆柱的结构特点,利用IVCBC涡方法适合高雷诺数下数值计算的特点,建立了高雷诺数下串联双圆柱绕流的数值计算模型;采用经典算例验证了IVCBC涡方法的收敛性;探索了雷诺数为2.5×104、间隙比分别为1.1,1.25,2,2.5,3,3.25和4的串联双圆柱绕流的尾流特征;清晰地展示了尾流中较小的漩涡的形成、分裂和融合,详细地阐述了串联双圆柱流体特征发生突变的原因;深刻地揭示了串联双圆在高雷诺数下的绕流机理。研究表明:尾流模式与经典的实验尾流模型吻合较好,两圆柱中间的涡对是串联双圆尾流发生突变的主要原因;间隙之间时,间隙上部小漩涡形成、间隙中间流体的振动与下游圆柱表面上涡的脱落是同步的;该流体模式能清晰地展示尾流中较小漩涡,说明与有网格方法比较,该计算模型具有较大的优越性,为进一步研究高雷诺数下串联双圆柱流体力的特征提供了重要的研究工具。     

纯电动汽车动力电池均衡技术分析

纯电动汽车所采用的动力电池组是由多个单体电池组成的。在目前的电池制造技术水平下,纯电动汽车的蓄电池虽然是同一型号、同一规格,但各蓄电池的电压、内阻及容量等参数存在差别。单体之间的性能差异在蓄电池整个生命周期里不可避免的存在,组合成多节串联电池组后,在充放电过程中的不一致会导致单体电池由于过充、过放而提前失效。这不仅缩短了动力电池的使用寿命,而且会因为单体电池的内阻增大和有效活性物质减少而使动力电池充放电能量转换效率下降和输出功率降低,并导致电动汽车的动力学下降。     

Genotypic diagnosis of long QT syndrome by analysis of candidate genes

Objective To diagnose 6 LQTS families by genetic analysis. Methods A total aof 6 LQTS pedigrees with 43 family members were brought together for genetic diagnosis by using short-sequence tandem-repeat (SIR) markers or sequencing. Genomic DNA was extracted from blood samples by standard procedure. STR markers or KCNQ1, KCNH2 and SCN5A were amplified. The haplotype analysis for LQTS was performed. If the family got the negative haplotype analysis, the sequencing was performed. Results LQTS patients were always linkaged with the SCNSA gene in family 1. KCNH2 was linkaged with the disease in family 2 to 5.21 gene carriers were identified from these 5 families. A mutation (A561V-KCNH2) was only found in the proband of family 6 and an SNP (G1691A) was found in all the members of the family. Conclusion Genetic diagnosis can not only improve presymptomatic diagnosis,bnt also provide the basis for personal therapy and research on disease-causing mutations.     

串联补偿电路的级数分析法

以电力系统中常见的串联补偿电路为研究对象,提出了一种新的分析方法－级数分析法。该方法用多项式来描述系统中铁磁元件的磁饱和特性,经过一系列数学推导,得到了可直接计算短路电流的解析式。     

大容量电池组串联充电均衡控制方法研究

本文从电池组串联充电的均衡方法出发,研究其性能特点,进而介绍了各种方法的均衡度、实用性和控制方案。本文最后指出了各种方法在处理大容量电池组串联充电方面的可行性,为进一步研究提供了一些理论分析依据。