对可控硅调压整流电路若干问题的分析     

朱厚荣 《武汉大学学报(信息科学版)》1989,(2)

本文比较了两种可控硅整流电路,在这两种电路中把反并联可控硅接入阳极变压器。文章介绍了电路的过压和过流的保护方法并给出了电路的计算公式和经验数据。  相似文献   

2015年广西区北部超高压输电线路一次连续覆冰事件的天气学特征     

王奇  张厚荣  宗莲  苏浩辉  杨元建  高志球 《热带气象学报》2021,37(4):579-589

广西区是我国南方电网西电东送输电的重要通道, 2015年1月26日—2月8日期间广西区北部桂林地区发生了一次大范围超高压输电线路的连续覆冰事件, 其最大覆冰厚度可达24.83 mm。利用ERA5再分析资料和气象观测资料结合南方电网超高压输电线路覆冰观测资料, 从天气形势、温湿垂直层结、局地气象要素以及大气环流指数等方面综合分析了此次电线覆冰的天气学成因。结果表明, 东亚大槽偏强, 阻塞高压引导脊前偏北气流南下, 冷空气入境与西太平洋副热带高压带来的暖湿气流汇合, 在北方寒潮与南方水汽的共同作用下, 地处高海拔的输电线塔杆易出现覆冰。冷暖气团在桂林北部山区上空相互对峙形成准静止锋时出现两种覆冰变化特征: 当冷空气强盛且水汽充沛时, 过冷却雨滴冻结或者雾滴凝华形成电线积冰; 而在暖气团主导下电线覆冰则自然融化。准静止锋的锋区移动在很大程度上影响着电线的覆冰增长过程, 特别地, 冷暖空气的交替主导是电线反复积冰的主要原因。   相似文献   

多波长数据线性回归光度法同时测定痕量钼和钛   总被引：3，自引：0，他引：3  

夏心泉  赵书林 《岩矿测试》1993,12(2):152-154

多波长数据线性回归分光光度同时测定两个相互干扰的组分,具有简便、快速等特点,已用于Mn和Zn、Be和Al、Mo和W以及Fe和A1等体系。本文在文献的基础上,探讨了不同波长下,Mo和Ti与苯基荧光酮络合物的摩尔吸光系数的差异,在520～540nm范围内,选择了10个波长测量吸光度,以数据线性回归法的原理,不经分  相似文献   

Primary molecular basis of androgenic gland endocrine sex regulation revealed by transcriptome analysis in Eriocheir sinensis     

Song  Chengwen  Liu  Lei  Hui  Min  Liu  Yuan  Liu  Hourong  Cui  Zhaoxia 《中国海洋湖沼学报》2019,37(1):223-234

In crustaceans, the male sexual differentiation and maintenance are specially regulated by androgenic gland (AG). However, little is known about the genes involved in the regulation process. RNA-Seq was performed on AG with ejaculatory duct (AG_ED) and ejaculatory duct (ED) as control in Eriocheir sinensis, one of the most important economic and fishery crabs with typically sex dimorphism. A total of 925 unigenes were identified as differentially expressed genes (DEGs) and the expression of nine genes randomly selected was confirmed by qRT-PCR. 667 unigenes were up-regulated in AG_ED, being supposed to be AG preferential genes. Among them, the full length of insulin-like androgenic gland factor (IAG) cDNA named as Es-IAG was obtained as a logo gene of AG, which together with the genes insulin-like receptor (INR), and single insulin binding domain protein (SIBD), might constitute the sex regulation pathway. Several sex related genes were identified, and their function will have to be investigated. Also, the identification of juvenile hormone epoxide hydrolase 1 (JHEH1), ecdysteroid 22-hydroxylase (DIB) and ecdysone receptor (ECR) preliminarily clarified the molecular regulation mechanism of eyestalk-AG-testis axis, which plays important roles in molting and reproduction. The results will enhance our understanding for the molecular basis of the AG involved in male sex regulation in crabs.

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