为保证封闭母线运行时绝缘性能可靠,需要定期对其进行预防性试验。结合某水电站20 k V封闭母线交流耐压试验,介绍了封闭母线串联谐振耐压试验的原理及方法,根据试验过程中声光现象和电压、绝缘电阻测量值,判断封闭母线是否存在缺陷及缺...为保证封闭母线运行时绝缘性能可靠,需要定期对其进行预防性试验。结合某水电站20 k V封闭母线交流耐压试验,介绍了封闭母线串联谐振耐压试验的原理及方法,根据试验过程中声光现象和电压、绝缘电阻测量值,判断封闭母线是否存在缺陷及缺陷的具体位置。针对缺陷原因,进行相应处理。展开更多
Scientists said on Monday they had genetically engineered rice to withstand drought, salt water and cold temperatures by borrowing a gene from the E. coli bacteria. [译文]星期一,科学家们称他们已经利用遗传工程学,借用...Scientists said on Monday they had genetically engineered rice to withstand drought, salt water and cold temperatures by borrowing a gene from the E. coli bacteria. [译文]星期一,科学家们称他们已经利用遗传工程学,借用大肠埃舍利希氏 杆菌的基因培育出了耐干旱、耐咸水、耐严寒的稻米。展开更多
IF there is one name that is familiar to Chinese aged 10 to 80 it is Guo Lanying. Recently a recital was held by CCTV in honor of her 60-year career. When Guo Lanying took the stage, she was met with a lengthy standin...IF there is one name that is familiar to Chinese aged 10 to 80 it is Guo Lanying. Recently a recital was held by CCTV in honor of her 60-year career. When Guo Lanying took the stage, she was met with a lengthy standing ovation. Her voice was choked with emotion. Behind her was a smiling photograph of her that was taken at the start of her opera career. Guo Lanying was born in 1930展开更多
文摘Scientists said on Monday they had genetically engineered rice to withstand drought, salt water and cold temperatures by borrowing a gene from the E. coli bacteria. [译文]星期一,科学家们称他们已经利用遗传工程学,借用大肠埃舍利希氏 杆菌的基因培育出了耐干旱、耐咸水、耐严寒的稻米。
文摘IF there is one name that is familiar to Chinese aged 10 to 80 it is Guo Lanying. Recently a recital was held by CCTV in honor of her 60-year career. When Guo Lanying took the stage, she was met with a lengthy standing ovation. Her voice was choked with emotion. Behind her was a smiling photograph of her that was taken at the start of her opera career. Guo Lanying was born in 1930
