排序方式: 共有32条查询结果,搜索用时 15 毫秒
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大家知道,3孔插座下面的2个插孔是左接中性线,右接相线,上面的插孔是接保护接地的。质量好的3脚插头的接地极要比其他2个极长2~3mm。其实,这是充分考虑到使用安全而专门设计的。这样的设计可以使插头在插入电源插座时,接地极首先接触插座内的接地线,然后电源极才接通;拔出电源插头时,电源极先与电源插座 相似文献
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大家知道,3孔插座下面的2个插孔是左接中性线,右接相线,上面的插孔是接保护接地的.质量好的3脚插头的接地极要比其他2个极长2~3 mm. 相似文献
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WU Hongda 《东北农业大学学报(英文版)》2009,16(2):54-57
In breeding season and non-breeding season, the effects of three kinds of progesterone plugs on estrous control in ewes were studied. Meanwhile, the advantages and the disadvantages of the progesterone plugs were analyzed. The results showed that there were no significant difference among three progesterone plugs on modulating the ewes' estrus and pregnancy, and affecting estrous rate and fecundation rate (P〉0.05). It was observed that the progesterone plug produced by Animal Husbandry Research Center of Heilongjiang Academy of Agricultural Sciences could modulate the ewes' estrus and pregnancy effectively, and the low cost and convenience in operation made it popularize in the reproducation of sheep widely. 相似文献
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合格插座:插座或单个包装上不仅标有生产厂名,有的还标有生产厂家的详细地址;有商标,检验合格证。除工艺精细,外观,插孔,接触铜片光滑外,接触铜片较厚,弹性好,拔插头时手感有力。接线螺丝能上紧而不打滑。插孔与接触铜片正对不偏。 相似文献
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