复式船闸
the pesticide "zhongnong calcium arsenate" was developed in 1938 for the control of insect pests on cotton, which is the beginning of research and preparation as well as application of chemical pesticide in large scale in china.
1938年制成中农砒酸钙农药,用以防治棉花害虫,是中国专门研制化学农药及大面积使用化学农药之始。
Thus the method could be considered an acceptable approach for the pollution-free disposal of the calcium arsenate sludge.
因此,本方法可以认为是一种无公害化处理砷钙渣的简易方法。
the effects of co_2 mainly occur on the 3 ∶ 2 and 5 ∶ 3 calcium arsenates, and less on the 4 ∶ 2 calcium arsenate.
CO2主要影响3∶2和5∶3的砷酸钙盐,而对4∶2砷酸钙盐的影响较小。
Insecticidal preparation or articles based on calcium arsenate
以砷酸钙为基料的杀虫剂或制品
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