电子冲击 meaning in English

electron impact
electron impingement

Standard practice for oil spill source identification by gas chromatography and positive ion electron impact low resolution mass spectrometry
用气相色谱法和正离子电子冲击低分辨率质谱法识别溢油源的标准实施规程
Standard guide for identification and quantitation of organic compounds in water by combined gas chromatography and electron impact mass spectrometry
用气相色谱与电子冲击光谱方法鉴别和定量测量水中有机化合物的标准实施规程