短语词组短语focal aperture spot 焦斑focal l spot 焦点;焦斑focal aperture spot diameter 焦斑直径nominal focal spot value [特医]焦点标称值;焦点标称值focal spot tracking 解释project focal spot 投射焦点thermal focal spot 热焦斑large focal spot 大焦点;大斑焦 返回 focal spot