底质 bed material; bed sediment; bedload; bed-load sediment; body; bottom material; bottom matter; bottom sediments; bottomcharacteristics; bottommaterial; character of the bottom; nature of the bottom; quality of the bottom,bottom characteristics; qualityofthebottom; substrate; substratum
质谱 [物理学] mass spectra; mass spectrum◇质谱测量 mass-spectrometer measurement; 质谱分析 mass spectrum analysis; mass spectrographic analysis;质谱计 mass spectrograph; 质谱线 line; 质谱学 mass spectrometry