Put-piàn chit-liōng

Put-piàn chit-liōng (不變質量) sī chi̍t ê bu̍t-thé ia̍h hē-thóng pún-sin ê chit-liōng, bōe khì siū tio̍h hē-thóng chóng-thé sóa-tāng chêng-hêng ê éng-hióng.