Comparing tbe apparent absorption spectrum with the (control minusMg~(++)) difference spectrum, we observed that the sites of maximum diminution cau-sed by Mg~(++) ion were not on the peaks but shorter than the peaks about 3 nm.

• 比较了吸收光谱和差异光谱。 Mg~(++)离子引起吸收降低最大的位置,不在峰上,而略有蓝移(3nm左右)。