通过显微镜照片与相对增殖率结果分析，得到以下结论：

（1）纯锌浸提液未稀释，其毒性为3级；稀释2-4倍后，其毒性降为1级；稀释6-8倍后毒性降为0级。

（2）Zn-0.8Cu浸提液未稀释，其毒性为3级；稀释2倍后，毒性仍为3级；稀释4倍后，其毒性为1级；稀释6-8倍后，毒性降为0级。

（3）Zn-2Cu浸提液未稀释，其毒性为3级；稀释2倍后，毒性仍为3级；稀释4倍后，其毒性为2级；稀释6-8倍后，毒性降为1级。

（4）Zn-4Cu浸提液未稀释，其毒性为4级；稀释至2-8倍后，其毒性仍为3级。

在本部分研究中，Zn和Zn-0.8Cu实验组的浸提液稀释6倍以上后，细胞相对增殖率均超过了100%，证实了低浓度Zn²⁺/Cu²⁺对细胞增殖的促进作用。当铜含量增加到2wt.%时,粗大第二相开始出现（图3-5(c)）并导致微电流腐蚀的形成，可能是合金腐蚀速率提高、Zn²⁺/Cu²⁺浓度增大的直接原因。

Through the analysis of the results of the microscope photos and the relative proliferation rate, the following conclusions are obtained:

(1) The pure zinc extract is undiluted, and its toxicity is level 3; after diluting 2-4 times, its toxicity is reduced to level 1; after diluting 6-8 times, its toxicity is reduced to level 0.

(2) The Zn-0.8Cu extract is undiluted, and its toxicity is level 3; after diluting twice, the toxicity is still level 3; after diluting 4 times, its toxicity is level 1; after diluting 6-8 times, the toxicity is reduced It is level 0.

(3) The Zn-2Cu extract is undiluted, and its toxicity is level 3; after diluting twice, the toxicity is still level 3; after diluting 4 times, its toxicity is level 2; after diluting 6-8 times, the toxicity is reduced to Level 1.

(4) The Zn-4Cu extract is undiluted, and its toxicity is grade 4; after diluting to 2-8 times, its toxicity is still grade 3.

In this part of the study, the relative proliferation rate of cells in the Zn and Zn-0.8Cu experimental group was diluted more than 6 times, and the relative cell proliferation rate exceeded 100%, which confirmed the promotion of cell proliferation by low concentration of Zn²⁺/Cu²⁺. When the copper content increases to 2wt.%, the coarse second phase begins to appear (Figure 3-5(c)) and leads to the formation of microcurrent corrosion, which may be the direct cause of the increase in alloy corrosion rate and the increase of Zn²⁺/Cu²⁺ concentration.