锌制的

Study on Improvement of Recovery of Gold and Silver from the Copper Dross Smelting in Reverberatory Furnace;2. After that, the copper in leach liquor can be extracted with the ternary extractant mainly containing P204, and the gold and silver in leach residue can be recovered by a process of cyanidation-replacement of Z.

为避免硫酸烧渣对环境的污染，以硫酸烧渣为原料，通过添加活性还原剂，用废硫酸直接还原浸出铁并制铁黄，而后用以P2 0 4为主体的三元萃取剂萃取回收浸液中的铜，用全泥氰化和锌粉置换工艺从浸渣中提取金银，较经济有效地回收利用了烧渣中的有价金属，铁、铜和金的回收率分别达到了 93。

The reaction of cyclic b-keto esters with CF3CO2ZnCH2I provides the corresponding ring-expanded products with the advantage of mild condition in moderate to good yields. A simple and efficient procedure has been developed for a variety of 1,3-diketones converted into the corresponding 1,4-diketones and trans-1,2-disubstituted cyclopropanols in high yields. In conclusion, this new type of organozinc reagents has been developed for many useful reaction in organic synthesis.

利用有机锌试剂所具有的双重特性，在新型的Baylis-Hillman反应中，可以直接与炔基酮和醛反应一锅制得多官能团的三取代的顺式烯；在b-酮酯化合物的扩环反应中，取得了重要进展，得到了增加一个碳的扩环产物，&一步法&合成，反应条件温和、环境友好；在1，3-二酮分子中成功地插入1个碳，合成出1，4-二酮和环丙醇，为现代有机合成提供了新的合成方法，具有良好的应用前景。

By doing so, the grain size of prepared alkali zinc carbonate was 9.5 nm, Zn's mass-fraction was 56.18%, and that of Mg was 1.31%.

在此工艺下，可制得Zn的质量分数为56.18%，Mg的质量分数为1.31%，晶粒度为9.5 nm的碱式碳酸锌。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐