<正>为了分离和克隆与杉木木材形成相关的重要基因，笔者以杉木2～3年生枝条，5～6月份形成层活动期的茎段形成层组织为材料，用表达型噬菌体载体ZAP构建了cDNA文库,文库宿主菌为E。coliXL1-Blue，亚克隆空菌为E。coliXLOLR。试验结果表明：初级文库的库容量达到6.1×105pfu，扩增文库的滴度达到5.2×10.pfu/mL，重组率达到95%，插入片段大小在0.5～3.0kb。

Earlier fatigue failure phenomenon of SOFIM engine connecting rod bolt is concen tred. After a finite element model was established, a finite element analysis and a fatigue test were carried out. The comparing result showed that the arc transition area between rod and head was easy to produce stress concentration which results in fatigue failure. In order to solve this problem, a extending fatigue life’s method by rolling means was put forward. The finite element analysis showed that the method was reasonable and practicable.