名词 precursor:

1. a substance from which another substance is formed (especially by a metabolic reaction)

2. a person who goes before or announces the coming of another

3. something that precedes and indicates the approach of something or someone

precursorn.先驱；前任；前兆；[生物]前体，前驱体precursor time前兆时间precursor rRNApre-rRNAprecursor cell前体细胞Precursory wave“前驱波”precursor fault初始断层precursor decay弹性前驱波precursory cell前身细胞precursor power前驱粉Precursor means前兆手段precursor pulse前兆脉冲,先行脉冲

1. Rare earth luminescence materials of alkaline earth stannates have also been prepared via thermal decomposition of hydroxo stannate precursors.
   利用某些新型带羟基的碱土锡酸盐作为前驱体，固相反应合成掺稀土的锡酸盐发光材料。
2. The two cyclopentadienyl groups in metallocence compexes can be linked by one or two bridging groups to form ansa-metallocence catalyst precursors.
   摘要茂金属化合物中两个茂环可以通过一个或两个桥基相连接，形成各种桥联茂金属催化剂前驱体。