methylene-violet

例句：

1. 1. The chemical was used as a tracer in the study of molecular structure.
   这种化学物质被用作研究分子结构的一个示踪剂。
2. 2. The compound is known for its ability to change color under UV light.
   这种化合物因其在紫外光下变色的能力而闻名。
3. 3. The dye is often used in printing and dyeing processes.
   这种染料常用于印刷和染色过程中。