The second set consisted of patina ― a chemicalfilm encrustation on one of the limestone boxes.
第二套样本中包含有铜绿――在一个石灰石盒子上附着的一种化学物质。
2
A layer of chemicalfilm can be formed on the surface of solid through chemical reaction. The quality of film is decided by the speed of chemical reaction of film surface.
通过化学反应可以在某些固体表面上形成一层化学薄膜，膜的质量是由成膜时膜表面的化学反应速率决定的。
3
Inside Kodak, this was known as the "silver halide" strategy -named after the chemical compounds in its film.