a new chemical method的用法和样例：
- He is experimenting with a new chemical.
- The woodwork has been treated with a new chemical.
- The cockroach were killed off by a new chemical.
- We report a new chemical thermal diffusion method for permeating 45 steel with zirconium.
- A new method of producing sand binder of mixing resid treated by chemical method with soluble poly-mer was discussed.