Looking for relevant literature, combining with the experimental research background, summarizing the existing relevant theoretical achievements, paving the way for the paper. Just write according to the purpose of summary and research.

The theoretical basis is similar to theoretical summary, including historical development, content overview, development trend and application or research results at home and abroad. The undergraduate course mainly refers to periodical literature and master's and doctor's literature, which is used to clarify the thinking and understand the development status and trend.