I am a University lecturer and am planning to attend a research workshop in Chengdu next month.

Amed, I think you can apply for an F type for that. The required documents include your passport and its copy, the completed application form, a passport-style photo, and an invitation letter from the research workshop.
You don’t need to make an appointment.
If you choose the rush service, it is possible for you to get the result within one working day.
You should submit your application to the embassy of PRC to apply for it.