Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Schedule of estimated useful lives

	Useful Life
Office equipment	3 years
Mechanical equipment	3 – 5 years
Electronic equipment	3 – 5 years

Schedule of noncontrolling interests

	December 31, 2022		December 31, 2023		December 31, 2023
	RMB		RMB		USD
Ocean HK		291,921		86,196		14,187
Total non-controlling interests		291,921		86,196		14,187