Concentration of risk	12 Months Ended
Dec. 31, 2022
Risks and Uncertainties [Abstract]
Concentration of risk	Note 17 — Concentration of risk Credit risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and short-term investments consisting of time deposit. In China, the insurance coverage for cash deposits at each bank is RMB 500,000. As of December 31, 2022 and 2021, cash and time deposit balance of RMB 151,119,985 (USD 21,910,338) and RMB 48,006,979 (USD 7,533,934) and was deposited with financial institutions located in China, of which 140,010,910 (USD 20,299,674) and RMB 39,962,354 (USD 6,271,457) was uninsured. While management believes that these financial institutions are of high credit quality, it also continually monitors their credit worthiness. A majority of the Company’s expense transactions are denominated in RMB and a significant portion of the Company and its subsidiaries’ assets and liabilities are denominated in RMB. RMB is not freely convertible into foreign currencies. In the PRC, certain foreign exchange transactions are required by law to be transacted only by authorized financial institutions at exchange rates set by the PBOC. Remittances in currencies other than RMB by the Company in China must be processed through the PBOC or other China foreign exchange regulatory bodies which require certain supporting documentation in order to affect the remittance. To the extent that the Company needs to convert U.S. dollars into RMB for capital expenditures and working capital and other business purposes, appreciation of RMB against the U.S. dollar would have an adverse effect on the RMB amount the Company would receive from the conversion. Conversely, if the Company decides to convert RMB into U.S. dollar for the purpose of making payments for dividends, strategic acquisition or investments or other business purposes, appreciation of the U.S. dollar against the RMB would have a negative effect on the U.S. dollar amount available to the Company. Customer concentration risk For the years ended December 31, 2022, one customer accounted for 12.9% of the Company’s total revenues. For the years ended December 31, 2021, one customer accounted for 18.7% of the Company’s total revenues. As of December 31, 2022, two customers accounted for 26.4% and 15.8% of the Company’s accounts receivable, respectively. As of December 31, 2021, two customers accounted for 27.8%, and 19.9% of the Company’s accounts receivable, respectively. Vendor concentration risk For the years ended December 31, 2022, one vendor accounted for 13.8% of the Company’s total purchases. For the years ended December 31, 2021, two vendors accounted for 35.1% and 15.0% of the Company’s total purchases, respectively. As of December 31, 2022, two vendors accounted for 63.6% and 10.0% of the Company’s accounts payable, respectively. As of December 31, 2021, three vendors accounted for 41.1%, 18.6%, and 15.9% of the Company’s accounts payable, respectively.

Concentration of risk

12 Months Ended

Dec. 31, 2022

Note 17 — Concentration of risk

Credit risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and short-term investments consisting of time deposit. In China, the insurance coverage for cash deposits at each bank is RMB 500,000. As of December 31, 2022 and 2021, cash and time deposit balance of RMB 151,119,985 (USD 21,910,338) and RMB 48,006,979 (USD 7,533,934) and was deposited with financial institutions located in China, of which 140,010,910 (USD 20,299,674) and RMB 39,962,354 (USD 6,271,457) was uninsured. While management believes that these financial institutions are of high credit quality, it also continually monitors their credit worthiness.

A majority of the Company’s expense transactions are denominated in RMB and a significant portion of the Company and its subsidiaries’ assets and liabilities are denominated in RMB. RMB is not freely convertible into foreign currencies. In the PRC, certain foreign exchange transactions are required by law to be transacted only by authorized financial institutions at exchange rates set by the PBOC. Remittances in currencies other than RMB by the Company in China must be processed through the PBOC or other China foreign exchange regulatory bodies which require certain supporting documentation in order to affect the remittance.

To the extent that the Company needs to convert U.S. dollars into RMB for capital expenditures and working capital and other business purposes, appreciation of RMB against the U.S. dollar would have an adverse effect on the RMB amount the Company would receive from the conversion. Conversely, if the Company decides to convert RMB into U.S. dollar for the purpose of making payments for dividends, strategic acquisition or investments or other business purposes, appreciation of the U.S. dollar against the RMB would have a negative effect on the U.S. dollar amount available to the Company.

Customer concentration risk

For the years ended December 31, 2022, one customer accounted for 12.9% of the Company’s total revenues. For the years ended December 31, 2021, one customer accounted for 18.7% of the Company’s total revenues.

As of December 31, 2022, two customers accounted for 26.4% and 15.8% of the Company’s accounts receivable, respectively. As of December 31, 2021, two customers accounted for 27.8%, and 19.9% of the Company’s accounts receivable, respectively.

Vendor concentration risk

For the years ended December 31, 2022, one vendor accounted for 13.8% of the Company’s total purchases. For the years ended December 31, 2021, two vendors accounted for 35.1% and 15.0% of the Company’s total purchases, respectively.

As of December 31, 2022, two vendors accounted for 63.6% and 10.0% of the Company’s accounts payable, respectively. As of December 31, 2021, three vendors accounted for 41.1%, 18.6%, and 15.9% of the Company’s accounts payable, respectively.