| Schedule of future minimum rental payments for operating leases |
| | | | | | | | | As of December 31, | | | 2024 | | 2025 | | | RMB | | RMB | | US$ | 1 year (Including 1 year) | | 19,881,698 | | 4,396,500 | | 628,691 | 1 year to 2 years (Including 2 years) | | 15,925,475 | | 718,780 | | 102,784 | 2 years to 3 years (Including 3 years) | | 10,233,700 | | — | | — | 3 years to 4 years (Including 4 years) | | 9,335,618 | | — | | — | 4 years to 5 years (Including 5 years) | | 6,713,328 | | — | | — | Over 5 years | | 14,278,622 | | — | | — | Total lease payments | | 76,368,441 | | 5,115,280 | | 731,475 | Less: imputed interest | | 8,965,407 | | 227,400 | | 32,518 | Present value of lease liabilities | | 67,403,034 | | 4,887,880 | | 698,958 | Less: Current portion | | (18,696,986) | | (4,232,810) | | (605,284) | Non-current portion of lease liabilities | | 48,706,048 | | 655,070 | | 93,674 |
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| Schedule of operating lease supplemental cash flow information |
| | | | | | | | | For the years ended December 31, | | | 2024 | | 2025 | | | RMB | | RMB | | US$ | Cash payments for operating leases | | 30,645,878 | | 13,668,558 | | 1,954,578 | Operating ROU assets released in exchange for operating lease liabilities | | 24,904,133 | | 51,317,359 | | 7,338,285 | Operating ROU assets obtained in exchange for new operating lease liabilities | | 51,284,880 | | 2,054,335 | | 293,766 |
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