| Schedule of other receivables, net |
| | | | | | | | | | | | June 30, | | June 30, | | June 30, | | | 2025 | | 2026 | | 2026 | Third Party | | RMB | | RMB | | US Dollars | Business advances to officers and staffs (A) | | ¥ | 797,263 | | ¥ | 2,027,919 | | $ | 298,878 | Deposits for projects | | | 1,433,882 | | | 1,229,575 | | | 181,217 | VAT recoverable | | | 1,139,075 | | | 6,033,448 | | | 889,220 | Others | | | 1,127,654 | | | 1,029,692 | | | 151,758 | Allowance for credit losses | | | (736,993) | | | (441,116) | | | (65,012) | Total Other receivable, net | | ¥ | 3,760,881 | | ¥ | 9,879,518 | | $ | 1,456,061 |
| (A) | Business advances to officers and staffs represent advances for business travel and sundry expenses related to oilfield or on-site installation and inspection of products through customer approval and acceptance. Included herein are business advances of ¥nil and ¥120,000 ($17,686) due from key management personnel as of June 30, 2025 and June 30, 2026. |
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| Schedule of movement of allowance for credit losses |
| | | | | | | | | | | | June 30, | | June 30, | | June 30, | | | 2025 | | 2026 | | 2026 | | | RMB | | RMB | | US Dollars | Beginning balance | | ¥ | 800,374 | | ¥ | 736,993 | | $ | 108,619 | Reversal of allowance | | | (63,381) | | | (295,877) | | | (43,607) | Ending balance | | ¥ | 736,993 | | ¥ | 441,116 | | $ | 65,012 |
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