Note 4 - Summary of Significant Accounting Policies - Exchange Rates Used to Translate Amounts in RMB Into US$ (Details)	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Balance sheet items, except for equity accounts	6.9646	6.3757
Items in the statements of operations and comprehensive loss	6.7261	6.4515

Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section S99
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6897108&loc=SL6897125-166521

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=6450520&loc=d3e32618-110901

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant