https://www.cas.cn/cm/202309/t20230918_4970846.shtml

On September 17, the first launch of the second series of commemorative covers of “Important Scientific and Technological Inventions and Creations in Ancient China” was held in Beijing. A total of nine commemorative covers were issued, including the Mawangdui map, the Grand Canal, celestial records, materia medica, rice cultivation, hook and loop tolerance circle, movable type printing, Xinmang copper calipers, and watertight bulkheads. The ancient Chinese scientific and technological inventions in this commemorative cover belong to the fields of optical geology and metrology, civil engineering, astronomy, medicine, agronomy and textile, mathematics, materials and tools, machines and instruments, ships and boats, gunpowder and firearms. According to reports, the “ancient China important scientific and technological inventions and creations” series of commemorative covers are planned to be divided into 10 series, 3 years to complete the issue. They are based on the Chinese Academy of Sciences Institute of the History of Natural Sciences stage research results “important scientific and technological inventions in ancient China” 88, by the Chinese Postal Service and the Chinese Academy of Sciences Bureau of Science Communication, the Chinese Association for Science and Technology Communication Center jointly launched.