Titlebook: Neutron Radiography; Proceedings of the S John P. Barton,Gérard Farny,Heinz R?ttger Conference proceedings 1987 ECSC, EEC, EAEC, Brussels a

不要嚴(yán)酷

Book 1994e ancient Chinese people have made outstanding contribu- tions. In the book ‘Lu‘s Spring and Autumn‘, written near the end of the Warring States Period, i. e. in the third century B. C. , there is a statement on the "attraction of iron by lodestones". So at that time it was known that magnets can at