The 22-year cycle in sunspot activity that was discovered in 1925 by the US astronomer George Ellery Hale (1868–1938). The Hale cycle may result from the coupling of 11-year sunspot cycles with opposite magnetic polarization.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。