sunspot number

The sunspot number of Cycle 21 attained its peak 165.3 at 1979.9. To judge on various prediction results of Cycle 21, the criterion 165.3 ± 16.5 and 1979 ± 0.5 year are suggested.

第21周的太阳黑子数于1979.9（1979年12月）到达它的峰值165.3。本文提出用165.3±16.5和1979.9±0.5年的容许变幅，来检验第21周多种多样的预测结果。

In this paper, The mean of a month, mean of a year for the number of sunspots are worked out by the observations of sunspot from 1986 to 1995 in Beijing Planetarium, and we also study and analyze the solar activity of the 22-nd Cycle.

就北京天文馆天文台1986～1995年内的太阳黑子观测资料进行整理，得到黑子数的月均值、年均值，并对本周太阳活动性作了分析研究。

Predicting on the time series of sunspot number based on chaos theory

基于混沌理论的太阳黑子数时间序列预测

Sunspot number prediction based on process neural network with time-varying threshold functions

基于时变阈值过程神经网络的太阳黑子数预测