Effective reproduction number of the time-dependent SIR model of the COVID-19 in China. The circle-marked solid curve with blue color is the based on the given data from Jan. 27, 2020 to Feb. 20, 2020, the star-marked dashed curve with purple color is the predicted based on the data from Jan. 27, 2020 to Feb. 15, 2020, and the dashed line with red color is the percolation threshold 1 for the effective reproduction number.