搜一下，这个问题被问过多次了：
The activity number is determined in this way:
time = number of two-week periods in which you've posted since your registration
activity = min(time * 14, posts)

Activity is updated every 30 minutes.

发帖间隔时间
waittime = 360;
if(activity >= 15)
        waittime = (int)(90 - activity);
if(activity >= 60)
        waittime=(int)(34.7586 - (0.0793103 * activity));
if(activity >= 100)
        waittime = max((int)(14-(activity/50)), 4);