“临界值”用英语怎么说

兴奋性刺激超过某一临界值以前毫无反应.Nothing happens until the excitatory stimulus exceeds a certain'threshold'value.临界点所对应的刺激强度为临界值.The ceitical valueis stimulus intensity corresponding to the critical point.因为9.55>3.78, 其中3.78...