This normal variation in rhythm is known as sinus arrhythmia . 节律的这种正常变化称为窦性心律失常。
2.
The ability of the ionosphere to reflect these waves is dependent upon normal variations in the electron density at different levels . 电离层反射电波的能力取决于不同高度上电子密度的正常差别。
3.
Energy metabolism measurement in clinic ; normal variation and measurement of body temperature 临床应用的能量代谢测定法;机体体温的正常变异和测定法。