fractionaladj.微不足道的；断片的；分数的；小数的fractional reserve部分准备fractional driving分级传动fractional pointer分巷指针Fractional-N PLL小数分频锁相环fractional mu tube小于傅里叶的电子管fractional element分数元fractional concept分段概念fractional systems非整数阶系统fractional dividor小数分频器fractional culture分级培养法