非固定的

It is an established convention to speak of the fixed stars as a standard unaccelerated reference frame .

把固定恒星说成是标准加速参照系，这是一种已经确立习惯。

The two dimensional pseudohomogeneous model was often used for the non isothermal, non adiabatic fixed bed reactor that was widely used for the strongly exothermic reactions.

恒固定床反应广泛应用于强反应体系。