function description的用法和样例：
例句
- The state-space representation and the transfer function representation of fractional order linear time-invariant systems are introduced.
摘要介绍了分数阶线性定常系统的状态方程描述和传递函数描述。 - The wetting front moved nearly parallel to the soil surface, and its length could be described by a power function of time, when the distribution of initial soil water was uniform.
当初始含水量分布均匀时，降雨入渗过程中湿润锋面几乎平行坡面运移，湿润锋深度与时间的关系可用幂函数描述。
