中文摘要：

本文通过数值方法求解均匀动脉中的非平稳脉动流，给出了通过测量非平稳脉动血流量确定壁面切应力的方法。作为算例，采用实测的大鼠颈总动脉流量信号，求出了均匀动脉壁面切应力波形。进一步对求得的切应力波形进行经验模态分解（EMD），得到了切应力波形的各内在模态（IMF），以及Hilbert幅值谱。从切应力波形经Hilbert-Huang变换得到的IMF和Hilbert谱图可以明显地看出切应力各频率成分的物理意义。所得结果为进一步深入研究非平稳脉动切应力与血管重建的关系提供了一种方法学基础。

英文摘要：

The nonstationary pulsatile flow in uniform straight arteries was numerically investigated to calculate the nonstationary wall shear stress （WSS） by measuring nonstationary pulsatile blood flow. As an example, the nonstationary WSS in the common carotid arteries of a Wistar Kyoto（WKY） rat was calculated by measuring the nonstationary blood flow rate. The calculated WSS signal was decomposed into the Intrinsic Mode Functions （IMFs） by use of Empirical Mode Decomposition （EMD）. The Hilbert spectrum of the IMFs was obtained by use of Hilbert transformation. The physical significance of each frequency component of WSS was clearly seen from the IMFs and Hilbert spectrum of the WSS, which is obtained from Hilbert-Huang Transformation. The results provide a methodology base for the further investigation of the relationship between nonstationary pusatile shear stress and vascular remodeling.