Thus the improved form of Heaviside expansion obtained.

文中还给出了海维赛展开式的改进形式。

If you are ambitious, try this alternative procedure: Note that f'(x)involves the Heaviside stepfunction.

如果你有雄心的话，可以用另外步骤试之：注意f’（X）包含亥维塞阶梯函数。

That discontinuous function is not only convenient for integral and derivative, but also can be better reflect the displacement character after crack than heaviside function.

指数型间断函数具有在数学上的便于积分和求导的优点，且比阶梯间断函数更能反映实际破裂后的变形情况。