Given the stability, error estimate and numerical experiments for the nonlinear equation of second order backwarddifference(4)Given the weighted of second order convolution quadrature.
给出非线性方程的二阶向后差分格式稳定性、误差估计。 （4）给出二阶卷积积分的权重。
2
By using backwarddifference of space-time intensity correlation function with respect to time delay, the two-dimensional velocity vector of a moving diffuser can be measured.
利用远场时变散斑空-时强度相关函致的有限差商可以测量散射体运动的二维速度矢量。
3
This paper compares the difference between science and technology, and analyses the reason why China is backward in terms of science and technology.