解压

Based on the elastic theory of large deflection and by taking into account the variation of the axial force and its effects on bending deformation of the drillstring in vertical section ,the vibration of the drillstring induced by fluctuating weight on bit is described by a parametrically excited system.

基于弹性大变形理论，考虑到轴力沿钻柱轴线的变化及其对钻柱弯曲变形的影响等因素，将受自重作用的铅垂井段钻柱在波动钻压激励下的振动转化为一个参数激励系统，用 Galerkin方法首次得到了描述此系统的 Mathieu方程，并通过将方程的解展成富里叶级数的方法，得到了该振动系统的动力分岔值曲线及其所包围的动力不稳定区。

To compute the solution to the nonlinear equation of pressure in the Riemann problem for the pressure grdient equations, the Godunov scheme gives a reasonable approximate value for the exact solution. By using the Newton-Ruphson iteration method and some necessary computation, we get the inter-cell numerical flux directly.

为求压差方程黎曼问题中关于压力的非线性方程的解，Godunov格式给出一个合理的初始近似值，利用Newton迭代法和一些必要的计算得到格式中的数值流。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。