微分

For the elliptic cylindrical surface which is the trunk of the blade,the geodesic and non- geodesic differential equations are deduced.

并针对叶片主干部分的椭圆柱面，分别推导其测地线和非测地线的微分方程式。

The problem of nonlinear dynamic buckling of symmetrically laminated, cylindrically orthotropic truncated shells including transverse shear has been studied.

研究了复合材料层合开顶扁球壳的非线性动态屈曲问题。建立了对称层合圆柱正交异性开顶扁球壳考虑横向剪切的非线性振动微分方程，根据突变理论建立了该壳体动态屈曲的突变模型，得到了动态屈曲的临界方

To study the taxiing-induced dynamic response of the aircraft with multiple wheels and multiple landing gears due to runway unevenness, base on several reasonable and necessary assumptions, the mathematical model of aircraft in taxiing is established using the d'alembert's principle. It can simulate taxiing inpact properties accurately, it considers in detail the vertical and horizontal motion and pitching about its center of gravity and the significant symmetric elastic modes.

在一些必要合理的假设下，利用达朗贝尔原理，建立了多轮多支柱式及小车式起落架飞机地面滑跑动态响应分析的全机模型，考虑全机沉浮、机体弹性和定常气动力的影响，起落架支柱的弹性变形，小车式起落架的车架的俯仰运动以及弹性变形，对等速滑跑飞机建立了全机运动的微分方程，并以旧金山28-R跑道为地面输入，利用时域积分的方法得到飞机滑跑的各种响应。

Finally, the change of joint angular velocity of the supporting leg is deduced based on the Lagrange dynamic equation when a foot of the robot collides with the ground.3, Dynamic stability conditions of the robot in stance phase and flight phase are derived based on the D\'Alembert principle.

这种动力学方程由微分方程和代数约束方程组成，其优点是通过稍微修改约束方程和雅克比矩阵，就可以方便地建立各自动力学方程，建模速度快、精度高。

D'Alembert Solution in one dimension wave equation is a very important basic formula.

弦振动方程中的D'Alembert公式是偏微分方程中一个非常重要的基本公式。

In this thesis, we express one dimension wave equation by arithmetic theory and prove D'Alembert Solution in the light of method on one stage linear partial differential equations.

本文从另一角度即算子的方法，将弦振动方程写成算子的形式，再根据一阶线性偏微分方程的求解方法，最终推导出D'Alembert公式。

All these results provide some theoretical foundation and justification for the DAE control system design.

这些工作一定程度上为电力系统基于微分代数模型的几何控制设计提供了理论基础。

Based on the proposed method, the strategies for index analysis of discontinuous DAE models are presented.

最后，针对定结构与变结构的非连续微分代数模型给出了相应的指标分析策略。

Therefore, DAE is a common mathematic tool to describe the structure-preserving power system models.

因此，微分代数系统是描述电力系统结构保留模型的一般数学工具。

The paper presents a linear transient solution for the solitary wave generated by a piston-type paddle in a finite flume based on the boundary condition derived by Dean and Dalrymple (1991). The wavemaker problem is simplified by decomposing the wave potential into two parts. One is the evanescent wave and the other is progressive wave. The possible solution for the evanescent wave is expressed in form of the Fourier series.

本文根据Dean与Dalrymple（1991）描述造波水槽内部之线性边界条件，将水槽内部之流速势分为振荡波与前进波以简化问题，再以Fourier级数展开，可将问题化为二非齐次常微分方程式，在给定造波初始条件的情况下即可解析有限长度造波水槽自静止开始造波一段时间后停止之线性暂态解。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。