上微分

In this dissertation, two methods were adopted to build dynamics model for vehicle ride comfort analysis: one is eight freedom vehicle ride comfort differential equation model in which lateral movement of driver and vehicle body was considered. Combined with time domain model of random road input, we got the driver and vehicles moving displacement.

本文采用两种方法建立了车辆平顺性分析的动力学模型：8自由度车辆平顺性分析的微分方程模型，考虑了驾驶员和车体的侧倾，结合随机路面激励的时域模型，在B级路面输入条件下，进行了时域仿真求解，得到车辆和驾驶员在汽车坐标系中各个方位上随时间历程的运动位移；利用ADAMS软件建立的福田小卡汽车，共计596个自由度的三维实体整车虚拟汽车模型，全面地考虑了影响平顺性的各种因素，然后通过对路面功率谱的变换生成适合于ADAMS／Tire的路面文件，实现了整车虚拟样机在随机输入激励下，车辆振动模型的时域仿真求解。

In this dissertation, two methods were adopted to build dynamics model for vehicle ride comfort analysis: one is eight freedom vehicle ride comfort differential equation model in which lateral movement of driver and vehicle body was considered. Combined with time domain model of random road input, we got the driver and vehicle's moving displacement. The other method, we built a Forland truck virtual prototyping using ADAMS, it is a 3D machine model, totally with 596 freedom degrees, every factor that influences the vehicle ride comfort was considered, finally complete the time domain simulation on random road input.

本文采用两种方法建立了车辆平顺性分析的动力学模型：8自由度车辆平顺性分析的微分方程模型，考虑了驾驶员和车体的侧倾，结合随机路面激励的时域模型，在B级路面输入条件下，进行了时域仿真求解，得到车辆和驾驶员在汽车坐标系中各个方位上随时间历程的运动位移；利用ADAMS软件建立的福田小卡汽车，共计596个自由度的三维实体整车虚拟汽车模型，全面地考虑了影响平顺性的各种因素，然后通过对路面功率谱的变换生成适合于ADAMS/Tire的路面文件，实现了整车虚拟样机在随机输入激励下，车辆振动模型的时域仿真求解。

"Mathematical analysis ","probability theory and mathematical statistics","function of complex variable"," differential equation ","mathematical experimentation ", etc..

数学分析》、《概率论与数理统计》、《复变函数》、《常微分方程》、《数学实验》等。2000年以来，在《云南大学学报》等刊物上公开发表学术论文7篇。

The last chapter talks about the positive solution\'s existence of periodic boundary value problem of functional differential equation.

最后一章通过锥上不动点定理讨论了泛函微分方程周期边值问题正解的存在性问题。

Lastly, the existence theorem of three positive solutions for the boundary value problem of second-order singular functional differential equation be established by applying the index theory of fixed points in a cone.

最后，我们应用锥上的不动点指标理论建立了二阶非线性奇异泛函微分方程边值问题的三个正解的存在性定理。

Under some moderate conditions, the prior estimate of the solutions of the system is obtained. Making use of constructing Picard iterative sequence, Doob martingale inequality, Gronwall inequality, Borel-Cantelli lemma and some fundamental inequalities, together with the uniform Lipschitz conditions, the existence and uniqueness of the solution for stochastic functional differential equations with infinite delay is derived on the interval t0,∞.

在适当的条件下，得到了随机泛函微分方程的解的先验估计；再结合一致Lipschitz条件，通过构造Picard迭代序列，利用Doob较不等式、Gronwall不等式、Borel-Cantelli引理及一些基本不等式，得到该方程的解在区间[t0，∞]上是存在且唯一的。

The primary contents are as follows:(1) Based on the fundamental seepage physical equation, the basic differential equation of saturated-unsaturated seepage in porous mediums has been deduced, in which the pressure head is the fundamental unknown quantity.

总体说来，本文主要从以下几个方面开展了研究：(1)由基本渗流物理方程出发，以压力水头为基本未知量推导多孔介质三维饱和—非饱和渗流微分方程，在此基础上分析了边坡在有降雨入渗条件下渗流的定解条件和计算模型。

A systematic study on computing the integral curvature line on NURBS surface is presented. Discrete normal is used to simplify calculation of the second fundamental form of the surface, resulting in accelerating the Euler iteration process in solving the differential equation of curvature line. Discrete points on the curvature line are then obtained and approximated by an explicitly presented B-spline curve on the NURBS surface using singular mixed interpolation and capable of controlling the error within a given tolerance.

对NURBS曲面的曲率线的积分进行了系统的公式推导，并利用NURBS曲面的离散法向量有效地简化了曲面第二基本量的计算，加速了Euler法迭代求解曲率线微分方程的过程；在求得曲率线上的离散点集以后，应用奇异混合插值技术，在可控精度内把曲率线用显式直接表示为位于NURBS曲面上的B样条曲线。

Remarkable is that this more than a century ago almost directly with the achievement of modern mathematics, the following methods, the general flow is concepts, algebra to geometry closely linked, he and his successors -- Beiertelami, Christopher Tuofeier, Lee Puxici developed differential Zhang volume analysis has gradually become more research on the flow geometry and analysis of an important tool.

令人赞叹的是，这一个多世纪前的成就几乎直接同现代数学中的拓扑方法、一般流形概念、代数几何学等紧密相连，他和他的接班人——贝尔特拉米、克里斯托费尔、李普希茨所发展的微分张量分析逐渐成为研究流形上几何结构和分析的一个重要工具。

The stiffeners are taken to be smeared over the surface of the element, and Hamilton＇s principle is used to derive the appropriate modifications which must be made to the plate differential equations.

对于板上加强筋的处理，则通过Hamilton原理对板的运动方程作相应的修正，最终得到加筋板的运动微分方程。

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。