微分

In Riemannian manifolds, one studies Riemannian metric, covariant derivative, Riemannian connection, basic properties of the Riemann curvature tensor, curvature forms etc.

黎曼流形部分主要涉及黎曼度量，黎曼流形的定义，切向量场的协变微分，黎曼联络，黎曼几何的基本定理，曲率张量，曲率形式等概念和理论。

Vector analysis, Dyads, index notation, covariant and contravariant derivatives, Christoffel symbols, Riemann tensor, hydro-dynamical field equation.

张量及场方程式：三维向量，张量符号，张量微分，克里斯多夫符号，黎曼张量，流体动力场方程式。

In this paper we define the concept of Projective Blaschke manifolds and extend the theory of equiaffine differential geometry to the projective Blaschke manifolds. We prved that if M be a complete projective Blaschke n-sphere and its universal covering manifold is isometric to a complete (n+1) dimensional parabolic, elliptic or hyperbolic affine hypersphere, then M is a quotient space of E^n, S^n or D^n by a isometric subgroup of its corresponding spaces.

在这篇文章中我们定义了射影Blaschke流形的概念，将等仿射微分几何的理论推广到了射影Blaschke流形，并证明：如果n维完备射影Blaschke 超球面 M 的通用覆盖流形分别是完备的抛物型、椭圆型或双曲型仿射球，则M分别是n维欧氏空间、n维超球面或n维单位圆盘关于各自空间的一个等距离散子群的商，从而对完备射影Blaschke 超球面进行了分类。

An approximate solution can be derived by using Crammer\'s rule.Illustrative examples are given to show that the method in the present paper is simple and efficient.

采用微分的方法首先把两点边值问题转化为Fredholm积分方程，再应用本文的方法求解，通过数值例子展示了该方法的简单有效性。

An approximate solution can be derived by using Crammer\'srule.Illustrative examples are given to show that the method in the present paper is simple and efficient.

第六章总结了前面讨论的用Taylor展开方法解Fredholm-Volterra积分方程以及线性常微分方程的两点边值问题。

A detailed calculation on the scattering of a conduct disk is given by means of Incremental Length Diffraction Coefficient method and Phyzical Optics method. The relation between Radar cross section of the conduct disk and the incident angle and the relation between the optimal polarization and the incident angle are investgated and the calculation results from ILDC and that from PO are compared.

用微分边缘绕射系数法和物理光学法对金属圆盘的散射作了详细地分析计算，讨论了其极化散射特性给出了雷达截面积随角度的变化曲线并与用物理光学法计算的结果进行了对比，同时还给出了其最优极化随角度变化时的分布图。

The calculated result of cross section agrees well with the experiment.

微分截面的计算结果与最新实验相符合。

By means of the eigenvalue theory of partial differential equation, the crosswind and vertical sub-Green functions corresponding to the boundary types are derived.

引用Green函数的概念，提出了公路机动车多源扩散方程的求解思路，利用微分方程的特征理论，求得了Green函数的横风和垂直向分量。

By means of the eigenvalue theory of partial differential equation, the crosswind and vertical sub-Green functions corresponding to different boundary types are derived in a systematic fashion.

利用偏微分方程的本征理论，系统地求得了各类边界条件下Green函数的横风向和垂直分量。

Based on the domain superposition method and the differential cubature method as well as the Levy s general solution technique, a new semi-analytical solution has been developed in this paper, for free vibration analysis of moderately thick plates with abrupt thickness.

采用Mindlin中厚板理论，基于Levy解法和微分容积法，给出一种求解轴向受压的阶梯式变厚度板的自由振动问题的半解析解，板的边界条件为两对边简支、另两边任意。

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。