上微分

Runge - Kutta method to solve the differential equation is more commonly used method, in understanding how mathematics is one thing, the availability of the way is easy, it is an iterative process.

龙格---库塔方法是求解微分方程比较常用的方法，在理解数学上是怎么一回事后，编制这个程是相当容易的，就是个迭代的过程。

The value solution adopts "the step-type" format to solve separate lights for the approximate value. The Euler method and the Runge—Kutta method are the most typical commonly value method to solve the differential equation.

数值解法采取"步进式"的方式求解离散点上的近似值，欧拉方法和龙格——库塔方法是求解微分方程最典型常用的数值方法。

Many methods, including difference methods,collocation methods and standard finite element methods for singular parabolic equations have been proposed and analyzed ,and some good results have been obtained.

但利用非标准有限元方法，对奇异微分方程进行研究的文章迄今很少见到。时空有限元法将时间和空间两个变量统一起来，在时间和空间两个方向上同时发挥有限元的优势，实现时间和空间两个方向的高精度。

In accord with the characteristics of singular integrals in boundary element method for solving problems of thick plates on two parameter foundation,all formulas for calculating singular integrals are set up by selecting the displacements and stresses which satisfy the governing differential equations in this paper,on the principle of virtual energy.

根据双参数地基上厚板弯曲问题边界单元法中所遇奇异积分的特点，选取满足该问题微分控制方程的位移及内力场，建立了全部奇异积分的计算公式，有效地解决了边界元法在该问题应用中高阶奇异积分的计算问题

By means of a nonlinear alternative theorem of Leray-Schauder type and Guo-Krasnoselskiis fixed point theorem in a cone, we establish the existence theorem of a positive solution to a singular coupled system of nonlinear fractional differential equations.

借助于锥上的非线性Leray-Schauder择一型定理和郭-Krasnoselskiis不动点定理，我们建立了非线性奇异耦合分数次微分方程组正解的存在性定理。

By means of a nonlinear alternative theorem of Leray-Schauder type and Guo-Krasnoselskii's fixed point theorem in a cone, we establish the existence theorem of a positive solution to a singular coupled system of nonlinear fractional differential equations.

借助于锥上的非线性Leray-Schauder择一型定理和郭-Krasnoselskii's不动点定理，我们建立了非线性奇异耦合分数次微分方程组正解的存在性定理。

The use of spherical coordinates brings new certain difficuhy of numerical simulation, since partial differential equations might possess singularity at the center of ball.

然而，球面坐标的引入也给我们带来了新的困难，特别是偏微分方程在球的中心处会出现形式上的奇异性。

It is not conformable with many images on the surface such as cylindrical map image,spherical map image,which can be found in reality.

而现实中往往可见到许多曲面上的图像，比如柱面帖图、球面帖图，处理此类图像采用基于直角坐标系的微分算子显然不能胜任。

On this basis, an angle stability criterion is proposed by which the angle stability of power system can be conveniently judged.

该微分方程组描述了相点在一维坐标轴上的运动，可用于观察电力系统的功角稳定性。

Geometry quality for these mappings can be obtained from these inqualities,and some sufficiency conditions for starlike mappings and spirallike mappings are given.

本文建立了多复变数单位球上全纯映照的一些偏微分不等式，由此可映照本身的一些几何性质，并得到星形映照和螺形映照的充分判别条件。

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。