条件方程

Firstly, from Gauss' equations and relative motion equations, the relation of control impulse and relative motion was expressed as analysis formulas and simplified based on the near circular condition. By deeply analyzing the mechanism of impulses in each directions (radial, in-track and cross-track directions) effect on relative motion respectively, two maneuvers to establish formation flying are provided: one is to utilize the impulses in radial and cross-track directions, the other is to utilize the impulses in along-track and cross-track directions. Both of the two methods can establish satellite formation flying of any configuration. The method with impulses irradial and cross-track directions needs only 3 impulses, while the method with impulses in along-back and cross-track directions needs 4 impulses. Lastly, by an example of establishing a space-circle formation flying, two maneuvers were compared with each other in the amount of impulses and fuel consuming estimation.

首先由高斯型拉格朗日轨道摄动运动方程得到轨道坐标系中控制冲量与轨道根数偏差的关系，基于近圆轨道的条件简化并带入相对运动方程，得到控制冲量与相对运动的关系表达式；通过深入分析各个方向（径向、沿迹向与轨道面法向）的控制冲量对相对运动的影响，给出了分别用径向与轨道面法向控制冲量组合和沿迹向与轨道面法向控制冲量组合实现编队捕获的两种控制策略；最后给出了一个空间圆编队捕获实例，并从燃料消耗、施加冲量次数及捕获时间等角度对比研究了两种控制策略的特点。

According to the properties of Wiener increments and the independent relation between the Wiener increments and the numerical solutions, the difference equation obtained by applying the numerical method to the general linear test equation is studied carefully in mean square sense and the conditions under which the numerical method is MS-stable and GMS-stable are determined.

依据维纳增量的性质以及维纳增量和数值解间的独立关系在均方意义下详细分析了数值方法应用到线性试验方程上得到的差分方程，并进一步确定了半隐式Milstein方法MS-稳定和GMS-稳定的条件。

Central South University, Changsha 410075, China）Abstract: Based on 2D steady and incompressible Navier-Stokes equation and k-ε turbulent model,the lateral aerodynamic performances of four types of car, i.e. passenger car, gondola car, boxcar and tank car were analyzed and compared by finite volume method, when these cars were in the cross winds of the same velocity and on the railway with the embankment of the same height.

摘 要：根据二维定常不可压缩Navier-Stokes方程和k-ε双方程紊流模型，采用有限体积法对客车、敞车、棚车和罐车4种不同外形铁路车辆在路堤高度、横风风速相同条件下的横向气动性能进行分析与比较。

And obtain an analogy result of Kazdan and Warner's, and then we use our theorem to study the vortex equation in Holomorphic line bundle over non-Kahler complex manifolds.

在第三部分我们考虑了一类Kazdan-Warner型的方程，并且证明了一个存在性的定理，借助于这一结果我们给出了一般的紧复流形M上的全纯线丛上的vortex方程解的存在性的一个充分性条件，或许这一考虑有其它方面的作用的。

It was proved that under Lipschitz coefficients, the solutions of SDEs driven by Brownian motion or a continuous semimartingale form a stochastic homeomorphism flow.

在方程系数Lipschitz连续的条件下，由Brown运动或连续半鞅驱动的随机微分方程的解形成一随机同胚流。

According to the boundary conditions,Laplace equation of SEW before the media changing abruptly and the homogeneous wave equation after the media changing abruptly were constructed.

结合相应的边界条件，建立了球面电磁波入射到时变媒质时的Laplace方程和时变媒质突变后的齐次波动方程。

According to the boundary conditions, inhomogeneous wave equation of point source before the media changing abruptly and the homogeneous wave equation after the media changing abruptly were constructed.

根据相应的边界条件，建立了球空间时变媒质点源激励的非齐次波动方程及媒质突变后的齐次波动方程。

In §2, four met0hods for solving the integrable second order homogeneous linear ordinary differential equation with variable coefficientsy +py'+Qy=0 are given. Thus, the equation can be solved by means of elementary integrals and algebra.

给出了二阶变系数线性方程y＂＋py＇＋Qy＝0在可积的条件下的几种不同的求解方程，从而说明了这种可积的二阶方程不仅能用初等积分法求解而且也可以把它代数化，并使其通解公式化。

Numerical experiments show that because Navier-Stokes equations at highReynolds number are a hyperbolic system,the boundary conditions are appli-cable to prescribe their boundary problems.

数值实验表明，在高Reynolds数下，由于Navier-Stokes方程呈现出很强的双曲型方程的性质，上述经过某些线性化处理得到的无反射边界条件是可以用来指定其边界值问题的。

But if the surrounding temperature is between -100 and 25 centigrade, the ideal gas equation cannot satisfy the practice demand.

但是，如环境温度在-100℃～25℃的低温条件下，理想气体状态方程往往就不能满足实际计算的需要，这就需要低温下能较为正确地描述气体热物性的方程。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。