条件方程

By virtue of inverse Fourier transform and convolution theorem, a semi-analytical solution for the velocity response of a pile subjected to a semi-sine wave exciting torque is obtained in the time domain.

进一步根据桩土接触面上的位移、应力连续条件，求解了桩身动力平衡方程，在频域内得到了桩顶动力响应的解析解。

Taking the unknown coordinate in curved surface and curve as design variables, the equation of curved surface as constrained condition, and the distance between unknown coordinate as objective function, optimization is proposed to minimize the distance between curved surface and curve.

建立以曲面、曲线上未知，点坐标设计变量，以曲面和曲线方程为约束条件，以曲线和曲面距离为目标函数的约束优化方法来精确地确定曲面和曲线之间最短距离，同时确定获得最短距离对应的坐标点。

Two conservation equations are derived from a Wigner-Fokker-Planck model, they contain a third-order quantum correction term and second-order viscous term...

然后 在弱的亚音速条件下利用截断技术建立解的先验估计，在此基础上根据Leray-Schauder 不动点定理得到四阶方程弱解的存在性。

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。

The thesis can be divided into five parts as follows: First, the structural characteristics of finned-pipe evaporator are analyzed. After selecting suitable microelement controller, the heat-transfer and mass-transfer processes are analyzed for every microelement under the conditions of dryness, wetness and frostiness. Based on previous equations, some parameters of frostiness are confirmed and the frost-growing model is set up under frost condition. Some hypotheses are postulated and with the help of the equation of mass-conservation, energy-conservation and momentum-conservation, the evaporation model which fits in the dynamic simulation is built, which set a solid foundation for system simulation. Second, the starting and stopping behaviors under disturbed condition are analyzed and calculated by using the dynamic concentrative parameter model, which gives some advice to better prescribe refrigeration system and set theoretic foundation for carrying out automatic control of refrigeration system. Third, the normal running process is analyzed and calculated by means of rational matching theory, which gives some advice on how to better understand the parameter change under steady state and the affection of inlet-parameter on evaporator. Fourth, the simulation software with dynamic characteristic is designed, which can be applied to calculate thernio-parameter of cryogen, air humidity and frost thickness under different initial and boundary conditions, and to carry out dynamic simulation under conditions of dryness, wetness and frostiness, at the same time, to achieve detection and simulation at any stage from starting to stopping.

本文的主要内容如下：1对翅片管蒸发器结构特点进行分析，选取适当的微元控制体，就干、湿和霜工况下对每个微元分别进行传热传质分析，基于经验关系式确定霜的有关参数，对于霜工况下的霜生长建立模型，经适当假设，运用质量守恒、能量守恒和动量守恒方程建立适合动态仿真的蒸发器数学模型，为系统仿真奠定基础； 2对蒸发在大扰动下的开、停机过程，运用动态集中参数模型进行分析和计算，为更好地描述制冷系统运行的全过程奠定基础，同时也为制冷系统实现自动控制提供一定的理论基础； 3对蒸发器正常运行过程，运用动态分布参数和参数间定量耦合的观点来分析和计算，为更好地了解稳态工况下各点参数的变化情况及各入口参数对蒸发器动态特性的影响即蒸发器性能对各参数变化的敏感性； 4编写翅片管蒸发器动态特性仿真计算程序，可以计算不同边界条件和初始条件下的制冷剂热力参数、空气温湿度和霜厚度分布场，实现对翅片管蒸发器在干、湿和霜工况下的动态仿真。

This paper studies a class of cubic system with planar polynomial.We use the qualitative theory of ordinary differential equations method of analysis, reached the following conclusions of four parts: First, we analyze the quality of all critical points of the system,and draw the conditions of existence of singular integrals for the system , in front based on the analysis, using Pioncare form series method to calculate the focal value of o(0,0). Finally, we also study the behavior of critical points at infinity.

中文摘要：本文研究了一类平面三次多项式系统，我们采用常微分方程的定性理论的分析方法，得出如下四个部分结论：第一部分，分析系统所有奇点的性态，并得出系统存在奇异积分直线的条件；在前面分析的基础上，用Pioncare形式级数法，计算出了系统在奇点o(0，0)的三个焦点量；最后，研究了系统无穷远奇点的性态。

At first, the velocity which is the outlet velocity of 2-D numerical model by using the VOF and κ~εmodel is used as the inlet velocity of the 3-D numerical model. The control equations of 3-D water and sediment movement are described in the orthogonal curvilinear coordinates, and the equations is segregated by using the Finite Volume Method.

以二维的水气两相流的VOF 模型结合雷诺时均法的κ~ε双方程模型进行水气两相流计算，得到稳定流场作为三维水沙计算的初始进口条件。

First, under general conditions, we solvethe locomotive's cyclic working current equation with the analyticaland the numerical methods combined, giving a computing module quitefitting in with practicl results.

文中首先在一般条件下用解析法和数值方法综合求解了SSI型电力机车的周期工作电流方程，给出了比较切合实际的计算模型。

According to the structure and motion characteristics of the spherical offset mono-cone bit, compound cylindrical coordinates were set up, and basic geometric equations and the conditions of teeth to penetrate rock for the bit were presented.

针对偏心单牙轮钻头的结构和运动特点，利用复合圆柱坐标系统的基本原理，建立了偏心单牙轮钻头几何学基本方程和牙齿对岩石的吃入条件。

With boundary conditions,pressure distribution and the damping force on the plate can be found by solving the differential equation.

结合边界条件求解该方程可以得到各种压膜阻尼结构中的阻尼压强分布和阻尼力。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新