元数学的

The boundary element method is applied to find a numerical model on 2-D orifice in this paper.

本文利用边界元法建立了一个求解二维孔口的数学模型。

The mathematics model and the method of numecial simulation can be analysised, using the boundary element method.

采用边界元方法分析了船舶腐蚀防护的数学模型及数值模拟的方法。

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。

Cellular automata are dynamical systems in which space and time are discrete.

元胞自动机是一种有自组织行为的时空离散、状态离散的并行数学模型。

The problem of the equipment is that the calculation results appear distortion when angle is near to 45°.

论文在深入研究现有算法存在问题的基础上，采用了一种广泛用于刚体定位的数学参数算法——四元数法。

Boundary element method is a kind of numerical algorithm on boundary; it is based on the boundary integral equation and employs the element discretization technique.

边界元属于边界型的数值方法，它是以边界积分方程为数学基础，同时采用了有限元法的单元离散技术。

Then we summarize three basic mathematical-mechanical models of granular flow dynamics: kinetic theory model, friction-plasticity model and discrete element simulation model.

首先叙述了颗粒流研究的背景和基本概念，接着概述了颗粒流动力学研究的三种基本数学力学模型：颗粒动理论模型、摩擦塑性模型和离散元模拟模型。

Bernstein type theorem; Quaternion Euclidean space; minimal Lagrangian graphs; Twisted special Lagrangian submanifold; twisted normal bundle; Austere submanifolds; Real space form; Complex space form; Hamiltonian minimal submanifold; A Lagrangian submanifold with conformal Maslov form

基础科学，数学，几何、拓扑伯恩斯坦型定理；四元数欧氏空间；极小拉格朗日图；扭曲特殊拉格朗日子流形；扭曲法丛； Austere子流形；实空间形式；复空间形式；哈密尔顿极小子流形；具有共形Maslov形式的拉格朗日子流形

Element approach is employed, and the amount of each component holdup is calculated element by element with a proper void fraction model.

将换热器分解成若干微元，选用恰当的空泡数学模型，计算各组分在换热器中的滞留量。

The application of quaternion to mathematics, physics and computer graphics is significant.

因此，四元数在数学、物理学和计算机图形学中具有很高的应用价值。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。