6.1 Source terms in momentum equations and two key issues in numerically solving momentum equation 6.1.1 Introduction 6.1.2 Source in momentum equations 6.1.3 Two key issues in solving flow field 6.2 Staggered grid system and discretization of momentum equation 6.2.1 Staggered grid(交叉网格) 6.2.2 Discretization of momentum equation in staggered grid 6.2.3 Interpolation in staggered grid 6.2.4 Remarks 1. Flow rate at a node 2. Density at interface 3. Conductance at interface 6.3 Pressure correction methods for N-S equation 6.3.1 Basic idea of pressure correction methods 6.3.2 Equations for velocity corrections of u ’, v ’ 6.3.3 Derivation of equation of pressure correction p ’ 6.3.4 Boundary condition for pressure correction

在3.5%NaCl溶液中,铝镁合金在充N2除O2条件下,阳极极化至电流密度为10-2A·cm-2时,试样表面出现大量蚀孔。为了得到蚀孔发生的统计规律,利用泊松概率分布函数求得腐蚀活性点出现个数的规律,利用古比极值统计第一类近似函数求得最深腐蚀孔深度的概率分布。统计分析得到满意的结果。对于大量的点蚀腐蚀数据都可以按此理论进行统计分析,价用来评价材料的耐点蚀性能和估算管线的使用寿命

平推流反应器 Piston Flow Reactor (PFR) 活塞流模型或理想置换模型 This type of units is illustrated in the following figure. This reactor consists of a tube inside which the reaction medium flows. This makes i t t h e s i m p l e s t s t r u c t u r e conceivable f or a continuou s o p e r a ti o n s ys t em . Th e h ea t exchange necessary to add heat to the system or to remove it generally occurs ac ros s the tube wall

A ring that contains at least one heteroatom (an atom other than carbon) is called a heterocycle, and a substance based on a heterocyclic ring is a heterocyclic compound. Heterocyclic compounds containing N, O or S are by far the most common

Discrete-Time Systems A discrete-time system processes a given input sequence x[] to generates an output sequencey[n] with more desirable properties In most applications, the discrete-time system is a single-input, single-output system:

考察一般线性方程组 +a12x2++ainn=b , ① ax1+a32x2+…+=b 其中x1,x2,xn为未知量,s为方程个数 a(i1,2,sj=1,2,n)称为方程组系数: b(i=1,2,s)称为常数项

问题:如何利用系数矩阵A和增广矩阵B的秩, 讨论线性方程组Ax=b的解. 定理1n元齐次线性方程组Ax=0有非零解

一、选择填空： 1. 两进程使用同一临界资源时产生的制约关系是——。 A：合作关系 B：异步关系 C：互斥关系 D：任意关系 2．再单处理机系统中，如果系统中有 N 个进程，运行的进程最多几个，最少几个？

（1992 年全国大学生数 学模型联赛题 A） 某地区作物生长所需的营 养素主要是氮(N)、钾(K)、磷(P).某作物研究所在某地 区对土豆与生菜做了一定数量的实验, 实验数据如下 列 表所示, 其中 ha 表示公顷, t 表示吨，kg 表示公斤.当 一个营养素的施 肥量变化时

1.子式:在A中,选取k行与k列,位于交叉处的k2个数按照原来的相对位置构成k阶行列式,称为A的一个k阶子式,记作Dk对于给定的k,不同的k阶子式总共有C个 2.矩阵的秩:在A中,若 (1)有某个r阶子式D≠0; (2)所有的r+1阶子式D+1=0(如果有r+1阶子式的话) 称A的秩为r,记作 rankA=r,或者r(A)=r.规定: rankO=0性质:(1) rankA min{m,n}