the short-circuit input impedance I12=0 the short-circuit forward current gain I1V2=0 Let 1=0 he open-circuit reverse voltage gain I1=0 the open-circuit output admittance

Three-phase sources have three Q terminals called the line terminals(a, b,c). + Neutral connection--n an b+V n bn Balanced three-phase sources may

Example 1: If 0=4v2 cos\tV, Z=2/600Q2 Find p(t)and P. Solution:

The forced response The steady state responseThe(t) has been switched into the circuit at some remote U.=V. cos ot time in the past, and the natural response has died-out completely. The forced response(steady state response)must satisfy the differential equation

The Normal Distribution: the distribution of a continuous r.v. whose value depends on a number of factors, yet no single factor dominates the other. 1. Properties of the normal distribution: 1)The normal distribution curve is symmetrical around its mean valueu. 2)The PDF of the distribution is the highest at its mean value but tails off at its extremities

习题14-2 解:(1)由x=0.1cos20t+与x=Acos(t+)比较得振幅A=0.1(m)角频率=20初相π频率V==10周期T==0.1(s)

一、热力学(thermodynamics)的研究对象与研究方法 物态(state of matter):物质存在的物理状态 物质主要存在三种基本物理状态:固态、液态 和气态 热学是研究一切物态的热现象的学科,我们这里主 要研究气态,但有时也会牵涉到固态和液态。 从宏观上看,热学研究物体的宏观热现象:与温度有 关的物态的物理性质的变化。由观察和实验来总结热 现象的规律,得出热现象的宏观理论,这部分称为热 力学。 热力学利用宏观上可观测的物理量,如:,V,T 来研究热现象的规律

1.名词(substantivum)(简称 subst.或s.)表示人,地,事物的名称。变格。 2.形容词(adiectivum)(简称a)表示人和事物的特征。词尾的变化随名词走。变格 3.动词(verbum)(简称v)表示人或事物的动作或状态。变格。植物学中一般不用,故省略

63.1 Power System Analysis Introduction Types of Power System Analyses The Power Flow Problem. Formulation of the Bus Admittance Matrix.Example L.L. Grigsby and Formulation of the Power Flow Equations. P-V Buses.Bus

1.液体的表面自由能Y可以表示为 (A)(a H/a) T.p, n (B)( F/a A) T, p, n (C) (a U/aA S, V, n (1) (a G/a).,n