在弹性介质中传播的机械纵波，一般统称为声波.声强级：人们规定声强 （即相当于频率为 1000 Hz 的声波能引起听觉的最弱的声强）为测定声强的标准. 如某声波的声强为 I ， 则比值的对数，叫做相应于 I 的声强级 LI

This chapter was written so I would have something to talk about on the first day of class. I wanted to give students an idea of what economics was all about, and what my lectures would be like, and yet not have anything that was really critical for the course. (At Michigan, students are still shopping around on the first day, and a good number of them won’t necessarily be at the lecture.)

一、实验目的 1. 学习和掌握三相异步电动机的启动特性 二、实验内容及步骤 ： 本实验利用交流电流表或万用表测量三相异步电动机的输入电流（如图 1-1 I1 和 I2 两 点之间的电流）。从而得出三相异步动机的启动特性。 实验步骤 ：

关于本章内容:属于分析力学体系 矢量力学(矢量物理量:F,i,a,O,a,F,M,动量K,动量矩) 牛顿( Newton,1642-1727)——牛顿三定律 分析力学(标量物理量:广义坐标9,广义速度i,能量 T,V,功W) 拉格朗日(j-l. Lagrange,1736-1813 13)虚位移原理 本章将虚位移原理用于静力学平衡问题

9.1 设真实模型为无截距模型： Y X u i i = + 2 2 回归分析中却要求截距项不能为零，于是，有人采用的实证分析回归模型为：

八.凸集与凸函数 1凸集 (1)凸组合:已知XcR,任取k个点x∈X,如果存在常数 a≥0(i=1,2,k), a1=1,使得ax=x,则称x为x (i=1,2,,k)的凸组合。 (2)凸集:设集合XR,如果X中任意两点的凸组合 仍然属于,则称Ⅹ为凸集

课本P122第5题 解:用(K1K2K3)表示三个开关的状态,取值为0时表示闭合,为1时表示打开 则初始状态为(0,1,0)。根据题设要求,一个状态I的下一个状态和I只能有一位取 值不同(此即状态转换规则),据此可以画出状态空间图

Particularism and virtue ethics I. Universalism and Particularism We've considered before some basic questions that we would expect a moral theory to answer i)Which acts are right and which are wrong? Which acts ought we to perform(understanding the\ought\as a moral

2. 直流传输特性曲线 c区：νI 0(小)，A′→B点

1. Who am I? Chris Wallace, Lecturer at the Department of Economics, Oxford University and Fellow in Economics at Trinity College. 2. What do I do? Teach economics and research in the field of game theory. 3. Who are you? First year students taking either the Philosophy, Politics and Economics (PPE) degree