§13.1 动力计算的特点和动力自由度 §13.2 单自由度体系的运动方程 §13.3 单自由度体系的自由振动（不计阻尼） §13.4 单自由度体系的强迫振动（不计阻尼） §13.5 阻尼对振动的影响 §13.6 多自由度体系的自由振动 §13.7 多自由度体系主振型的正交性和主振型矩阵 §13.8 多自由度体系在简谐荷载下的强迫振动（不计阻尼） §13.9 多自由度体系在一般动荷载下的强迫振动 §13.10 近似法求自振频率

唐宋时期，我国古代里坊制由鼎盛走向崩溃。这一崩溃过程，萌芽于唐代中晚期的长安城。北宋东京开封城内，里坊的崩溃，以“侵街”为突破口。由于宋廷极力制止，使得崩溃过程出现了复杂性与反复性，直至北宋末年，里坊制才彻底走进坟墓。从此，宋东京城内街市、楼阁遍布，官民混合而居，呈现出崭新的城市景观

第一节 概述 第二节 极限弯矩和塑性铰 第三节 梁的极限荷载 第四节 判定极限荷载的一般定理 第五节 刚架的极限荷载

第一节 位移法基本概念 第二节 等截面直杆的单元刚度方程 第三节 无侧移刚架的计算 第四节 有侧移刚架的计算 第五节 位移法基本体系 第六节 位移法的对称性利用

1. Listen and talk about the problem of drug abuse 2. Read about the disastrous effects of Ecstasy 3. Write about the risks of taking drugs or other harmful substance 4. Practice reading skills: text cohesive devices 5. Practice translating skills: translation of “it” 6. Learn and practice paragraph development by cause and effect 7. Learn to write a public warning message

1. Listen and talk about travel 2. Read about what can be learnt from traveling 3. Write an introduction to your home town 4. Practice reading skills: pragmatic meaning 5. Practice translating skills: synthesis 6. Learn and practice paragraph development by comparison and contrast 7. Learn to write a trip itinerary

1) To listen to and then talk about business successes 2) To read about brand names 3) To write about a brand-name product 4) To practice reading skills: conceptual meaning 5) To learn and practice paragraph development by process 6) To practice Translating skills: Omission 7) To Learn to write advertisements 8) To visit Culture Salon about brand-name products

1) provide some clues to what makes a Nobel Prize Winner. 2) give guidance to learners to listen and talk about famous person. 3) provide students with new words and expressions 4) learn how to analyze word formation 5) ask learners to write in a chronological sequence

1. first listen to and then talk about environmental problems 2. read about an interview of a group of exports on environmental problems 3. write about what we should do to protect our Earth 4. practice reading skills: word attack strategies 5. practice translating skills: extension 6. learn and practice sentence functions 7. learn how to write a letter of invitation to an symposium, forum or conference 8. visit Culture Salon about our environment

钢结构是由钢板、型钢通过必要的连接组成基本构 件,再通过一定的安装连结装配成空间整体结构。连 接的构造和计算是钢结构设计的重要组成部分