Chapter One Nitrogen Family(Group V) Central contents 1. Know the general properties of elements of the nitrogen group and inert electron pair effect 2. Know the reactions of ammonia, understand the thermal decomposition trend of ammonium salts 3. Know the properties of nitrous acid and nitrites; understand the structure of nitric acid and nitrate radical; understand the thermal decomposition trend of nitrates

1、早期的太阳系 The Early Solar System Billions of years ago, out of a swirling mass of gas and dust, evolved a system of varied planets hurtling around a nuclear-powered star-our solar system. One of these planets, and one only, give rise to complex life forms. Over time

Atomic Structure All natural and most synthetic substances on earth are made from the ninety naturally occurring chemical elements. An atom is the smallest particle into which an element can be divided while still retaining the chemical characteristics of that element (fig 3. 1). The nucleus, at the center of the atom contains one or more particles with a positive electrical charge(protons fif and usually some particles of similar mass that have no charge(neutrons

Plate Tectonics Geologic Tectonics Earthquake Tsunamis海啸 and Coastal Flooding

第1章机构的组成和结构 机构:具有确定运动的实物组合体 1.1机构的组成 1.2机构运动简图 1.3机构具有确定运动的条件 1.4机构的组成原理和结构分析

11.1的衡类和平衡方法 11.2刚性转子的平衡设计 11.3刚性转子的平衡试验 11.4挠性转子平衡简介 11.5平面机构的平衡设计

13.1机械产品的设计过程 13.2机械总体方案设计的目的和内容 13.3机械总体方案设计中的设计思想

第15章机械传动系统的方案设计和原动机选择 15.1机械传动系统的方案设计 15.2原动机的选择 15.3机械控制系统简介

一、凸轮机构的组成与类型 二、从动件运动规律设计 三、凸轮轮廓的设计 四、凸轮机构基本尺寸的确定 五、凸轮机构的计算机辅助设计

5.1轮系分类及传动比计算 5.2轮系的功能 5.3轮系的设计 5.4其它类型的行星传动