齿轮机构是在各种机构(连杆、凸轮等)中应用最为广泛的一种传动机构齿 轮传动是机械传动中应用最广泛的一类传动,形式很多。它的先进与否可以衡量一 个国家的工业水

1.常见传动系统的传动比:圆柱齿轮=5,锥齿轮=3,链=8,带=6,1平带=3 蜗杆:5≤i≤100,15≤i≤50 2.手表30°=720{17 360°×60 大d=17×720×3mm=36.72m一对齿轮

一、凸轮机构的应用:常用的高副机构自动机械和半自动机械装置中,实现运动比连杆(最多9个点)容易,使用广泛

Chapter 16: Concurrency Control Lock- Based Protocols(基于锁的协议) Timestamp-Based- Protocols(基于时间戳的协议) Validation-Based- Protocols(基于有效性检查的协议 Multiple Granularity(多粒度) Multiversion Schemes(多版本机制) Deadlock Handling(死锁处理)

Chapter 7: Relational Database Design First Normal Form Pitfalls in Relational Database Design Functional Dependencies Decomposition Boyce-Codd Normal Form Third Normal Form Multivalued Dependencies and Fourth Normal Form

Chapter 4: SQL Background Basic Structure Set Operations Aggregate Functions Null Values Nested Subqueries Derived Relations Views Modification of the Database Joined Relations

Chapter 2: Entity-Relationship Model Basic Concepts Constraints Keys Design Issues E-R Diagram Weak Entity Sets Extended E-R Features Design of an E-R Database Schema Reduction of an E-R Schema to Tables

7.1进制数字调制 7.1.1二进制幅度键控(2ASK)

5.1脉冲编码调制(PCM) 5.1.1脉冲编码调制的基本原理

3.1双边带调幅 3.1.1常规调幅(AM)