4-5调制与解调 一、调制与解调的概念 调制信号:低频e(t)

Parasitology(寄生虫学), the study of parasites(寄生虫) and their relationships to the hosts(TE E), is one of the most fascinating areas of the biology. While it is entirely proper to classify many bacteria(细菌) and fungi(真菌) and all viruses as parasites

一、证明cost,cos(2t),,cos(nt)(n为正整数),是在区间(0,2)的正交函数集,它是否是完备的正交函数集? 二、实周期信号f(t)在区间(-,)内的能量定义为 E=f2()dt

第四章的思想:一是将信号分解为e虚指数信号的叠加傅 氏级数和傅氏变换。二是响应的合成。即把作为测试信号,系统 频率特性H(jo)响应为eH(jo)叠加。对分析谐波成分、频率响应、 波形失真、取样、滤波十分有效

一、掌握维生素A、B1、C、D、E的结构、性质和鉴别、检查、含量测定方法。 二、熟悉本类药物其它的含量测定方法以及杂质检查方法。 三、了解维生素A三点校正法的推导过程

一、对数频率特性 1.增益 设H(jo)=|H(j)e) 令G()=lnH(jo)(对数)增益,单位Np(奈培)或G()=201ogH(jo)常用对数增益,dB分贝东南大学移动通信国家重点实验室

(1)1/0方程:D(p)r(t)=N(p)e(t) (2)系统函数H(s)=(s) (3)框图/流图 (4)状态方程

可逆矩阵 一、逆矩阵的概念与性质 1.定义5.1设A是一个n阶方阵,若存在n阶方阵B 使 AB=BA=E 则称B为A的逆矩阵,并称A可逆

asynchronous[a'si6 k ranas]a.异步的 serial[' sirian]a.串行的,串联的 transmission[ t raen z'mi∫an]a.传输,发送 interface[ i n taf e i s]r.接口

Chapter 1 Introduction of Electronic commerce 1. 1 Development of Electronic Commerce(e-commerce 1.1.1 Histor Throughout history, attempts to promote new means of communication were simply means with which to increase opportunities for ease, efficiency and security. The foundations on which electronic commerce is based started 125 years ago with the use of telegraph