一
(1) In fact carbon is not classified by chemists as a semiconductor even though diamond
does semiconduct at relatively high temperatures (well above room temperature). The
technical reason is that carbon has very strong molecular bonds which do not break down
very easily (the energy ‘gap’ between the valence band and the conduction band is
greater than that provided by ambient heat at room temperature.)
事实上，碳是不分化学家半导体尽管钻石在相对较高的温度下做半导体（室温以上）。技术原因是碳具有很强的分子键的不很容易打破（能源缺口的价带和导带之间是大于所提供的环境热室温。）
(2) A pure silicon crystal at any temperature above absolute zero will have some bonds
broken by the random action of heat and so there will be some free electrons in the
structure and you will get some conduction.
在任何温度高于绝对零度的纯硅晶体会有一些债券热的随机行动打破，所以会有一些结构中的自由电子，你会得到一些传导。
二
(1)This is partly because it is easier to fabricate in integrated circuit form but
信号系统英语词汇专业排版
消息（Message）信息（Information）信号（Signal）电子信息科学与技术Electronic Information Science and Technology
光学工程Optical Engineering物理电子学Physical Electronics
光电检测与信息处理Optoelectric Inspecting and Information
Processing
传感器技术Transducer Technique
光电检测技术Optoelectric Inspection Technique
信号与系统Signal and System
光电信息处理Opto-electric Information Processing
专业外语Professional English
无线光通信Free Space Optical Communication
确定信号(Certain Signal)随机信号(Random Signal)
周期信号(Periodic Signal)非周期信号(Aperiodic Signal)
连续时间信号(Continuous Temporal Signal)离散时间信号(Discrete Temporal Signal)
基函数(Primary Function)正交函数(Orthogonal Function)误差函数(Error Function)
正交矢量(Orthogonal Vector)正交函数集(Orthogonal
Function Set)
完备正交函数集(Complete Orthogonal Functional Set) 复变函数(Complex Function)线性组合(Linear Combination
最佳近似(Optimum Approximation)均方误差(Mean Square
Lession 1
Function in use
•normal probability function 概率正态分布函数
•orthonormal function 正交函数
•self-correlation function 自相关函数
•trigonometrical function 三角函数
•unbounded function 无界函数
•unit step function 单位阶跃函数
•zero Bessel function 零次贝塞尔函数
•function of first degree 一次函数
•function of many variables 多元函数
•function of random variable 随机变量函数
Periodic signals 周期信号
Time-domain description 时域描述
Polynomial expansion 多项式
Taylor series 泰勒级数
Fourier series 傅里叶级数
Frequency-domain description 频域描述
Orthogonal function 正交函数
Vectors 矢量
Description in dictionary
•描述：描述的行为，过程或技术
•声明，叙述：描述某事的声明或叙述
•用画表示：
•一种，一类：
Description in text
•A discussion of orthogonal functions and of their value for the description of signals
may be conveniently introduced by considering the analogy between signals and
信号与系统英文专业词
signal and system 信号与系统 digital signal 数字信号 exponential 指数级数
analog signal 模拟信号 generalized 广义级数 exponential signal 指数信号
Fourier transform 傅立叶变换 sine signal 正弦信号 (DFT) discrete Fourier
transform 离散傅立叶变换 cosine signal 余弦信号
angular frequency 角频率
region of convergence 收敛域
axis （Abscissa ）of convergence 收敛轴（坐标）
effective value 有效值
discontinous point 间断点（不连续点）
rational fraction 有理分式
initial state 初始状态
linear system 线性系统
original state 起始状态
nonlinear system 非线性系统
time-shifting property 时移特性
time –invariant system 时不变系统
odd function 奇函数
time-varying system 时变系统
even function 偶数函
continuous-time system 连续时间系统
odd harmonic function 奇谐函数
discrete-time system 离散时间系统
singularity function 奇异函数
lumped-parameter system 集总参数系统 sampling function 抽样函数
