4.1 态的表象 The representation of the state 4.2 算符的矩阵表示 Matrix representation of operators 4.3 量子力学公式的矩阵表示 Matrix representation of formula for quantum mechanism 4.4幺正变换(可移至本章结尾) Unitary transformation 4.5 狄喇克符号 Dirac symbols 4.6 线形谐振子与占有数表象 Linear oscillator and occupation number representation