例句與造句

1. Author , secondly , starts from the approximate expandness of square root operator , perform mathematical calculations for finite difference operator in frequency - space domain , fourier finite difference operator in mixing domain ( frequency - space and frequency - wavenumber domain ) and general screen operator in mixing domain , compare and discuss their precision of their wavefield , adaptability for lateral velocity variations , computation efficiency and stability . thirdly , author , applies the steady variational reference slowness rytov approximation general screen wavefield extrapolation operator ( vrselrf ) in frequency - wavenumber domain , to the prestack and poststack forward modeling and depth migration
   第二，從平方根算子的近似展開出發(fā)對頻率?空間域的有限差分算子、混合域(頻率?空間域；頻率?波數(shù)域)的fourier有限差分算子、混合域的廣義屏算子進行了推導并對其波場描述精度、對橫向變速的適應性、計算效率和穩(wěn)定性進行了比較與評述。
2. It's difficult to find finite difference operator in a sentence. 用finite difference operator造句挺難的