Fourasn.富拉(在法国；西经 1º06' 北纬 45º59')fournum.四four-wave mixing signal四波混合信号four-phase-difference四相位差分four dimension coordinate四维坐标Four Leaves and One Shoot四叶一心Four petal ilex macropoda四花青皮four separative rice mill四分离碾米机Fourier-Legendre series傅里叶-勒让德级数Fourier finite difference傅里叶有限差分four high roller leveller四轧辊式矫直机four-stage coordination协调四阶段