短語詞組短語narrow slip beam 窄條梁radiation narrow -beam 細(xì)束輻射attenuation narrow -beam 細(xì)束衰減Narrow w beam condition 窄射束narrow -beam 窄射線;強(qiáng)指曏性射束;窄束narrow w beam 狹窄的光線;窄束narrow laser beam 細(xì)激光束 返回 narrow beam