The article describes 6 types of gemstones which show phenomena such as chatoy-ancy and asterism.The gemstones have not ......

阐述了利用激光回波信号进行目标检测的理论依据,讨论了对激光回波信号的光谱、偏振、位置、运动、振动特征的提取的原理,最后分析......