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分析了空中无线电监测平台的系统构成,并对当前市场上几类主要的空中监测实例应用进行对比,阐述了各种空中监测平台的特点及适用场景,分析了空中监测平台在卫星上行信号干扰监测定位工作中的应用和意义。 相似文献
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用飞秒脉冲激光照射砷化镓(gallium arsenide, GaAs)晶体,透射光出现了多级的干涉环.利用透射式Z-扫描光路,改变飞秒脉冲激光入射到GaAs晶体表面时的功率密度,观察到干涉环有规律地收缩(或扩张):功率密度越大,出现的干涉环越多,张角也越大.高强度飞秒脉冲激光的非线性效应局部地改变了GaAs晶体的折射率,从而导致光程差的出现,这是一种非线性效应(克尔透镜).超快光脉冲在GaAs晶体里产生的克尔透镜不能像理想的薄透镜那样把光束聚焦,而是让透镜光束形成了干涉环.通过分析干涉环的变化,可以得到GaAs晶体的非线性吸收系数和非线性折射率. 相似文献
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Tingting Shi 《中国物理 B》2021,30(12):124208-124208
Coherent rainbows can be formed by focusing white-light laser into liquids. They are bilaterally symmetric interference rings with various shapes. Such interference rings arise from the temperature distribution of the liquid induced by laser heating, i.e., thermal lens effect, which changes the refractive index locally and thus the optical path difference. The up-down asymmetry of the interference rings is caused by convection in the liquid. With the increase of the viscosity, the interference rings change their shape from oval to circular shape. After a shutter is opened and the laser shines into the liquid, the interference rings are circular at the beginning. As time goes on, they gradually turn into an oval shape. Let the liquid go a free-fall at the beginning, the interference rings remain circular. All the three experiments have confirmed that the asymmetric interference rings are due to convection in the liquid associated with thermal lens effect. We also numerically simulate the two-dimensional heat conduction with and without convection, whose results agree well with our experimental observations. 相似文献
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发射标识是一种无线电信号特征描述的国际通用技术指标,使用之处非常广泛。本文介绍了国际频率登记通报(BR IFIC)以及发射标识的含义,并结合实际监测工作,对BR IFIC中登记的短波频率信号的典型发射标识进行了简析。 相似文献
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