We analyze bi-directional compatibility between radar and outside electromagnetism circumstance and also bring a detailed introduction to narrowband receiver, DDS ( Digital Direct Synthesis ) frequency synthesizer and side lobe cancellation ( SLC ). 文中分析了雷达与外部电磁环境之间的双向兼容性问题,并对所采取的窄带接收机、数字直接合成(DDS)频率源和副瓣对消技术作了介绍。
Cerebral vascular disease is the direct cause of VCI, but leukoaraiosis and prefrontal lobe atrophy especially leukoaraiosis is closely related to VCI. 脑血管病变是导致VCI发生的直接原因,但脑白质疏松和前额叶萎缩,尤其是脑白质疏松与VCI的发病关系更为密切。