目前,世界上主要的卫星导航系统包括美国GPS、欧盟Galileo、俄罗斯GLONASS和中国BDS。GPS是目前已存在的技术比较成熟的卫星导航系统,BDS是在2012年12月27日起正式提供卫星导航
In this work,α-NLT nanocomposites(NCs)and β-NLT NCs with diameter about~13 nm were fabricated by a high temperature decomposition reaction method.The effe
Thin films of undoped and Sb doped SnO2 were deposited on quartz by sol-gel dip coating technique.The structure,optical,and electrical properties of thin fi
we can use borate with rare earth to convert high-energy photons to absorb near-infrared light,as to improve the silicon cell efficiency.Layered compounds h