Uysn.尤伊斯Un.字母UU - shaped composite beam新型外包钢组合梁UWB wireless communications超宽带无线通信U.N. World Food Program联合国世界粮食计划Uextro-pantothenylalcohol右旋泛醇U.N. Information Officen.联合国新闻处UAV - unmanned air vehicle无人机U.N. rs nuclear watchdog联合国核监查机构ULF electromagnetic emission电磁辐射异常U.N. Trusteeship Counciln.联合国信托管理理事会U.S.Army Chemical Center美国陆军化学品中心