详细解释:【计】 传输测试设备, 事务跟踪系统
【化】 三异硬脂酰基钛酸异丙酯
【医】 戒酒硫, 四乙秋兰姆化二硫
英语解释：
名词 tt:
(astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motions同义词：terrestrial time, TT, terrestrial dynamical time, TDT, ephemeris time