thunder, lightning bolt

today, this day / nowadays

one day, 24 hours / the daytime, the period from dawn until dusk / (figuratively) a short period of time / one day, someday, an unspecified day / the first day of the month

strontium, Sr

continuing unchanged as long as there has been heaven and earth

Kyūjitai form of 中華民国: Republic of China.

the Big Dipper, the Plough

(linear algebra) transposed matrix

the Republic of China

transmission, a gearbox (a mechanical assembly of gears that changes the torque and speed of shaft rotations)