例句與造句

1. In 1944, while a student in Utrecht, he predicted the existence of the 21 cm hyperfine line of neutral interstellar hydrogen.
2. In June 1983, Valdes and Freitas used the 26 m radiotelescope at Hat Creek Radio Observatory to search for the tritium hyperfine line at 1516 MHz from 108 assorted astronomical objects, with emphasis on 53 nearby stars including all visible stars within a 20 light-year radius.
3. The tritium frequency was deemed highly attractive for SETI work because ( 1 ) the isotope is cosmically rare, ( 2 ) the tritium hyperfine line is centered in the SETI waterhole region of the terrestrial microwave window, and ( 3 ) in addition to beacon signals, tritium hyperfine emission may occur as a byproduct of extensive nuclear fusion energy production by extraterrestrial civilizations.
4. It's difficult to find hyperfine line in a sentence. 用hyperfine line造句挺難的