特别地，磁单极子可以存在于称为“Dirac弦”的，也就是携带磁场的长管的两端。

Specifically, monopoles could exit at the ends of long tubes carrying magnetic fields called "Dirac strings.

youdao

这根弦大约一微米长，直径两纳米，是根炭纳米管。

The wires are made of carbon nanotubes that measure approximately 2 nanometers in diameter.

youdao

静静的望着穿梭在云层的秋月，凉凉的夜风，牵出月光的长琴，多情的弦系于你我之间。

Hope to wear shuttle the autumn month in bank of clouds quietly, very cool night breeze, lead long a long piano of moonlight, affectionate in you my its.

youdao

Here is the pitch in--of--a string an octave higher so you can see it this way. As you probably know, if you take a long string and pluck it, it's going to take that long string a long time to pass that sort of cycle, if you will, just one pass through that cycle.

这也是个音高,一个高八度的音弦,你可以这样这样看 你们可能知道,如果你拨动长弦,长弦要经过很长时间,才能完成一个震动周期,如果你想,可以尝试下

耶鲁公开课 - 聆听音乐课程节选