n. 强音节, 弱拍

Arsis \Ar"sis\ ([aum]r"s[i^]s), n. [L. arsis, Gr. 'a`rsis a
raising or lifting, an elevation of the voice, fr. a'i`rein
to raise or lift up. Its ordinary use is the result of am
early misapprehension; originally and properly it denotes the
lifting of the hand in beating time, and hence the unaccented
part of the rhythm.]
1. (Pros.)
(a) That part of a foot where the ictus is put, or which
is distinguished from the rest (known as the thesis)
of the foot by a greater stress of voice. --Hermann.
(b) That elevation of voice now called {metrical
accentuation}, or the rhythmic accent.

Note: It is uncertain whether the arsis originally consisted
in a higher musical tone, greater volume, or longer
duration of sound, or in all combined.

2. (Mus.) The elevation of the hand, or that part of the bar
at which it is raised, in beating time; the weak or
unaccented part of the bar; -- opposed to {thesis}.
--Moore.