upper ridge (upper-level ridge)
upper trough (upper-level trough)
upper-air chart (upper-level charty)
water diversion from the upper Yangtze River in the south to the upper Yellow River in the north
close-link chain [= short-link chain]
direct current link DC-Link
direct current link(DC-Link)
link-by-link encryption
un-link (earth-to-space link)
1221 upper working face
2×2 Upper Triangular Operator Matrixes
95% Upper confidence limit