biàn huàn
to transform
to convert
to vary
to alternate
a transformation
Fù lì yè biàn huàn
(math.) Fourier transform
jī fēn biàn huàn
integral transform (math.)
biàn huàn qún
(math.) transformation group
biàn huàn shè bèi
converter
conversion device
shè yǐng biàn huàn
a projective transformation