The theory describing nuclear cross-polarization from a spin-1 to spin
-1/2 is generalized to sweeps of the radio-frequency field amplitude.
This allows efficient cross-polarization over the entire width of the
deuterium NMR spectrum of partially oriented systems, such as liquid c
rystals. Such experiments permit the assignment and measurement of the
deuterium quadrupolar couplings, and hence the quantification of the
order parameters which characterize the dynamics of such systems. The
evolution of the spin system can be understood in terms of individual
quasiadiabatic population exchanges, allowing the prediction of the ef
fects of the various experimental parameters on the efficiency of cros
s-polarization. (C) 1998 American Institute of Physics.