From the manuscript
Pulse sequence for WATERGATE Suppression with double gradients for solvent resonance elimination.
Bar symbol: Pulse. Open symbol: Frequency selective pulse train, i.e. W5 for this expt. Δ : Time interval that is just enough to allow for gradient switching and recovery.
From Pulse Program Catalogue NMRGuide 4.1
1D 1H Excitation Sculpting Spectrum using w5 pulse train
G: gradient strength. Curved shapes indicate sine bell-shaped pulsed magnetic files gradient along with the z-axis.
1D 1H zgppw5 of 15N, 13C-labeled Ubiquitin and glycerol-d8, at 283K (10 deg)
References
PDF Liu, M.L., Mao, X.A., Ye, C.H., Huang, H., Nicholson, J.K., Lindon, J.C. Improved WATERGATE pulse sequences for solvent suppression in NMR spectroscopy, Journal of Magnetic Resonance,1998.132(1) pp 125-9