| 摘要 |
Selective irradiation is used to isolate a planar slice of nuclear spins in a nuclear magnetic resonance (NMR) sample. Selective radio frequecy pulses, applied in the presence of magnetic field gradients, are then employed to define a smaller sensitive volume in a predetermined region of the isolated planar slice. An NMR spin echo signal produced by excited nuclear spins situated in the thusly localized volume is observed in the absence of magnetic field gradients and, upon Fourier transformation, yields the desired localized chemical shift spectra.
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