MODIFIED NMR PULSE SHAPES FOR BIOMOLECULES AND IMAGING

核磁共振（NMR）已经发展成为一种极其强大的技术

Nuclear magnetic resonance (NMR) has developed into an extremely powerful technique for probing the structure of biologically interesting molecules and for imaging tissues with nondestructive radiation. Virtually all NMR experiments have used radiation pulses with rectangular envelopes, since the theory is particularly simple for this special case. We propose the application of radiation pulses with crafted, nonrectangular shapes. We have recently published a theoretical paper which shows that such shapes give better resolution (which is important for interpreting the complex spectra of proteins), less heating, and better reproducibility. We have designed particularly simple shapes to replace the pulses in conventional sequences. This proposal lets us test these shapes experimentally, and extends our work to generation of narrowband and narrow reject pulses, measurements of spatially resolved diffusion constants, correction of spectrometer imperfections, and reduction of noise in sophisticated two-dimensional experiments. This approach promises to significantly enhance the applicability of NMR to extremely complex systems.