MODIFIED NMR PULSE SHAPES FOR BIOMOLECULES AND IMAGING

核磁共振（NMR）已经发展成为一种非常强大的 用于探测生物学上感兴趣的分子结构的技术 以及用于利用非破坏性辐射对组织成像。 几乎所有的NMR 实验已经使用具有矩形包络的辐射脉冲，因为 对于这种特殊情况，理论特别简单。 我们建议 使用特制的非矩形辐射脉冲。 我们 最近发表了一篇理论论文，表明这种形状 提供更好的分辨率（这对于解释复杂的 蛋白质的光谱），更少的加热和更好的再现性。 我们有 设计了特别简单的形状，以取代传统的脉冲， 序列的 这个提议让我们通过实验来测试这些形状， 将我们的工作扩展到窄带和窄拒绝脉冲的产生， 空间分辨扩散常数的测量，校正 光谱仪的缺陷，并减少复杂的噪音 二维实验 这种方法有望大大 增强NMR对极其复杂系统的适用性。

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.