Jeschke G, Mandelshtam V A, Shaka A J
Max-Planck-Institut für Polymerforschung, Mainz, 55028, Germany.
J Magn Reson. 1999 Mar;137(1):221-30. doi: 10.1006/jmre.1998.1658.
Harmonic inversion of electron spin echo envelope (ESEEM) time-domain signals by filter diagonalization is investigated as an alternative to Fourier transformation. It is demonstrated that this method features enhanced resolution compared to Fourier-transform magnitude spectra, since it can eliminate dispersive contributions to the line shape, even if no linear phase correction is possible. Furthermore, instrumental artifacts can be easily removed from the spectra if they are narrow either in time or frequency domain. This applies to echo crossings that are only incompletely eliminated by phase cycling and to spurious spectrometer frequencies, respectively. The method is computationally efficient and numerically stable and does not require extensive parameter adjustments or advance knowledge of the number of spectral lines. Experiments on gamma-irradiated methyl-alpha-d-glucopyranoside show that more information can be obtained from typical ESEEM time-domain signals by filter-diagonalization than by Fourier transformation.
研究了通过滤波器对角化对电子自旋回波包络（ESEEM）时域信号进行谐波反演，作为傅里叶变换的替代方法。结果表明，与傅里叶变换幅度谱相比，该方法具有更高的分辨率，因为即使无法进行线性相位校正，它也可以消除对线形的色散贡献。此外，如果仪器伪像在时域或频域中较窄，则可以很容易地从光谱中去除。这分别适用于仅通过相位循环不能完全消除的回波交叉和杂散光谱仪频率。该方法计算效率高且数值稳定，不需要大量的参数调整或谱线数量的先验知识。对γ辐照的甲基-α-D-吡喃葡萄糖苷的实验表明，通过滤波器对角化从典型的ESEEM时域信号中获得的信息比通过傅里叶变换更多。
