The apparent enhancement of spectral resolution is one of the attractive features of two-dimensional correlation spectroscopy (2D-COS). Highly overlapped adjacent bands often encountered in one-dimensional spectra may be effectively differentiated and identified by spreading peaks along the second dimension. This differentiating feature or selectivity is especially prominent in asynchronous spectra, where even a slight difference in the variation patterns of overlapped bands in response to a given perturbation results in the generation of cross-peaks. While cross-peaks in asynchronous spectra can identify signals originating from different moieties or bands, they do not effectively specify which regions of spectra actually share the same molecular origin. Overreliance on asynchronous spectra alone risks the potential false negative assessment or lack of sufficient specificity, leading to the failure of classifying signals into a reasonable set of component groups. The combined use of synchronous and asynchronous spectra coupled with the scaling techniques, elimination of anti-correlated negative synchronous peaks, and a robust line shape narrowing method provides a means to achieve both selectivity and specificity for resolution-enhancement of 2D-COS.

中文翻译：

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增强光谱分辨率和二维相关光谱 (2D-COS)

光谱分辨率的明显增强是二维相关光谱（2D-COS）的吸引人的特征之一。一维光谱中经常遇到的高度重叠的相邻频带可以通过沿第二维扩展峰来有效区分和识别。这种区分特征或选择性在异步光谱中尤其突出，其中即使响应给定扰动的重叠谱带的变化模式存在微小差异，也会导致交叉峰的生成。虽然异步光谱中的交叉峰可以识别源自不同部分或带的信号，但它们不能有效地指定光谱的哪些区域实际上共享相同的分子起源。仅过度依赖异步频谱就有可能出现潜在的假阴性评估或缺乏足够的特异性，从而导致无法将信号分类到一组合理的成分组中。同步和异步光谱与缩放技术的结合使用、消除反相关负同步峰以及稳健的线形窄化方法提供了一种实现 2D-COS 分辨率增强的选择性和特异性的方法。