A 2D Spectrum Inversion Algorithm Based on lsqr for Low Field NMR

Abstract

The invention relates to an LSQR (Least Squares QR Decomposition)-based low-field two-dimensional NMR spectrum inversion algorithm and belongs to the field of NMR signal processing. The LSQR-based low-field two-dimensional NMR spectrum inversion algorithm has the advantages that compared with other low-field NMR inversion algorithms reported in existing domestic and foreign literature, the LSQR-based low-field two-dimensional NMR spectrum inversion algorithm can select suitable iterations by the aid of the 'L' curve in a self-adaption mode, and obtained solutions can embody real spectral distribution better; nonnegative restriction is achieved through iterative correction, so that calculation accuracy is high, robustness is good, and stable inversion results can be obtained under different signal to noise ratio data conditions.

Description

technical field [0001] The invention relates to the field of nuclear magnetic resonance signal processing, and relates to a low-field nuclear magnetic resonance two-dimensional spectrum inversion algorithm, specifically, a low-field nuclear magnetic resonance two-dimensional spectrum inversion algorithm based on LSQR. Background technique [0002] Low-field nuclear magnetic resonance equipment has been widely used in energy, food, agriculture, medicine and other fields due to its relatively low cost, easy miniaturization, and industrial integration. Low-field NMR analysis technology is an important detection method in these fields. The original signal collected by NMR contains rich but incomprehensible sample structure information, which requires inversion to obtain the time-domain spectrum that provides intuitive information about the reaction. Among them, the CPMG (Carr-Purcell-Meiboom-Gill) sequence is fast and is one of the most commonly used sequences in low-field NMR....

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Problems solved by technology

[0003] Two-dimensional spectral inversion needs to process a huge amount of data, which brings great challenges to two-dimensional inversion. Coupled with the technological monopoly of related foreign companies, they only provide instrument rental and paid interpretation services. Domestic two-dimensional inversion technology The development of the

However, similar to most iterative inversion algorithms, the solutions with practical application value often appear in the early stage of the iteration. Although the subsequent iterations can further reduce the fitting error, the structure of the solution will gradually deviate from the real spectral distribution.

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