摘要
In this study,low-field nuclear magnetic resonance(LF-NMR)was used to collect the transverse relaxation signals of camphor seeds that had been dried at different temperatures and for different durations.The transverse relaxation time of the hydrogen nucleus was obtained by SIRT(Simultaneous Iterative Reconstruction Technique)inversion,and the correlation between the moisture content on dry basis and the amplitude of NMR signal of camphor seeds sampled at different drying stages was analyzed.The results showed that water existed in three main forms strongly bound water,weakly bound water and free water in camphor seeds.During the drying process,the peak position of strongly bound water remained unchanged,but the peak positions of weakly bound water and free water fluctuated.Drying rate increased with drying temperature increasing.In addition,there was a very significant linear relationship between the total NMR signal amplitude and moisture content on dry basis,and the correlation coefficient reached 0.984 4.
In this study, low-field nuclear magnetic resonance(LF-NMR) was used to collect the transverse relaxation signals of camphor seeds that had been dried at different temperatures and for different durations. The transverse relaxation time of the hydrogen nucleus was obtained by SIRT(Simultaneous Iterative Reconstruction Technique) inversion, and the correlation between the moisture content on dry basis and the amplitude of NMR signal of camphor seeds sampled at different drying stages was analyzed. The results showed that water existed in three main forms strongly bound water, weakly bound water and free water in camphor seeds. During the drying process, the peak position of strongly bound water remained unchanged, but the peak positions of weakly bound water and free water fluctuated. Drying rate increased with drying temperature increasing. In addition, there was a very significant linear relationship between the total NMR signal amplitude and moisture content on dry basis, and the correlation coefficient reached 0.984 4.
