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核磁共振成象是近20年来出现的一种新的核磁共振技术。自从1973年Lauterbur发表第一篇核磁共振成象(NMRI)论文以来,这一技术发展很快,已得到广泛的应用。近几年,核磁共振成象技术也开始应用于煤结构的研究中。然而,由于煤是一种非常复杂的天然有机物质,同时在固体煤中质子间存在有强的自旋偶极-偶极相互作用能使T_2值变小,并且导致谱线增宽,因此限制了成象的分辨率。目前有关煤的核磁共振成象的文献报道的很少。Dieckman等人通过使用多脉冲质子去偶技术和投影重建核磁共振成象方法,获得了几个干燥煤样的二维核磁共振图象,并区分了他们的基本微观结构。空间分辨率约为200μm。我们用吡啶饱和蒸气处理了抚顺西露天长焰煤和老虎台气煤等几种煤,通过质子密度成象,观察了进入煤样中的溶剂的分布情况,并获得了一些有关煤结构的信息。
Magnetic resonance imaging is a new nuclear magnetic resonance technique that has appeared in the past 20 years. Since the publication of the first NMRI paper by Lauterbur in 1973, this technique has developed rapidly and has been widely used. In recent years, nuclear magnetic resonance imaging technology has also begun to be used in coal structure research. However, because coal is a very complex natural organic matter, and there is a strong spin dipole-dipole interaction between the protons in the solid coal, which makes the T 2 value smaller and results in broadening of the spectrum, thus limiting The resolution of the image. At present, little is reported about the MRI of coal. Dieckman et al. Obtained two-dimensional nuclear magnetic resonance images of several dry coal samples by using multi-pulse proton depolarization and projection reconstruction of the magnetic resonance imaging, and distinguished their basic microstructure. The spatial resolution is about 200μm. We treated several kinds of coal, such as Fushun West open-air long-flame coal and Tiger station gas coal, with saturated vapor of pyridine to observe the distribution of the solvent entering the coal sample by proton density imaging and obtained some information about coal structure .