利用X射线的空间相干特性,可实现低Z介质内部结构的高衬度成像.人参主要由碳、氢、氧、氮等轻元素组成,原则上可以利用相衬成像来实现其特征结构的无损成像.由于具有更高的相干通量,利用第三代同步辐射光源成像可获得更高的时间和空间分辨,可用于研究更高分辨的人参特征显微结构.本文利用新建成的上海光源,较为系统地研究了野山参的显微特征结构.作为比较,给出了相应的园参特征结构,并与野山参进行了比对、分析.发现了一种未曾报道过的结构,这很可能是一个新的人参特征结构.研究结果表明,X射线相衬显微有望成为野山参鉴定的一种新的手段.
X-ray phase contrast microscopy (XPCM) achieves the high contrast imaging of low electron density materials with the spatial coherence peculiarity of X-rays. Considering that ginsengs are mainly composed of C,H,O,N and other low- Z elements,XPCM is an ideal tool to nondestructively investigate the characteristic microstructures of ginsengs in principle. Owing to the higher fluxes and luminance of the third generation of synchrotron radiation facility,it can present clearer and finer microstructures of ginsengs with better spatial and temporal resolutions. In this paper,the characteristic microstructures of wild ginseng ware investigated systemically by XPCM at Shanghai Synchrotron Radiation Facility (SSRF). For comparison,the characteristic structures of cultivated ginseng are also studied correspondingly. Moreover,a kind of new microstructure is found in young ginsengs,which is possibly a new characteristic structure of ginsengs. The results demonstrates that XPCM is a promising new method of identifying wild ginseng.