1.College of Materials Science and Engineering, Jilin University,Changchun 130026, China;2. Institute of Geomechanics, Chinese Academy of Geological Sciences ,Beijing 100081, China;3.College of Life Science Dalian Nationalities,Dalian,Liaoning 116600,China;4.Cultural Relics Institute of Yungang Grottoes,Datong, Shanxi 037007, China;5.Protection of Cultural Relics Institute in Xiangtan Grottoes,Handan, Hebei 056200, China;6. College of Physics, Jilin University,Changchun 130021,China