文献类型：期刊文献

中文题名：核磁共振(NMR)T2分布对云冈石窟风化的初步研究

英文题名：Weathering research of Yungang Grottoes by(NMR) relaxation studies

作者：周华[1,2];赵芳琴[3];高峰[4];魏侠[5];王昌燧[2]

第一作者：周华

机构：[1]北京联合大学应用文理学院;[2]中科院古脊椎动物与古人类研究所;[3]哈尔滨工业大学深圳研究院材料科学与工程学科部;[4]中国文化遗产研究院;[5]武汉大学测试中心

第一机构：北京联合大学应用文理学院

年份：2013

期号：4

起止页码：106-113

中文期刊名：文物保护与考古科学

外文期刊名：Sciences of Conservation and Archaeology

收录：CSTPCD;;国家哲学社会科学学术期刊数据库;北大核心:【北大核心2011】；CSSCI:【CSSCI_E2012_2013】；

基金：国家科技支撑计划课题资助(2009BAK53B01)

语种：中文

中文关键词：核磁共振;孔径分布;横向弛豫时间T2;风化

外文关键词：Nuclear magnetic resonance; Pore size distribution; Transverse NMR relaxation T2;Wearthering

摘要：云冈石窟的保护受到我国文物保护工作者的重视。恶劣的自然环境，加上人为的污染，使云冈石窟的保护问题日显严峻，必须综合治理。然而，在这些复杂因素中，岩体的风化治理最为关键。岩石的孔隙尺寸及其分布是表征岩石力学、水理性质的重要参数。同种岩石，其孔隙率越高或者孔隙分布越大，则表示岩石的力学和水理性质越差。由此可见，借助孔隙率及孔隙分布状况，可表征同种岩石的风化情况。核磁共振横向弛豫时间T2与岩石孔径分布具有一定的线性关系。随着石雕风化的加剧，岩石可视孔隙率增大，孔径大小的平均值也将相应增大。基于这一前提，本研究尝试采用核磁共振横向弛豫时间T2分析石雕文物不同深处的孔径分布情况，通过实验室对云冈石窟新鲜岩石样品，结合抗盐风化安定性实验，和对自然风化样品采用便携式核磁进行无损检测，探讨其风化程度和深度，以便深入研究石雕文物的风化状况。研究结果表明，风化岩石的新鲜层只有一类小孔隙，弛豫时间约为2～6ms，风化层岩石有大孔隙生成，且随着岩石风化程度增强，小孔径孔隙所占孔隙比例降低，大孔径孔隙所占比例增多。根据不同深度岩样的孔径分布情况，及新鲜岩石的孔径分布情况，可以得出岩石的风化深度为5mm左右。本研究可为后续的现场保护措施提供有价值的信息。
Pore structure and pore size distribution are key properties of stone relic and building materials. In the past, Got pore size distribution of porous materials by mercury intrusion porosimetry, which was a laboratory method, and damage for samples. Transverse NMR relaxation also could get pore information of stone relics, Relaxation times and relaxation time distributions of the protons from water saturated samples were measured by low - field NMR using homogenous and inhomogeneous fields, the advantage of NMR measurement are more quick- ly, easily and attrition small, the NMR - Mouse could by very portable, it can be operated on 24V from a car battery, as an invasion and harmless technology, it was irreplaceable for immovable cultural heritage protection in situ. Pore size and its distribution are characterized by rock mechanics, physical properties of water. As the same lithology, the higher the porosity, the worse of physical properties of stone. Thus, the porosity and pore distribution could assess stone＇s weathering. Based on this premise, the different depths of the pore size distribution of stone relics was research by transverse NMR relaxation, and to explore the extent and depth of weathering of stone relics. The results show that through portable NMR- Mouse and homogeneous fields research, the average pore radius of three categories were all increased, and the large pores the most obvious; three categories pores, the number of small and large pores were significantly increased, however, the proportion of micropores of the total were reduced as weathering enhanced ; the result of profile test of weathering stones was 5 ram, the good correlation of weathering and pore size distribution could be indicators of weathering classification and weathering depth research. It can be predicted, application transverse NMR relaxation obtained the pore structure of stone relics has broad prospects.