马蹄寺石窟群地处河西走廊中部,气候条件十分恶劣。由于常年受到温度、湿度、酸碱盐等作用的影响,石窟岩体性能出现了不同程度的劣化现象。通过开展室内模拟试验,研究以上多种恶劣环境的循环作用对于岩体抗压强度、波速、质量的影响规律...马蹄寺石窟群地处河西走廊中部,气候条件十分恶劣。由于常年受到温度、湿度、酸碱盐等作用的影响,石窟岩体性能出现了不同程度的劣化现象。通过开展室内模拟试验,研究以上多种恶劣环境的循环作用对于岩体抗压强度、波速、质量的影响规律,同时使用X射线衍射仪(X-ray diffraction,XRD)、X射线荧光光谱(X-ray fluorescence,XRF)和扫描电子显微镜(scanning electron microscope,SEM)对循环作用过程中样品的矿物组分、元素含量和微观形貌进行分析研究。研究结果表明,循环作用使样品中的长石类矿物和方解石含量降低,黏土类矿物含量增加,胶结程度下降,孔隙逐渐发展成为横向微裂隙,导致样品的性能出现不同程度的劣化现象。循环作用对岩体性能的影响程度从大到小依次为冻融循环、耐盐循环、耐碱循环、耐酸循环和温湿循环。展开更多
Light intensity distribution in the vicinity of inclusions and etched cracks in polished fused silica at wavelength scale are simulated by using the finite-difference time-domain algorithm. Light intensity enhancement...Light intensity distribution in the vicinity of inclusions and etched cracks in polished fused silica at wavelength scale are simulated by using the finite-difference time-domain algorithm. Light intensity enhancement factor as functions of diameter and refractive index of inclusions are investigated, more than 10 times that of incident beam is obtained in the simulation. We model the etched crack in close proximity to a real structure, which is characterized by AFM. We find that the peak light intensity of the crack is a function of its cross sectional breadth depth ratio, providing good hints for the effective processing of fused silica samples to improve the damage threshold.展开更多
文摘马蹄寺石窟群地处河西走廊中部,气候条件十分恶劣。由于常年受到温度、湿度、酸碱盐等作用的影响,石窟岩体性能出现了不同程度的劣化现象。通过开展室内模拟试验,研究以上多种恶劣环境的循环作用对于岩体抗压强度、波速、质量的影响规律,同时使用X射线衍射仪(X-ray diffraction,XRD)、X射线荧光光谱(X-ray fluorescence,XRF)和扫描电子显微镜(scanning electron microscope,SEM)对循环作用过程中样品的矿物组分、元素含量和微观形貌进行分析研究。研究结果表明,循环作用使样品中的长石类矿物和方解石含量降低,黏土类矿物含量增加,胶结程度下降,孔隙逐渐发展成为横向微裂隙,导致样品的性能出现不同程度的劣化现象。循环作用对岩体性能的影响程度从大到小依次为冻融循环、耐盐循环、耐碱循环、耐酸循环和温湿循环。
文摘Light intensity distribution in the vicinity of inclusions and etched cracks in polished fused silica at wavelength scale are simulated by using the finite-difference time-domain algorithm. Light intensity enhancement factor as functions of diameter and refractive index of inclusions are investigated, more than 10 times that of incident beam is obtained in the simulation. We model the etched crack in close proximity to a real structure, which is characterized by AFM. We find that the peak light intensity of the crack is a function of its cross sectional breadth depth ratio, providing good hints for the effective processing of fused silica samples to improve the damage threshold.
