This paper deals with reflection spectra and polarized reflection spectra of 20 sorts of rock in 2π space, and then creates a model of reflection spectra of rock surface in 2π space. We measured the change of reflec...This paper deals with reflection spectra and polarized reflection spectra of 20 sorts of rock in 2π space, and then creates a model of reflection spectra of rock surface in 2π space. We measured the change of reflection and polarized reflection spectra as altering the incidence angle, vertex angle, azimuth angle, band and polarization. The results show that influence of the incidence angle on spectral curves is very strong. And when the vertex angle is constant, the horizontal azimuth polarizes rock spectra, and distorts the circular spectrum to become elliptic. The polarization influences the reflection intensity of rock spectra, but has no evident influence on the characteristics of wave forms of rock in 2π space. Therefore, we can describe the whole reflection spectral characteristics, including polarization, of rock surface in 2π space by measuring and calculating the e and p values in several key directions.展开更多
Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety impl...Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety implications of the near-fault effect on nuclear power plant facilities designed according to the Chinese code. To this end, a set of near- fault ground motions at rock sites with typical forward-directivity effect is examined with special emphasis on several key parameters and response spectra. Spectral comparison of the selected records with the Chinese and other code design spectra was conducted. The bi-normalized response spectra in terms of different comer periods are utilized to derive nuclear design spectra. It is concluded that nuclear design spectra on rock sites derived from typical rupture directivity records are significantly influenced both by the earthquake magnitude and the rupture distance. The nuclear design spectra specified in the code needs to be adjusted to reflect the near-fault directivity effect of large earthquakes.展开更多
岩石颜色不仅反映沉积环境而且指示特有矿物与元素,是纵向横向沉积演化,地层对比的重要依据和指标之一。目前岩石颜色主要依赖肉眼识别和主观描述,或使用色卡进行对比判读。这些方法受个体差异和环境影响较大,缺少定量计算方法,无法满...岩石颜色不仅反映沉积环境而且指示特有矿物与元素,是纵向横向沉积演化,地层对比的重要依据和指标之一。目前岩石颜色主要依赖肉眼识别和主观描述,或使用色卡进行对比判读。这些方法受个体差异和环境影响较大,缺少定量计算方法,无法满足颜色批量精准识别的需要。因此快速、批量、高效实现颜色的客观识别和数值量化对地质工作研究和应用具有重要意义。该研究基于色度学原理,利用光谱分析技术,结合Python计算机语言编译的岩石颜色定量化识别软件,实现岩石颜色的数值定量化和批量自动化转换,提高颜色的判断精度和识别效率。通过对《Munsell Rock Book》对比发现,CIE RGB颜色系统计算结果与色卡一致性较高,Munsell系统计算结果中色相值(<3个NBS单位)一致性达到86.7%,明度值和纯度值的一致性分别达到92.2%和82.2%,相关性为98.83%和87.50%,均属于较小色差范围。相较于Munsell系统计算结果,31个岩石样品的CIE RGB计算结果与样品颜色的一致性和准确性更高。造成颜色差异的原因复杂多样,不仅与颜色系统之间的转换误差和人为主观对比及判读有关,而且与岩石样品的特殊性和环境等因素密切相关。本次研究为岩石颜色的快速、高效、客观批量化和定量化表征提供了一种可行性方法和思路,具有较好的应用价值。展开更多
文摘This paper deals with reflection spectra and polarized reflection spectra of 20 sorts of rock in 2π space, and then creates a model of reflection spectra of rock surface in 2π space. We measured the change of reflection and polarized reflection spectra as altering the incidence angle, vertex angle, azimuth angle, band and polarization. The results show that influence of the incidence angle on spectral curves is very strong. And when the vertex angle is constant, the horizontal azimuth polarizes rock spectra, and distorts the circular spectrum to become elliptic. The polarization influences the reflection intensity of rock spectra, but has no evident influence on the characteristics of wave forms of rock in 2π space. Therefore, we can describe the whole reflection spectral characteristics, including polarization, of rock surface in 2π space by measuring and calculating the e and p values in several key directions.
基金National Natural Science Foundation of China Under Grant No.50808168Ministry of Science and Technology of Weihai Under Grant No.2008087Beijing Natural Science Foundation Under Grant No.8092029
文摘Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety implications of the near-fault effect on nuclear power plant facilities designed according to the Chinese code. To this end, a set of near- fault ground motions at rock sites with typical forward-directivity effect is examined with special emphasis on several key parameters and response spectra. Spectral comparison of the selected records with the Chinese and other code design spectra was conducted. The bi-normalized response spectra in terms of different comer periods are utilized to derive nuclear design spectra. It is concluded that nuclear design spectra on rock sites derived from typical rupture directivity records are significantly influenced both by the earthquake magnitude and the rupture distance. The nuclear design spectra specified in the code needs to be adjusted to reflect the near-fault directivity effect of large earthquakes.
文摘岩石颜色不仅反映沉积环境而且指示特有矿物与元素,是纵向横向沉积演化,地层对比的重要依据和指标之一。目前岩石颜色主要依赖肉眼识别和主观描述,或使用色卡进行对比判读。这些方法受个体差异和环境影响较大,缺少定量计算方法,无法满足颜色批量精准识别的需要。因此快速、批量、高效实现颜色的客观识别和数值量化对地质工作研究和应用具有重要意义。该研究基于色度学原理,利用光谱分析技术,结合Python计算机语言编译的岩石颜色定量化识别软件,实现岩石颜色的数值定量化和批量自动化转换,提高颜色的判断精度和识别效率。通过对《Munsell Rock Book》对比发现,CIE RGB颜色系统计算结果与色卡一致性较高,Munsell系统计算结果中色相值(<3个NBS单位)一致性达到86.7%,明度值和纯度值的一致性分别达到92.2%和82.2%,相关性为98.83%和87.50%,均属于较小色差范围。相较于Munsell系统计算结果,31个岩石样品的CIE RGB计算结果与样品颜色的一致性和准确性更高。造成颜色差异的原因复杂多样,不仅与颜色系统之间的转换误差和人为主观对比及判读有关,而且与岩石样品的特殊性和环境等因素密切相关。本次研究为岩石颜色的快速、高效、客观批量化和定量化表征提供了一种可行性方法和思路,具有较好的应用价值。
