The aim of this study is to examine and present the results of the scientific examinations carried out on the ground layers with paint samples collected from the decorated surfaces of the wooden coffin dated back to t...The aim of this study is to examine and present the results of the scientific examinations carried out on the ground layers with paint samples collected from the decorated surfaces of the wooden coffin dated back to the late period from Saqqara excavation that belonged to the Ministry of Antiquities. Many analytical methods were performed as optical microscopy, scanning electron microscopy coupled with energy-dispersive X-ray analysis （ESEM-EDX）, X-ray diffraction analysis as well as fourier transform infrared spectroscopy have been used to both characterise the inorganic composition and the binding media used. The analytical results showed that the materials composition and technique used to plaster applied on the wooden surface are in good agreement with the information gathered through the historical survey. The coffin was in bad and poor condition. There was cracking on the surface and in the structure, serious flaking, cupping of some pigments and serious damage in both the wooden support and gesso layer. Conservation treatment processes carried out included consolidation of lifting areas of the paint film, disturbing restoration materials, repair of cracks in the wooden support and a dry surface cleaning of the pigments.展开更多
基于传统的分离式霍普金森拉杆系统,设计了应变控制的冲击疲劳寿命测试实验,研究了冲击疲劳加载下纯钛的微观演化机制及冲击疲劳对材料宏观力学行为的影响。通过对不同冲击疲劳试验阶段的试样开展准静态力学性能测试,借助扫描电子显微镜...基于传统的分离式霍普金森拉杆系统,设计了应变控制的冲击疲劳寿命测试实验,研究了冲击疲劳加载下纯钛的微观演化机制及冲击疲劳对材料宏观力学行为的影响。通过对不同冲击疲劳试验阶段的试样开展准静态力学性能测试,借助扫描电子显微镜(scanning electron microscope,SEM)和电子背散射衍射(electron backscatter diffraction,EBSD)技术表征试样在不同阶段的微观组织以及冲击疲劳失效后的断口形貌,研究纯钛在冲击疲劳失效过程中的循环硬化/软化规律及其微观演化机制。结果表明:通过改变子弹长度可以实现应变控制的冲击疲劳寿命测试;Manson-Coffin疲劳寿命模型可以较好地反映纯钛的冲击疲劳寿命与应变幅值之间的关系;纯钛在冲击疲劳失效过程中表现出循环硬化的现象,这主要是疲劳过程中孪生变形引起的细晶强化和塑性变形引起的应变硬化共同作用的结果,纯钛的冲击疲劳损伤主要表现为变形能力的损失。展开更多
文摘The aim of this study is to examine and present the results of the scientific examinations carried out on the ground layers with paint samples collected from the decorated surfaces of the wooden coffin dated back to the late period from Saqqara excavation that belonged to the Ministry of Antiquities. Many analytical methods were performed as optical microscopy, scanning electron microscopy coupled with energy-dispersive X-ray analysis （ESEM-EDX）, X-ray diffraction analysis as well as fourier transform infrared spectroscopy have been used to both characterise the inorganic composition and the binding media used. The analytical results showed that the materials composition and technique used to plaster applied on the wooden surface are in good agreement with the information gathered through the historical survey. The coffin was in bad and poor condition. There was cracking on the surface and in the structure, serious flaking, cupping of some pigments and serious damage in both the wooden support and gesso layer. Conservation treatment processes carried out included consolidation of lifting areas of the paint film, disturbing restoration materials, repair of cracks in the wooden support and a dry surface cleaning of the pigments.
文摘基于传统的分离式霍普金森拉杆系统,设计了应变控制的冲击疲劳寿命测试实验,研究了冲击疲劳加载下纯钛的微观演化机制及冲击疲劳对材料宏观力学行为的影响。通过对不同冲击疲劳试验阶段的试样开展准静态力学性能测试,借助扫描电子显微镜(scanning electron microscope,SEM)和电子背散射衍射(electron backscatter diffraction,EBSD)技术表征试样在不同阶段的微观组织以及冲击疲劳失效后的断口形貌,研究纯钛在冲击疲劳失效过程中的循环硬化/软化规律及其微观演化机制。结果表明:通过改变子弹长度可以实现应变控制的冲击疲劳寿命测试;Manson-Coffin疲劳寿命模型可以较好地反映纯钛的冲击疲劳寿命与应变幅值之间的关系;纯钛在冲击疲劳失效过程中表现出循环硬化的现象,这主要是疲劳过程中孪生变形引起的细晶强化和塑性变形引起的应变硬化共同作用的结果,纯钛的冲击疲劳损伤主要表现为变形能力的损失。
