The microstructural analysis of muds and mudrocks requires very high-resolution measurement. Recent advances in electron microscopy have contributed significantly to the improved characterisation of mudrock microstruc...The microstructural analysis of muds and mudrocks requires very high-resolution measurement. Recent advances in electron microscopy have contributed significantly to the improved characterisation of mudrock microstructures and their consequent petrophysical properties. However, imaging through electron microscopy is limited to small areas of coverage such that upscaling of these properties is a great challenge. In this paper, we develop a new methodology for multiple large-area imaging using scanning electron microscopy through automated acquisition and stitching from polished thin-sections and ion-milled samples. The process is fast, efficient and minimises user-input and bias. It can provide reliable, quantifiable data on sediment grain size, grain orientation, pore size and porosity. Limitations include the time involved for individual runs and manual segmentation, the large amount of computer memory required, and instrument resolution at the nano-scale. This method is applied to selected samples of Quaternary muddy sediments from the Iberian margin at IODP Site 1385. The section comprises finegrained(very fine clayey silts), mixed-composition, biogenic-terrigenous hemipelagites, with a pronounced but non-regular colour cyclicity. There is a multi-tiered and diverse trace fossil assemblage of the deep-water Zoophycos ichnofacies. The sediment microstructures show small-scale heterogeneity in all properties, and an overall random fabric with secondary preferred grain-alignment. These results on the fabric differ, in part, from previous studies of hemipelagic muds. Further work is underway on their comparison with other deep-water sediment facies.展开更多
Since the discovery of high T_c oxide superconductor, scientists and engineers aredeeply concerned with the possibility of its application to the electric machine withstrong operating current at high magnetic fields. ...Since the discovery of high T_c oxide superconductor, scientists and engineers aredeeply concerned with the possibility of its application to the electric machine withstrong operating current at high magnetic fields. Because of the serious problem ofweak link in the sintered bulk materials processed by regular ceramic powder technolo-gy, the critical current density at 77.3 K is low and it gets much lower with theincreasing magnetic field. Scientists look forward to heighening J_c of the high T_c ma-展开更多
基金the sponsorship received from Petroleum Technology Development Fund, Nigeria
文摘The microstructural analysis of muds and mudrocks requires very high-resolution measurement. Recent advances in electron microscopy have contributed significantly to the improved characterisation of mudrock microstructures and their consequent petrophysical properties. However, imaging through electron microscopy is limited to small areas of coverage such that upscaling of these properties is a great challenge. In this paper, we develop a new methodology for multiple large-area imaging using scanning electron microscopy through automated acquisition and stitching from polished thin-sections and ion-milled samples. The process is fast, efficient and minimises user-input and bias. It can provide reliable, quantifiable data on sediment grain size, grain orientation, pore size and porosity. Limitations include the time involved for individual runs and manual segmentation, the large amount of computer memory required, and instrument resolution at the nano-scale. This method is applied to selected samples of Quaternary muddy sediments from the Iberian margin at IODP Site 1385. The section comprises finegrained(very fine clayey silts), mixed-composition, biogenic-terrigenous hemipelagites, with a pronounced but non-regular colour cyclicity. There is a multi-tiered and diverse trace fossil assemblage of the deep-water Zoophycos ichnofacies. The sediment microstructures show small-scale heterogeneity in all properties, and an overall random fabric with secondary preferred grain-alignment. These results on the fabric differ, in part, from previous studies of hemipelagic muds. Further work is underway on their comparison with other deep-water sediment facies.
基金Project supported by the National Center for R & D on Superconductivity of China.
文摘Since the discovery of high T_c oxide superconductor, scientists and engineers aredeeply concerned with the possibility of its application to the electric machine withstrong operating current at high magnetic fields. Because of the serious problem ofweak link in the sintered bulk materials processed by regular ceramic powder technolo-gy, the critical current density at 77.3 K is low and it gets much lower with theincreasing magnetic field. Scientists look forward to heighening J_c of the high T_c ma-
