The variation of in situ stress before and after earthquakes is an issue studied by geologists. In this paper, on the basis of the fault slip dislocation model of Wenchuan Ms8.0 earthquake, the changes of co-seismic d...The variation of in situ stress before and after earthquakes is an issue studied by geologists. In this paper, on the basis of the fault slip dislocation model of Wenchuan Ms8.0 earthquake, the changes of co-seismic displacement and the distribution functions of stress tensor around the Longmen Shan fault zone are calculated. The results show that the co-seismic maximum surface displacement is 4.9 m in the horizontal direction and 6.5 m in the vertical direction, which is almost consistent with the on-site survey and GPS observations. The co-seismic maximum horizontal stress in the hanging wall and footwall decreased sharply as the distance from the Longmen Shan fault zone increased. However, the vertical stress and minimum horizontal stress increased in the footwall and in some areas of the hanging wall. The study of the co-seismic displacement and stress was mainly focused on the long and narrow region along the Longmen Shan fault zone, which coincides with the distribution of the earthquake aftershocks. Therefore, the co-seismic stress only affects the aftershocks, and does not affect distant faults and seismic activities. The results are almost consistent with in situ stress measurements at the two sites before and after Wenchuan Ms8.0 earthquake. Along the fault plane, the co-seismic shear stress in the dip direction is larger than that in the strike direction, which indicates that the faulting mechanism of the Longmen Shan fault zone is a dominant thrust with minor strike-slipping. The results can be used as a reference value for future studies of earthquake mechanisms.展开更多
The effects of temperature on the convecsion of Li2 CO3 Co LiOH in a Ca（OH）2 suspension were investigated. Li2CO3 microplates were used as the Li source. The results showed that Li2CO3 was converted to LiOH via in s...The effects of temperature on the convecsion of Li2 CO3 Co LiOH in a Ca（OH）2 suspension were investigated. Li2CO3 microplates were used as the Li source. The results showed that Li2CO3 was converted to LiOH via in situ ion-exchange and dissolution-precipitation routes. The formation of mixed CaxLiz-2xCO3 inter- mediate species confirmed that at 25℃ need/e-like CaCO3 was formed heterogeneously on the Li2CO3 surface via in situ ion-exchange. At 60-100℃, isolated CaCO3 agglomerates were formed homogeneously via dissolution-precipitation. Temperature increases accelerated the dissolution and conversion of Li2 CO3 to LiOH, producing solutions with high [CO32-1][Ca^2＋] ratios; this favored homogeneous precipitation of isolated CaCO3 agglomerates,展开更多
基金supported by the Sinoprobe Deep Exploration in China(SinoProbe-07)research funds of the Institute of Geomechanics,Chinese Academy of Geological Sciences(Grant No.DZLXJK201105)National Basic Research Program of China(973 Program)(Grant No.2008CB425702)
文摘The variation of in situ stress before and after earthquakes is an issue studied by geologists. In this paper, on the basis of the fault slip dislocation model of Wenchuan Ms8.0 earthquake, the changes of co-seismic displacement and the distribution functions of stress tensor around the Longmen Shan fault zone are calculated. The results show that the co-seismic maximum surface displacement is 4.9 m in the horizontal direction and 6.5 m in the vertical direction, which is almost consistent with the on-site survey and GPS observations. The co-seismic maximum horizontal stress in the hanging wall and footwall decreased sharply as the distance from the Longmen Shan fault zone increased. However, the vertical stress and minimum horizontal stress increased in the footwall and in some areas of the hanging wall. The study of the co-seismic displacement and stress was mainly focused on the long and narrow region along the Longmen Shan fault zone, which coincides with the distribution of the earthquake aftershocks. Therefore, the co-seismic stress only affects the aftershocks, and does not affect distant faults and seismic activities. The results are almost consistent with in situ stress measurements at the two sites before and after Wenchuan Ms8.0 earthquake. Along the fault plane, the co-seismic shear stress in the dip direction is larger than that in the strike direction, which indicates that the faulting mechanism of the Longmen Shan fault zone is a dominant thrust with minor strike-slipping. The results can be used as a reference value for future studies of earthquake mechanisms.
文摘The effects of temperature on the convecsion of Li2 CO3 Co LiOH in a Ca（OH）2 suspension were investigated. Li2CO3 microplates were used as the Li source. The results showed that Li2CO3 was converted to LiOH via in situ ion-exchange and dissolution-precipitation routes. The formation of mixed CaxLiz-2xCO3 inter- mediate species confirmed that at 25℃ need/e-like CaCO3 was formed heterogeneously on the Li2CO3 surface via in situ ion-exchange. At 60-100℃, isolated CaCO3 agglomerates were formed homogeneously via dissolution-precipitation. Temperature increases accelerated the dissolution and conversion of Li2 CO3 to LiOH, producing solutions with high [CO32-1][Ca^2＋] ratios; this favored homogeneous precipitation of isolated CaCO3 agglomerates,
