The comparative research of southern Andes and Antarctic Peninsula is a key to explain the break-up of Gondwanaland. "Cuspate" , "Arcuate", "Continuing". "Overlapping" and "Modified Gulf of California" model illustrated, to some extent, southern Andes-Antarctic Peninsula relations. However, those models did not discuss the dynamic mechanism and specific evolution process of the two Plates' divergence. "Wedge" model, on the bases of eight geological evidences including tectono-stratigraphic unit, strike-slip fault system, carthquake, igneous activity and so on, not only discussed southern Andes-Antarctic Peninsula relations and its evolution process, but also presented an argument that Scotia minor-plate, which once acted as one part of Pacific Plate wedged in between the two Plates and gave rise to the break-up of Gondwanaland-The argument represents the the latest achievement made in geological research there. On the whole, all models mentioned-above are, more or less, of one-sided view. Where the dynam 相似文献
A campaign was conducted to assess and compare the personal exposure in L3 of Tianjin subway, focusing on PM2.5 levels, chemical compositions, morphology analysis, as well as the health risk of heavy metal in PM2.5. The results indicated that the average concentration of the PM2.5 was 151.43 μg/m3 inside the train of the subway during rush hours. PM2.5 concentrations inside car under the ground are higher than those on the ground, and PM2.5 concentrations on the platform are higher than those inside car. Regarding metal concentrations, the highest element in PM2.5 samples was Fe; the level of which is 17.55 μg/m3. OC is a major component of PM2.5 in Tianjin subway. Secondary organic carbon is the formation of gaseous organic pollutants in subway. SEM–EDX and TEM–EDX exhibit the presence of individual particle with a large metal content in the subway samples. For small Fe metal particles, iron oxide can be formed easily. With regard to their sources, Fe-containing particles are generated mainly from mechanical wear and friction processes at the rail–wheel–brake interfaces. The non-carcinogenic risk to metals Cr, Ni, Cu, Zn and Pb, and carcinogenic hazard of Cr and Ni were all below the acceptable level in L3 of Tianjin subway.