Shortly after the large\|scale rural\|urban migration in 1990s, migrants return became another public concern relating to policy alternatives in China’s urbanization and employment strategies.Some people point out th...Shortly after the large\|scale rural\|urban migration in 1990s, migrants return became another public concern relating to policy alternatives in China’s urbanization and employment strategies.Some people point out that returned migrants will bring an investment wave in rural areas. This paper reviewed the literatures in migrants return and studied it in a socio\|economic framework. The paper also discussed the features of returned migrants based on sample survey data in Anhui and Sichuan provinces. The preliminary observation showed that structural change in general and labor mobility in particular at the present stage will continue to be a major channel for farmers to generate more off\|farm job opportunities and, therefore, to enhance their income level.展开更多
The mainshock of April 20,2013 Sichuan Lushan MS7.0 earthquake was relocated using a 3-D velocity model.Double difference algorithm was applied to relocate aftershock sequences of Lushan earthquake.The locations of 24...The mainshock of April 20,2013 Sichuan Lushan MS7.0 earthquake was relocated using a 3-D velocity model.Double difference algorithm was applied to relocate aftershock sequences of Lushan earthquake.The locations of 2405 aftershocks were determined.The location errors in E-W,N-S and U-D direction were 0.30,0.29 and 0.59 km on average,respectively.The location of the mainshock is 102.983°E,30.291°N and the focal depth is 17.6 km.The relocation results show that the aftershocks spread approximately 35 km in length and 16 km in width.The dominant distribution of the focal depth ranges from 10 to 20 km.A few earthquakes occurred in the shallow crust.Focal depth profiles show fault planes dip to the northwest,manifested itself as a listric thrust fault.The dip angle is steep in the shallow crust and gentle in the deep crust.Although the epicenters of aftershocks distributed mainly along both sides of the Shuangshi-Dachuan fault,the seismogenic fault may be a blind thrust fault on the eastern side of the Shuangshi-Dachuan fault.Earthquake relocation results reveal that there is a southeastward tilt aftershock belt intersecting with the seismogenic fault with y-shape.We speculate it is a back thrust fault that often appears in a thrust fault system.Lushan earthquake triggered the seismic activity of the back thrust fault.展开更多
文摘Shortly after the large\|scale rural\|urban migration in 1990s, migrants return became another public concern relating to policy alternatives in China’s urbanization and employment strategies.Some people point out that returned migrants will bring an investment wave in rural areas. This paper reviewed the literatures in migrants return and studied it in a socio\|economic framework. The paper also discussed the features of returned migrants based on sample survey data in Anhui and Sichuan provinces. The preliminary observation showed that structural change in general and labor mobility in particular at the present stage will continue to be a major channel for farmers to generate more off\|farm job opportunities and, therefore, to enhance their income level.
基金supported by the National Natural Science Foundation of China(41074068)the National Science and Technology Support Program(2012BAK19B01)China National Special Fund for Earthquake Scientific Research in Public Interest(201308013)and Scientific Investigation of April 20,2013 M7.0 Lushan,Sichuan Earthquake
文摘The mainshock of April 20,2013 Sichuan Lushan MS7.0 earthquake was relocated using a 3-D velocity model.Double difference algorithm was applied to relocate aftershock sequences of Lushan earthquake.The locations of 2405 aftershocks were determined.The location errors in E-W,N-S and U-D direction were 0.30,0.29 and 0.59 km on average,respectively.The location of the mainshock is 102.983°E,30.291°N and the focal depth is 17.6 km.The relocation results show that the aftershocks spread approximately 35 km in length and 16 km in width.The dominant distribution of the focal depth ranges from 10 to 20 km.A few earthquakes occurred in the shallow crust.Focal depth profiles show fault planes dip to the northwest,manifested itself as a listric thrust fault.The dip angle is steep in the shallow crust and gentle in the deep crust.Although the epicenters of aftershocks distributed mainly along both sides of the Shuangshi-Dachuan fault,the seismogenic fault may be a blind thrust fault on the eastern side of the Shuangshi-Dachuan fault.Earthquake relocation results reveal that there is a southeastward tilt aftershock belt intersecting with the seismogenic fault with y-shape.We speculate it is a back thrust fault that often appears in a thrust fault system.Lushan earthquake triggered the seismic activity of the back thrust fault.
