In the stability study of the regional structures in the area of the Longyang Gorge Hydroelectrical Power Station, a model of the current stress-deformation field of the area was constructed based on analyses of avail...In the stability study of the regional structures in the area of the Longyang Gorge Hydroelectrical Power Station, a model of the current stress-deformation field of the area was constructed based on analyses of available data of regional surveys and historical earthquakes and field investigations of active faults and ancient earthquakes. This model was examined and verified by physical and mathematical simulation experiments, and quantitative relations and data were obtained.展开更多
The extensive intrusion (covering an area of 83.7-238.3 km;and accounting for 18.6-31.5% of the total area of the plain), the presence of a transitional zone 1.5-6.0 km in width, and the interconnection in distribut...The extensive intrusion (covering an area of 83.7-238.3 km;and accounting for 18.6-31.5% of the total area of the plain), the presence of a transitional zone 1.5-6.0 km in width, and the interconnection in distribution between the seawater intrusion district and the region lower than the sea level caused by the strong drop of the groundwater level are major characteristics of the seawater intrusion in the study area. Cation exchange played an important role during the formation of chemical composition of the groundwater in the seawater intrusion district.展开更多
Desertification is one of the most serious eco-environmental problems around Qinghai Lake.Based on GIS and RS,GIS analysis was used to obtain the information of spatial-temporal change and different pattern of deserti...Desertification is one of the most serious eco-environmental problems around Qinghai Lake.Based on GIS and RS,GIS analysis was used to obtain the information of spatial-temporal change and different pattern of desertification in each county around Qinghai Lake in four phases of1976,1987,1995 and 2006.Using the function of intersect and overlay supported by ARCGIS,with analyzing attributes of vector RS images,we obtained transition data and established transfer matrix of land-use types in recent 30 years,besides,protracted land-use transition maps of all desertification classes.In further,we analyzed transition quantity and direction of desertification in each county,moreover,reconstructed the process of spatial-temporal evolution of desertification.The results are showed below:(1)it's the transition between desertified land and others but not in the desertified that played the main role in Gangcha and Gonghe County,while the transfer between desertified lands were greater than that with other land-use types in Haiyan County.(2)Extremely severe desertified land mainly distributes in Ketu and Sand Islands that belongs to Haiyan County,and moderate desertified land in riversides of Gangcha County,also,the light desertification expanded too rapidly to become the most desertified land-use type in the surrounding of Qinghai Lake since 1976.(3)By using relative change rate of desertified land,the regional variability rank from top to toe was Gangcha,Haiyan and Gonghe.展开更多
The membrane’s dynamics is very important for cells.A membrane in 2-dimensional space can be seen as an incompressible closed curve in a plane or a cylindrical surface in 3-dimensional space.In this paper,we design a...The membrane’s dynamics is very important for cells.A membrane in 2-dimensional space can be seen as an incompressible closed curve in a plane or a cylindrical surface in 3-dimensional space.In this paper,we design a second-order accurate numerical algorithm to simulate the shape transformation of the membrane.In the algorithm,we use the tangent angles to present the curve and avoid the difficulties from the constraint of curve’s incompressible condition.A lot of interesting phenomena are obtained.Some of them are very like the life processes of cells,such as exocytosis and endocytosis.Furthermore,we can see the relation between two dynamic models clearly.At last,considering the influence of the inner incompressible fluids partially,we add a constraint:the area circled by the membrane maintain invariable.The numerical results show the dynamic motions of a curve remaining its local arc length and inner area constant.展开更多
文摘In the stability study of the regional structures in the area of the Longyang Gorge Hydroelectrical Power Station, a model of the current stress-deformation field of the area was constructed based on analyses of available data of regional surveys and historical earthquakes and field investigations of active faults and ancient earthquakes. This model was examined and verified by physical and mathematical simulation experiments, and quantitative relations and data were obtained.
基金This paper is the State key scientific research project 75-57-01-02-05 funded by the National Natural Science Foundation of China. Participating in the field work of the project were also Liu Coufan. Li Chunwei. Zou Zeyuan, Lin Jun, Ren Peiqi, Jiang Kehu
文摘The extensive intrusion (covering an area of 83.7-238.3 km;and accounting for 18.6-31.5% of the total area of the plain), the presence of a transitional zone 1.5-6.0 km in width, and the interconnection in distribution between the seawater intrusion district and the region lower than the sea level caused by the strong drop of the groundwater level are major characteristics of the seawater intrusion in the study area. Cation exchange played an important role during the formation of chemical composition of the groundwater in the seawater intrusion district.
基金National Key Technology R&D Program of China(2007BAC30B03)"The Fundamental Research Funds for the Central Universities"and"Forestry Industry Research Special Funds for Public Welfare"(201004025)
文摘Desertification is one of the most serious eco-environmental problems around Qinghai Lake.Based on GIS and RS,GIS analysis was used to obtain the information of spatial-temporal change and different pattern of desertification in each county around Qinghai Lake in four phases of1976,1987,1995 and 2006.Using the function of intersect and overlay supported by ARCGIS,with analyzing attributes of vector RS images,we obtained transition data and established transfer matrix of land-use types in recent 30 years,besides,protracted land-use transition maps of all desertification classes.In further,we analyzed transition quantity and direction of desertification in each county,moreover,reconstructed the process of spatial-temporal evolution of desertification.The results are showed below:(1)it's the transition between desertified land and others but not in the desertified that played the main role in Gangcha and Gonghe County,while the transfer between desertified lands were greater than that with other land-use types in Haiyan County.(2)Extremely severe desertified land mainly distributes in Ketu and Sand Islands that belongs to Haiyan County,and moderate desertified land in riversides of Gangcha County,also,the light desertification expanded too rapidly to become the most desertified land-use type in the surrounding of Qinghai Lake since 1976.(3)By using relative change rate of desertified land,the regional variability rank from top to toe was Gangcha,Haiyan and Gonghe.
基金the special funds for Major State Research Projects 2005CB321704National Science Foundation of China for Distinguished Young Scholars 10225103 and 20490222.
文摘The membrane’s dynamics is very important for cells.A membrane in 2-dimensional space can be seen as an incompressible closed curve in a plane or a cylindrical surface in 3-dimensional space.In this paper,we design a second-order accurate numerical algorithm to simulate the shape transformation of the membrane.In the algorithm,we use the tangent angles to present the curve and avoid the difficulties from the constraint of curve’s incompressible condition.A lot of interesting phenomena are obtained.Some of them are very like the life processes of cells,such as exocytosis and endocytosis.Furthermore,we can see the relation between two dynamic models clearly.At last,considering the influence of the inner incompressible fluids partially,we add a constraint:the area circled by the membrane maintain invariable.The numerical results show the dynamic motions of a curve remaining its local arc length and inner area constant.