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 well-documented decrease in the discharge of sediment into the Yellow River has attracted considerable attention in recent years. The present study analyzed the spatial and temporal variation of sediment yield bas...The well-documented decrease in the discharge of sediment into the Yellow River has attracted considerable attention in recent years. The present study analyzed the spatial and temporal variation of sediment yield based on data from 46 hydrological stations in the sediment-rich region of the Yellow River from 1955 to 2010. The results showed that since 1970 sediment yield in the region has clearly decreased at different rates in the 45 sub-areas controlled by hydrological stations. The decrease in sediment yield was closely related to the intensity and extent of soil erosion control measures and rainstorms that occurred in different periods and sub-areas. The average sediment delivery modulus(SDM) in the study area decreased from 7,767.4 t/(km^2·a) in 1951–1969 to 980.5 t/(km^2·a) in 2000–2010. Our study suggested that 65.5% of the study area with the SDM below 1,000 t/(km^2·a) is still necessary to control soil deterioration caused by erosion, and soil erosion control measures should be further strengthened in the areas with the SDM above 1,000 t/(km^2·a).展开更多
Space weather has a remarkable effect on modern human activities,e.g.,communication,navigation,space exploration etc.Space physics study from polar stations is as an important part of the entire solar-terrestrial spac...Space weather has a remarkable effect on modern human activities,e.g.,communication,navigation,space exploration etc.Space physics study from polar stations is as an important part of the entire solar-terrestrial space,and conducts quantitative research from the perspective of overall space plasma behavior.One of the most important issues is to identify the dominant processes that transfer plasma and momentum from the solar wind to Earth’s magnetosphere.Thus,it is necessary to carry out research for combination the observations from polar ground stations and spacecraft observations in the space.Observations at polar regions can be as a window to the space for satellite traffic controls.The operation of the observation chain―Zhongshan-Taishan-Kunlun Station could monitor polar space debris in a large area with high temporal and spatial resolution.Also,night-time measurements of astronomical seeing at Dome A in Antarctica make it less challenging to locate a telescope above it,thereby giving greater access to the free atmosphere because of a thinner boundary layer.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funded by the Major Programs of the Chinese Academy of Sciences (KZZD-EW-04-03-04)the National Science-technology Support Plan Project (2006BAD09B10)the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-EW-406)
文摘The well-documented decrease in the discharge of sediment into the Yellow River has attracted considerable attention in recent years. The present study analyzed the spatial and temporal variation of sediment yield based on data from 46 hydrological stations in the sediment-rich region of the Yellow River from 1955 to 2010. The results showed that since 1970 sediment yield in the region has clearly decreased at different rates in the 45 sub-areas controlled by hydrological stations. The decrease in sediment yield was closely related to the intensity and extent of soil erosion control measures and rainstorms that occurred in different periods and sub-areas. The average sediment delivery modulus(SDM) in the study area decreased from 7,767.4 t/(km^2·a) in 1951–1969 to 980.5 t/(km^2·a) in 2000–2010. Our study suggested that 65.5% of the study area with the SDM below 1,000 t/(km^2·a) is still necessary to control soil deterioration caused by erosion, and soil erosion control measures should be further strengthened in the areas with the SDM above 1,000 t/(km^2·a).
基金supported by the National Natural Science Foundation of China(Grant nos.42242406,42230202)Innovation Fund from Joint Innovation Center of Space Science(Aerospace Shanghai).
文摘Space weather has a remarkable effect on modern human activities,e.g.,communication,navigation,space exploration etc.Space physics study from polar stations is as an important part of the entire solar-terrestrial space,and conducts quantitative research from the perspective of overall space plasma behavior.One of the most important issues is to identify the dominant processes that transfer plasma and momentum from the solar wind to Earth’s magnetosphere.Thus,it is necessary to carry out research for combination the observations from polar ground stations and spacecraft observations in the space.Observations at polar regions can be as a window to the space for satellite traffic controls.The operation of the observation chain―Zhongshan-Taishan-Kunlun Station could monitor polar space debris in a large area with high temporal and spatial resolution.Also,night-time measurements of astronomical seeing at Dome A in Antarctica make it less challenging to locate a telescope above it,thereby giving greater access to the free atmosphere because of a thinner boundary layer.