Araneiforms are spider-like ground patterns that are widespread in the southern polar regions of Mars.A gas erosion process driven by the seasonal sublimation of CO_(2) ice was proposed as an explanation for their for...Araneiforms are spider-like ground patterns that are widespread in the southern polar regions of Mars.A gas erosion process driven by the seasonal sublimation of CO_(2) ice was proposed as an explanation for their formation,which cannot occur on Earth due to the high climatic temperature.In this study,we propose an alternative mechanism that attrib-utes the araneiform formation to the erosion of upwelling salt water from the subsurface,relying on the identification of the first terrestrial analog found in a playa of the Qaidam Basin on the northern Tibetan Plateau.Morphological analysis indicates that the structures in the Qaidam Basin have fractal features comparable to araneiforms on Mars.A numerical model is developed to investigate the araneiform formation driven by the water-diffusion mechanism.The simulation res-ults indicate that the water-diffusion process,under varying ground conditions,may be responsible for the diverse aranei-form morphologies observed on both Earth and Mars.Our numerical simulations also demonstrate that the orientations of the saltwater diffusion networks are controlled by pre-existing polygonal cracks,which is consistent with observations of araneiforms on Mars and Earth.Our study thus suggests that a saltwater-related origin of the araneiform is possible and has significant implications for water searches on Mars.展开更多
Sichuan Basin is an important agricultural production base,where peanut cultivation is widely distributed,and the size of planting areas is relatively concentrated,however there are several problems in the peanut prod...Sichuan Basin is an important agricultural production base,where peanut cultivation is widely distributed,and the size of planting areas is relatively concentrated,however there are several problems in the peanut production such as variety complexity,quality degradation,poor marketability,as well as non-standardized cultivation techniques and deep processing delay and so on.Overview of the study area was introduced,and characteristics of production and quality of peanut were analyzed.The results showed that,affected by ecological conditions,the fat content of peanut was higher,protein content of peanut was medium and the O/L was generally high.In the spatial distribution,the protein content of peanut was higher in the south than it in the north,however the fat content of peanut decreased gradually form northeast to southwest,while the O/L of peanut was higher in the eastern hilly area than it in the west plains,and the main producing areas of peanut was lower than it in the non-main producing areas.The article pointed out that the area should focus the peanut as an important economic corps and advantages of agricultural products in the region,and significantly enhance the peanut plant efficiency as the core to enhance the space for rational distribution,implement standardized production of pollution-free and base production,improve the rate of input-output per unit area,enhance the level of deep processing,caste national ＂ vegetable protein source,processing of raw materials sources and agricultural bio-complementary source＂,and realize the increase production and incomes of farmer and sustainable development of regional peanut industry.展开更多
The Sichuan Basin is endowed with unique natural and cultural conditions, which provide good conditions for the creation of traditional ＂shan-shui dries＂. As an important constituent dement of ＂shan-hui cities＂M, ...The Sichuan Basin is endowed with unique natural and cultural conditions, which provide good conditions for the creation of traditional ＂shan-shui dries＂. As an important constituent dement of ＂shan-hui cities＂M, boundaries delimit cities and nature and determine the scope and scale of cities. This paper divides the boundaries into dty boundary, mountain boundary, water boundary and celestial horizon, which integrate with each other and embody the boundary feature of four in one.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB41000000)the Fundamental Research Funds for the Central Universities(WK2080000144)。
文摘Araneiforms are spider-like ground patterns that are widespread in the southern polar regions of Mars.A gas erosion process driven by the seasonal sublimation of CO_(2) ice was proposed as an explanation for their formation,which cannot occur on Earth due to the high climatic temperature.In this study,we propose an alternative mechanism that attrib-utes the araneiform formation to the erosion of upwelling salt water from the subsurface,relying on the identification of the first terrestrial analog found in a playa of the Qaidam Basin on the northern Tibetan Plateau.Morphological analysis indicates that the structures in the Qaidam Basin have fractal features comparable to araneiforms on Mars.A numerical model is developed to investigate the araneiform formation driven by the water-diffusion mechanism.The simulation res-ults indicate that the water-diffusion process,under varying ground conditions,may be responsible for the diverse aranei-form morphologies observed on both Earth and Mars.Our numerical simulations also demonstrate that the orientations of the saltwater diffusion networks are controlled by pre-existing polygonal cracks,which is consistent with observations of araneiforms on Mars and Earth.Our study thus suggests that a saltwater-related origin of the araneiform is possible and has significant implications for water searches on Mars.
基金Supported by the Supporting Program of the " Eleventh Five-year Plan" for Sci & Tech Research of China (2006BAD21B04)~~
文摘Sichuan Basin is an important agricultural production base,where peanut cultivation is widely distributed,and the size of planting areas is relatively concentrated,however there are several problems in the peanut production such as variety complexity,quality degradation,poor marketability,as well as non-standardized cultivation techniques and deep processing delay and so on.Overview of the study area was introduced,and characteristics of production and quality of peanut were analyzed.The results showed that,affected by ecological conditions,the fat content of peanut was higher,protein content of peanut was medium and the O/L was generally high.In the spatial distribution,the protein content of peanut was higher in the south than it in the north,however the fat content of peanut decreased gradually form northeast to southwest,while the O/L of peanut was higher in the eastern hilly area than it in the west plains,and the main producing areas of peanut was lower than it in the non-main producing areas.The article pointed out that the area should focus the peanut as an important economic corps and advantages of agricultural products in the region,and significantly enhance the peanut plant efficiency as the core to enhance the space for rational distribution,implement standardized production of pollution-free and base production,improve the rate of input-output per unit area,enhance the level of deep processing,caste national ＂ vegetable protein source,processing of raw materials sources and agricultural bio-complementary source＂,and realize the increase production and incomes of farmer and sustainable development of regional peanut industry.
基金Sponsored by Fundamental Research Funds for the Central Universities(2682018CX57)
文摘The Sichuan Basin is endowed with unique natural and cultural conditions, which provide good conditions for the creation of traditional ＂shan-shui dries＂. As an important constituent dement of ＂shan-hui cities＂M, boundaries delimit cities and nature and determine the scope and scale of cities. This paper divides the boundaries into dty boundary, mountain boundary, water boundary and celestial horizon, which integrate with each other and embody the boundary feature of four in one.
