Dynamic urban expansion simulation at regional scale is one of the important research methodologies in Land Use/Cover Change （LUCC） and global environmental change influenced by urbanization. However, previous studi...Dynamic urban expansion simulation at regional scale is one of the important research methodologies in Land Use/Cover Change （LUCC） and global environmental change influenced by urbanization. However, previous studies indicate that the single urban expansion simulation for future scenarios at local scale cannot meet the requirements for characterizing and interpreting the interactive mechanisms of regional urbanization and global environmental change. This study constructed a regional Dynamic Urban Expansion Model （Reg-DUEM） suitable for different scenarios by integrating the Artificial Neural Network （ANN） and Cellular Automaton （CA） model. Firstly we analyzed the temporal and spatial characteristics of urban expansion and acquired a prior knowledge rules using land use/cover change datasets of Beijing-Tianjin-Tangshan metropolitan area. The future urban expansion under different scenarios is then simulated based on a baseline model, economic models, policy models and the structural adjustment model. The results indicate that Reg-DUEM has good reliability for a non-linear expansion simulation at regional scale influenced by macro-policies. The simulating results show that future urban expansion patterns from different scenarios of the metropolitan area have the tremendous spatio-temporal differences. Future urban expansion will shift quickly from Beijing metropolis to the periphery of Tianjin and Tangshan city along coastal belt.展开更多
Nanowires(NWs) exhibit size-dependent mechanical properties due to the high surface/volume ratio, in which temperature also plays an important role. The surface eigenstress model is further developed here to quantitat...Nanowires(NWs) exhibit size-dependent mechanical properties due to the high surface/volume ratio, in which temperature also plays an important role. The surface eigenstress model is further developed here to quantitatively predict the size-dependent mechanical properties of NWs and results in analytic formulas. Molecular dynamics(MD) simulations are conducted to study the size-dependent mechanical of [100], [110] and [111] Ni and Si nanowires within the temperature range of 100–400 K and the MD results verify perfectly the newly developed surface eigenstress model.展开更多
基金The Young Scientist Fund of National Natural Science Foundation of China, No.40901224 National Basic Research Program of China, No.2010CB950900+2 种基金 Opening Foundation of State Key Laboratory of Remote Sensing Science, No.2009KFJJ005 Opening Foundation of State Key Lab of Resources and Environmental Information System, No.A0725 Swedish Research Links, No.2006-24724-44416-13
文摘Dynamic urban expansion simulation at regional scale is one of the important research methodologies in Land Use/Cover Change （LUCC） and global environmental change influenced by urbanization. However, previous studies indicate that the single urban expansion simulation for future scenarios at local scale cannot meet the requirements for characterizing and interpreting the interactive mechanisms of regional urbanization and global environmental change. This study constructed a regional Dynamic Urban Expansion Model （Reg-DUEM） suitable for different scenarios by integrating the Artificial Neural Network （ANN） and Cellular Automaton （CA） model. Firstly we analyzed the temporal and spatial characteristics of urban expansion and acquired a prior knowledge rules using land use/cover change datasets of Beijing-Tianjin-Tangshan metropolitan area. The future urban expansion under different scenarios is then simulated based on a baseline model, economic models, policy models and the structural adjustment model. The results indicate that Reg-DUEM has good reliability for a non-linear expansion simulation at regional scale influenced by macro-policies. The simulating results show that future urban expansion patterns from different scenarios of the metropolitan area have the tremendous spatio-temporal differences. Future urban expansion will shift quickly from Beijing metropolis to the periphery of Tianjin and Tangshan city along coastal belt.
基金supported by the National Key R&D Program of China (Grant No. 2017YFB0701600)the National Natural Science Foundation of China (Grant No. 11672168)the Science and Technology Commission of Shanghai Municipality (Grant Nos. 15DZ2260300 and 16DZ2260600)
文摘Nanowires(NWs) exhibit size-dependent mechanical properties due to the high surface/volume ratio, in which temperature also plays an important role. The surface eigenstress model is further developed here to quantitatively predict the size-dependent mechanical properties of NWs and results in analytic formulas. Molecular dynamics(MD) simulations are conducted to study the size-dependent mechanical of [100], [110] and [111] Ni and Si nanowires within the temperature range of 100–400 K and the MD results verify perfectly the newly developed surface eigenstress model.
