The coupling relation exists in water and soil conser-vation and economic-social development. The article analyses the relation of soil and water conservation and economic-social development stages as well as the coup...The coupling relation exists in water and soil conser-vation and economic-social development. The article analyses the relation of soil and water conservation and economic-social development stages as well as the coupling analytical method. Then calculates the expecting income by dispersing Markov decision and calculates the correlation coefficient and the re-lationship degree. The article obtains the relationship of soil and water conservation investments and all kinds of incomes. Finally, it analyzes the important meaning in socio-economic development of water and soil conservation.展开更多
OECD/NEA （Organization for Economic Cooperation and Development/Nuclear Energy Agency） launched the SERENA （steam explosion resolution for nuclear application） project to resolve internationally the ex-vessel stea...OECD/NEA （Organization for Economic Cooperation and Development/Nuclear Energy Agency） launched the SERENA （steam explosion resolution for nuclear application） project to resolve internationally the ex-vessel steam explosion issue, which is one of major unresolved issues after a TMI-2 （three mile island-2） accident. One of main conclusions of OECD/NEA SERENA Phase 1, which was completed in 2005, was that some damage to the cavity is to be expected for an ex-vessel explosion. One major uncertainty that does not allow for a convergence toward consistent predictions was that there are no data on the component distribution in a pre-mixture at the time of an explosion, especially the level of the void. The other major uncertainty is the explosion behavior of corium melts. Therefore, SERENA Phase 2 was launched on October 1, 2007 to resolve the uncertainties of the coolant void and material effect by performing a limited number of well-designed tests with advanced instrumentation reflecting a large spectrum of ex-vessel melt compositions and conditions, and the required analytical work to bring the code capabilities to a sufficient level for use in reactor case analyses. The recent status of the OECD-SERENA Phase 2 project for the resolution of ex-vessel steam explosion risks will be described.展开更多
The urban vulnerability poses a serious challenge to achieving sustainable devel- opment. With the concentration of the population and the economy, cities must manage the higher frequencies and risks of various hazard...The urban vulnerability poses a serious challenge to achieving sustainable devel- opment. With the concentration of the population and the economy, cities must manage the higher frequencies and risks of various hazards and are becoming more vulnerable. Re- search on the assessment and regulatory control of urban vulnerability is of great significance for both urbanization quality improvement and sustainable development in China or other countries in the world. Because of the complexity of cities and vulnerability concepts, existing studies have focused on different aspects of urban vulnerability. And the research content of urban vulnerability is scattered and relatively independent, leading to a lack of comparability among the research data and resulting in tremendous difficulties in summarizing the conclu- sions through comparison of independent research data. Therefore the goal of this study was to construct urban vulnerability index （UV/） from the perspective of sustainable development that could assess urban vulnerability comprehensively. In this study, we selected 10 subin- dexes involving 36 specific parameters from four aspects （resources, eco-environmental sys- tems, economics, and social development） to construct a comprehensive index system. We also established the standard values of measurements. Then we take 288 prefecture-level cities in China as a study area and evaluate its overall urban vulnerability and its spatial differentiation. Results indicate that urban vulnerability of China has a remarkable spatial differentiation of both ＂gradient distribution＂ and ＂clustered distribution＂; the extent of urban vulnerability corresponds to city size, the bigger the city, the lower its vulnerability; re- source-based cities are more vulnerable than comprehensive cities; a city＇s economic growth rate does not reflect the extent of its urban vulnerability. Further, we offer a few suggestions to cope with urban vulnerability in China.展开更多
This paper presents new results for strong solutions and their coincidence sets of the obstacle problem for linear hyperbolic operators of first order. An inequality similar to the LewyStampacchia ones for elliptic an...This paper presents new results for strong solutions and their coincidence sets of the obstacle problem for linear hyperbolic operators of first order. An inequality similar to the LewyStampacchia ones for elliptic and parabolic problems is shown. Under nondegeneracy conditions the stability of the coincidence set is shown with respect to the variation of the data and with respect to approximation by semilinear hyperbolic problems. These results are applied to the asymptotic stability of the evolution problem with respect to the stationary coercive problem with obstacle.展开更多
文摘The coupling relation exists in water and soil conser-vation and economic-social development. The article analyses the relation of soil and water conservation and economic-social development stages as well as the coupling analytical method. Then calculates the expecting income by dispersing Markov decision and calculates the correlation coefficient and the re-lationship degree. The article obtains the relationship of soil and water conservation investments and all kinds of incomes. Finally, it analyzes the important meaning in socio-economic development of water and soil conservation.
文摘OECD/NEA （Organization for Economic Cooperation and Development/Nuclear Energy Agency） launched the SERENA （steam explosion resolution for nuclear application） project to resolve internationally the ex-vessel steam explosion issue, which is one of major unresolved issues after a TMI-2 （three mile island-2） accident. One of main conclusions of OECD/NEA SERENA Phase 1, which was completed in 2005, was that some damage to the cavity is to be expected for an ex-vessel explosion. One major uncertainty that does not allow for a convergence toward consistent predictions was that there are no data on the component distribution in a pre-mixture at the time of an explosion, especially the level of the void. The other major uncertainty is the explosion behavior of corium melts. Therefore, SERENA Phase 2 was launched on October 1, 2007 to resolve the uncertainties of the coolant void and material effect by performing a limited number of well-designed tests with advanced instrumentation reflecting a large spectrum of ex-vessel melt compositions and conditions, and the required analytical work to bring the code capabilities to a sufficient level for use in reactor case analyses. The recent status of the OECD-SERENA Phase 2 project for the resolution of ex-vessel steam explosion risks will be described.
基金National Natural Science Foundation of ChinaNo.41371177
文摘The urban vulnerability poses a serious challenge to achieving sustainable devel- opment. With the concentration of the population and the economy, cities must manage the higher frequencies and risks of various hazards and are becoming more vulnerable. Re- search on the assessment and regulatory control of urban vulnerability is of great significance for both urbanization quality improvement and sustainable development in China or other countries in the world. Because of the complexity of cities and vulnerability concepts, existing studies have focused on different aspects of urban vulnerability. And the research content of urban vulnerability is scattered and relatively independent, leading to a lack of comparability among the research data and resulting in tremendous difficulties in summarizing the conclu- sions through comparison of independent research data. Therefore the goal of this study was to construct urban vulnerability index （UV/） from the perspective of sustainable development that could assess urban vulnerability comprehensively. In this study, we selected 10 subin- dexes involving 36 specific parameters from four aspects （resources, eco-environmental sys- tems, economics, and social development） to construct a comprehensive index system. We also established the standard values of measurements. Then we take 288 prefecture-level cities in China as a study area and evaluate its overall urban vulnerability and its spatial differentiation. Results indicate that urban vulnerability of China has a remarkable spatial differentiation of both ＂gradient distribution＂ and ＂clustered distribution＂; the extent of urban vulnerability corresponds to city size, the bigger the city, the lower its vulnerability; re- source-based cities are more vulnerable than comprehensive cities; a city＇s economic growth rate does not reflect the extent of its urban vulnerability. Further, we offer a few suggestions to cope with urban vulnerability in China.
基金Partially supported by the Project FCT-POCTI/34471/MAT/2000
文摘This paper presents new results for strong solutions and their coincidence sets of the obstacle problem for linear hyperbolic operators of first order. An inequality similar to the LewyStampacchia ones for elliptic and parabolic problems is shown. Under nondegeneracy conditions the stability of the coincidence set is shown with respect to the variation of the data and with respect to approximation by semilinear hyperbolic problems. These results are applied to the asymptotic stability of the evolution problem with respect to the stationary coercive problem with obstacle.
