Aquaculture ponds are one of the fastest-growing land use types in valuable and fertile coastal areas and have caused serious environmental problems. Quantitative assessment of the extent, spatial distribution, and dy...Aquaculture ponds are one of the fastest-growing land use types in valuable and fertile coastal areas and have caused serious environmental problems. Quantitative assessment of the extent, spatial distribution, and dynamics of aquaculture ponds is of utmost importance for sustainable economic development and scientific management of land and water resources in the coastal area. An object-oriented classification approach was applied to Landsat images acquired over three decades to investigate the long-term change of aquaculture ponds in the coastal region of the Yellow River Delta. The results indicated that the aquaculture ponds in the study area undergone a sharp expansion from 40.38 km^2 in 1983 to 1406.89 km^2 in 2015, and the fast expansion occurred during the period of 2010–2015 and 1990–2000. Natural wetlands, especially mudflat, and cropland were main land use types contributing to the increase of aquaculture ponds. The patches of aquaculture ponds were consequently prevalence in the north of the Yellow River Estuary and landscape metrics indicated an increase of the aquaculture ponds of the study area in the quantity and complexity. The expansion of aquaculture ponds inevitably had negative effects on the coastal environment, including loss of natural wetlands, water pollution and land subsidence, etc. The results from this study provide baseline data and valuable information for efficiently planning and managing aquaculture practices and for effectively implementing adequate regulations and protection measures.展开更多
Mathematical economic modeling is widely used to provide a reference for policy makers and guidance for the specific work of many departments, such as saving expenditures, reducing costs and improving profit. Particul...Mathematical economic modeling is widely used to provide a reference for policy makers and guidance for the specific work of many departments, such as saving expenditures, reducing costs and improving profit. Particularly, it can predict and estimate the future, playing a great role in promoting the rapid development of science and technology as well as the management of market economy. In general, mathematics does not directly deal with the objective conditions on the management of market economy. In order to use mathematics to solve problems in the field of the management of market economic, it is necessary to carry out mathematical economic modeling.展开更多
Standard is an effective carrier of developing circular economy while standard- ization is the foundation of scientific management of circular economy and the bridge for scientific research, production and application...Standard is an effective carrier of developing circular economy while standard- ization is the foundation of scientific management of circular economy and the bridge for scientific research, production and application. Therefore, it is necessary to explore how to give full play to the important roles of standardization in the development of circular economy, how to make use of standardization to accelerate the promotion and application of advanced technology for circular economy and to develop the circular economy with the help of standardization.展开更多
Public economics is a science of studying government economic behaviors, and an interdiscipline of politics and economics. As China is at the primary stage of socialism and the development of various domestic causes i...Public economics is a science of studying government economic behaviors, and an interdiscipline of politics and economics. As China is at the primary stage of socialism and the development of various domestic causes is still in a period of exploration, it is very important for the reform of the socialist modernization to strengthen domestic administrative management. Society is the subject of national reform and development in the long run, and thus maintaining the stability of domestic social order is not only the prerequisite for the long-term survival and development of China, but also the key requirement of ensuring people to live and work in peace and contentment. This thesis, first of all, introduces the management concept of public economy and the necessity of government＇s involvement in supervising economy. And on the basis of these, the thesis put forward the direction of transforming government economic functions and several precautions that should be noticed in government economic behaviors.展开更多
基金Under the auspices of National Program on Key Basic Research Project(No.2013CB430401)
文摘Aquaculture ponds are one of the fastest-growing land use types in valuable and fertile coastal areas and have caused serious environmental problems. Quantitative assessment of the extent, spatial distribution, and dynamics of aquaculture ponds is of utmost importance for sustainable economic development and scientific management of land and water resources in the coastal area. An object-oriented classification approach was applied to Landsat images acquired over three decades to investigate the long-term change of aquaculture ponds in the coastal region of the Yellow River Delta. The results indicated that the aquaculture ponds in the study area undergone a sharp expansion from 40.38 km^2 in 1983 to 1406.89 km^2 in 2015, and the fast expansion occurred during the period of 2010–2015 and 1990–2000. Natural wetlands, especially mudflat, and cropland were main land use types contributing to the increase of aquaculture ponds. The patches of aquaculture ponds were consequently prevalence in the north of the Yellow River Estuary and landscape metrics indicated an increase of the aquaculture ponds of the study area in the quantity and complexity. The expansion of aquaculture ponds inevitably had negative effects on the coastal environment, including loss of natural wetlands, water pollution and land subsidence, etc. The results from this study provide baseline data and valuable information for efficiently planning and managing aquaculture practices and for effectively implementing adequate regulations and protection measures.
文摘Mathematical economic modeling is widely used to provide a reference for policy makers and guidance for the specific work of many departments, such as saving expenditures, reducing costs and improving profit. Particularly, it can predict and estimate the future, playing a great role in promoting the rapid development of science and technology as well as the management of market economy. In general, mathematics does not directly deal with the objective conditions on the management of market economy. In order to use mathematics to solve problems in the field of the management of market economic, it is necessary to carry out mathematical economic modeling.
文摘Standard is an effective carrier of developing circular economy while standard- ization is the foundation of scientific management of circular economy and the bridge for scientific research, production and application. Therefore, it is necessary to explore how to give full play to the important roles of standardization in the development of circular economy, how to make use of standardization to accelerate the promotion and application of advanced technology for circular economy and to develop the circular economy with the help of standardization.
文摘Public economics is a science of studying government economic behaviors, and an interdiscipline of politics and economics. As China is at the primary stage of socialism and the development of various domestic causes is still in a period of exploration, it is very important for the reform of the socialist modernization to strengthen domestic administrative management. Society is the subject of national reform and development in the long run, and thus maintaining the stability of domestic social order is not only the prerequisite for the long-term survival and development of China, but also the key requirement of ensuring people to live and work in peace and contentment. This thesis, first of all, introduces the management concept of public economy and the necessity of government＇s involvement in supervising economy. And on the basis of these, the thesis put forward the direction of transforming government economic functions and several precautions that should be noticed in government economic behaviors.
