This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which busi...This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which business services firms play the crucial role in city network formation, information is gathered about the presence of global service firms in cities. This information is converted into data to provide the′service value′of a city for a firm′s provision of corporate services in a 526(cities)×175(firms) matrix. These data are then used as the input to the interlocking network model in order to measure cities′connectivity and its predominant geographical orientation. Here we focus on the position of some key Chinese cities in this regard, and discuss and interpret results in the context of the urban dimensions of the′opening up′of the Chinese economy.展开更多
In this study, the authors use a political perspective to explore the relative global status of cities in China. Two questions are addressed. Firstly, by using international organizations as the subjects and quantitat...In this study, the authors use a political perspective to explore the relative global status of cities in China. Two questions are addressed. Firstly, by using international organizations as the subjects and quantitative analysis of the spatial distribution of their offices, the overall position of Chinese cities in the global distribution of international organizations is estimated. The results show that 22 Chi- nese cities are involved in international political affairs. Beijing, Shanghai and Guangzhou dominate these activities and have high po- litical global-city status. Secondly, through qualitative analysis of Guangzhou City, the authors explore how its status as a center for intemational organizations has been shaped in recent years. The locational decision-making process is analyzed and the factors are demonstrated at both national and city scales. The definition of international organizations as used in this study refers not only to those supranational bodies that have the ability to manage relations across states (such as the European Union), but also those in- ter-governmental organizations (IGOs), international non-governmental organizations (INGOs) and diplomatic representatives and delegations that today also manage and regulate relations between and among states.展开更多
The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analy...The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analyzed the air pollution index(API) in four cities(Shanghai, Nanjing, Hangzhou and Ningbo) in the YRD from 2001 to 2012. We attempted to empirically examine the relationship between meteorological factors and air quality in the urban areas of the YRD. According to the monitoring data, the API in Shanghai, Nanjing, Hangzhou slightly declined and that in Ningbo increased over the study period. We analyzed the inter-annual, seasonal, and monthly variations of API, from which we found that the air quality had different temporal changes in the four cities. It was indicated that air quality was poor in winter and spring and best in summer. Furthermore, different weather conditions affected air quality level. The wind direction was considered as an important and influential factor to air pollution, which has an impact on the accumulating or cleaning processes of pollutants. The air quality was influenced by the different wind directions that varied with seasons and cities.展开更多
Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of ...Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of urban areas. With a comparative study of international experiences, this article analyzed the mechanism and consequences of urban expansion, reviewed the typical planning and financial policies adopted by other countries for controlling urban sprawl, and discussed the suitable densities of urban areas. The analysis results suggested that Chinese cities have no better choice but compact urban forms. To achieve the goal of compact development, intensive use of public transportation and high proportion of collective houses should be encouraged, and 60–100 m2 per capita is recommended as the reasonable range of urban density in large cities.展开更多
Brownfield redevelopment is a new urban land use strategy to pursue the ideal of sustainable development. It relieves environmental pressure and resolves the glaring contradiction between urban land idleness and urban...Brownfield redevelopment is a new urban land use strategy to pursue the ideal of sustainable development. It relieves environmental pressure and resolves the glaring contradiction between urban land idleness and urban sprawl. It addresses issues of urban land use and farmland protection in China. This paper compares brownfield with greenfield, and defines brownfield and its redevelopment. It elaborates general and special government policies for this sustainable land use strategy in the context of China. General policies contain two aspects: clarifying brownfield redevelopment's priority in Chinese urban planning and land use and setting a general quantitative redevelopment target. The extent of the government's special policies, which aim at coordinating three factors in the redevelopment process, namely govern- ments, developers and users, are divided into five areas: statistics and categorization, assessment and remediation, fi- nancial supports and tax incentives, environmental and legal liability, and publicity and guidance. The paper concludes the major functions of different levels of Chinese government in the redevelopment process, i.e. making general strategy, formulating legislation, spectifying regulations and technical standards, estimating and categorizing brownfield sites, drawing up brownfield planning, providing information and financial support, guiding developers, publicizing the strategy to the public, and checking reuse results.展开更多
Studying the change of resources consumption and eco-environmental carrying capacity are of importance to the sustainable development of urbanization.Based on the China's economic and social statistical data from ...Studying the change of resources consumption and eco-environmental carrying capacity are of importance to the sustainable development of urbanization.Based on the China's economic and social statistical data from 1950 to 2006,the ecological footprint,eco-logical footprint intensity,ecological deficit and surplus,and eco-environment quality com-prehensive index are calculated,the correlation between urbanization and eco-environmental change is analyzed and the eco-environmental guarantee for China's urbanization in 2030 is forecasted.The major results could be summarized as follows:(1) there is a positive linear relation between urbanization and ecological footprint,negative linear relation between ur-banization and ecological footprint intensity,ecological deficit and surplus and the negative exponential relation between urbanization and eco-environment quality comprehensive index.(2) By 2030,the urbanization level will reach 61.32%,the ecological deficit will increase to 42.2866×108 hm2 and the eco-environment quality comprehensive index will drop to 0.3016 on the condition that the total quantity ecological footprint achieves 55.9348×108 hm2.(3) Under the existing urban development pattern,the ecological overload will be more serious in the next 24 years.Constructing the reasonable industrial structure and establishing the intensive resources utilization system to alleviate the eco-environmental pressure are the tough challenges in China's urbanization process.展开更多
Chongqing is the largest municipality under the Chinese Central Government (MCG) in terms of administrative area and population and is now the most important economic and cultural center of the upper Yangtze River and...Chongqing is the largest municipality under the Chinese Central Government (MCG) in terms of administrative area and population and is now the most important economic and cultural center of the upper Yangtze River and Three Gorges area. The Three Gorges Dam project, one of the largest world infrastructure projects, causes a great deal of immigration to Chongqing and results in the rapid urbanization of the city, and it has brought in a great deal of environmental impact, which is a global concerned issue. This paper introduces the city profile of Chongqing municipality and its urbanization impact on energy and environment. The demand and the trend of energy consumption in built environment (building and transport) have been analysed. The living environment of Chongqing residents and the local energy efficient policy have been introduced. Finally the authors discuss the key issues of the sustainable urban development of Chongqing.展开更多
With rapid development of urbanization and regional interaction and interdependence, regional urban agglomeration planning becomes more and more important in China, in order to promote integrated development of variou...With rapid development of urbanization and regional interaction and interdependence, regional urban agglomeration planning becomes more and more important in China, in order to promote integrated development of various cities with close interrelationship. However, it is still arguable academically on how to define the boundary or which cities to be included for the urban agglomeration of a region. This paper aims to shed lights on how to identify urban spheres of influence scientifically by introducing field modeling method and by practicing a case study on 168 cities in Central China. In our field modeling method, the influence intensities of cities were measured by a compre-ensive index and urban spheres of influence were represented spatially by field intensity. Then, their classification and spatial distribution characteristics of study area in 2007 were identified and explored by using GIS and statistical methods. The result showed that: 1) Wuhan is the absolute dominant city in Central China; 2) the provincial capital cities dominate their own provinces and there are no other lower grade agglomeration centers; and 3) the basic types of organization form of urban sphere of influence are single-polar type, agglomeration type, close-related group type and loose-related group type.展开更多
Nitrogen cycling has been poorly characterized in urban ecosystems.An in-situ buried bag incubation technique was used to quantify net rates of N mineralization and nitrification in soils of two urban sites,a street g...Nitrogen cycling has been poorly characterized in urban ecosystems.An in-situ buried bag incubation technique was used to quantify net rates of N mineralization and nitrification in soils of two urban sites,a street greening belt and a university campus,and a suburban site,a forest park,in Hefei,East China.The average concentration of extractable NO 3 in the surface soil (0-10 cm) was significantly higher at the urban sites than the suburban park site,whereas extractable NH + 4 concentration was significantly higher at the suburban park site than the urban sites.The forest park soil had greater potential N mineralization (148.1 μg N cm 3) than the soils from the campus (138.3 μg N cm 3) and street (99.8 μg N cm 3).The net mineralization rates varied between 1.63 and 2.69 μg N cm 3 d 1 and net nitrification rates between 0.82 and 1.02 μg N cm 3 d 1 at the suburban forest park site,but the rates varied from 1.27 to 2.41 μg N cm 3 d 1 and from 1.07 to 1.49 μg N cm 3 d 1,respectively,at the urban campus site.Both net mineralization and nitrification rates were lower during dry seasons.Results from regression analysis indicated that net N mineralization was significantly and positively correlated with soil moisture and soil C/N ratio,and was negatively correlated with soil pH.Relative nitrification was,however,significantly and negatively correlated with soil moisture and soil C/N ratio,and was positively correlated with soil pH.Mean relative nitrification was 0.763,indicating the dominance of nitrate cycling relative to ammonium cycling at the urban sites.The urban soils had the great potential for N losses compared to the suburban soils.展开更多
Background The incidence of coronary heart disease (CHD) is higher in Northern than that in Southern China, however differences in traditional CHD risk factors do not fully explain this. No study has examined the di...Background The incidence of coronary heart disease (CHD) is higher in Northern than that in Southern China, however differences in traditional CHD risk factors do not fully explain this. No study has examined the differences in subclinical atherosclerosis that may help explain the differences in incidence. This study examined these differences in subclinical atherosclerosis using coronary computed tomography (CT) for calcification between the Northern and Southern China. Methods We selected a random sample of participants in a large multi-center ongoing epidemiologic study for coronary calcium scanning in one northern city (North) (Beijing, n = 49) and in two southern cities (South) (Shanghai, n = 50, and Guangzhou, n = 50). Participants from the three field centers (mean age 67 years) underwent coronary risk factor evaluation and cardiac CT scanning for coronary calcium measurement using the Multi-Ethnic Study of Atherosclerosis scanning protocol. Results Adjusted log-transformed coronary artery calcium score in North China (Beijing) was 3.1 ±0.4 and in South China (Shanghai and Guangzhou) was 2.2 +_ 0.3 (P = 0.04). Mean calcium score for the northern city of Beijing was three times higher than that of the southern city of Guangzhou (P = 0.01) and 2.5 times higher than for the southern city of Shanghai (P = 0.03). Conclusions The extent of subclinical atherosclerosis is significantly higher in the northern city of Beijing than that in the two southern cities of Guangzhou and Shanghai, even after adjusting for standard cardiac risk factors. This finding suggests that standard risk factors do not fully explain north south differences in clinical CHD incidence.展开更多
As a major aspect of the ′China Model′, urbanization in China is being heatedly discussed in the Anglophone literature in the last two decades. By considering China′s urbanization as a ′testing ground′ of ′west...As a major aspect of the ′China Model′, urbanization in China is being heatedly discussed in the Anglophone literature in the last two decades. By considering China′s urbanization as a ′testing ground′ of ′western′ theories, these studies are important for the understanding of China′s ongoing urban restructuring and exchanging knowledge with ′western′ insights. Based on a survey of existing studies, this paper identifies various endogenous and exogenous concepts and explanations of China′s urbanization. It is suggested that China′s urbanization is mainly driven by a combination of political decentralization and neoliberalization with various forms of social stratification and mobility. However, it is argued that the distinctness of the ′China Model′, which is usually used to support the legitimacy of studies of China′s urbanization, has led to many controversial arguments and diminished the due contributions of Chinese scholars in the knowledge production of China′s urbanization. To consolidate the legitimacy of studies on China′s urbanization and enhance the roles of Chinese scholars, we suggest future studies to pay more attentions to the fundamental theories with looser constraints and ′true questions′ on China′s urbanization.展开更多
Taking Nanjing as a case, the paper explains the spatial behavior differences existing in the information technology use among different groups of residents and households, by virtue of analyzing the survey data of ur...Taking Nanjing as a case, the paper explains the spatial behavior differences existing in the information technology use among different groups of residents and households, by virtue of analyzing the survey data of urban households in the 11 districts of Nanjing, from the social, spatial, life and other non-technical angles. Also it makes various analyses and evaluation quantitatively and qualitatively on the social and spatial effect of information technology. The results show that the new technology is changing the social spatial behaviors of urban residents. New behavioral spaces of urban family such as telecommuting, email and QQ have begun to emerge. With the help of Internet, the communication scope of families has expanded greatly, and more new forms of publicizing community information have begun to emerge. Telecommunication contact forms have been developing swiftly, and their frequencies of contact have been increasing dramatically.展开更多
A number of urban and regional plans have been developed with the advancement of urbanization and regional integration, among which the delineation of sphere of urban influence and improvement of integration between t...A number of urban and regional plans have been developed with the advancement of urbanization and regional integration, among which the delineation of sphere of urban influence and improvement of integration between the city and its hinterland have be- come vital important for guiding practices. In terms of delineating sphere of urban influence, existing studies have been focused on static study by using single year data or single method, resulting in a lack of time-series longitudinal analysis or comprehensive analysis based on multiple methods This study emphasizes on comparing two methods from both the theoretical and empirical perspective. Both gravity model and improwd field model are applied to the selected study area for measurements and comparison, to explore their strengths and weaknesses. A research framework for comprehensive analysis on delineating sphere of urban influence is proposed. In the end, the differences of deli:aeating methods are illustrated and the feasibility of comprehensive analysis is discussed. Recommendations are provided for selecting appropriate methods for delineating sphere of urban influence or developing regional hierarchy system plans and urban spatial structure schemes.展开更多
The increasing globalization of the Chinese economy has been enabled by both Chinese financial institutions operating globally as well as international firms operating within China. In geographical terms, this has bee...The increasing globalization of the Chinese economy has been enabled by both Chinese financial institutions operating globally as well as international firms operating within China. In geographical terms, this has been organized through a number of strategic cities serving as gateways for the exchange of financial functions, products and practices between China and the global economy. Drawing on location data of financial service firms in China listed on stock exchanges in Shenzhen, Shanghai and Hong Kong, this paper shows that Chinese financial firms are expanding globally and how Chinese financial centers are positioned and connected in the urban networks shaped by these financial service firms. It is found that Hong Kong, China, holds strategic positions in the integration of Chinese cities into global financial center networks, and that establishing a foothold in global financial centers such as New York and London has been a priority for Chinese financial institutions. The increasing capital flows directed by Chinese financial institutionssuggests a shifting global financial geography, with numerous Chinese cities playing increasingly important roles within global financial center networks.展开更多
There have long been arguments about the impact of urbanization on local meteorological observations. This letter reviews up-to-date studies of the urbanization-related warming in the observed land surface air tempera...There have long been arguments about the impact of urbanization on local meteorological observations. This letter reviews up-to-date studies of the urbanization-related warming in the observed land surface air temperature series in China. Many previous studies have suggested that, over the past few decades, the local warming due to urbanization could have been about 0.1 °C/10 yr, or even larger. However, based on recently developed homogenized temperature records, the estimated urban bias is smaller. Major uncertainties arise from either the data quality or the techniques used to estimate the urbanization effect. A key example is the ‘observationminus-reanalysis' method, which tends to overestimate the urban signal in this region, partly due to systematic bias in the multi-decadal variability of surface air temperature in the reanalysis data. It is expected that improved numerical modeling with high-resolution information regarding the changing land surface in the region will help to further understand and quantify the effect of urbanization in local temperature records.展开更多
Sustainable development is a complex and systemic issue. It is essential to study it by the component analysis method from the view of system science. The urban developmental sustainability is one of focuses that peop...Sustainable development is a complex and systemic issue. It is essential to study it by the component analysis method from the view of system science. The urban developmental sustainability is one of focuses that people has paid more attention to, however, little common understanding how to measure and evaluate the sustainability has been gotten. In this paper, a framework is designed to evaluate the developmental sustainability of Suihua City, Heilongiiang Province in China from the aspects of economy, society, population, resources and environment. We adopt the Principal Components Analysis (PCA) to decrease dimensions and simplify the original indexes into 12 indexes. Also, the hierarchy and comprehensive multiple-criterion evaluative methods are employed to assess the sustainable development system in Suihua City. Then, the weights of indexes are attained by Analytic Hierarchy Process (AHP) method. Furthermore, urban comprehensive development level, developmental sustainability, coordinate degree are calculated and analyzed. By analyzing, we know the fluctuation of development level of subsystem, especially resources and environment subsystem, is acute. The comprehensive development level of sustainable development system in Suihua has been on the rise since 1999. That results from the effect of traditional economic development mode with high energy-consumed being decreased in the city after 1999. At the same time, it is obvious that there was an instability of development level in Suihua City during 1990-2002, the status'trend was more harmonious in 1999-2002. with a turn in 1998, and the development could be sustainable,展开更多
基金Under the auspices of European Research Council under the European Community's Seventh Framework Programme(No.PIOF-GA-2010-274027)Key Laboratory of Ecology and Energy-saving of Dense Habitat(Tongji University),Ministry of Education of the People's Republic of China
文摘This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which business services firms play the crucial role in city network formation, information is gathered about the presence of global service firms in cities. This information is converted into data to provide the′service value′of a city for a firm′s provision of corporate services in a 526(cities)×175(firms) matrix. These data are then used as the input to the interlocking network model in order to measure cities′connectivity and its predominant geographical orientation. Here we focus on the position of some key Chinese cities in this regard, and discuss and interpret results in the context of the urban dimensions of the′opening up′of the Chinese economy.
基金Under the auspices of National Natural Science Foundation of China(No.41130747,41320104001)
文摘In this study, the authors use a political perspective to explore the relative global status of cities in China. Two questions are addressed. Firstly, by using international organizations as the subjects and quantitative analysis of the spatial distribution of their offices, the overall position of Chinese cities in the global distribution of international organizations is estimated. The results show that 22 Chi- nese cities are involved in international political affairs. Beijing, Shanghai and Guangzhou dominate these activities and have high po- litical global-city status. Secondly, through qualitative analysis of Guangzhou City, the authors explore how its status as a center for intemational organizations has been shaped in recent years. The locational decision-making process is analyzed and the factors are demonstrated at both national and city scales. The definition of international organizations as used in this study refers not only to those supranational bodies that have the ability to manage relations across states (such as the European Union), but also those in- ter-governmental organizations (IGOs), international non-governmental organizations (INGOs) and diplomatic representatives and delegations that today also manage and regulate relations between and among states.
基金Under the auspices of Special Research Fund of the Ministry of Land and Resources for the Non-Profit Sector(No201411014-03)National Key Technology Research and Development Program of China(No.2012BAH28B04)
文摘The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analyzed the air pollution index(API) in four cities(Shanghai, Nanjing, Hangzhou and Ningbo) in the YRD from 2001 to 2012. We attempted to empirically examine the relationship between meteorological factors and air quality in the urban areas of the YRD. According to the monitoring data, the API in Shanghai, Nanjing, Hangzhou slightly declined and that in Ningbo increased over the study period. We analyzed the inter-annual, seasonal, and monthly variations of API, from which we found that the air quality had different temporal changes in the four cities. It was indicated that air quality was poor in winter and spring and best in summer. Furthermore, different weather conditions affected air quality level. The wind direction was considered as an important and influential factor to air pollution, which has an impact on the accumulating or cleaning processes of pollutants. The air quality was influenced by the different wind directions that varied with seasons and cities.
基金supported by Natural Science Foundation of China (Grant no. 40671063)
文摘Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of urban areas. With a comparative study of international experiences, this article analyzed the mechanism and consequences of urban expansion, reviewed the typical planning and financial policies adopted by other countries for controlling urban sprawl, and discussed the suitable densities of urban areas. The analysis results suggested that Chinese cities have no better choice but compact urban forms. To achieve the goal of compact development, intensive use of public transportation and high proportion of collective houses should be encouraged, and 60–100 m2 per capita is recommended as the reasonable range of urban density in large cities.
文摘Brownfield redevelopment is a new urban land use strategy to pursue the ideal of sustainable development. It relieves environmental pressure and resolves the glaring contradiction between urban land idleness and urban sprawl. It addresses issues of urban land use and farmland protection in China. This paper compares brownfield with greenfield, and defines brownfield and its redevelopment. It elaborates general and special government policies for this sustainable land use strategy in the context of China. General policies contain two aspects: clarifying brownfield redevelopment's priority in Chinese urban planning and land use and setting a general quantitative redevelopment target. The extent of the government's special policies, which aim at coordinating three factors in the redevelopment process, namely govern- ments, developers and users, are divided into five areas: statistics and categorization, assessment and remediation, fi- nancial supports and tax incentives, environmental and legal liability, and publicity and guidance. The paper concludes the major functions of different levels of Chinese government in the redevelopment process, i.e. making general strategy, formulating legislation, spectifying regulations and technical standards, estimating and categorizing brownfield sites, drawing up brownfield planning, providing information and financial support, guiding developers, publicizing the strategy to the public, and checking reuse results.
基金Knowledge Innovation Project of CAS,No.KZCX2-YW-307-02No.KZCX2-YW-321-05Major Project of 11th Five-year Scientific and Technological Support Plan of China,No.2006BAJ05A06
文摘Studying the change of resources consumption and eco-environmental carrying capacity are of importance to the sustainable development of urbanization.Based on the China's economic and social statistical data from 1950 to 2006,the ecological footprint,eco-logical footprint intensity,ecological deficit and surplus,and eco-environment quality com-prehensive index are calculated,the correlation between urbanization and eco-environmental change is analyzed and the eco-environmental guarantee for China's urbanization in 2030 is forecasted.The major results could be summarized as follows:(1) there is a positive linear relation between urbanization and ecological footprint,negative linear relation between ur-banization and ecological footprint intensity,ecological deficit and surplus and the negative exponential relation between urbanization and eco-environment quality comprehensive index.(2) By 2030,the urbanization level will reach 61.32%,the ecological deficit will increase to 42.2866×108 hm2 and the eco-environment quality comprehensive index will drop to 0.3016 on the condition that the total quantity ecological footprint achieves 55.9348×108 hm2.(3) Under the existing urban development pattern,the ecological overload will be more serious in the next 24 years.Constructing the reasonable industrial structure and establishing the intensive resources utilization system to alleviate the eco-environmental pressure are the tough challenges in China's urbanization process.
基金UK FCO GOF(PGI GCC 000012) and Chongqing Small town Programme (CSTC-2004AA7008)
文摘Chongqing is the largest municipality under the Chinese Central Government (MCG) in terms of administrative area and population and is now the most important economic and cultural center of the upper Yangtze River and Three Gorges area. The Three Gorges Dam project, one of the largest world infrastructure projects, causes a great deal of immigration to Chongqing and results in the rapid urbanization of the city, and it has brought in a great deal of environmental impact, which is a global concerned issue. This paper introduces the city profile of Chongqing municipality and its urbanization impact on energy and environment. The demand and the trend of energy consumption in built environment (building and transport) have been analysed. The living environment of Chongqing residents and the local energy efficient policy have been introduced. Finally the authors discuss the key issues of the sustainable urban development of Chongqing.
基金Under the auspices of National Natural Science Foundation of China (No. 40971102)Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-322)Special Grant for Postgraduates' Scientific Innovation and Social Practice in 2008
文摘With rapid development of urbanization and regional interaction and interdependence, regional urban agglomeration planning becomes more and more important in China, in order to promote integrated development of various cities with close interrelationship. However, it is still arguable academically on how to define the boundary or which cities to be included for the urban agglomeration of a region. This paper aims to shed lights on how to identify urban spheres of influence scientifically by introducing field modeling method and by practicing a case study on 168 cities in Central China. In our field modeling method, the influence intensities of cities were measured by a compre-ensive index and urban spheres of influence were represented spatially by field intensity. Then, their classification and spatial distribution characteristics of study area in 2007 were identified and explored by using GIS and statistical methods. The result showed that: 1) Wuhan is the absolute dominant city in Central China; 2) the provincial capital cities dominate their own provinces and there are no other lower grade agglomeration centers; and 3) the basic types of organization form of urban sphere of influence are single-polar type, agglomeration type, close-related group type and loose-related group type.
基金Project supported by the National Natural Science Foundation of China (Nos. 30471386 and 30771719)the Natural Science Research Foundation of the Education Department of Anhui Province,China (No. 2003KJ030ZD)
文摘Nitrogen cycling has been poorly characterized in urban ecosystems.An in-situ buried bag incubation technique was used to quantify net rates of N mineralization and nitrification in soils of two urban sites,a street greening belt and a university campus,and a suburban site,a forest park,in Hefei,East China.The average concentration of extractable NO 3 in the surface soil (0-10 cm) was significantly higher at the urban sites than the suburban park site,whereas extractable NH + 4 concentration was significantly higher at the suburban park site than the urban sites.The forest park soil had greater potential N mineralization (148.1 μg N cm 3) than the soils from the campus (138.3 μg N cm 3) and street (99.8 μg N cm 3).The net mineralization rates varied between 1.63 and 2.69 μg N cm 3 d 1 and net nitrification rates between 0.82 and 1.02 μg N cm 3 d 1 at the suburban forest park site,but the rates varied from 1.27 to 2.41 μg N cm 3 d 1 and from 1.07 to 1.49 μg N cm 3 d 1,respectively,at the urban campus site.Both net mineralization and nitrification rates were lower during dry seasons.Results from regression analysis indicated that net N mineralization was significantly and positively correlated with soil moisture and soil C/N ratio,and was negatively correlated with soil pH.Relative nitrification was,however,significantly and negatively correlated with soil moisture and soil C/N ratio,and was positively correlated with soil pH.Mean relative nitrification was 0.763,indicating the dominance of nitrate cycling relative to ammonium cycling at the urban sites.The urban soils had the great potential for N losses compared to the suburban soils.
文摘Background The incidence of coronary heart disease (CHD) is higher in Northern than that in Southern China, however differences in traditional CHD risk factors do not fully explain this. No study has examined the differences in subclinical atherosclerosis that may help explain the differences in incidence. This study examined these differences in subclinical atherosclerosis using coronary computed tomography (CT) for calcification between the Northern and Southern China. Methods We selected a random sample of participants in a large multi-center ongoing epidemiologic study for coronary calcium scanning in one northern city (North) (Beijing, n = 49) and in two southern cities (South) (Shanghai, n = 50, and Guangzhou, n = 50). Participants from the three field centers (mean age 67 years) underwent coronary risk factor evaluation and cardiac CT scanning for coronary calcium measurement using the Multi-Ethnic Study of Atherosclerosis scanning protocol. Results Adjusted log-transformed coronary artery calcium score in North China (Beijing) was 3.1 ±0.4 and in South China (Shanghai and Guangzhou) was 2.2 +_ 0.3 (P = 0.04). Mean calcium score for the northern city of Beijing was three times higher than that of the southern city of Guangzhou (P = 0.01) and 2.5 times higher than for the southern city of Shanghai (P = 0.03). Conclusions The extent of subclinical atherosclerosis is significantly higher in the northern city of Beijing than that in the two southern cities of Guangzhou and Shanghai, even after adjusting for standard cardiac risk factors. This finding suggests that standard risk factors do not fully explain north south differences in clinical CHD incidence.
基金Under the auspices of National Natural Science Foundation of China(No.41271165,41130747)Humanities and Social Science Research Planning Fund,Ministry of Education of China(No.12YJAGJW007)
文摘As a major aspect of the ′China Model′, urbanization in China is being heatedly discussed in the Anglophone literature in the last two decades. By considering China′s urbanization as a ′testing ground′ of ′western′ theories, these studies are important for the understanding of China′s ongoing urban restructuring and exchanging knowledge with ′western′ insights. Based on a survey of existing studies, this paper identifies various endogenous and exogenous concepts and explanations of China′s urbanization. It is suggested that China′s urbanization is mainly driven by a combination of political decentralization and neoliberalization with various forms of social stratification and mobility. However, it is argued that the distinctness of the ′China Model′, which is usually used to support the legitimacy of studies of China′s urbanization, has led to many controversial arguments and diminished the due contributions of Chinese scholars in the knowledge production of China′s urbanization. To consolidate the legitimacy of studies on China′s urbanization and enhance the roles of Chinese scholars, we suggest future studies to pay more attentions to the fundamental theories with looser constraints and ′true questions′ on China′s urbanization.
基金Under the auspices of Key Project of National Natural Science Foundation of China (No. 40435013, 40301014)
文摘Taking Nanjing as a case, the paper explains the spatial behavior differences existing in the information technology use among different groups of residents and households, by virtue of analyzing the survey data of urban households in the 11 districts of Nanjing, from the social, spatial, life and other non-technical angles. Also it makes various analyses and evaluation quantitatively and qualitatively on the social and spatial effect of information technology. The results show that the new technology is changing the social spatial behaviors of urban residents. New behavioral spaces of urban family such as telecommuting, email and QQ have begun to emerge. With the help of Internet, the communication scope of families has expanded greatly, and more new forms of publicizing community information have begun to emerge. Telecommunication contact forms have been developing swiftly, and their frequencies of contact have been increasing dramatically.
基金Under the auspices of National Natural Science Foundation of China(No.40901088)
文摘A number of urban and regional plans have been developed with the advancement of urbanization and regional integration, among which the delineation of sphere of urban influence and improvement of integration between the city and its hinterland have be- come vital important for guiding practices. In terms of delineating sphere of urban influence, existing studies have been focused on static study by using single year data or single method, resulting in a lack of time-series longitudinal analysis or comprehensive analysis based on multiple methods This study emphasizes on comparing two methods from both the theoretical and empirical perspective. Both gravity model and improwd field model are applied to the selected study area for measurements and comparison, to explore their strengths and weaknesses. A research framework for comprehensive analysis on delineating sphere of urban influence is proposed. In the end, the differences of deli:aeating methods are illustrated and the feasibility of comprehensive analysis is discussed. Recommendations are provided for selecting appropriate methods for delineating sphere of urban influence or developing regional hierarchy system plans and urban spatial structure schemes.
基金Under the auspices of the National Natural Science Foundation of China(No.41201107)the Fundamental Research Funds for the Central Universities(No.2015KJJCB30)
文摘The increasing globalization of the Chinese economy has been enabled by both Chinese financial institutions operating globally as well as international firms operating within China. In geographical terms, this has been organized through a number of strategic cities serving as gateways for the exchange of financial functions, products and practices between China and the global economy. Drawing on location data of financial service firms in China listed on stock exchanges in Shenzhen, Shanghai and Hong Kong, this paper shows that Chinese financial firms are expanding globally and how Chinese financial centers are positioned and connected in the urban networks shaped by these financial service firms. It is found that Hong Kong, China, holds strategic positions in the integration of Chinese cities into global financial center networks, and that establishing a foothold in global financial centers such as New York and London has been a priority for Chinese financial institutions. The increasing capital flows directed by Chinese financial institutionssuggests a shifting global financial geography, with numerous Chinese cities playing increasingly important roles within global financial center networks.
基金supported by the National Natural Science Foundation of China[grant number 41475078]Strategic Priority Research Program–Climate Change:Carbon Budget and Relevant Issues of the Chinese Academy of Sciences[grant number XDA05090105]
文摘There have long been arguments about the impact of urbanization on local meteorological observations. This letter reviews up-to-date studies of the urbanization-related warming in the observed land surface air temperature series in China. Many previous studies have suggested that, over the past few decades, the local warming due to urbanization could have been about 0.1 °C/10 yr, or even larger. However, based on recently developed homogenized temperature records, the estimated urban bias is smaller. Major uncertainties arise from either the data quality or the techniques used to estimate the urbanization effect. A key example is the ‘observationminus-reanalysis' method, which tends to overestimate the urban signal in this region, partly due to systematic bias in the multi-decadal variability of surface air temperature in the reanalysis data. It is expected that improved numerical modeling with high-resolution information regarding the changing land surface in the region will help to further understand and quantify the effect of urbanization in local temperature records.
基金Under the auspices of Scientific Research Foundation of Heilongjiang Provincial Education Department (No. 11511133)Key Teacher Foundation of Harbin Normal University (No. KG2007-06)
文摘Sustainable development is a complex and systemic issue. It is essential to study it by the component analysis method from the view of system science. The urban developmental sustainability is one of focuses that people has paid more attention to, however, little common understanding how to measure and evaluate the sustainability has been gotten. In this paper, a framework is designed to evaluate the developmental sustainability of Suihua City, Heilongiiang Province in China from the aspects of economy, society, population, resources and environment. We adopt the Principal Components Analysis (PCA) to decrease dimensions and simplify the original indexes into 12 indexes. Also, the hierarchy and comprehensive multiple-criterion evaluative methods are employed to assess the sustainable development system in Suihua City. Then, the weights of indexes are attained by Analytic Hierarchy Process (AHP) method. Furthermore, urban comprehensive development level, developmental sustainability, coordinate degree are calculated and analyzed. By analyzing, we know the fluctuation of development level of subsystem, especially resources and environment subsystem, is acute. The comprehensive development level of sustainable development system in Suihua has been on the rise since 1999. That results from the effect of traditional economic development mode with high energy-consumed being decreased in the city after 1999. At the same time, it is obvious that there was an instability of development level in Suihua City during 1990-2002, the status'trend was more harmonious in 1999-2002. with a turn in 1998, and the development could be sustainable,