Promoting the coupling coordination development of port and its hinterland city environments is an important way to improve urban economic competitiveness.Based on relevant data of 13 coastal port cities in eastern Ch...Promoting the coupling coordination development of port and its hinterland city environments is an important way to improve urban economic competitiveness.Based on relevant data of 13 coastal port cities in eastern China from 2000 to 2018,this study explores the coupling coordination development of port and city environments and its impact on urban economic competitiveness by constructing the coupling coordination degree model and the panel threshold model.The research results show that:(1)In terms of the coupling coordination development of port and city environments,most coastal ports and their hinterland cities are in a state of moderate or serious disorder.Overall,the degree of coupling coordination of port and city environments needs to be further improved;(2)The coupling coordination degree of port and city environments has a significant impact on urban economic competitiveness,and this effect gradually increases with the development of the ports and the urban economy.Among the variables that impact the urban economic competitiveness,fixed assets investment and foreign trade are significant factors that can enhance urban economic competitiveness.(3)At present,there is a“U-shaped”relationship between the coupling coordination degree of port-city environments and the urban economic competitiveness.This relationship lies on the right side of the inflection point of the“U-shaped”curve.Therefore,following the concept of assigning priority to ecological development,expanding fixed assets investment and actively developing foreign trade can further enhance the urban economic competitiveness.展开更多
Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region,but due to the hyper-arid climatic conditions,the cost of irrigation and plant maintenance is very high.Exist...Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region,but due to the hyper-arid climatic conditions,the cost of irrigation and plant maintenance is very high.Existing strategies to reduce the monetary and ecological costs involve the cultivation of native xerophytic plantations,and/or the use of soil improvers to increase water-and nutrient-holding capacity of the sandy soils.Various soil improvers based on mineral,organic,or synthetic materials have entered the United Arab Emirates(UAE)market in recent years,but there is considerable uncertainty about how they should best be used in combination with ornamental plant stands involving xerophytic native plants.The present study investigated the effect of soil amendment and deep pipe irrigation on perennial ornamental plant stands involving native plants(Tephrosia appolinea(Gel.)Link in combination with Aerva javanica(Burm.f.)Juss.ex Schult.)and native-exotic plants(T.appolinea in combination with Ruelia simplex C.Wright)either or not topsoil and subsoil amendment with bentonite and hydrophobic sand under the irrigation water supply of less than 50%of reference evapotranspiration(ET0).After one year of cultivation,T.appolinea and A.javanica(native vs.native)produced high biomass and exhibited high water use efficiency(WUE)as compared with T.appolinea and R.simplex(native vs.exotic)combination given that no significant differences were found under the soil amendment treatments.All stands thrived under irrigation water supply far below what is usually supplied to exotic ornamental stands in public parks of the Al Ain City,the UAE.However,subsoil amendment in combination with deep pipe irrigation reduced the occurrence of weeds and increased the overall plant rooting depth.Our results suggest that subsoil amendment and irrigation up to 60-80 cm depth can potentially control ephemeral weed infestation,which is a great challenge in various plant production systems of the Gulf Region.The results of the present study suggest that the impact of soil amendment on the WUE of exotic plants is marginal and might not be economically justified.Replacing exotic with native ornamental plant species seems to have a far greater water-saving potential than the amendment of the soil,while weeds can be suppressed in the absence of topsoil moisture.展开更多
Within the global urban system, the statistical relationship between urban eco-environment(UE) and urban competitiveness(UC)(RUEC) is researched. Data showed that there is a statistically inverted-U relationship betwe...Within the global urban system, the statistical relationship between urban eco-environment(UE) and urban competitiveness(UC)(RUEC) is researched. Data showed that there is a statistically inverted-U relationship between UE and UC. Eco-environmental factor is put into the classification of industries, and gets six industrial types by two indexes viz. industries' eco-environmental demand and pressure. The statistical results showed that there is a strong relationship, for new industrial classification, between the changes of industrial structure and evolvement of UE. The drive mechanism of the evolvement of urban eco-environment, with human demand and global work division was analyzed. The conclusion is that the development stratege, industrial policies of cities, and environmental policies fo cities must be fit with their ranks among the global urban system. At the era of globalization, so far as the environmental policies, their rationality could not be assessed with the level of strictness, but it can enhance cities' competitiveness when they are fit with cities' capabilities to attract and control some sections of the industry's value-chain. None but these kinds of environmental policies can probably enhance the UC.展开更多
Common prosperity,an important goal of human development,increasingly has to be achieved through the common prosperity of cities.The research into and discovery of the determinants which create differences in urban ec...Common prosperity,an important goal of human development,increasingly has to be achieved through the common prosperity of cities.The research into and discovery of the determinants which create differences in urban economic competitiveness is of great signi ficance as,thereby,the research and expected discovery can help with the formulation of relevant policies for development,competition,and cooperation to promote win-win conditions among cities.However,such research is still rare.Based on the economic competitiveness data of 1,007 cities,this paper uses OLS regression and Shapley-value based decompositions regression to analyze factors affecting the economic competitiveness of global cities and differences that the cities made.Combined with quantile regression,studying the law of changing of each factor's effect on cities with different levels of economic competitiveness is of theoretical and practical signi ficance.The study findings are as follows.(1)The variability of global urban economic competitiveness is quite large.Cities in North America and Europe are still the benchmarks of global urban economic prosperity.(2)Financial services,technological innovation,industrial system,business environment,institutional environment,infrastructure,among other factors,have signi ficant impacts on the economic competitiveness of cities.(3)The primary factor that in fluenced the variability in economic competitiveness is technological innovation.(4)The ranking of the main in fluencing factors varied slightly between cities at different levels of economic competitiveness.These indicate that the international community should promote innovation in and diffusion of science and technology to achieve common prosperity by narrowing the gap between cities.The relevant decision-making departments,e.g.urban planning departments with strong economic and finance expertise of the cities in different development zones should adopt different measures in accordance with their actual situations.展开更多
Heavy metals can be introduced into urban soils at the same time. Therefore, their selective retention and competitive adsorption by the soils become of major importance in determining their availability and movement ...Heavy metals can be introduced into urban soils at the same time. Therefore, their selective retention and competitive adsorption by the soils become of major importance in determining their availability and movement throughout the soil. In this study, the availability and mobility of six heavy metals in eight urban soils collected from different cities of Zhejiang Province, southeastern China were assessed using distribution coefficients(Kd) and retardation factor(Rf). The results showed that there were great differences in the Kd and Rfamong the tested soils. The adsorption sequences were Cr〉Pb〉Cu〉Cd〉Zn〉Ni, and the Kd decreased with increasing levels of metal addition. Ni generally has the lowest Rf values followed closely by Cd, and Zn whereas Cr and Pb reached the highest values. The results suggest that Ni and Zn have the highest mobility associated to the lowest adsorption, Cr and Pb present the opposite behavior. Correlation analysis indicates that soil pH, CaCO3 content, and cation exchange capacity (CEC) are key factors controlling the solubility and mobility of the metals in the urban soils.展开更多
The tourism competitiveness of the cities around the Beibu Gulf was studied using the entropy method from the perspective of the 14 indexes of tourism current competitiveness,tourism support competitiveness and touris...The tourism competitiveness of the cities around the Beibu Gulf was studied using the entropy method from the perspective of the 14 indexes of tourism current competitiveness,tourism support competitiveness and tourism potential competitiveness.The results show that the cities of Sanya,Nanning and Haikou have the stronger competitiveness;the cities of Zhanjiang,Beihai,Chongzuo and Maoming have moderate competitiveness;and the cities of Yulin,Qinzhou,Yangjiang and Fangchenggang have the weak competitiveness.According to the analysis of the index weight and comprehensive ranking,almost each aspect contributes to the city competitiveness.The index weights of the tourism current competitiveness,tourism support competitiveness and tourism potential competitiveness are 0.27222,0.3938 and 0.33398,respectively.Based on the niche theory,the article put forward the strategies:dislocation development,balanced development and regional tourism competition and cooperation development.展开更多
The inter-urban competition seems to be of paramount importance for city-development today. The extensive reliance of competitiveness-oriented urban governance agendas on the knowledge-based, "new" economy, introduc...The inter-urban competition seems to be of paramount importance for city-development today. The extensive reliance of competitiveness-oriented urban governance agendas on the knowledge-based, "new" economy, introduced the notion of "creativity" into discussion on the future of urban development. Though still on the margins of serious urban theory, the discourse on "creative cities" that emerged in the early 2000s, has already had massive influence on the ways in which cities are managed and transformed in Europe. After examination of how the competitiveness-oriented strategies based on creativity and related to the qualities of place increase cultural and social sustainability of urban transformation and development, this paper briefly rethinks the current urban development policy of the city of Sarajevo in relation to the notion of "place", by leaning on the contemporary European urban development paradigm. The conclusion points out that the sustainable increase of urban competitiveness in Sarajevo should be pursued by the development projects of urban transformation promoting creative knowledge sector, based on the inclusive cultural urban narratives related to places, thus assuring simultaneous growth of creative knowledge industries and preservation of diverse social geography.展开更多
This paper discusses aspects related to competitiveness in the ITB (invitation to bid) of the public tender for the concession of the urban bus public transport services in the RMR (Metropolitan Region of Recife) ...This paper discusses aspects related to competitiveness in the ITB (invitation to bid) of the public tender for the concession of the urban bus public transport services in the RMR (Metropolitan Region of Recife) in the Brazilian northeastern region. The bid was made public through a consortium formed by the two major cities of the RMR--Recife and Olinda, and the government of the State of Pernambuco. Throughout the paper, the basic features of the bidding terms are presented and some aspects of these characteristics that undermine competitiveness are pointed out and submitted to criticisms. Aspects such as the small number of lots, the lack of diversification of lot sizes and the possibility of forming consortia with unlimited number of participants were targeted. In order to prove the criticisms stated, a simulation of an arrangement amongst incumbents is presented, based on the rules of the tender, in which the allocation of incumbents ex post bidding does not differ from the ex ante scenario. Thus, the main objective of this article is to assess whether good practices that foster competition were followed by the ITB and the main conclusion is that competitiveness was put in jeopardy.展开更多
The article establishes the appraisal index system for entire urban agglomeration and its interior cities individually,concretely including five aspects:driving forces for tourism development,the level of tourism deve...The article establishes the appraisal index system for entire urban agglomeration and its interior cities individually,concretely including five aspects:driving forces for tourism development,the level of tourism development,tourism impacts,tourism economic connection and tourism contributions of different cities to the whole urban agglomeration.As tourism competitiveness has the characteristics of comprehensiveness,systematicness and dynamicness,the article attempts to apply the structural prediction means of system dynamics to evaluating tourism competitiveness,aiming to provide some research methods and analysis ideas for tourism competitiveness measurement and trends analysis in urban agglomeration.Taking Shandong Peninsula urban agglomeration as the study area,the article simulates and analyzes the tourism competitiveness trend of the whole region and its interior cities from 2005 to 2020,and the result reflects that integrated development and regional combination of tourism are important means to upgrade tourism competitiveness in this region.展开更多
Based on the current situation of urbanization development in West China, this paper analyses main factors responsible for sluggish urbanization in West China as follows: impact of environment factor, impact of popula...Based on the current situation of urbanization development in West China, this paper analyses main factors responsible for sluggish urbanization in West China as follows: impact of environment factor, impact of population quality and quantity, lagging of public product service, stagnancy of technological development, backwardness of slow growth, and rigidity of system building. And then this paper analyses the restriction mechanism of urbanization in West China: at the superficial level, the constraints of urbanization in West China arise from the shortage of capital; at the profound level, the backward culture contributes to the constraints of urbanization in West China. The thread of resolving restriction mechanism of urbanization in West China is put forward from system, economy and culture. On the basis of this thread, we construct the power system for the development of urbanization in West China. The power system for urbanization in West China should be propelled by "four forces", namely, pull of external forces, cohesive strength of regional market environment, expansion power inside countryside, traction of industrial structure adjustment. Innovation is the engine of impetus for urbanization in West China; spatial clustering and modernization of industry is the major driving force for urbanization; the government behaviour, driving of foreign investment, great projects and other forces are supplementary power. Via the main power, we should take the market as medium to achieve the role of power in promoting urbanization.展开更多
The urban competitive advantages rely on the combination and interaction of influential factors. As a dynamic progressive process, the city at different time has different competition influential factors combination. ...The urban competitive advantages rely on the combination and interaction of influential factors. As a dynamic progressive process, the city at different time has different competition influential factors combination. Because of this, the urban competitive advantages take on time-series characteristics. Stages of urban competition can be summed up into three ones, the basic factor-driven, the investment-driven and the innovation-driven. The finding of the study on the stages of urban competitive advantages in Suzhou is that in the current stage of Suzhou its competitive advantage is the investment-driven. The investment, especially FDI, plays remarkable functions for Suzhou competition with other cities.展开更多
Urban competition refers to capacities of cities for attracting, capturing, controlling, dominating and transforming certain resources during urban development, and capacities for wealth creating, life-standard improv...Urban competition refers to capacities of cities for attracting, capturing, controlling, dominating and transforming certain resources during urban development, and capacities for wealth creating, life-standard improving and sustainable development maintenance. This paper first analyzes the external sources of urban competitive advantages: the global network-based advantages and the location-based ones. Then with the aid of method of principal component analysis in SPSS 10.0 for Windows, the Chinese urban global and local competitive advantages are explored. The finding is that the global network-and location-based advantages are remarkable for the cities in the eastern China. While for those in the western and the middle regions, affected by much lower regional competitive advantages and lower degrees of urban-regional integration, the urban competitive advantages are deeply influenced and weakened.展开更多
Based on the theoretical system of urban competitiveness,the evaluation model of urban competitiveness from the perspective of competition and cooperation was established.According to the significance index and explan...Based on the theoretical system of urban competitiveness,the evaluation model of urban competitiveness from the perspective of competition and cooperation was established.According to the significance index and explanatory index,the urban competitiveness was divided into urban comprehensive competitiveness(UC),urban internal node competitiveness(NC)and external competitiveness of urban network(EC).The scores and rankings of UC,NC and EC in 2006,2010 and 2015 were obtained by conducting the comprehensive evaluation of the urban competitiveness of Dongguan City with integrated usage of the principal component analysis and Technique for Order Preference by Similarity to an Ideal Solution and the data of other 20 cities in Guangdong province,Hong Kong and Macao.The research showed that the competitiveness of Dongguan City has been greatly improved during the decade of 2006–2015,and the regional cities in Guangdong Province had significant differences,which are reflected in the two dimensions of urban internal node competitiveness(NC)and external competitiveness of urban network(EC).Based on this,this study further analyzed Dongguan’s urban competitiveness from two dimensions of NC and EC,and took Dongguan Songshan Lake High-tech Zone as an example to study how to promote Dongguan’s urban competitiveness from the industrial level.展开更多
With the national economy’s transition from a planning one to a market one, the factors affecting regional economic pattern has changed greatly. In this paper we first construct an index system for evaluating competi...With the national economy’s transition from a planning one to a market one, the factors affecting regional economic pattern has changed greatly. In this paper we first construct an index system for evaluating competitiveness of Chinese cities based on modern competitive advantage theory. With principal component analysis and cluster analysis methods, we compare the factors affecling cities’ integrated competitiveness in 1990 and 1997. We find that four major factors are capital (including investment, FDI and urban financial revenue ), urban ithestructure (transporiation and communication, urbanization level, education etc. ), industrial performance and structure, degree of market openness and that these factors have become more advanced and complicated since 1990. Most Chinese cities are transforming from productive factors-oriented type to investment-oriented type and a few are becoming innovation oriented. The integrated competitiveness is closely related to cities’ scale, urban function, regional policy and degree of market openness and displays an uneven spatial pattern. The difference between the south and the north and the difference between the west and the east co-exist bul the former has been more larger. Finally, we discuss the mechanism behind the pattern and attribute the unevenness to change of factors dominating the cities’ compehtiveness regional innovation capacity and geographical differenceof traditional culture.展开更多
Urban competitiveness is always the focus of researches on urban economy. The variety of definitions and evaluation systems of urban competitiveness are the results of lack of accurate and comprehensive understanding ...Urban competitiveness is always the focus of researches on urban economy. The variety of definitions and evaluation systems of urban competitiveness are the results of lack of accurate and comprehensive understanding on urban competitiveness. This paper reviews five groups of definitions on urban competitiveness and establishes a conceptual model for urban competitiveness.展开更多
Urban competitiveness has been the hot topic for researches and studies over years. The aim of this paper is to elaborate urban competitiveness. First, definition of competitiveness is discussed in detail and then the...Urban competitiveness has been the hot topic for researches and studies over years. The aim of this paper is to elaborate urban competitiveness. First, definition of competitiveness is discussed in detail and then the differences of competitiveness of nations and enterprises are presented. In Section 2, urban competitiveness is defined. Since the assessment of urban competitiveness is the focus of many studies, Section 3 elaborates four models or frameworks for assessing urbancompetitiveness. Last, but by no means the least, Chengdu has been discussed as a case on how to improve urban competitiveness. Three suggestions are put forward, which are clustering strategy, more efficient governance and urban marketing campaigns respectively.展开更多
Background:Invasive species affect community dynamics and ecosystem functions,but the mechanisms of their impacts are poorly understood.Hypotheses on invasion impact range from Superior Competitor to Novel Function,fr...Background:Invasive species affect community dynamics and ecosystem functions,but the mechanisms of their impacts are poorly understood.Hypotheses on invasion impact range from Superior Competitor to Novel Function,from Enemy Escape to Microbial Mediation.In this study,we examined the effects of an urban tree invader,Acer platanoides(Norway maple,NM),on a mesic deciduous forest in contrast to its native congener Acer rubrum(red maple,RM)with a split-plot design experiment.A total of 720 maple seedlings were transplanted to 72 plots under 24 trees of three canopy types.The three experimental treatments were removal of resource competition at above-and belowground and removal of leaf-litter effect.Soil moisture and nitrogen-related microbial activities were followed for each plot.Results:We found that partial canopy removal increased canopy openness and light transmission to the forest floor,but to a greater extent under NM than under RM trees.NM seedlings were more shade tolerant than RM seedlings in height growth.During the reciprocal transplantation in the mixed forest,biomass accumulation of NM seedlings under RM trees were twice as much as under NM,while that of RM seedlings under NM trees was 23.5%less than under RM.Soil net nitrification and relative nitrification were significantly higher,but mineralization rate was much lower under NM than under RM trees,which would lead to faster N leaching and lower N availability in the soil.Plots with litter removal had significantly higher seedling mortality due to herbivory by the end of 2 years,especially for NM seedlings under NM trees.Trenching enhanced soil water availability but there was no difference among canopy types.Conclusions:Our results demonstrated that invasion of NM not only altered forest canopy structure but also changed herbivory rate for seedlings and N dynamics in the soils.NM seedlings were more shade tolerant under NM canopies than RM seedlings and were more protected by NM litter under NM canopies than under RM canopies.These altered biotic and abiotic environments will likely facilitate further invasion of NM in the forests,hence positive feedbacks,and make it an increasingly serious tree invader in North America.展开更多
基金This research is supported by Hunan Provincial Natural Science Foundation of China(Grant No.2021JJ30304)the General Topics of Hunan Social Science Achievement Evaluation Committee of China(Grant No.XSP22YBC366)the Key Scientific Research Project of Hunan Provincial Department of Education of China(Grant No.21B0592).
文摘Promoting the coupling coordination development of port and its hinterland city environments is an important way to improve urban economic competitiveness.Based on relevant data of 13 coastal port cities in eastern China from 2000 to 2018,this study explores the coupling coordination development of port and city environments and its impact on urban economic competitiveness by constructing the coupling coordination degree model and the panel threshold model.The research results show that:(1)In terms of the coupling coordination development of port and city environments,most coastal ports and their hinterland cities are in a state of moderate or serious disorder.Overall,the degree of coupling coordination of port and city environments needs to be further improved;(2)The coupling coordination degree of port and city environments has a significant impact on urban economic competitiveness,and this effect gradually increases with the development of the ports and the urban economy.Among the variables that impact the urban economic competitiveness,fixed assets investment and foreign trade are significant factors that can enhance urban economic competitiveness.(3)At present,there is a“U-shaped”relationship between the coupling coordination degree of port-city environments and the urban economic competitiveness.This relationship lies on the right side of the inflection point of the“U-shaped”curve.Therefore,following the concept of assigning priority to ecological development,expanding fixed assets investment and actively developing foreign trade can further enhance the urban economic competitiveness.
基金partly funded by the Al Ain MunicipalityNational Water and Energy Center, United Arab Emirates University。
文摘Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region,but due to the hyper-arid climatic conditions,the cost of irrigation and plant maintenance is very high.Existing strategies to reduce the monetary and ecological costs involve the cultivation of native xerophytic plantations,and/or the use of soil improvers to increase water-and nutrient-holding capacity of the sandy soils.Various soil improvers based on mineral,organic,or synthetic materials have entered the United Arab Emirates(UAE)market in recent years,but there is considerable uncertainty about how they should best be used in combination with ornamental plant stands involving xerophytic native plants.The present study investigated the effect of soil amendment and deep pipe irrigation on perennial ornamental plant stands involving native plants(Tephrosia appolinea(Gel.)Link in combination with Aerva javanica(Burm.f.)Juss.ex Schult.)and native-exotic plants(T.appolinea in combination with Ruelia simplex C.Wright)either or not topsoil and subsoil amendment with bentonite and hydrophobic sand under the irrigation water supply of less than 50%of reference evapotranspiration(ET0).After one year of cultivation,T.appolinea and A.javanica(native vs.native)produced high biomass and exhibited high water use efficiency(WUE)as compared with T.appolinea and R.simplex(native vs.exotic)combination given that no significant differences were found under the soil amendment treatments.All stands thrived under irrigation water supply far below what is usually supplied to exotic ornamental stands in public parks of the Al Ain City,the UAE.However,subsoil amendment in combination with deep pipe irrigation reduced the occurrence of weeds and increased the overall plant rooting depth.Our results suggest that subsoil amendment and irrigation up to 60-80 cm depth can potentially control ephemeral weed infestation,which is a great challenge in various plant production systems of the Gulf Region.The results of the present study suggest that the impact of soil amendment on the WUE of exotic plants is marginal and might not be economically justified.Replacing exotic with native ornamental plant species seems to have a far greater water-saving potential than the amendment of the soil,while weeds can be suppressed in the absence of topsoil moisture.
文摘Within the global urban system, the statistical relationship between urban eco-environment(UE) and urban competitiveness(UC)(RUEC) is researched. Data showed that there is a statistically inverted-U relationship between UE and UC. Eco-environmental factor is put into the classification of industries, and gets six industrial types by two indexes viz. industries' eco-environmental demand and pressure. The statistical results showed that there is a strong relationship, for new industrial classification, between the changes of industrial structure and evolvement of UE. The drive mechanism of the evolvement of urban eco-environment, with human demand and global work division was analyzed. The conclusion is that the development stratege, industrial policies of cities, and environmental policies fo cities must be fit with their ranks among the global urban system. At the era of globalization, so far as the environmental policies, their rationality could not be assessed with the level of strictness, but it can enhance cities' competitiveness when they are fit with cities' capabilities to attract and control some sections of the industry's value-chain. None but these kinds of environmental policies can probably enhance the UC.
文摘Common prosperity,an important goal of human development,increasingly has to be achieved through the common prosperity of cities.The research into and discovery of the determinants which create differences in urban economic competitiveness is of great signi ficance as,thereby,the research and expected discovery can help with the formulation of relevant policies for development,competition,and cooperation to promote win-win conditions among cities.However,such research is still rare.Based on the economic competitiveness data of 1,007 cities,this paper uses OLS regression and Shapley-value based decompositions regression to analyze factors affecting the economic competitiveness of global cities and differences that the cities made.Combined with quantile regression,studying the law of changing of each factor's effect on cities with different levels of economic competitiveness is of theoretical and practical signi ficance.The study findings are as follows.(1)The variability of global urban economic competitiveness is quite large.Cities in North America and Europe are still the benchmarks of global urban economic prosperity.(2)Financial services,technological innovation,industrial system,business environment,institutional environment,infrastructure,among other factors,have signi ficant impacts on the economic competitiveness of cities.(3)The primary factor that in fluenced the variability in economic competitiveness is technological innovation.(4)The ranking of the main in fluencing factors varied slightly between cities at different levels of economic competitiveness.These indicate that the international community should promote innovation in and diffusion of science and technology to achieve common prosperity by narrowing the gap between cities.The relevant decision-making departments,e.g.urban planning departments with strong economic and finance expertise of the cities in different development zones should adopt different measures in accordance with their actual situations.
文摘Heavy metals can be introduced into urban soils at the same time. Therefore, their selective retention and competitive adsorption by the soils become of major importance in determining their availability and movement throughout the soil. In this study, the availability and mobility of six heavy metals in eight urban soils collected from different cities of Zhejiang Province, southeastern China were assessed using distribution coefficients(Kd) and retardation factor(Rf). The results showed that there were great differences in the Kd and Rfamong the tested soils. The adsorption sequences were Cr〉Pb〉Cu〉Cd〉Zn〉Ni, and the Kd decreased with increasing levels of metal addition. Ni generally has the lowest Rf values followed closely by Cd, and Zn whereas Cr and Pb reached the highest values. The results suggest that Ni and Zn have the highest mobility associated to the lowest adsorption, Cr and Pb present the opposite behavior. Correlation analysis indicates that soil pH, CaCO3 content, and cation exchange capacity (CEC) are key factors controlling the solubility and mobility of the metals in the urban soils.
基金Supported by National Natural Science Foundation of China(41571116)National Spark Plan Project(2013GA780092)Science and Technology Planning Project of Guangdong Province(2014A070713037)
文摘The tourism competitiveness of the cities around the Beibu Gulf was studied using the entropy method from the perspective of the 14 indexes of tourism current competitiveness,tourism support competitiveness and tourism potential competitiveness.The results show that the cities of Sanya,Nanning and Haikou have the stronger competitiveness;the cities of Zhanjiang,Beihai,Chongzuo and Maoming have moderate competitiveness;and the cities of Yulin,Qinzhou,Yangjiang and Fangchenggang have the weak competitiveness.According to the analysis of the index weight and comprehensive ranking,almost each aspect contributes to the city competitiveness.The index weights of the tourism current competitiveness,tourism support competitiveness and tourism potential competitiveness are 0.27222,0.3938 and 0.33398,respectively.Based on the niche theory,the article put forward the strategies:dislocation development,balanced development and regional tourism competition and cooperation development.
文摘The inter-urban competition seems to be of paramount importance for city-development today. The extensive reliance of competitiveness-oriented urban governance agendas on the knowledge-based, "new" economy, introduced the notion of "creativity" into discussion on the future of urban development. Though still on the margins of serious urban theory, the discourse on "creative cities" that emerged in the early 2000s, has already had massive influence on the ways in which cities are managed and transformed in Europe. After examination of how the competitiveness-oriented strategies based on creativity and related to the qualities of place increase cultural and social sustainability of urban transformation and development, this paper briefly rethinks the current urban development policy of the city of Sarajevo in relation to the notion of "place", by leaning on the contemporary European urban development paradigm. The conclusion points out that the sustainable increase of urban competitiveness in Sarajevo should be pursued by the development projects of urban transformation promoting creative knowledge sector, based on the inclusive cultural urban narratives related to places, thus assuring simultaneous growth of creative knowledge industries and preservation of diverse social geography.
文摘This paper discusses aspects related to competitiveness in the ITB (invitation to bid) of the public tender for the concession of the urban bus public transport services in the RMR (Metropolitan Region of Recife) in the Brazilian northeastern region. The bid was made public through a consortium formed by the two major cities of the RMR--Recife and Olinda, and the government of the State of Pernambuco. Throughout the paper, the basic features of the bidding terms are presented and some aspects of these characteristics that undermine competitiveness are pointed out and submitted to criticisms. Aspects such as the small number of lots, the lack of diversification of lot sizes and the possibility of forming consortia with unlimited number of participants were targeted. In order to prove the criticisms stated, a simulation of an arrangement amongst incumbents is presented, based on the rules of the tender, in which the allocation of incumbents ex post bidding does not differ from the ex ante scenario. Thus, the main objective of this article is to assess whether good practices that foster competition were followed by the ITB and the main conclusion is that competitiveness was put in jeopardy.
基金Project supported by the Social Science Foundation of Shandong Province,China (Grand no.04BJZ44)the Science and Technology project of Shandong Province,China (Grand no.2004GG3206003)
文摘The article establishes the appraisal index system for entire urban agglomeration and its interior cities individually,concretely including five aspects:driving forces for tourism development,the level of tourism development,tourism impacts,tourism economic connection and tourism contributions of different cities to the whole urban agglomeration.As tourism competitiveness has the characteristics of comprehensiveness,systematicness and dynamicness,the article attempts to apply the structural prediction means of system dynamics to evaluating tourism competitiveness,aiming to provide some research methods and analysis ideas for tourism competitiveness measurement and trends analysis in urban agglomeration.Taking Shandong Peninsula urban agglomeration as the study area,the article simulates and analyzes the tourism competitiveness trend of the whole region and its interior cities from 2005 to 2020,and the result reflects that integrated development and regional combination of tourism are important means to upgrade tourism competitiveness in this region.
基金Supported by the National Natural Science Foundation (51178372)
文摘Based on the current situation of urbanization development in West China, this paper analyses main factors responsible for sluggish urbanization in West China as follows: impact of environment factor, impact of population quality and quantity, lagging of public product service, stagnancy of technological development, backwardness of slow growth, and rigidity of system building. And then this paper analyses the restriction mechanism of urbanization in West China: at the superficial level, the constraints of urbanization in West China arise from the shortage of capital; at the profound level, the backward culture contributes to the constraints of urbanization in West China. The thread of resolving restriction mechanism of urbanization in West China is put forward from system, economy and culture. On the basis of this thread, we construct the power system for the development of urbanization in West China. The power system for urbanization in West China should be propelled by "four forces", namely, pull of external forces, cohesive strength of regional market environment, expansion power inside countryside, traction of industrial structure adjustment. Innovation is the engine of impetus for urbanization in West China; spatial clustering and modernization of industry is the major driving force for urbanization; the government behaviour, driving of foreign investment, great projects and other forces are supplementary power. Via the main power, we should take the market as medium to achieve the role of power in promoting urbanization.
基金Under the auspices of Chinese Postdoctoral Science Foundation (No. 2003034038)
文摘The urban competitive advantages rely on the combination and interaction of influential factors. As a dynamic progressive process, the city at different time has different competition influential factors combination. Because of this, the urban competitive advantages take on time-series characteristics. Stages of urban competition can be summed up into three ones, the basic factor-driven, the investment-driven and the innovation-driven. The finding of the study on the stages of urban competitive advantages in Suzhou is that in the current stage of Suzhou its competitive advantage is the investment-driven. The investment, especially FDI, plays remarkable functions for Suzhou competition with other cities.
基金Under the auspices of Chinese Postdoctora Slcience Foundations(No .2003034038)
文摘Urban competition refers to capacities of cities for attracting, capturing, controlling, dominating and transforming certain resources during urban development, and capacities for wealth creating, life-standard improving and sustainable development maintenance. This paper first analyzes the external sources of urban competitive advantages: the global network-based advantages and the location-based ones. Then with the aid of method of principal component analysis in SPSS 10.0 for Windows, the Chinese urban global and local competitive advantages are explored. The finding is that the global network-and location-based advantages are remarkable for the cities in the eastern China. While for those in the western and the middle regions, affected by much lower regional competitive advantages and lower degrees of urban-regional integration, the urban competitive advantages are deeply influenced and weakened.
基金Funded Project of Advanced Innovation Center for Future Urban Design of Beijing University of Civil Engineering and Architecture(udc2018010921).
文摘Based on the theoretical system of urban competitiveness,the evaluation model of urban competitiveness from the perspective of competition and cooperation was established.According to the significance index and explanatory index,the urban competitiveness was divided into urban comprehensive competitiveness(UC),urban internal node competitiveness(NC)and external competitiveness of urban network(EC).The scores and rankings of UC,NC and EC in 2006,2010 and 2015 were obtained by conducting the comprehensive evaluation of the urban competitiveness of Dongguan City with integrated usage of the principal component analysis and Technique for Order Preference by Similarity to an Ideal Solution and the data of other 20 cities in Guangdong province,Hong Kong and Macao.The research showed that the competitiveness of Dongguan City has been greatly improved during the decade of 2006–2015,and the regional cities in Guangdong Province had significant differences,which are reflected in the two dimensions of urban internal node competitiveness(NC)and external competitiveness of urban network(EC).Based on this,this study further analyzed Dongguan’s urban competitiveness from two dimensions of NC and EC,and took Dongguan Songshan Lake High-tech Zone as an example to study how to promote Dongguan’s urban competitiveness from the industrial level.
文摘With the national economy’s transition from a planning one to a market one, the factors affecting regional economic pattern has changed greatly. In this paper we first construct an index system for evaluating competitiveness of Chinese cities based on modern competitive advantage theory. With principal component analysis and cluster analysis methods, we compare the factors affecling cities’ integrated competitiveness in 1990 and 1997. We find that four major factors are capital (including investment, FDI and urban financial revenue ), urban ithestructure (transporiation and communication, urbanization level, education etc. ), industrial performance and structure, degree of market openness and that these factors have become more advanced and complicated since 1990. Most Chinese cities are transforming from productive factors-oriented type to investment-oriented type and a few are becoming innovation oriented. The integrated competitiveness is closely related to cities’ scale, urban function, regional policy and degree of market openness and displays an uneven spatial pattern. The difference between the south and the north and the difference between the west and the east co-exist bul the former has been more larger. Finally, we discuss the mechanism behind the pattern and attribute the unevenness to change of factors dominating the cities’ compehtiveness regional innovation capacity and geographical differenceof traditional culture.
文摘Urban competitiveness is always the focus of researches on urban economy. The variety of definitions and evaluation systems of urban competitiveness are the results of lack of accurate and comprehensive understanding on urban competitiveness. This paper reviews five groups of definitions on urban competitiveness and establishes a conceptual model for urban competitiveness.
文摘Urban competitiveness has been the hot topic for researches and studies over years. The aim of this paper is to elaborate urban competitiveness. First, definition of competitiveness is discussed in detail and then the differences of competitiveness of nations and enterprises are presented. In Section 2, urban competitiveness is defined. Since the assessment of urban competitiveness is the focus of many studies, Section 3 elaborates four models or frameworks for assessing urbancompetitiveness. Last, but by no means the least, Chengdu has been discussed as a case on how to improve urban competitiveness. Three suggestions are put forward, which are clustering strategy, more efficient governance and urban marketing campaigns respectively.
基金WF received funding for the field study from Sigma Xi,Association of Women in Sciences and International Society of ArboricultureWF is currently supported by NSF 18-600 Program(ID:1921773)National Natural Science Foundation of China Major International Joint Research Project(ID:81620108010).
文摘Background:Invasive species affect community dynamics and ecosystem functions,but the mechanisms of their impacts are poorly understood.Hypotheses on invasion impact range from Superior Competitor to Novel Function,from Enemy Escape to Microbial Mediation.In this study,we examined the effects of an urban tree invader,Acer platanoides(Norway maple,NM),on a mesic deciduous forest in contrast to its native congener Acer rubrum(red maple,RM)with a split-plot design experiment.A total of 720 maple seedlings were transplanted to 72 plots under 24 trees of three canopy types.The three experimental treatments were removal of resource competition at above-and belowground and removal of leaf-litter effect.Soil moisture and nitrogen-related microbial activities were followed for each plot.Results:We found that partial canopy removal increased canopy openness and light transmission to the forest floor,but to a greater extent under NM than under RM trees.NM seedlings were more shade tolerant than RM seedlings in height growth.During the reciprocal transplantation in the mixed forest,biomass accumulation of NM seedlings under RM trees were twice as much as under NM,while that of RM seedlings under NM trees was 23.5%less than under RM.Soil net nitrification and relative nitrification were significantly higher,but mineralization rate was much lower under NM than under RM trees,which would lead to faster N leaching and lower N availability in the soil.Plots with litter removal had significantly higher seedling mortality due to herbivory by the end of 2 years,especially for NM seedlings under NM trees.Trenching enhanced soil water availability but there was no difference among canopy types.Conclusions:Our results demonstrated that invasion of NM not only altered forest canopy structure but also changed herbivory rate for seedlings and N dynamics in the soils.NM seedlings were more shade tolerant under NM canopies than RM seedlings and were more protected by NM litter under NM canopies than under RM canopies.These altered biotic and abiotic environments will likely facilitate further invasion of NM in the forests,hence positive feedbacks,and make it an increasingly serious tree invader in North America.