Nowadays city of Alexandria has a very wide range of urban development projects;some of them have a major influence on the physical being of the city meanwhile others just have a small interpretation to its characteri...Nowadays city of Alexandria has a very wide range of urban development projects;some of them have a major influence on the physical being of the city meanwhile others just have a small interpretation to its characteristics.The rapid growth of Alexandria city in the nineteenth century led to calls for parks to be provided for the health of all categories in the society.This could be seen as an early precedent to highlight the role of open spaces in supporting what we now call sustainable development.This paper proposes an urban development project which makes a replacement of an urban crawl in Alexandria city into unique open space through presenting a comprehensive approach for assessing this suggested project to create a walkability area based on a combination of its conceptual and applicable aspects.Discussion of the sustainability modules to this new urban development project in Alexandria will be accomplished,by the aim of investigating its ability to stand against the future challenges.It is concluded that a significant attribute of urban design achieves continuity of the urban fabric and streets,because this facilitates flows.Wherever movements occur,there is vitality and flow creates eyes on the street producing spontaneous surveillance.Also,comparison of contextual and neighbourhood before and after the project revealed the positive impact of the suggested project either on the built(physical)environment’s or health and social well-being.展开更多
Based on the origin and development of landscape urbanism,with several representative cases,this paper introduces the origin of ecological urbanism,as well as the main concepts and strategies,and then compared the cha...Based on the origin and development of landscape urbanism,with several representative cases,this paper introduces the origin of ecological urbanism,as well as the main concepts and strategies,and then compared the changes from Landscape Urbanism to Ecological Urbanism.At last,this paper discusses its enlightenment on China’s urban construction and landscape development with the focus on the actual situation in China.展开更多
Growing from water, Can Tho is a region on delta area of Southern Vietnam carved up by the currents of Mekong’s tributary, where settlements and water are closely interact. Being an important city, Can Tho puts in hi...Growing from water, Can Tho is a region on delta area of Southern Vietnam carved up by the currents of Mekong’s tributary, where settlements and water are closely interact. Being an important city, Can Tho puts in high expectations for investment calls that activate the growth of the city towards a new direction of urbanism. This trend seems to neglect its nature way of coping with water. In this connection, the intention of the research is to understand the urbanism in delta area of Can Tho, its confidences and fears the region has to experience and deal with. The intensive field work reveals an evaluation towards Can Tho’s spatial quality and major water problems. As a closing, the last section has share thoughts that different strategies of urban design to retrieve back the wisdom of living with water which are required for future urbanity of Can Tho region.展开更多
In current times urban developments can no longer be seen as straightforward building of the required number of houses, industries and parking spaces. Instead, the problems in many cities are of different nature: urba...In current times urban developments can no longer be seen as straightforward building of the required number of houses, industries and parking spaces. Instead, the problems in many cities are of different nature: urban conurbations may shrink, or climate impacts cause a serious disaster. These problems all have a different pace of development. The fast development must be combined with slower development pace fitting with shrinking cities and the sudden change climatic impacts requires. Therefore, in this article three types of urbanisms are proposed, which each care for an increase of resilience in the city. Fast urbanism accommodates the growth of the city in a calculated way in periods of economic prosperity;slow urbanism designs spaces for slowly developing uses such as ecology or food in times of shrinkage;and suddenism anticipates future climate impacts through designing spaces for temporary use.展开更多
High concentration of population and other elements brought by high urbanization has pushed the future construction of urban public spaces to be both "compact" and "ecological". Theory and methodol...High concentration of population and other elements brought by high urbanization has pushed the future construction of urban public spaces to be both "compact" and "ecological". Theory and methodology of landscape urbanism provides a new perspective for the construction of public spaces in high-density urban environment. Based on the concept and basic standpoints of landscape urbanism, this paper elaborated its potential value in spatial connection, functional integration and vitality promotion, and also analyzed practical strategies of landscape urbanism from three perspectives of structure, fold and stage by combining with typical cases, so as to provide references for designing urban public spaces in high-density environment.展开更多
Landscape urbanism has attracted the attention from scholars of human settlement science, and landscape designers have also grown in the development process of landscape urbanism and their identification has been brok...Landscape urbanism has attracted the attention from scholars of human settlement science, and landscape designers have also grown in the development process of landscape urbanism and their identification has been broken through. Moreover, they are faced with new challenges in the age of big data and computer. The paper explored role definition of landscape designer in landscape urbanism and analyzed the trend of landscape urbanism, providing theoretical reference to forecast career development of landscape designer.展开更多
This article reviews the background,preparation,development and birth stage,and the main content and framework of the new urbanism theory,then understands new urbanism from a historical perspective and then discusses ...This article reviews the background,preparation,development and birth stage,and the main content and framework of the new urbanism theory,then understands new urbanism from a historical perspective and then discusses how the seaside project in Florida developed a smalltown community with a strong community atmosphere and a beautiful environment,guided by the theory of New Urbanism.This is followed by an in-depth analysis of the high construction and maintenance costs ofNew Urbanism in practice,the impact on the privacy of residents9 lives,the relative reduction of community ties,and other problems,and finally,it gives opinions on the sustainable development of the New Urbanism theory in the future.展开更多
The Charter of New American Urbanism signed in 1996 represents a gesture that was spread out through Europe intended as the basis to the Charter of New European Urbanism,2003.In this manuscript the new urbanism(NU),is...The Charter of New American Urbanism signed in 1996 represents a gesture that was spread out through Europe intended as the basis to the Charter of New European Urbanism,2003.In this manuscript the new urbanism(NU),is considered a movement whose aims are to recover values of traditional cities,concerning the neighborhood patterns and the land mixed use.Looking to design the region,city,town,neighborhood,district and the in-fill projects,set out on garden-city principles the NU concerns also the urban sprawl,natural resources economy and to maximize the transit system.Doing so,this movement could be settled in the role of disciplines concerned to sustainability,as explained by the place chosen to welcome the meeting where the Charter of Stockholm was signed.展开更多
This paper examines historical urban fabrics’challenges regarding quality of life and visual disturbances despite their cultural and identity value.Regeneration and socialoriented approaches considering social,econom...This paper examines historical urban fabrics’challenges regarding quality of life and visual disturbances despite their cultural and identity value.Regeneration and socialoriented approaches considering social,economic,and cultural dimensions preserve and enhance these valuable materials.Tactical urbanism,with its people-oriented approach,can address these issues.This study focused on Sarpol in Khomeinishahr County,Isfahan Province of Iran.The city’s urban structure divides into two parts:despite its active social structure and valuable spaces,Sarpol is a historic neighborhood with significant deterioration.We followed Corbin and Strauss’s version of Grounded Theory in the qualitative research methodology.Purposive and snowball sampling methods were employed to select 21 participants from the Sarpol neighborhood for semi-structured interviews.The analysis involved three stages of coding:open,axial,and selective.The themes included religious participation,identity,sustainable social bonds,indigenous dependence,and low environmental quality.The central issue identified was the crucial role of religious and cultural values as a driving force for tactical urbanism,which emerged as the most critical semantic domain related to the research problem.展开更多
Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,pote...Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially threatening the structure and function of natural ecosystems.MPs in terrestrial and aquatic ecosystems alter the growth and functional characteristics of organisms.However,little attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate warming.MPs collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and identification.The results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow samples.Fibers were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great extent.High-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional diversity.MPs may have an interference effect on the individual growth and functional expression of microorganisms in snow.In addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of MPs.For instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban area.The MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.展开更多
Cities hold a critical responsibility for achieving the Sustainable Development Goals(SDGs)due to their high population density,extensive resource consumption,and significant economic contributions.To examine the pres...Cities hold a critical responsibility for achieving the Sustainable Development Goals(SDGs)due to their high population density,extensive resource consumption,and significant economic contributions.To examine the present state of understandings regarding urban sustainability(SDG 11:Sustainable Cities and Communities)within Chinese research communities,this study collected 15950 papers from 1994 to 2022 on the 12 indicators of SDG 11,from the China National Knowledge Infrastructure(CNKI),a hub of Chinese academic papers,that directly relate to policymaking.Significant research topics on SDG 11 were identified for each indicator using bibliometrics analysis approaches.The high-frequency keywords and clusters of keywords over the last three decades reveal that existing studies primarily concentrated on the physical aspects,such as transportation and environment,while there is a lack of consideration of societal aspects.This indicates a limited and biased understanding of the urban sustainability within the Chinese academic community.Hence,it is crucial to prioritize the societal aspects in order to develop a research agenda that further advances urban sustainability.展开更多
With the rapid development and application of emerging information technologies such as cloud computing,big data,artificial intelligence,5G,satellite communication,and blockchain in urban rail transit,China’s urban r...With the rapid development and application of emerging information technologies such as cloud computing,big data,artificial intelligence,5G,satellite communication,and blockchain in urban rail transit,China’s urban rail transit has entered an era of intelligent transformation and upgrading.The development of intelligent systems and the construction of smart urban rail transit have formed a consensus in the industry.The electromechanical system is an important component of urban rail transit engineering,covering power supply stations,vehicles,stations,and lines.The depot and control center are important support for promoting the development of urban rail transit towards informatization and intelligence.However,research on the technical standards for the smart urban rail vehicle-ground integrated electromechanical system has just begun,and a technical standards system has not yet been formed,which cannot better support the electromechanical system.Therefore,it is necessary to conduct research on the technical standards system,propose the common criteria structure and standards list of the standards system,which can provide reference and guidance for the planning and establishment of China’s smart urban rail standards system.展开更多
Le Corbusier’s urbanism is routinely met with a backlash of criticism,which often overlooks the complexity of his work.There is a tendency to focus on the characteristics of his proposal for Paris in 1925 or on the i...Le Corbusier’s urbanism is routinely met with a backlash of criticism,which often overlooks the complexity of his work.There is a tendency to focus on the characteristics of his proposal for Paris in 1925 or on the ideas of CIAM’s Athens Charter.However,such affirmations ignore the conceptual and qualitative evolution of his urban proposals.In this sense,the research hypothesis is that Corbusian urban models go beyond the Plan Voisin,diffused by urban planning theories as the unique paradigm of his urban ideas.Through analysis and characterisation of the inner-city urban plans of Le Corbusier,this report seeks to demonstrate the existence of other models and compares them to those often showcased in the partial examination of Le Corbusier’s urbanism.The following parameters will be analysed:(1)population densities and areas for(2)buildings,(3)vehicles,and(4)pedestrians.The results of this research indicate the need to parameterise and analyse Le Corbusier’s cities beyond a single case to demonstrate the diversity and evolution of his urbanistic work.This process seeks to dissipate the common view that falsely extrapolates ideas of his urban planning,largely that of his first proposal,for Paris.展开更多
Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban...Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.展开更多
With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control ...With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control the urban sprawl.Reasonable delineation of UGB can inhibit the disorderly spread of urban space and guide the normal development of the city.It is of practical significance for the construction of green urban space.The study utilizes GIS technology to establish a land construction suitability evaluation system for Nankang city,which is experiencing rapid urban expansion,and outlines the preliminary UGB under the future land use simulation(FLUS)model.At the same time,considering the coupled coordination of"Production-Living-Ecological Space",and based on the suitability evaluation,we revised the preliminary UGB by combining the advantages of the patch-generating land use simulation(PLUS)model and the convex hull model to delineate the final UGB.The results show that:1)the comprehensive score of the evaluation of the suitability of the construction of land from high to low shows the distribution of the center of the city to the surrounding circle type spread,the center of the city has the highest suitability score.The results of convex hull model show that the urban expansion type of Nankang is epitaxial.In the future,the urban expansion will mainly occur in the northern part of the city.The PLUS model predicts an increase of 3359.97 hm^(2)of construction land in Nankang by 2035,of which 2022.97 hm^(2)is urban construction land.2)The FLUS model has a prediction accuracy of 86.3%and delineates a preliminary UGB area of 9215.07 hm^(2).3)We used the results of the construction suitability evaluation,PLUS model simulation results,and convex hull model predictions to revise the originally delineated UGB.The final delineated UGB area is 8895.67 hm^(2)and it is capable of meeting the future development of the study area.The results of the delineation can promote sustainable urban development,and the delineation methodology can provide a reference basis for the preparation of territorial spatial planning.展开更多
The patterns of material accumulation in buildings and infrastructure accompanied by rapid urbanization offer an important,yet hitherto largely missing stock perspective for facilitating urban system engineering and i...The patterns of material accumulation in buildings and infrastructure accompanied by rapid urbanization offer an important,yet hitherto largely missing stock perspective for facilitating urban system engineering and informing urban resources,waste,and climate strategies.However,our existing knowledge on the patterns of built environment stocks across and particularly within cities is limited,largely owing to the lack of sufficient high spatial resolution data.This study leveraged multi-source big geodata,machine learning,and bottom-up stock accounting to characterize the built environment stocks of 50 cities in China at 500 m fine-grained levels.The per capita built environment stock of many cities(261 tonnes per capita on average)is close to that in western cities,despite considerable disparities across cities owing to their varying socioeconomic,geomorphology,and urban form characteristics.This is mainly owing to the construction boom and the building and infrastructure-driven economy of China in the past decades.China’s urban expansion tends to be more“vertical”(with high-rise buildings)than“horizontal”(with expanded road networks).It trades skylines for space,and reflects a concentration-dispersion-concentration pathway for spatialized built environment stocks development within cities in China.These results shed light on future urbanization in developing cities,inform spatial planning,and support circular and low-carbon transitions in cities.展开更多
Human disturbances are considered to break reproduction barriers among species.Significant increases in hybridization events have been reported among a large number of taxonomic groups in anthropogenic environments,pr...Human disturbances are considered to break reproduction barriers among species.Significant increases in hybridization events have been reported among a large number of taxonomic groups in anthropogenic environments,providing novel insights into species evolution mechanisms and conservation management in the Anthropocene.The Eastern Golden Frog(Pelophylax plancyi)and BlackSpotted Frog(P.nigromaculatus)are two sympatric anuran species with a long history of mitochondrial genome introgression in highly urbanized continental East Asia.However,there is only limited understanding of the pattern of their contemporary hybridization and factors influencing their interspecific relationship under anthropogenic disturbances.Here,interspecific hybridization between P.plancyi and P.nigromaculatus at the population level was investigated in Shanghai.All except two haplotypes obtained from both species in Shanghai were mixed together,and located in the introgression clade,implying multiple ancient mitochondrial introgression events occurred in the populations of our study area.Asymmetric genetic introgression was detected by microsatellite markers,with 0.7%of P.plancyi and 14.6%of P.nigromaculatus identified as contemporary admixed individuals.Consistent with the trend of population density,higher genetic diversity of neutral microsatellite loci was found in the more abundant P.plancyi;however,variation in mitochondrial(Cyt-b)and nuclear(POMC)genes was higher in relatively rare P.nigromaculatus.The population density of P.plancyi and number of water patches within local habitats were significantly positively correlated with both occurrences and proportions of admixed individuals in the populations of P.plancyi and P.nigromaculatus.Considering the prevalent transformation of habitats in urbanized areas,these results imply that a high population density in isolated artificially altered habitats is likely to increase interspecific hybridization.Thus,population monitoring and improvement of landscape connectivity between habitats would be needed to control the intensity of interspecific hybridization between P.plancyi and P.nigromaculatus in anthropogenic-disturbed environments.展开更多
Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion...Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.展开更多
文摘Nowadays city of Alexandria has a very wide range of urban development projects;some of them have a major influence on the physical being of the city meanwhile others just have a small interpretation to its characteristics.The rapid growth of Alexandria city in the nineteenth century led to calls for parks to be provided for the health of all categories in the society.This could be seen as an early precedent to highlight the role of open spaces in supporting what we now call sustainable development.This paper proposes an urban development project which makes a replacement of an urban crawl in Alexandria city into unique open space through presenting a comprehensive approach for assessing this suggested project to create a walkability area based on a combination of its conceptual and applicable aspects.Discussion of the sustainability modules to this new urban development project in Alexandria will be accomplished,by the aim of investigating its ability to stand against the future challenges.It is concluded that a significant attribute of urban design achieves continuity of the urban fabric and streets,because this facilitates flows.Wherever movements occur,there is vitality and flow creates eyes on the street producing spontaneous surveillance.Also,comparison of contextual and neighbourhood before and after the project revealed the positive impact of the suggested project either on the built(physical)environment’s or health and social well-being.
文摘Based on the origin and development of landscape urbanism,with several representative cases,this paper introduces the origin of ecological urbanism,as well as the main concepts and strategies,and then compared the changes from Landscape Urbanism to Ecological Urbanism.At last,this paper discusses its enlightenment on China’s urban construction and landscape development with the focus on the actual situation in China.
文摘Growing from water, Can Tho is a region on delta area of Southern Vietnam carved up by the currents of Mekong’s tributary, where settlements and water are closely interact. Being an important city, Can Tho puts in high expectations for investment calls that activate the growth of the city towards a new direction of urbanism. This trend seems to neglect its nature way of coping with water. In this connection, the intention of the research is to understand the urbanism in delta area of Can Tho, its confidences and fears the region has to experience and deal with. The intensive field work reveals an evaluation towards Can Tho’s spatial quality and major water problems. As a closing, the last section has share thoughts that different strategies of urban design to retrieve back the wisdom of living with water which are required for future urbanity of Can Tho region.
文摘In current times urban developments can no longer be seen as straightforward building of the required number of houses, industries and parking spaces. Instead, the problems in many cities are of different nature: urban conurbations may shrink, or climate impacts cause a serious disaster. These problems all have a different pace of development. The fast development must be combined with slower development pace fitting with shrinking cities and the sudden change climatic impacts requires. Therefore, in this article three types of urbanisms are proposed, which each care for an increase of resilience in the city. Fast urbanism accommodates the growth of the city in a calculated way in periods of economic prosperity;slow urbanism designs spaces for slowly developing uses such as ecology or food in times of shrinkage;and suddenism anticipates future climate impacts through designing spaces for temporary use.
文摘High concentration of population and other elements brought by high urbanization has pushed the future construction of urban public spaces to be both "compact" and "ecological". Theory and methodology of landscape urbanism provides a new perspective for the construction of public spaces in high-density urban environment. Based on the concept and basic standpoints of landscape urbanism, this paper elaborated its potential value in spatial connection, functional integration and vitality promotion, and also analyzed practical strategies of landscape urbanism from three perspectives of structure, fold and stage by combining with typical cases, so as to provide references for designing urban public spaces in high-density environment.
文摘Landscape urbanism has attracted the attention from scholars of human settlement science, and landscape designers have also grown in the development process of landscape urbanism and their identification has been broken through. Moreover, they are faced with new challenges in the age of big data and computer. The paper explored role definition of landscape designer in landscape urbanism and analyzed the trend of landscape urbanism, providing theoretical reference to forecast career development of landscape designer.
文摘This article reviews the background,preparation,development and birth stage,and the main content and framework of the new urbanism theory,then understands new urbanism from a historical perspective and then discusses how the seaside project in Florida developed a smalltown community with a strong community atmosphere and a beautiful environment,guided by the theory of New Urbanism.This is followed by an in-depth analysis of the high construction and maintenance costs ofNew Urbanism in practice,the impact on the privacy of residents9 lives,the relative reduction of community ties,and other problems,and finally,it gives opinions on the sustainable development of the New Urbanism theory in the future.
文摘The Charter of New American Urbanism signed in 1996 represents a gesture that was spread out through Europe intended as the basis to the Charter of New European Urbanism,2003.In this manuscript the new urbanism(NU),is considered a movement whose aims are to recover values of traditional cities,concerning the neighborhood patterns and the land mixed use.Looking to design the region,city,town,neighborhood,district and the in-fill projects,set out on garden-city principles the NU concerns also the urban sprawl,natural resources economy and to maximize the transit system.Doing so,this movement could be settled in the role of disciplines concerned to sustainability,as explained by the place chosen to welcome the meeting where the Charter of Stockholm was signed.
文摘This paper examines historical urban fabrics’challenges regarding quality of life and visual disturbances despite their cultural and identity value.Regeneration and socialoriented approaches considering social,economic,and cultural dimensions preserve and enhance these valuable materials.Tactical urbanism,with its people-oriented approach,can address these issues.This study focused on Sarpol in Khomeinishahr County,Isfahan Province of Iran.The city’s urban structure divides into two parts:despite its active social structure and valuable spaces,Sarpol is a historic neighborhood with significant deterioration.We followed Corbin and Strauss’s version of Grounded Theory in the qualitative research methodology.Purposive and snowball sampling methods were employed to select 21 participants from the Sarpol neighborhood for semi-structured interviews.The analysis involved three stages of coding:open,axial,and selective.The themes included religious participation,identity,sustainable social bonds,indigenous dependence,and low environmental quality.The central issue identified was the crucial role of religious and cultural values as a driving force for tactical urbanism,which emerged as the most critical semantic domain related to the research problem.
基金supported by the funds for the National Natural Science Foundation of China(52070183)the International Cooper ation and Exchange of the National Natural Science Foundation of China(51820105011)the Program of the Youth Innovation Promotion Association of Chinese Academy of Sciences(2019044).
文摘Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially threatening the structure and function of natural ecosystems.MPs in terrestrial and aquatic ecosystems alter the growth and functional characteristics of organisms.However,little attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate warming.MPs collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and identification.The results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow samples.Fibers were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great extent.High-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional diversity.MPs may have an interference effect on the individual growth and functional expression of microorganisms in snow.In addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of MPs.For instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban area.The MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.
基金National Natural Science Foundation of China(No.42171449)。
文摘Cities hold a critical responsibility for achieving the Sustainable Development Goals(SDGs)due to their high population density,extensive resource consumption,and significant economic contributions.To examine the present state of understandings regarding urban sustainability(SDG 11:Sustainable Cities and Communities)within Chinese research communities,this study collected 15950 papers from 1994 to 2022 on the 12 indicators of SDG 11,from the China National Knowledge Infrastructure(CNKI),a hub of Chinese academic papers,that directly relate to policymaking.Significant research topics on SDG 11 were identified for each indicator using bibliometrics analysis approaches.The high-frequency keywords and clusters of keywords over the last three decades reveal that existing studies primarily concentrated on the physical aspects,such as transportation and environment,while there is a lack of consideration of societal aspects.This indicates a limited and biased understanding of the urban sustainability within the Chinese academic community.Hence,it is crucial to prioritize the societal aspects in order to develop a research agenda that further advances urban sustainability.
文摘With the rapid development and application of emerging information technologies such as cloud computing,big data,artificial intelligence,5G,satellite communication,and blockchain in urban rail transit,China’s urban rail transit has entered an era of intelligent transformation and upgrading.The development of intelligent systems and the construction of smart urban rail transit have formed a consensus in the industry.The electromechanical system is an important component of urban rail transit engineering,covering power supply stations,vehicles,stations,and lines.The depot and control center are important support for promoting the development of urban rail transit towards informatization and intelligence.However,research on the technical standards for the smart urban rail vehicle-ground integrated electromechanical system has just begun,and a technical standards system has not yet been formed,which cannot better support the electromechanical system.Therefore,it is necessary to conduct research on the technical standards system,propose the common criteria structure and standards list of the standards system,which can provide reference and guidance for the planning and establishment of China’s smart urban rail standards system.
基金This research was funded by the Ministry of Science,Innovation and Universities of the Government of Spain(FPU17/03701)supported by the University of SevilleAdditionally,this article has been funded by the Grants for Research Internationalisation IUACC 2020 from the Research and Transfer Plan of the University of Seville[Ayudas a la Internacionalizacion de la Investigacion IUACC 2020 del Plan Propio de Investigacion y Transferencia,Universidad de Sevilla].
文摘Le Corbusier’s urbanism is routinely met with a backlash of criticism,which often overlooks the complexity of his work.There is a tendency to focus on the characteristics of his proposal for Paris in 1925 or on the ideas of CIAM’s Athens Charter.However,such affirmations ignore the conceptual and qualitative evolution of his urban proposals.In this sense,the research hypothesis is that Corbusian urban models go beyond the Plan Voisin,diffused by urban planning theories as the unique paradigm of his urban ideas.Through analysis and characterisation of the inner-city urban plans of Le Corbusier,this report seeks to demonstrate the existence of other models and compares them to those often showcased in the partial examination of Le Corbusier’s urbanism.The following parameters will be analysed:(1)population densities and areas for(2)buildings,(3)vehicles,and(4)pedestrians.The results of this research indicate the need to parameterise and analyse Le Corbusier’s cities beyond a single case to demonstrate the diversity and evolution of his urbanistic work.This process seeks to dissipate the common view that falsely extrapolates ideas of his urban planning,largely that of his first proposal,for Paris.
基金the Youth Growth Technology Project,Science and Technology Department of Jilin Province(20230508130RC)Bureau of Forestry and Landscaping of Changchun.
文摘Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.
基金supported by the Humanities and Social Sciences Program of Jiangxi Universities(Grant No.GL21129)the Graduate Student Innovation Fund Program of Gannan Normal University(Grant No.YCX23A043)the Open Subject of Geography Discipline Construction of Gannan Normal University(Grant No.200084).
文摘With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control the urban sprawl.Reasonable delineation of UGB can inhibit the disorderly spread of urban space and guide the normal development of the city.It is of practical significance for the construction of green urban space.The study utilizes GIS technology to establish a land construction suitability evaluation system for Nankang city,which is experiencing rapid urban expansion,and outlines the preliminary UGB under the future land use simulation(FLUS)model.At the same time,considering the coupled coordination of"Production-Living-Ecological Space",and based on the suitability evaluation,we revised the preliminary UGB by combining the advantages of the patch-generating land use simulation(PLUS)model and the convex hull model to delineate the final UGB.The results show that:1)the comprehensive score of the evaluation of the suitability of the construction of land from high to low shows the distribution of the center of the city to the surrounding circle type spread,the center of the city has the highest suitability score.The results of convex hull model show that the urban expansion type of Nankang is epitaxial.In the future,the urban expansion will mainly occur in the northern part of the city.The PLUS model predicts an increase of 3359.97 hm^(2)of construction land in Nankang by 2035,of which 2022.97 hm^(2)is urban construction land.2)The FLUS model has a prediction accuracy of 86.3%and delineates a preliminary UGB area of 9215.07 hm^(2).3)We used the results of the construction suitability evaluation,PLUS model simulation results,and convex hull model predictions to revise the originally delineated UGB.The final delineated UGB area is 8895.67 hm^(2)and it is capable of meeting the future development of the study area.The results of the delineation can promote sustainable urban development,and the delineation methodology can provide a reference basis for the preparation of territorial spatial planning.
基金supported by the National Natural Science Foundation of China (71991484,42271471,72088101,and 41830645)Danish Agency for Higher Education and Science (International Network Project,0192-00056B)the Fundamental Research Funds for the Central Universities (Peking University).
文摘The patterns of material accumulation in buildings and infrastructure accompanied by rapid urbanization offer an important,yet hitherto largely missing stock perspective for facilitating urban system engineering and informing urban resources,waste,and climate strategies.However,our existing knowledge on the patterns of built environment stocks across and particularly within cities is limited,largely owing to the lack of sufficient high spatial resolution data.This study leveraged multi-source big geodata,machine learning,and bottom-up stock accounting to characterize the built environment stocks of 50 cities in China at 500 m fine-grained levels.The per capita built environment stock of many cities(261 tonnes per capita on average)is close to that in western cities,despite considerable disparities across cities owing to their varying socioeconomic,geomorphology,and urban form characteristics.This is mainly owing to the construction boom and the building and infrastructure-driven economy of China in the past decades.China’s urban expansion tends to be more“vertical”(with high-rise buildings)than“horizontal”(with expanded road networks).It trades skylines for space,and reflects a concentration-dispersion-concentration pathway for spatialized built environment stocks development within cities in China.These results shed light on future urbanization in developing cities,inform spatial planning,and support circular and low-carbon transitions in cities.
基金supported by the National Natural Science Foundation of China(32071529)the Yangtze Delta Estuarine Wetland Ecosystem Observation and Research Station(Z202204)+1 种基金Shanghai Key Lab for Urban Ecological Processes and EcoRestoration(SHUES2020B06,SHUES2021C04)the Fundamental Research Funds for the Central Universities.
文摘Human disturbances are considered to break reproduction barriers among species.Significant increases in hybridization events have been reported among a large number of taxonomic groups in anthropogenic environments,providing novel insights into species evolution mechanisms and conservation management in the Anthropocene.The Eastern Golden Frog(Pelophylax plancyi)and BlackSpotted Frog(P.nigromaculatus)are two sympatric anuran species with a long history of mitochondrial genome introgression in highly urbanized continental East Asia.However,there is only limited understanding of the pattern of their contemporary hybridization and factors influencing their interspecific relationship under anthropogenic disturbances.Here,interspecific hybridization between P.plancyi and P.nigromaculatus at the population level was investigated in Shanghai.All except two haplotypes obtained from both species in Shanghai were mixed together,and located in the introgression clade,implying multiple ancient mitochondrial introgression events occurred in the populations of our study area.Asymmetric genetic introgression was detected by microsatellite markers,with 0.7%of P.plancyi and 14.6%of P.nigromaculatus identified as contemporary admixed individuals.Consistent with the trend of population density,higher genetic diversity of neutral microsatellite loci was found in the more abundant P.plancyi;however,variation in mitochondrial(Cyt-b)and nuclear(POMC)genes was higher in relatively rare P.nigromaculatus.The population density of P.plancyi and number of water patches within local habitats were significantly positively correlated with both occurrences and proportions of admixed individuals in the populations of P.plancyi and P.nigromaculatus.Considering the prevalent transformation of habitats in urbanized areas,these results imply that a high population density in isolated artificially altered habitats is likely to increase interspecific hybridization.Thus,population monitoring and improvement of landscape connectivity between habitats would be needed to control the intensity of interspecific hybridization between P.plancyi and P.nigromaculatus in anthropogenic-disturbed environments.
基金funded by the National Natural Science Foundation of China (No.32360418)the Guizhou Provincial Basic Research Program (Natural Science)(No.QianKeHeJiChu-ZK[2024]YiBan022)。
文摘Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.