During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil d...During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.展开更多
Up till now,no systematic studies on railway route selection in urban areas,HSR route selection in particular,have been taken in China.Based on the Shenzhen Railway Terminal Project and the Shenzhen-Shanwei Railway Pr...Up till now,no systematic studies on railway route selection in urban areas,HSR route selection in particular,have been taken in China.Based on the Shenzhen Railway Terminal Project and the Shenzhen-Shanwei Railway Project,research on HSR route selection in complicated urban areas has been conducted.An optimal route selection plan is determined after studying the local geological and environmental conditions and the complexity of tunnel construction.The research concludes that there are four major concerns in HSR route selection:the match between the new route and the urban planning,the potential economic return for the massive investment,the likely impacts of land expropriation on social stability,and the best synthesis of multiple controlling factors to meet the HSR standard.Moreover,six principles should be followed in railway route selection in complicated urban areas:the new route should be in alignment with the railway deployment;the route should align with the existing passage as much as possible;extensive analysis and in-depth demonstrations should be done to find the most appropriate combination of open and hidden excavation in tunnel construction;geological conditions and tunnel construction complexities are among the priorities;environmental sensitive sites and environmental vibration noise should be avoided as much as possible;special attention should be paid to the relocation of the power supply,television and communication facilities and the rearrangement of tubes and wires.展开更多
In this paper, the authors first analyse the problems existing in the situation of land use, structure of travel mode and road network by applying the basic principle of traffic engineering and system engineering meth...In this paper, the authors first analyse the problems existing in the situation of land use, structure of travel mode and road network by applying the basic principle of traffic engineering and system engineering methods. Then, the authors make it clear the strategies to be adopted for solving the existing traffic problems in the ancient urban area of Suzhou(AUAS), namely insisting on the goal based strategy; the strategy to develop the public transit system in priority and decreasing the demand on cars from the view point of land use strategy. On the basis of such analysis the authors put forth proposals about major measures to be taken to improve traffic conditions of the AUAS, such as construction of express artery ring around the ancient city, appropriate transformation of the roads in the AUAS and rational distribution of car parking areas at the outskirt, which are of positive significance in guiding the protection of the AUAS and transportation construction. In this paper, specialized software is used to establish criteria for the construction scale and extent analysis and evaluation of the ancient city construction project, which is of some reference significance to the transformation of old urban areas in other cities.展开更多
The air quality model CMAQ-MADRID （Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution） was employed to simulate summer O3 formation in Beijing China, in order to explore...The air quality model CMAQ-MADRID （Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution） was employed to simulate summer O3 formation in Beijing China, in order to explore the impacts of four heterogeneous reactions on O3 formation in an urban area. The results showed that the impacts were obvious and exhibited the characteristics of a typical response of a VOC-limited regime in the urban area. For the four heterogeneous reactions considered, the NO2 and HO2 heterogeneous reactions have the most severe impacts on O3 formation. During the O3 formation period, the NO2 heterogeneous reaction increased new radical creation by 30%, raising the atmospheric activity as more NO→NO2 conversion occurred, thus causing the O3 to rise. The increase of O3 peak concentration reached a maximum value of 67 ppb in the urban area. In the morning hours, high NO titration reduced the effect of the photolysis of HONO, which was produced heterogeneously at night in the surface layer. The NO2 heterogeneous reaction in the daytime is likely one of the major reasons causing the O3 increase in the Beijing urban area. The HO2 heterogeneous reaction accelerated radical termination, resulting in a decrease of the radical concentration by 44% at the most. O3 peak concentration decreased by a maximum amount of 24 ppb in the urban area. The simulation results were improved when the heterogeneous reactions were included, with the O3 and HONO model results close to the observations.展开更多
The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analy...The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analyzed the air pollution index(API) in four cities(Shanghai, Nanjing, Hangzhou and Ningbo) in the YRD from 2001 to 2012. We attempted to empirically examine the relationship between meteorological factors and air quality in the urban areas of the YRD. According to the monitoring data, the API in Shanghai, Nanjing, Hangzhou slightly declined and that in Ningbo increased over the study period. We analyzed the inter-annual, seasonal, and monthly variations of API, from which we found that the air quality had different temporal changes in the four cities. It was indicated that air quality was poor in winter and spring and best in summer. Furthermore, different weather conditions affected air quality level. The wind direction was considered as an important and influential factor to air pollution, which has an impact on the accumulating or cleaning processes of pollutants. The air quality was influenced by the different wind directions that varied with seasons and cities.展开更多
As an important coal-resource based city in eastern China, coal mining activities have greatly promoted economic development to Xuzhou while resulted in kinds of blocks for sustainable development. Subsidence areas ca...As an important coal-resource based city in eastern China, coal mining activities have greatly promoted economic development to Xuzhou while resulted in kinds of blocks for sustainable development. Subsidence areas caused by coal mining activities and rapid urbanization process led to the losing of ecological function and decreasing of landscape connectivity in the city. As the important life-support system, urban green infrastructure （GI as short） has great significance in improving human well-beings. Taking Xuzhou urban area as the study object, this paper proposed a green infrastructure construction method based on the principle of ecological priority. Firstly, key ecological patches were identified by GIS and RS methods. Secondly, we established corridors by minimum cost path model. Then, we built GI network and evaluated the ecological importance of different patches. Finally, by comparing the status of patches and coal mining subsidence areas, we proposed a framework for constructing GI network in Xuzhou urban area.展开更多
In this paper, some experimental studies on the impact of effluent from an exhaust tower of an underground tunnel with special construction are reported. By measuring the flow field downstream of the tower in NJU mete...In this paper, some experimental studies on the impact of effluent from an exhaust tower of an underground tunnel with special construction are reported. By measuring the flow field downstream of the tower in NJU meteorological wind tunnel, some flow characteristics in the make area were established. Based on these, an advanced random\|walk dispersion model was set up and applied successfully to the simulation of dispersion in the wake area. The modelling results were in accordance with wind tunnel measurements. The computed maximum of ground surface concentration in the building case was a factor of 3-4 higher than that in the flat case and appeared much closer to the source. The simulation indicated that random walk modelling is an effective and practical tool for the wake stream impact assessment.展开更多
In order to meet the application requirements of autonomous vehicles, this paper proposes a simultaneous localization and mapping （SLAM） algorithm, which uses a VoxelGrid filter to down sample the point cloud data, ...In order to meet the application requirements of autonomous vehicles, this paper proposes a simultaneous localization and mapping （SLAM） algorithm, which uses a VoxelGrid filter to down sample the point cloud data, with the combination of iterative closest points （ICP） algorithm and Gaussian model for particles updating, the matching between the local map and the global map to quantify particles＇ importance weight. The crude estimation by using ICP algorithm can find the high probability area of autonomous vehicles＇ poses, which would decrease particle numbers, increase algorithm speed and restrain particles＇ impoverishment. The calculation of particles＇ importance weight based on matching of attribute between grid maps is simple and practicable. Experiments carried out with the autonomous vehicle platform validate the effectiveness of our approaches.展开更多
To evaluate the HIV pandemic in Chongqing, the pooled PCR, IgG-capture BED enzyme immunoassay （BED-CEIA）, and cohort observations were used to estimate the HIV incidences among men who have sex with men （MSM）. 617...To evaluate the HIV pandemic in Chongqing, the pooled PCR, IgG-capture BED enzyme immunoassay （BED-CEIA）, and cohort observations were used to estimate the HIV incidences among men who have sex with men （MSM）. 617 MSM subjects completed the survey at a voluntary counseling and testing （VCT） site. The observed HIV incidence was 12.5 per 100 P-Ys （95% CI = 9.1-15.7）.展开更多
This paper makes a detailed analysis of the vanous drawbacks of the continued use of adwhnistrative area in dividing urban and rural areas in spite of the serious discrepancies between urban admnistrative boundaries a...This paper makes a detailed analysis of the vanous drawbacks of the continued use of adwhnistrative area in dividing urban and rural areas in spite of the serious discrepancies between urban admnistrative boundaries and the 'real' urban space in China. The autiors believe that to solve this problem, it is essential to establish the concept of physical urban area with both adaptability to Chinese situation and intemational comparability and use it as the basis of urban-rural division and statistics. It is proposed that physical urban area should be defined in terms of prescribed minimum population scale, dngee of nonaghculturalization and population density.Based on extensive substantive research and a classifiotion of the space figurations of Chinese cities and towns, a new scheme to classify physical urban areas is proposed.展开更多
Firstly,the daily variations of NO2 concentration in the urban area of Wanzhou in 2012 were analyzed,and then the relationship between NO2 concentration and meteorological factors（ precipitation,atmospheric pressure,...Firstly,the daily variations of NO2 concentration in the urban area of Wanzhou in 2012 were analyzed,and then the relationship between NO2 concentration and meteorological factors（ precipitation,atmospheric pressure,wind speed,temperature,relative humidity and sunshine hours） was discussed. Finally,the multiple linear regression equation was established to predict NO2 concentration. The results showed that NO2 concentration in the urban area of Wanzhou did not exceed 80 μg /m3in most days from January 1 to December 31 in 2012. Among the six meteorological factors,NO2 concentration correlated significantly with three meteorological factors,that is,NO2 concentration correlated negatively with atmospheric pressure and wind speed but positively with relative humidity. NO2 concentration in the urban area of Wanzhou could be predicted using the multiple linear regression model. According to the rose diagram of wind directions,the wind blowing from the NNW was dominant in the urban area of Wanzhou.展开更多
Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the devel- opment of the multifunctional ag...Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the devel- opment of the multifunctional agriculture and urbanization any more, so multifunctional agricultural land use is going to be promoted in the city. This article proposes the evolvement of the land use change from 1992 to 2004 and discusses some evolvement views.展开更多
Based on investigating the present greening situation of 18 overpasses in the urban area of Kunming City,4 typical plant furnishing modes for overpass were concluded,that is,Type Ⅰ,which was the multi-layered plant d...Based on investigating the present greening situation of 18 overpasses in the urban area of Kunming City,4 typical plant furnishing modes for overpass were concluded,that is,Type Ⅰ,which was the multi-layered plant disposition pattern composed of all arbor,shrub and herbaceous plant species;TypeⅡ,which was mainly composed of shrub and herbaceous species with a 2-layered structure;Type Ⅲ was the turf grass pattern with sparsely disposed trees;Type Ⅳ,which was the simple groundcover greening pattern.1 or 2 typical overpasses from each type were sampled separately for evaluating the landscape effects of the typical green space around each type of overpass by adopting AHP model,and the results showed that the evaluated landscape effect of Type Ⅰ was 'good',that of Type Ⅱ was 'moderate',that of Type Ⅲ was 'moderate to good',and that of Type Ⅳ was 'poor'.展开更多
A method that enables the user to assess air pollution originated from vehicle emission in the urban center was described by taking Macao as an example. The method involved the use of mathematical models for the calcu...A method that enables the user to assess air pollution originated from vehicle emission in the urban center was described by taking Macao as an example. The method involved the use of mathematical models for the calculation of urban pollutant emissions and concentrations, of which a revised MOBILE5 was adopted to calculate the emission factors and two dispersion models of CAR and OSPM were used to calculate the long term and short term concentrations within street canyons, respectively. The results show consistency with the monitoring data, and some conclusions of controlling vehicle emissions are given based on the calculation results.展开更多
Fatal traffic accidents in urban areas can adversely affect the urban road traffic system and pose many challenges for urban traffic management.Therefore,it is necessary to first classify emergency responses to such a...Fatal traffic accidents in urban areas can adversely affect the urban road traffic system and pose many challenges for urban traffic management.Therefore,it is necessary to first classify emergency responses to such accidents and then handle them quickly and correctly.The aim of this paper is to develop an evaluation index system and to use appropriate methods to investigate emergency-response classifications to fatal traffic accidents in Chinese urban areas.This study used a multilevel hierarchical structural model to determine emergency-response classification.In the model,accident attributes,urban road network vulnerability,and institutional resilience were used as classification criteria.Each evaluation indicator was selected according to importance ranking and independence screening and was given an interpretation and a quantitative criterion.The Fuzzy Delphi Method was used to rank the importance of the evaluation indices and the combined weight of each index was calculated using the G1 method.Finally,the case of a fatal traffic accident was used to validate the model.The results showed that the multilevel hierarchical structural model,Fuzzy Delphi Method,and G1 method can effectively address the problem of emergency-response classification.Because of its simplicity and adaptability,the approach presented here could be useful for decisionmakers and practitioners for determining emergency-response classifications.展开更多
This paper, based on the literature review and field investigation, studied the status quo of maker spaces in main urban district of Chengdu at a time when the development of the maker spaces has received strong suppo...This paper, based on the literature review and field investigation, studied the status quo of maker spaces in main urban district of Chengdu at a time when the development of the maker spaces has received strong support from national and local governments. In addition to introducing the related concepts and policy support of the maker space, it summarized its distribution characteristics, audience characteristics, and status quo as well as problems and presented the direction for the development of the maker space in main urban area of Chengdu grounded on a survey of the status quo of national maker spaces in main urban area of Chengdu.展开更多
The current situation,existing problems and characteristics of greening in the main urban area of Taizhou were analyzed,and the construction ideas and safeguard measures of plain greening in urban areas in the new era...The current situation,existing problems and characteristics of greening in the main urban area of Taizhou were analyzed,and the construction ideas and safeguard measures of plain greening in urban areas in the new era were put forward.展开更多
Sponge city construction,as an important measure of ecological construction in China,can effectively solve a series of problems such as large annual runoff,serious non-point source pollution,regional water shortage,lo...Sponge city construction,as an important measure of ecological construction in China,can effectively solve a series of problems such as large annual runoff,serious non-point source pollution,regional water shortage,low utilization rate of rain and flood resources,unsustainable ecological benefits of water landscape and poor landscape functions in urbanization construction. This paper uses LID concept to construct sponge city in the old urban area of Kunming,to reduce the total runoff and promote the utilization of rainfall and flood resources so as to rebuild,upgrade and optimize the regional environment and provide some reference for the regional construction of small-scale sponge city.展开更多
Multi-storey housing for low income society is a concept of redevelopment from many alternatives of housing development for slum in Jakarta. However, redevelopment directly or indirectly leads to displacement of low-i...Multi-storey housing for low income society is a concept of redevelopment from many alternatives of housing development for slum in Jakarta. However, redevelopment directly or indirectly leads to displacement of low-income residents. The new residents would be of a higher socio-economic status than the previous occupants. For controlling this phenomenon, a study about the influence of displacement to the successful of sustainable multi-storey housing development for low-income society has been done with descriptive method, observation and literature study. The result of this study give knowledge that displacement always happened when the quality of building and environment is increase, the location of multi-storey housing is near city center and commercial area. Low income society voluntary displaced their units to middle or high income society, because they are not affordable for paying operational and maintenance costs. The government has to make regulations for controlling displacement on multi-storey housing for low-income society and for the successful of sustainable multi-storey housing development in urban area.展开更多
Under the background of"people-oriented"thought and"green transportation",the idea of"priority for non-motor vehicles"came into being,which can improve the riding environment of non-motor...Under the background of"people-oriented"thought and"green transportation",the idea of"priority for non-motor vehicles"came into being,which can improve the riding environment of non-motor vehicle riders to a certain extent.According to the current situation of priority for non-motor vehicles in the old urban area of Nanchang,through field investigation,questionnaire investigation and interview,this study summarized the existing problems,and put forward optimization suggestions for these problems,in order to provide reference for areas with similar conditions.展开更多
基金financial supports for this research project by the National Natural Science Foundation of China(Nos.41602308,41967037)supported by Zhejiang Provincial Natural Science Foundation of China under Grant No.LY20E080005+1 种基金funded by National Key Research and Development Projects of China(No.2019YFC507502)Guangxi Science and Technology Plan Project(No.RZ2100000161).
文摘During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.
文摘Up till now,no systematic studies on railway route selection in urban areas,HSR route selection in particular,have been taken in China.Based on the Shenzhen Railway Terminal Project and the Shenzhen-Shanwei Railway Project,research on HSR route selection in complicated urban areas has been conducted.An optimal route selection plan is determined after studying the local geological and environmental conditions and the complexity of tunnel construction.The research concludes that there are four major concerns in HSR route selection:the match between the new route and the urban planning,the potential economic return for the massive investment,the likely impacts of land expropriation on social stability,and the best synthesis of multiple controlling factors to meet the HSR standard.Moreover,six principles should be followed in railway route selection in complicated urban areas:the new route should be in alignment with the railway deployment;the route should align with the existing passage as much as possible;extensive analysis and in-depth demonstrations should be done to find the most appropriate combination of open and hidden excavation in tunnel construction;geological conditions and tunnel construction complexities are among the priorities;environmental sensitive sites and environmental vibration noise should be avoided as much as possible;special attention should be paid to the relocation of the power supply,television and communication facilities and the rearrangement of tubes and wires.
文摘In this paper, the authors first analyse the problems existing in the situation of land use, structure of travel mode and road network by applying the basic principle of traffic engineering and system engineering methods. Then, the authors make it clear the strategies to be adopted for solving the existing traffic problems in the ancient urban area of Suzhou(AUAS), namely insisting on the goal based strategy; the strategy to develop the public transit system in priority and decreasing the demand on cars from the view point of land use strategy. On the basis of such analysis the authors put forth proposals about major measures to be taken to improve traffic conditions of the AUAS, such as construction of express artery ring around the ancient city, appropriate transformation of the roads in the AUAS and rational distribution of car parking areas at the outskirt, which are of positive significance in guiding the protection of the AUAS and transportation construction. In this paper, specialized software is used to establish criteria for the construction scale and extent analysis and evaluation of the ancient city construction project, which is of some reference significance to the transformation of old urban areas in other cities.
文摘The air quality model CMAQ-MADRID （Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution） was employed to simulate summer O3 formation in Beijing China, in order to explore the impacts of four heterogeneous reactions on O3 formation in an urban area. The results showed that the impacts were obvious and exhibited the characteristics of a typical response of a VOC-limited regime in the urban area. For the four heterogeneous reactions considered, the NO2 and HO2 heterogeneous reactions have the most severe impacts on O3 formation. During the O3 formation period, the NO2 heterogeneous reaction increased new radical creation by 30%, raising the atmospheric activity as more NO→NO2 conversion occurred, thus causing the O3 to rise. The increase of O3 peak concentration reached a maximum value of 67 ppb in the urban area. In the morning hours, high NO titration reduced the effect of the photolysis of HONO, which was produced heterogeneously at night in the surface layer. The NO2 heterogeneous reaction in the daytime is likely one of the major reasons causing the O3 increase in the Beijing urban area. The HO2 heterogeneous reaction accelerated radical termination, resulting in a decrease of the radical concentration by 44% at the most. O3 peak concentration decreased by a maximum amount of 24 ppb in the urban area. The simulation results were improved when the heterogeneous reactions were included, with the O3 and HONO model results close to the observations.
基金Under the auspices of Special Research Fund of the Ministry of Land and Resources for the Non-Profit Sector(No201411014-03)National Key Technology Research and Development Program of China(No.2012BAH28B04)
文摘The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analyzed the air pollution index(API) in four cities(Shanghai, Nanjing, Hangzhou and Ningbo) in the YRD from 2001 to 2012. We attempted to empirically examine the relationship between meteorological factors and air quality in the urban areas of the YRD. According to the monitoring data, the API in Shanghai, Nanjing, Hangzhou slightly declined and that in Ningbo increased over the study period. We analyzed the inter-annual, seasonal, and monthly variations of API, from which we found that the air quality had different temporal changes in the four cities. It was indicated that air quality was poor in winter and spring and best in summer. Furthermore, different weather conditions affected air quality level. The wind direction was considered as an important and influential factor to air pollution, which has an impact on the accumulating or cleaning processes of pollutants. The air quality was influenced by the different wind directions that varied with seasons and cities.
基金This work was supported by National Natural Science Foundation of China for funding the project ＂Research on Space-Time Evolution Laws and Optimization Model of Green Infrastructure in Coal Resource Based Cities＂ （No. 41671524）.
文摘As an important coal-resource based city in eastern China, coal mining activities have greatly promoted economic development to Xuzhou while resulted in kinds of blocks for sustainable development. Subsidence areas caused by coal mining activities and rapid urbanization process led to the losing of ecological function and decreasing of landscape connectivity in the city. As the important life-support system, urban green infrastructure （GI as short） has great significance in improving human well-beings. Taking Xuzhou urban area as the study object, this paper proposed a green infrastructure construction method based on the principle of ecological priority. Firstly, key ecological patches were identified by GIS and RS methods. Secondly, we established corridors by minimum cost path model. Then, we built GI network and evaluated the ecological importance of different patches. Finally, by comparing the status of patches and coal mining subsidence areas, we proposed a framework for constructing GI network in Xuzhou urban area.
文摘In this paper, some experimental studies on the impact of effluent from an exhaust tower of an underground tunnel with special construction are reported. By measuring the flow field downstream of the tower in NJU meteorological wind tunnel, some flow characteristics in the make area were established. Based on these, an advanced random\|walk dispersion model was set up and applied successfully to the simulation of dispersion in the wake area. The modelling results were in accordance with wind tunnel measurements. The computed maximum of ground surface concentration in the building case was a factor of 3-4 higher than that in the flat case and appeared much closer to the source. The simulation indicated that random walk modelling is an effective and practical tool for the wake stream impact assessment.
基金Supported by the Major Research Plan of the National Natural Science Foundation of China(91120003)Surface Project of the National Natural Science Foundation of China(61173076)
文摘In order to meet the application requirements of autonomous vehicles, this paper proposes a simultaneous localization and mapping （SLAM） algorithm, which uses a VoxelGrid filter to down sample the point cloud data, with the combination of iterative closest points （ICP） algorithm and Gaussian model for particles updating, the matching between the local map and the global map to quantify particles＇ importance weight. The crude estimation by using ICP algorithm can find the high probability area of autonomous vehicles＇ poses, which would decrease particle numbers, increase algorithm speed and restrain particles＇ impoverishment. The calculation of particles＇ importance weight based on matching of attribute between grid maps is simple and practicable. Experiments carried out with the autonomous vehicle platform validate the effectiveness of our approaches.
基金supported by the Department of Health and Family Counseling,Chongqing[2016HBRC009,2017ZDXM001]
文摘To evaluate the HIV pandemic in Chongqing, the pooled PCR, IgG-capture BED enzyme immunoassay （BED-CEIA）, and cohort observations were used to estimate the HIV incidences among men who have sex with men （MSM）. 617 MSM subjects completed the survey at a voluntary counseling and testing （VCT） site. The observed HIV incidence was 12.5 per 100 P-Ys （95% CI = 9.1-15.7）.
文摘This paper makes a detailed analysis of the vanous drawbacks of the continued use of adwhnistrative area in dividing urban and rural areas in spite of the serious discrepancies between urban admnistrative boundaries and the 'real' urban space in China. The autiors believe that to solve this problem, it is essential to establish the concept of physical urban area with both adaptability to Chinese situation and intemational comparability and use it as the basis of urban-rural division and statistics. It is proposed that physical urban area should be defined in terms of prescribed minimum population scale, dngee of nonaghculturalization and population density.Based on extensive substantive research and a classifiotion of the space figurations of Chinese cities and towns, a new scheme to classify physical urban areas is proposed.
基金Supported by the Municipal Key Laboratory Project of Colleges and Universities in Chongqing City,China(WEPKL2013MS-10)National Innovation Planning Project for University Students in 2013(201310643003)
文摘Firstly,the daily variations of NO2 concentration in the urban area of Wanzhou in 2012 were analyzed,and then the relationship between NO2 concentration and meteorological factors（ precipitation,atmospheric pressure,wind speed,temperature,relative humidity and sunshine hours） was discussed. Finally,the multiple linear regression equation was established to predict NO2 concentration. The results showed that NO2 concentration in the urban area of Wanzhou did not exceed 80 μg /m3in most days from January 1 to December 31 in 2012. Among the six meteorological factors,NO2 concentration correlated significantly with three meteorological factors,that is,NO2 concentration correlated negatively with atmospheric pressure and wind speed but positively with relative humidity. NO2 concentration in the urban area of Wanzhou could be predicted using the multiple linear regression model. According to the rose diagram of wind directions,the wind blowing from the NNW was dominant in the urban area of Wanzhou.
基金National Nature Science Foundation of China (Grant No. 40571056).
文摘Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the devel- opment of the multifunctional agriculture and urbanization any more, so multifunctional agricultural land use is going to be promoted in the city. This article proposes the evolvement of the land use change from 1992 to 2004 and discusses some evolvement views.
文摘Based on investigating the present greening situation of 18 overpasses in the urban area of Kunming City,4 typical plant furnishing modes for overpass were concluded,that is,Type Ⅰ,which was the multi-layered plant disposition pattern composed of all arbor,shrub and herbaceous plant species;TypeⅡ,which was mainly composed of shrub and herbaceous species with a 2-layered structure;Type Ⅲ was the turf grass pattern with sparsely disposed trees;Type Ⅳ,which was the simple groundcover greening pattern.1 or 2 typical overpasses from each type were sampled separately for evaluating the landscape effects of the typical green space around each type of overpass by adopting AHP model,and the results showed that the evaluated landscape effect of Type Ⅰ was 'good',that of Type Ⅱ was 'moderate',that of Type Ⅲ was 'moderate to good',and that of Type Ⅳ was 'poor'.
文摘A method that enables the user to assess air pollution originated from vehicle emission in the urban center was described by taking Macao as an example. The method involved the use of mathematical models for the calculation of urban pollutant emissions and concentrations, of which a revised MOBILE5 was adopted to calculate the emission factors and two dispersion models of CAR and OSPM were used to calculate the long term and short term concentrations within street canyons, respectively. The results show consistency with the monitoring data, and some conclusions of controlling vehicle emissions are given based on the calculation results.
基金supported by the Fifth 333 High-Level Talents Project of Jiangsu Province under Grant BRA2017443the Key Research Base of Jiangsu University Philosophy and Social Science under Grant 2018ZDJD-B007.
文摘Fatal traffic accidents in urban areas can adversely affect the urban road traffic system and pose many challenges for urban traffic management.Therefore,it is necessary to first classify emergency responses to such accidents and then handle them quickly and correctly.The aim of this paper is to develop an evaluation index system and to use appropriate methods to investigate emergency-response classifications to fatal traffic accidents in Chinese urban areas.This study used a multilevel hierarchical structural model to determine emergency-response classification.In the model,accident attributes,urban road network vulnerability,and institutional resilience were used as classification criteria.Each evaluation indicator was selected according to importance ranking and independence screening and was given an interpretation and a quantitative criterion.The Fuzzy Delphi Method was used to rank the importance of the evaluation indices and the combined weight of each index was calculated using the G1 method.Finally,the case of a fatal traffic accident was used to validate the model.The results showed that the multilevel hierarchical structural model,Fuzzy Delphi Method,and G1 method can effectively address the problem of emergency-response classification.Because of its simplicity and adaptability,the approach presented here could be useful for decisionmakers and practitioners for determining emergency-response classifications.
基金Sponsored by National Natural Science Fund(51508471)Philosophy and Social Science Project of Sichuan Province(MD16E017)+2 种基金Soft Science Project of Chengdu City(2015-RK00-00270-ZF)Operating Costs of Innovation Project of Science and Engineering in Colleges and Universities Administrated by Ministries and Their Attached Institutions in 2017(2682017CX016)Teaching Research and Reform Project for Undergraduate Education of Southwest Jiaotong University in 2017(201704048)
文摘This paper, based on the literature review and field investigation, studied the status quo of maker spaces in main urban district of Chengdu at a time when the development of the maker spaces has received strong support from national and local governments. In addition to introducing the related concepts and policy support of the maker space, it summarized its distribution characteristics, audience characteristics, and status quo as well as problems and presented the direction for the development of the maker space in main urban area of Chengdu grounded on a survey of the status quo of national maker spaces in main urban area of Chengdu.
文摘The current situation,existing problems and characteristics of greening in the main urban area of Taizhou were analyzed,and the construction ideas and safeguard measures of plain greening in urban areas in the new era were put forward.
基金Supported by Science Research Fund of Yunnan Provincial Department of Education(2017ZZX090)Key Scientific Research Project of University(XJZD1602)Open Fund Project of Key Laboratories for the Opening and Utilization of Characteristic Biological Resources in Colleges and Universities of Yunnan Province,Kunming University(GXKZ201714)
文摘Sponge city construction,as an important measure of ecological construction in China,can effectively solve a series of problems such as large annual runoff,serious non-point source pollution,regional water shortage,low utilization rate of rain and flood resources,unsustainable ecological benefits of water landscape and poor landscape functions in urbanization construction. This paper uses LID concept to construct sponge city in the old urban area of Kunming,to reduce the total runoff and promote the utilization of rainfall and flood resources so as to rebuild,upgrade and optimize the regional environment and provide some reference for the regional construction of small-scale sponge city.
文摘Multi-storey housing for low income society is a concept of redevelopment from many alternatives of housing development for slum in Jakarta. However, redevelopment directly or indirectly leads to displacement of low-income residents. The new residents would be of a higher socio-economic status than the previous occupants. For controlling this phenomenon, a study about the influence of displacement to the successful of sustainable multi-storey housing development for low-income society has been done with descriptive method, observation and literature study. The result of this study give knowledge that displacement always happened when the quality of building and environment is increase, the location of multi-storey housing is near city center and commercial area. Low income society voluntary displaced their units to middle or high income society, because they are not affordable for paying operational and maintenance costs. The government has to make regulations for controlling displacement on multi-storey housing for low-income society and for the successful of sustainable multi-storey housing development in urban area.
文摘Under the background of"people-oriented"thought and"green transportation",the idea of"priority for non-motor vehicles"came into being,which can improve the riding environment of non-motor vehicle riders to a certain extent.According to the current situation of priority for non-motor vehicles in the old urban area of Nanchang,through field investigation,questionnaire investigation and interview,this study summarized the existing problems,and put forward optimization suggestions for these problems,in order to provide reference for areas with similar conditions.
