Surface ozone(O3)and fine particulate matter(PM2.5)are dominant air pollutants in China.Concentrations of these pollutants can show significant differences between urban and nonurban areas.However,such contrast has ne...Surface ozone(O3)and fine particulate matter(PM2.5)are dominant air pollutants in China.Concentrations of these pollutants can show significant differences between urban and nonurban areas.However,such contrast has never been explored on the country level.This study investigates the spatiotemporal characteristics of urban-to-suburban and urban-tobackground difference for O3(Δ[O3])and PM2.5(Δ[PM2.5])concentrations in China using monitoring data from 1171 urban,110 suburban,and 15 background sites built by the China National Environmental Monitoring Center(CNEMC).On the annual mean basis,the urban-to-suburbanΔ[O3]is−3.7 ppbv in Beijing-Tianjin-Hebei,1.0 ppbv in the Yangtze River Delta,−3.5 ppbv in the Pearl River Delta,and−3.8 ppbv in the Sichuan Basin.On the contrary,the urban-to-suburbanΔ[PM2.5]is 15.8,−0.3,3.5 and 2.4μg m^−3 in those areas,respectively.The urban-to-suburban contrast is more significant in winter for bothΔ[O3]andΔ[PM2.5].In eastern China,urban-to-background differences are also moderate during summer,with−5.1 to 6.8 ppbv forΔ[O3]and−0.1 to 22.5μg m^−3 forΔ[PM2.5].However,such contrasts are much larger in winter,with−22.2 to 5.5 ppbv forΔ[O3]and 3.1 to 82.3μg m^−3 forΔ[PM2.5].Since the urban region accounts for only 2%of the whole country’s area,the urban-dominant air quality data from the CNEMC network may overestimate winter[PM2.5]but underestimate winter[O3]over the vast domain of China.The study suggests that the CNEMC monitoring data should be used with caution for evaluating chemical models and assessing ecosystem health,which require more data outside urban areas.展开更多
Forty middle and small rivers in three towns of Fengjing, Songjiang and Zhujiajiao of suburban Shanghai were chosen as sampling sites for water quality research. Measurement results of DO, CODCr, TP, TN and so on show...Forty middle and small rivers in three towns of Fengjing, Songjiang and Zhujiajiao of suburban Shanghai were chosen as sampling sites for water quality research. Measurement results of DO, CODCr, TP, TN and so on show that the rivers are under heavy eutropic conditions, which are several times greater than the critical values of the worst level (Type V) of water. Water pollution situation has different temporal and spatial characteristics. Non-point pollution, such as village domestic sewage, farmland runoff, livestock feces, has become the primary source of pollution of the middle and small rivers in suburban Shanghai.展开更多
Suburbanization is a stage of urbanization provess. The author discesses the situation of Beijing from the data of three population censuses(1964, 1982, 1990) and considers that the suburbanization in Beijing has been...Suburbanization is a stage of urbanization provess. The author discesses the situation of Beijing from the data of three population censuses(1964, 1982, 1990) and considers that the suburbanization in Beijing has been in process since 1982. During 1982-1990, population of all districts of the inner city lost 82 000 persons and in fact the permanent residents holding the household registration lost 144 000, which is about 6. 12% of permanent residents in the inner city.Like the West, suburbanization in China the happened against the macro backgrounds of improvements of transportation and loving conditions, growth of urban population moving from rural areas. But in the case of the forces that make decentralization possible, China is different from the western countries. In China, the levels of economy and urbanization are rather low, the red middle class is not rich; only very few Chinese families families provate cars, and the inner cities still have great attraction to Chinese people. The author considers three causes of decentralization: (1) reform of urban land use system brings about migration from the core area; (2) construction of a large number of city roads reinforces this process; (3) reforms of housing system and renovation of dilapidated houses encourage outward movement. However, the process wasn’t of spontaneity of any individual but of the leadership of government and “Dan Wei” (Work Unit).展开更多
Along with the development of urban economy. the growth of urban population and the increase of needs of urban society, the suburban ecological and economic system changes constantly and profoundly in its structure an...Along with the development of urban economy. the growth of urban population and the increase of needs of urban society, the suburban ecological and economic system changes constantly and profoundly in its structure and function.Intensifying the research on structural analysis of suburban ecological and economic system is of great significance for grasping light the laws governing the development and evolution of the suburban ecological and economic system and leading this system onto a path of sound circle. By making comprehensive use of the cluster analysis and latent structural analysis the author attempts to explore a new avenue of revealing the structure of suburban ecological and economic system, taking Tianjin suburbs and counties as an example. The results obtained from the above-stated analyses show that it is entirely possible and extremely effective to study the structure and function of suburban ecological and economic system and provide scientific evidence for control of this system by using mathematical methods and statistical analyses.展开更多
On the basis of comparative analysis on the vegetable input-output efficiency of suburban and rural areas in 2011- 2012,this paper made co-integration test,impulse response and variance decomposition for the vegetable...On the basis of comparative analysis on the vegetable input-output efficiency of suburban and rural areas in 2011- 2012,this paper made co-integration test,impulse response and variance decomposition for the vegetable input-output relationship of suburban areas in 1998-2012. Comparative analysis indicated that the vegetable input-output benefit of suburban area declines,while that of rural area rises; empirical analysis indicated that there is a long-term stable relationship between labor cost of vegetable planting and vegetable income and between material cost of vegetable planting and vegetable income,but the vegetable income itself has certain lag effect,followed by material cost,and the labor cost has minimum influence. Finally,it came up with recommendations for improving suburban vegetable input-output relationship,including improving vegetable input security mechanism,improving farmers' quality and innovation ability,and increasing technological input.展开更多
Bicycling is an important way for college students and employees to get around campuses. With a rise in bicycling on campuses there comes a rise in bicycle collisions with pedestrians walking to and from classes and w...Bicycling is an important way for college students and employees to get around campuses. With a rise in bicycling on campuses there comes a rise in bicycle collisions with pedestrians walking to and from classes and work. The literature review showed many papers involving bicycle conflict modeling but on roads with motor vehicles. While some aspects of this research can be applied to non-motorized paths, there is a lack of research strictly focusing on only bicycles and pedestrians. This study aims to fill this knowledge gap by developing a model to identify locations on roads and paths (hotspots) on college campuses that are likely to have a bicycle collision and predict the likelihood of a serious bicycle crash on a non-motorized path based on the characteristics of the path. This study identifies those interactions between bicyclists and pedestrians on non-motorized paths on a suburban college campus in Newark, USA. Findings suggest that pedestrian density of a path is a major factor in the maximum speed bicyclists can achieve. The wider the path is, the higher the maximum speed is that a bicyclist can obtain. This is because a wider path width decreases the pedestrian density. The grade of the path has little effect on bicycle speeds. The results of the models were displayed on a GIS map that is visually appealing to a viewer. The paths were color coded based on their level of safety, so it is easy to observe problematic areas of the network. This technique can be applied to the entire campus network of non-motorized paths to study the whole system. This can then be used by planners and designers to identify areas that need upgrading and improve the overall safety of the non-motorized path system.展开更多
On the basis of analyzing the development of suburban forest parks, the paper proposed the combination of eco-city construction and suburban forest parks, and the construction of "mega-landscape" mode, which...On the basis of analyzing the development of suburban forest parks, the paper proposed the combination of eco-city construction and suburban forest parks, and the construction of "mega-landscape" mode, which offers a new concept for the development of suburban forest parks.展开更多
Objective:To provide baseline information of parasitic infections in 3 suburban government schools,Lakhok subdistrict of Muang Pathum Thani,Thailand.Methods:This study was conducted between May-June 2010 using simple ...Objective:To provide baseline information of parasitic infections in 3 suburban government schools,Lakhok subdistrict of Muang Pathum Thani,Thailand.Methods:This study was conducted between May-June 2010 using simple direct smear and modified formalin ether and from a population of 1253 in 3 suburban government schools.Results:Total samples of 202registered and participated.The average of prevalence of infection from 3 schools was 13.9%,there were 13.7%,14.3%and 13.9%in N,S and R school,respectively with no significant difference between schools(P>0.05).The infection rates did not show significant difference between gender(P>0.05).The highest rate of infection was 20.4%in Pathom 2(8 years)students and the lowest was4%in Pathom 1(7 years)with statistically difference between age groups(P<0.05).The highest prevalence of pathogenic protozoa was Giardia lamblin(G.lamblia)which was found in 50%of infected cases,followed by 25%of Entamoeba Inictolytica(E.histolytica)and Blastocystis hominis(B.hominis).The highest prevalence of non-pathogenic protozoa was Endnhmat nano(E.nana)which was found in 88.9%,followed by 11.1%of Entamoeba coli(E.coli).Mixed infections between Blastocwstis hominis(B.hominis)and Endolimax nana(E.nana)were reported at 7.1%.The only helminthic infection found in this study area was hookworm,found in 1 student(3.8%).The formalin ether concentration technique showed a higher efficacy of detection(78%-100%)than the simple direct smear method(0%-50%).Conclusions:Surveillance of protozoan infections may need to be focused on suburban areas.展开更多
The characteristics and evolutions of the landscape patterns in the suburban ecotone are studied on the basis of landscape-ecological maps of different years derived from the corresponding aerial photos The relationsh...The characteristics and evolutions of the landscape patterns in the suburban ecotone are studied on the basis of landscape-ecological maps of different years derived from the corresponding aerial photos The relationship between landscape patterns and urban economical development is ana- lyzed. The diversity index is used to characterize the features of the landscape patterns in the ecotone and define the location of Sharp change.展开更多
Suburban sightseeing farm has always been restrained by such problems as focusing on form and visual effect, low design level, poor depth, similarity with others, poor sustainability and so on. This paper proposed maj...Suburban sightseeing farm has always been restrained by such problems as focusing on form and visual effect, low design level, poor depth, similarity with others, poor sustainability and so on. This paper proposed major characteristics of sightseeing farm design based on core connotations of behavior-driven design from the perspective of cognitive psychology. Cases were taken to analyze the design techniques of sightseeing farm, and it was concluded that sightseeing farm design based on behavior-driven perspective should orient to performancebased, refi ned, individualized and participatory from the four perspectives of highlighting functions, deepening the details, stressing originality, and optimizing experience, in order to provide new thoughts for solving existing problems of current sightseeing farm design.展开更多
Rural-urban development project in an ejidal community (portion of common land several owners) is located in the suburban area of Xalapa, Veracruz, Mexico.The place where the community is located has a lagoon that was...Rural-urban development project in an ejidal community (portion of common land several owners) is located in the suburban area of Xalapa, Veracruz, Mexico.The place where the community is located has a lagoon that was contaminated with water lily. Now we want to implement a suburban sustainable development project using ecological and appropriate technologies to the community and the place, taking advantage of that body of water to grow fish and as a recreational area for visitors and thus generating food and economic resources in favor of the community with the food sales, boat rentals and recreational spaces.The project adds to the achievement of 12 of the 17 Sustainable Development Goals of the United Nations Organization.展开更多
On the basis of introducing the connotation of agricultural industrial chain, taking Yongle Town in Nanming District of Guiyang City as an example, this paper analyzes the advantages and constraint factors of the subu...On the basis of introducing the connotation of agricultural industrial chain, taking Yongle Town in Nanming District of Guiyang City as an example, this paper analyzes the advantages and constraint factors of the suburban villages and towns in the process of expanding agricultural industrial chain in the context of urbanization. Corresponding strategies of expanding the agricultural industrial chain of Yongle Town in the process of urbanization as follows: vigorously develop the leading enterprises; strengthen the construction of farmers' specialized cooperatives and agricultural associations; build and perfect agricultural industrial chain organizations; set up the public information platform; rely on the food industrial park to propel the deep processing of agricultural products; vigorously develop the logistics of agricultural products; promote the development of operation model of "brand+ standard+ scale"; vigorously develop ecology-oriented rural tourism; give full play to the functional role of the government.展开更多
The role of retailing has diminished in the center of cities of Western countries since its heyday in the 1920s. This trend was caused by violent transformations in the economic, social and locational contexts which i...The role of retailing has diminished in the center of cities of Western countries since its heyday in the 1920s. This trend was caused by violent transformations in the economic, social and locational contexts which involve resi- dential suburbanization, as well as new forms of commercial development out of town. As far as transforming China is concerned, the downtown retailing center has also come to turning point of development in the context of suburbaniza- tion. Based on the survey of Beijing residents’ shopping behavior, the present research tends to making clear the actual change and development problem of downtown retailing center. Combining with the macro retailing environment, re- lated influencing factors are further discussed too. Study results show that downtown retailing still plays an important part in resident’s shopping activity. However, with rapid urban sprawl, retailing in urban center has been greatly threatened by booming out-of-town commerce. In the course of such spatial change, the suburbanization of resident, the prevalence of new commercial forms and the change of consumers’ life style all have exerted their own pressure on downtown retailing. But for the special socioeconomic background of development and the support of government policy, it will still keep its vitality of retailing for a long period of time.展开更多
This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic...This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic density function approach,we employ the nonparametric analysis to characterize the spatial pattern of population densities in the Beijing metropolitan area and identify the suburban subcenters.Our findings suggest that the population has spread with rapid urban growth in the Beijing metropolitan area,and the compact urban form has been replaced by a more dispersed polycentric spatial distribution.However,compared with the decentralization of western cities,the spatial extent of the decentralization of population in the Beijing metropolitan area is quite limited.The rapid growth of population in the near suburbs has expedited the sprawl of the central city,with a larger central agglomeration of population dominating the metropolitan area.In this sense,the spatial pattern of the Beijing metropolitan area is still characterized by the continuous compactness.However,our findings do provide the evidence that the city has been turning to a polycentric structure.We find significant population subcenters have emerged in the suburbs of Beijing since the 1980s.But the polycentricity emerged in the Beijing metropolitan area is very different by nature from that observed in Western cities.The subcenters emerged are adherent to the development scheme planned for the city,so it can be referred to as the so called 'planned polycentricity'.展开更多
This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics i...This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics in each category, based on which, some further studies such as regional manners of residential wood burning emission (PM2.5, the term used for a mixture of solid particles and liquid droplets found in the air, refers to particulate matter that is 2.5μm or smaller in size) could be carried out for the project of residential wood combustion. Demographic and infrastructure data with spatial characteristics were processed by integrating both Geographic Information System (GIS) and statistics method (Cluster Analysis), and then output to a category map as the result. It approached the quantitative and multi-variables description on the major characteristics variations among the urban, suburban and rural; and perfected the TIGER’s urban-rural classification scheme by adding suburban category. Based on the free public GIS data, the spatial analysis method provides an easy and ideal tool for geographic researchers, environmental planners, urban/regional planners and administrators to delineate different categories of regional function on the specific locations and dig out spatial distribution information they wanted. Furthermore, it allows for future adjustment on some parameters as the spatial analysis method is implemented in the different regions or various eco-social models.展开更多
Source apportionment of particulate matters with aerodynamic diameter less than 10 μm (PM_(10)) was conducted in the suburban area of Changsha, China. PM10 samples for 24 h collected with TEOM 1400a and ACCU system i...Source apportionment of particulate matters with aerodynamic diameter less than 10 μm (PM_(10)) was conducted in the suburban area of Changsha, China. PM10 samples for 24 h collected with TEOM 1400a and ACCU system in July and October 2008 were chemically analyzed by the wavelength dispersive X-ray fluorescence (WD-XRF). Source appointment was implemented by the principal component analysis/absolute principal component analysis (PCA/APCA) to identify the possible sources and to quantify the contributions of the sources to PM_(10). Results show that as the PM_(10) concentration is increased from (85.6±43.7) μg/m^3 in July 2008 to (107.6±35.7) μg/m^3 in October 2008, the concentrations of the anthropogenic elements (P, S, Cl, K, Mn, Ni, Cu, Zn, and Pb) are basically increased but concentrations of the natural elements (Na, Mg, Al, Si, Ca, Ti, and Fe) are essentially decreased. Six main sources of PM_(10) are identified in the suburban of Changsha, China: soil dust, secondary aerosols, domestic oil combustion, waste incineration, traffic emission, and industrial emission contribute 57.7%, 24.0%, 9.8%, 5.0%, 2.0%, and 1.5%, respectively. Soil dust and secondary aerosols are the two major sources of particulate air pollution in suburban area of Changsha, China, so effective measures should be taken to control these two particulate pollutants.展开更多
Objective To evaluate levels of lead(Pb) and cadmium(Cd) in the breast milk in the second postpartum month,to investigate the relationship between Pb/Cd levels in breast milk and some sociodemographic parameters,and t...Objective To evaluate levels of lead(Pb) and cadmium(Cd) in the breast milk in the second postpartum month,to investigate the relationship between Pb/Cd levels in breast milk and some sociodemographic parameters,and to explore whether these levels affect the infants' physical status or the mothers' psychological status(postpartum depression).Methods A cross-sectional study was conducted between November 2009 and December 2010.Altogether 170 healthy mothers were enrolled from Nanjing Maternity and Child Health Care Hospital.The inclusion criteria were:voluntary to participate in this study,healthy,with no chronic disease,breastfeeding in the second postpartum month,living in a suburban but not non-industrial area of Nanjing,and not occupationally exposed to toxic metals.All the mothers completed a questionnaire and were evaluated based on the Edinburgh Postpartum Depression Scale(EPDS) to identify the risk of postpartum depression.Pb and Cd levels in breast milk were determined by inductively coupled plasma mass spectroscopy.The infants of these mothers were examined for their z scores of weight for age,length for age,head circumference for age,and body mass index for age.Results The median breast milk levels of Pb and Cd were 40.6 μg/L and 0.67 μg/L,respectively.In 164(96.5%) of the 170 samples,Pb levels were higher than the limit reported by the World Health Organization(> 5 μg/L).Breast milk Cd level was > 1 μg/L in 54(31.8%) mothers.The mothers with a history of anemia had a higher breast milk Pb level than those without a history of anemia(41.1 μg/L vs.37.9 μg/L,P = 0.050).The median breast milk Cd level in those who were active and passive smokers during pregnancy was significantly higher than that in non-smokers(0.88 μg/L vs.0.00 μg/L,P = 0.025).The breast milk Cd level in the mothers not taking iron and vitamin supplements for 2 months postpartum was higher than in those taking the supplements(iron supplement:0.74 μg/L vs.0.00 μg/L,P = 0.025;vitamin supplement:0.78 μg/L vs.0.00 μg/L,P = 0.005).Breast milk Cd level at the second postpartum month was negatively correlated with the z scores of head circumference(r = 0.248,P = 0.042) and weight for age at birth(r = 0.241,P = 0.024) in girls.No correlation was found between the breast milk Pb/Cd levels and the EPDS scores.Conclusion Considering the high levels of Pb and Cd in breast milk in this study,breast milk monitoring programs are necessary.展开更多
Suburban leisure and tourism are important supplements to the suburban economic development and urban tourism and of great significance under the background of urban-rural integration. Tourism development of Wangcong ...Suburban leisure and tourism are important supplements to the suburban economic development and urban tourism and of great significance under the background of urban-rural integration. Tourism development of Wangcong Shrine in Chengdu is still in the initial stage. Regarding the development of tourism, Wangcong Shrine owns the advantage of environment, transportation, economy and history, but the disadvantage of landscape, architecture, content, identity, and publicity as well. Development of suburban leisure travel is one direction of tourism development of Wangcong Shrine. The people of Chengdu are main target tourists of a one-day trip. And various parks, Farmer's House Tour, leisure villa and other suburban attractions are its competitors. To developing Wangcong Shrine tourism, increase of historical contents is its focus. The positioning of the civilization of ancient Shu should be shifted to Shu civilization; and renewal of the Huangcheng (Imperial City) is necessary to attract more Chengdu people for short tour and leisure.展开更多
Suburbanization in large cities is an important phenomenon in the process of urbanization development in China in recent decades,which plays a very important role in promoting city development,whereas some side effect...Suburbanization in large cities is an important phenomenon in the process of urbanization development in China in recent decades,which plays a very important role in promoting city development,whereas some side effects on the eco-environment appeared at the same time.This paper,taking Xi'an City in China as a case study site,analyzed the features of population suburbanization and industry suburbanization and pointed out the impacts of suburbanization on urban eco-environment.Based on the research,suggestions of countermeasures for urban planning and municipal management of Xi'an City in protecting urban eco-environment and conserving natural ecology were put forward in the end.展开更多
基金This work was jointly supported by the National Key Research and Development Program of China(Grant No.2019YFA0606802)the National Natural Science Foundation of China(Grant No.41975155).
文摘Surface ozone(O3)and fine particulate matter(PM2.5)are dominant air pollutants in China.Concentrations of these pollutants can show significant differences between urban and nonurban areas.However,such contrast has never been explored on the country level.This study investigates the spatiotemporal characteristics of urban-to-suburban and urban-tobackground difference for O3(Δ[O3])and PM2.5(Δ[PM2.5])concentrations in China using monitoring data from 1171 urban,110 suburban,and 15 background sites built by the China National Environmental Monitoring Center(CNEMC).On the annual mean basis,the urban-to-suburbanΔ[O3]is−3.7 ppbv in Beijing-Tianjin-Hebei,1.0 ppbv in the Yangtze River Delta,−3.5 ppbv in the Pearl River Delta,and−3.8 ppbv in the Sichuan Basin.On the contrary,the urban-to-suburbanΔ[PM2.5]is 15.8,−0.3,3.5 and 2.4μg m^−3 in those areas,respectively.The urban-to-suburban contrast is more significant in winter for bothΔ[O3]andΔ[PM2.5].In eastern China,urban-to-background differences are also moderate during summer,with−5.1 to 6.8 ppbv forΔ[O3]and−0.1 to 22.5μg m^−3 forΔ[PM2.5].However,such contrasts are much larger in winter,with−22.2 to 5.5 ppbv forΔ[O3]and 3.1 to 82.3μg m^−3 forΔ[PM2.5].Since the urban region accounts for only 2%of the whole country’s area,the urban-dominant air quality data from the CNEMC network may overestimate winter[PM2.5]but underestimate winter[O3]over the vast domain of China.The study suggests that the CNEMC monitoring data should be used with caution for evaluating chemical models and assessing ecosystem health,which require more data outside urban areas.
基金National Natural Science Foundation of China No.40131020+4 种基金 No.40173030 Key Project for Basic Research of Shanghai No.02DJ14029 Project Foundation for Excellent Young Teachers of the Ministry of Education of China Ration Research of Phosphorus and
文摘Forty middle and small rivers in three towns of Fengjing, Songjiang and Zhujiajiao of suburban Shanghai were chosen as sampling sites for water quality research. Measurement results of DO, CODCr, TP, TN and so on show that the rivers are under heavy eutropic conditions, which are several times greater than the critical values of the worst level (Type V) of water. Water pollution situation has different temporal and spatial characteristics. Non-point pollution, such as village domestic sewage, farmland runoff, livestock feces, has become the primary source of pollution of the middle and small rivers in suburban Shanghai.
文摘Suburbanization is a stage of urbanization provess. The author discesses the situation of Beijing from the data of three population censuses(1964, 1982, 1990) and considers that the suburbanization in Beijing has been in process since 1982. During 1982-1990, population of all districts of the inner city lost 82 000 persons and in fact the permanent residents holding the household registration lost 144 000, which is about 6. 12% of permanent residents in the inner city.Like the West, suburbanization in China the happened against the macro backgrounds of improvements of transportation and loving conditions, growth of urban population moving from rural areas. But in the case of the forces that make decentralization possible, China is different from the western countries. In China, the levels of economy and urbanization are rather low, the red middle class is not rich; only very few Chinese families families provate cars, and the inner cities still have great attraction to Chinese people. The author considers three causes of decentralization: (1) reform of urban land use system brings about migration from the core area; (2) construction of a large number of city roads reinforces this process; (3) reforms of housing system and renovation of dilapidated houses encourage outward movement. However, the process wasn’t of spontaneity of any individual but of the leadership of government and “Dan Wei” (Work Unit).
文摘Along with the development of urban economy. the growth of urban population and the increase of needs of urban society, the suburban ecological and economic system changes constantly and profoundly in its structure and function.Intensifying the research on structural analysis of suburban ecological and economic system is of great significance for grasping light the laws governing the development and evolution of the suburban ecological and economic system and leading this system onto a path of sound circle. By making comprehensive use of the cluster analysis and latent structural analysis the author attempts to explore a new avenue of revealing the structure of suburban ecological and economic system, taking Tianjin suburbs and counties as an example. The results obtained from the above-stated analyses show that it is entirely possible and extremely effective to study the structure and function of suburban ecological and economic system and provide scientific evidence for control of this system by using mathematical methods and statistical analyses.
基金Supported by Special Project for Vegetable Innovation Team Construction of Shandong Modern Agriculture Industrial Technology System(SDAIT-02-022-13)
文摘On the basis of comparative analysis on the vegetable input-output efficiency of suburban and rural areas in 2011- 2012,this paper made co-integration test,impulse response and variance decomposition for the vegetable input-output relationship of suburban areas in 1998-2012. Comparative analysis indicated that the vegetable input-output benefit of suburban area declines,while that of rural area rises; empirical analysis indicated that there is a long-term stable relationship between labor cost of vegetable planting and vegetable income and between material cost of vegetable planting and vegetable income,but the vegetable income itself has certain lag effect,followed by material cost,and the labor cost has minimum influence. Finally,it came up with recommendations for improving suburban vegetable input-output relationship,including improving vegetable input security mechanism,improving farmers' quality and innovation ability,and increasing technological input.
文摘Bicycling is an important way for college students and employees to get around campuses. With a rise in bicycling on campuses there comes a rise in bicycle collisions with pedestrians walking to and from classes and work. The literature review showed many papers involving bicycle conflict modeling but on roads with motor vehicles. While some aspects of this research can be applied to non-motorized paths, there is a lack of research strictly focusing on only bicycles and pedestrians. This study aims to fill this knowledge gap by developing a model to identify locations on roads and paths (hotspots) on college campuses that are likely to have a bicycle collision and predict the likelihood of a serious bicycle crash on a non-motorized path based on the characteristics of the path. This study identifies those interactions between bicyclists and pedestrians on non-motorized paths on a suburban college campus in Newark, USA. Findings suggest that pedestrian density of a path is a major factor in the maximum speed bicyclists can achieve. The wider the path is, the higher the maximum speed is that a bicyclist can obtain. This is because a wider path width decreases the pedestrian density. The grade of the path has little effect on bicycle speeds. The results of the models were displayed on a GIS map that is visually appealing to a viewer. The paths were color coded based on their level of safety, so it is easy to observe problematic areas of the network. This technique can be applied to the entire campus network of non-motorized paths to study the whole system. This can then be used by planners and designers to identify areas that need upgrading and improve the overall safety of the non-motorized path system.
基金Sponsored by"Twelfth Five-year Plan"of Jiangxi Provincial Social Sciences Program(14SH05)
文摘On the basis of analyzing the development of suburban forest parks, the paper proposed the combination of eco-city construction and suburban forest parks, and the construction of "mega-landscape" mode, which offers a new concept for the development of suburban forest parks.
文摘Objective:To provide baseline information of parasitic infections in 3 suburban government schools,Lakhok subdistrict of Muang Pathum Thani,Thailand.Methods:This study was conducted between May-June 2010 using simple direct smear and modified formalin ether and from a population of 1253 in 3 suburban government schools.Results:Total samples of 202registered and participated.The average of prevalence of infection from 3 schools was 13.9%,there were 13.7%,14.3%and 13.9%in N,S and R school,respectively with no significant difference between schools(P>0.05).The infection rates did not show significant difference between gender(P>0.05).The highest rate of infection was 20.4%in Pathom 2(8 years)students and the lowest was4%in Pathom 1(7 years)with statistically difference between age groups(P<0.05).The highest prevalence of pathogenic protozoa was Giardia lamblin(G.lamblia)which was found in 50%of infected cases,followed by 25%of Entamoeba Inictolytica(E.histolytica)and Blastocystis hominis(B.hominis).The highest prevalence of non-pathogenic protozoa was Endnhmat nano(E.nana)which was found in 88.9%,followed by 11.1%of Entamoeba coli(E.coli).Mixed infections between Blastocwstis hominis(B.hominis)and Endolimax nana(E.nana)were reported at 7.1%.The only helminthic infection found in this study area was hookworm,found in 1 student(3.8%).The formalin ether concentration technique showed a higher efficacy of detection(78%-100%)than the simple direct smear method(0%-50%).Conclusions:Surveillance of protozoan infections may need to be focused on suburban areas.
文摘The characteristics and evolutions of the landscape patterns in the suburban ecotone are studied on the basis of landscape-ecological maps of different years derived from the corresponding aerial photos The relationship between landscape patterns and urban economical development is ana- lyzed. The diversity index is used to characterize the features of the landscape patterns in the ecotone and define the location of Sharp change.
文摘Suburban sightseeing farm has always been restrained by such problems as focusing on form and visual effect, low design level, poor depth, similarity with others, poor sustainability and so on. This paper proposed major characteristics of sightseeing farm design based on core connotations of behavior-driven design from the perspective of cognitive psychology. Cases were taken to analyze the design techniques of sightseeing farm, and it was concluded that sightseeing farm design based on behavior-driven perspective should orient to performancebased, refi ned, individualized and participatory from the four perspectives of highlighting functions, deepening the details, stressing originality, and optimizing experience, in order to provide new thoughts for solving existing problems of current sightseeing farm design.
文摘Rural-urban development project in an ejidal community (portion of common land several owners) is located in the suburban area of Xalapa, Veracruz, Mexico.The place where the community is located has a lagoon that was contaminated with water lily. Now we want to implement a suburban sustainable development project using ecological and appropriate technologies to the community and the place, taking advantage of that body of water to grow fish and as a recreational area for visitors and thus generating food and economic resources in favor of the community with the food sales, boat rentals and recreational spaces.The project adds to the achievement of 12 of the 17 Sustainable Development Goals of the United Nations Organization.
文摘On the basis of introducing the connotation of agricultural industrial chain, taking Yongle Town in Nanming District of Guiyang City as an example, this paper analyzes the advantages and constraint factors of the suburban villages and towns in the process of expanding agricultural industrial chain in the context of urbanization. Corresponding strategies of expanding the agricultural industrial chain of Yongle Town in the process of urbanization as follows: vigorously develop the leading enterprises; strengthen the construction of farmers' specialized cooperatives and agricultural associations; build and perfect agricultural industrial chain organizations; set up the public information platform; rely on the food industrial park to propel the deep processing of agricultural products; vigorously develop the logistics of agricultural products; promote the development of operation model of "brand+ standard+ scale"; vigorously develop ecology-oriented rural tourism; give full play to the functional role of the government.
基金Under the auspices of the National Natural Science Foundation of China (No. 40171034)
文摘The role of retailing has diminished in the center of cities of Western countries since its heyday in the 1920s. This trend was caused by violent transformations in the economic, social and locational contexts which involve resi- dential suburbanization, as well as new forms of commercial development out of town. As far as transforming China is concerned, the downtown retailing center has also come to turning point of development in the context of suburbaniza- tion. Based on the survey of Beijing residents’ shopping behavior, the present research tends to making clear the actual change and development problem of downtown retailing center. Combining with the macro retailing environment, re- lated influencing factors are further discussed too. Study results show that downtown retailing still plays an important part in resident’s shopping activity. However, with rapid urban sprawl, retailing in urban center has been greatly threatened by booming out-of-town commerce. In the course of such spatial change, the suburbanization of resident, the prevalence of new commercial forms and the change of consumers’ life style all have exerted their own pressure on downtown retailing. But for the special socioeconomic background of development and the support of government policy, it will still keep its vitality of retailing for a long period of time.
基金Under the auspices of National Key Basic Research Program of China (No. 2012CB955802)National Natural Science Foundation of China (No. 41001069)Grant Program of National Social Science Foundation of China (No.10zd&022)
文摘This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic density function approach,we employ the nonparametric analysis to characterize the spatial pattern of population densities in the Beijing metropolitan area and identify the suburban subcenters.Our findings suggest that the population has spread with rapid urban growth in the Beijing metropolitan area,and the compact urban form has been replaced by a more dispersed polycentric spatial distribution.However,compared with the decentralization of western cities,the spatial extent of the decentralization of population in the Beijing metropolitan area is quite limited.The rapid growth of population in the near suburbs has expedited the sprawl of the central city,with a larger central agglomeration of population dominating the metropolitan area.In this sense,the spatial pattern of the Beijing metropolitan area is still characterized by the continuous compactness.However,our findings do provide the evidence that the city has been turning to a polycentric structure.We find significant population subcenters have emerged in the suburbs of Beijing since the 1980s.But the polycentricity emerged in the Beijing metropolitan area is very different by nature from that observed in Western cities.The subcenters emerged are adherent to the development scheme planned for the city,so it can be referred to as the so called 'planned polycentricity'.
文摘This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics in each category, based on which, some further studies such as regional manners of residential wood burning emission (PM2.5, the term used for a mixture of solid particles and liquid droplets found in the air, refers to particulate matter that is 2.5μm or smaller in size) could be carried out for the project of residential wood combustion. Demographic and infrastructure data with spatial characteristics were processed by integrating both Geographic Information System (GIS) and statistics method (Cluster Analysis), and then output to a category map as the result. It approached the quantitative and multi-variables description on the major characteristics variations among the urban, suburban and rural; and perfected the TIGER’s urban-rural classification scheme by adding suburban category. Based on the free public GIS data, the spatial analysis method provides an easy and ideal tool for geographic researchers, environmental planners, urban/regional planners and administrators to delineate different categories of regional function on the specific locations and dig out spatial distribution information they wanted. Furthermore, it allows for future adjustment on some parameters as the spatial analysis method is implemented in the different regions or various eco-social models.
基金Project (FANEDD 200545) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of China Project (50408019) supported by the National Natural Science Foundation of China Project (2008BAJ12B03) supported by National Key Project of Scientific and Technical Supporting Programs of China
文摘Source apportionment of particulate matters with aerodynamic diameter less than 10 μm (PM_(10)) was conducted in the suburban area of Changsha, China. PM10 samples for 24 h collected with TEOM 1400a and ACCU system in July and October 2008 were chemically analyzed by the wavelength dispersive X-ray fluorescence (WD-XRF). Source appointment was implemented by the principal component analysis/absolute principal component analysis (PCA/APCA) to identify the possible sources and to quantify the contributions of the sources to PM_(10). Results show that as the PM_(10) concentration is increased from (85.6±43.7) μg/m^3 in July 2008 to (107.6±35.7) μg/m^3 in October 2008, the concentrations of the anthropogenic elements (P, S, Cl, K, Mn, Ni, Cu, Zn, and Pb) are basically increased but concentrations of the natural elements (Na, Mg, Al, Si, Ca, Ti, and Fe) are essentially decreased. Six main sources of PM_(10) are identified in the suburban of Changsha, China: soil dust, secondary aerosols, domestic oil combustion, waste incineration, traffic emission, and industrial emission contribute 57.7%, 24.0%, 9.8%, 5.0%, 2.0%, and 1.5%, respectively. Soil dust and secondary aerosols are the two major sources of particulate air pollution in suburban area of Changsha, China, so effective measures should be taken to control these two particulate pollutants.
基金supported by Nanjing Maternity and Child Health Care Hospital
文摘Objective To evaluate levels of lead(Pb) and cadmium(Cd) in the breast milk in the second postpartum month,to investigate the relationship between Pb/Cd levels in breast milk and some sociodemographic parameters,and to explore whether these levels affect the infants' physical status or the mothers' psychological status(postpartum depression).Methods A cross-sectional study was conducted between November 2009 and December 2010.Altogether 170 healthy mothers were enrolled from Nanjing Maternity and Child Health Care Hospital.The inclusion criteria were:voluntary to participate in this study,healthy,with no chronic disease,breastfeeding in the second postpartum month,living in a suburban but not non-industrial area of Nanjing,and not occupationally exposed to toxic metals.All the mothers completed a questionnaire and were evaluated based on the Edinburgh Postpartum Depression Scale(EPDS) to identify the risk of postpartum depression.Pb and Cd levels in breast milk were determined by inductively coupled plasma mass spectroscopy.The infants of these mothers were examined for their z scores of weight for age,length for age,head circumference for age,and body mass index for age.Results The median breast milk levels of Pb and Cd were 40.6 μg/L and 0.67 μg/L,respectively.In 164(96.5%) of the 170 samples,Pb levels were higher than the limit reported by the World Health Organization(> 5 μg/L).Breast milk Cd level was > 1 μg/L in 54(31.8%) mothers.The mothers with a history of anemia had a higher breast milk Pb level than those without a history of anemia(41.1 μg/L vs.37.9 μg/L,P = 0.050).The median breast milk Cd level in those who were active and passive smokers during pregnancy was significantly higher than that in non-smokers(0.88 μg/L vs.0.00 μg/L,P = 0.025).The breast milk Cd level in the mothers not taking iron and vitamin supplements for 2 months postpartum was higher than in those taking the supplements(iron supplement:0.74 μg/L vs.0.00 μg/L,P = 0.025;vitamin supplement:0.78 μg/L vs.0.00 μg/L,P = 0.005).Breast milk Cd level at the second postpartum month was negatively correlated with the z scores of head circumference(r = 0.248,P = 0.042) and weight for age at birth(r = 0.241,P = 0.024) in girls.No correlation was found between the breast milk Pb/Cd levels and the EPDS scores.Conclusion Considering the high levels of Pb and Cd in breast milk in this study,breast milk monitoring programs are necessary.
文摘Suburban leisure and tourism are important supplements to the suburban economic development and urban tourism and of great significance under the background of urban-rural integration. Tourism development of Wangcong Shrine in Chengdu is still in the initial stage. Regarding the development of tourism, Wangcong Shrine owns the advantage of environment, transportation, economy and history, but the disadvantage of landscape, architecture, content, identity, and publicity as well. Development of suburban leisure travel is one direction of tourism development of Wangcong Shrine. The people of Chengdu are main target tourists of a one-day trip. And various parks, Farmer's House Tour, leisure villa and other suburban attractions are its competitors. To developing Wangcong Shrine tourism, increase of historical contents is its focus. The positioning of the civilization of ancient Shu should be shifted to Shu civilization; and renewal of the Huangcheng (Imperial City) is necessary to attract more Chengdu people for short tour and leisure.
文摘Suburbanization in large cities is an important phenomenon in the process of urbanization development in China in recent decades,which plays a very important role in promoting city development,whereas some side effects on the eco-environment appeared at the same time.This paper,taking Xi'an City in China as a case study site,analyzed the features of population suburbanization and industry suburbanization and pointed out the impacts of suburbanization on urban eco-environment.Based on the research,suggestions of countermeasures for urban planning and municipal management of Xi'an City in protecting urban eco-environment and conserving natural ecology were put forward in the end.