Hue-Saturation-Intensity （HSI） color model, a psychologically appealing color model, was employed to visualize uncertainty represented by relative prediction error based on the case of spatial prediction of pH of to...Hue-Saturation-Intensity （HSI） color model, a psychologically appealing color model, was employed to visualize uncertainty represented by relative prediction error based on the case of spatial prediction of pH of topsoil in the peri-urban Beijing. A two-dimensional legend was designed to accompany the visualization-vertical axis （hues） for visualizing the predicted values and horizontal axis （whiteness） for visualizing the prediction error. Moreover, different ways of visualizing uncertainty were briefly reviewed in this paper. This case study indicated that visualization of both predictions and prediction uncertainty offered a possibility to enhance visual exploration of the data uncertainty and to compare different prediction methods or predictions of totally different variables. The whitish region of the visualization map can be simply interpreted as unsatisfactory prediction results, where may need additional samples or more suitable prediction models for a better prediction results.展开更多
上海中加贸易有限公司是欧洲专业的高端品牌纺织设备代理商,涵盖了从纺纱、织造、染色和后整理几乎所有领域。经过二十多年的不懈努力,公司现已获得数十家国际著名品牌供应商在中国市场的授权全权代理,同时专业的销售和服务团队也得到...上海中加贸易有限公司是欧洲专业的高端品牌纺织设备代理商,涵盖了从纺纱、织造、染色和后整理几乎所有领域。经过二十多年的不懈努力,公司现已获得数十家国际著名品牌供应商在中国市场的授权全权代理,同时专业的销售和服务团队也得到了国内广大用户的认可、支持与厚爱。代理的品牌包括意大利的LAFER、CORGHI、MCS、KD、LORIS BELLINI、LA WER、FLAINOX、DETTIN、PLM、SAL V ADE、PUGI、ZANCANER、ITB、COLOSIO、AUTOTEX以及德国的BRUCKNER、DORNIER,日本村田等。展开更多
The present paper deals with the description of a new collembolan species, Homidia fascia, sp. nov., It shares some characters with H. tibetensis Chen & Zhong, 1998, however, can be distinguished from the ...The present paper deals with the description of a new collembolan species, Homidia fascia, sp. nov., It shares some characters with H. tibetensis Chen & Zhong, 1998, however, can be distinguished from the latter by color pattern, labial setae L 1 and R 2, posterior macrochaetae on Abd. IV and relative position of line connecting macrochaetae Pr & Ed to median furrow on ventral tube.展开更多
Taking Nanjing as a case, the paper explains the spatial behavior differences existing in the information technology use among different groups of residents and households, by virtue of analyzing the survey data of ur...Taking Nanjing as a case, the paper explains the spatial behavior differences existing in the information technology use among different groups of residents and households, by virtue of analyzing the survey data of urban households in the 11 districts of Nanjing, from the social, spatial, life and other non-technical angles. Also it makes various analyses and evaluation quantitatively and qualitatively on the social and spatial effect of information technology. The results show that the new technology is changing the social spatial behaviors of urban residents. New behavioral spaces of urban family such as telecommuting, email and QQ have begun to emerge. With the help of Internet, the communication scope of families has expanded greatly, and more new forms of publicizing community information have begun to emerge. Telecommunication contact forms have been developing swiftly, and their frequencies of contact have been increasing dramatically.展开更多
AIM： To investigate the genetic characteristics and pathogenicity of hepatitis E virus （HEV） and assess the potential risk factors for sporadic hepatitis E.
Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in th...Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in the rural areas of China.The purpose of this study is to evaluate the effect of these land use changes on the soil properties,nu-trient absorption rate,and nutrient use economic efficiency ratio in an agricultural area of Beijing.Specifically,the cropland,the orchard and the vegetable field were examined.Results of this study suggest that land use and farming management practices significantly affect the content of soil organic carbon (SOC),total nitrogen (TN),total phos-phorus (TP),and available phosphorus in the surface layer of 0-25 cm (p<0.05) in the Yanqing Basin,northwestern Beijing.Soil nutrients in each agricultural land use type decrease rapidly with the increasing soil depth.Orchard and vegetable field tend to have higher soil nutrients than the cropland does.However,the soil nutrient-absorption rate (NAR) of the orchard and vegetable field is lower than that of the cropland,even though orchard and vegetable field may provide much higher economic benefit.While increasing SOC,TN,and TP in the orchard and vegetable field by intensive farming may be a valuable option to improve soil quality,potential increase in the risk of nutrient loss,or agricultural non-point source pollution can be a tradeoff if the intensive practices are not managed appropriately.展开更多
The institutional environment in China has quite evidently changed during modern socio-economic transitions.Driven both by local government and by marketing force,urban social space was redistributed after the reform ...The institutional environment in China has quite evidently changed during modern socio-economic transitions.Driven both by local government and by marketing force,urban social space was redistributed after the reform of urban land and real estate policies.Urban renewal makes for wide differential rent and therefore gentrification is occurring in China.This paper analyzes the background and institutional environment of gentrification in China,and further discusses the process,characteristics and evolutionary mechanisms in the case of Nanjing,through investigation of the attributes of 1075 residential communities built during the 1998-2008 at a macro level,and interviewing the residents and analyzing questionnaires in 6 different and typical communities at a micro level.As a socio-spatial course of two-way interaction,gentrification is divided into 3 stages of incubation,occurrence and fast development,according to the time of landmark events and policy reform on the leasehold of land in Nanjing during socio-economic transition.In terms of the socio-spatial characteristics of gentrification in Nanjing,the gentrification process under the trajectory of urban renewal makes urban social space present a new circle-layer structure;the rise of quite a number of gated communities results in the fragmentation of social space and privatization of public space;the management mode of modern communities and the change of life style have aggravated the indifference of neighborhood relationship of gentrified communities.Based on the empirical evidence of this study,this paper indicates that gentrification is quite different between China and western countries with respect to spatio-temporal order,dominant forces,paths of realization and spatial expression,and it further reveals the dynamic mechanism of gentrification developing in China at the present stage.展开更多
Integrated transportation and land use studies are of major interest to planners because they consider the interaction between transportation development and land use change. Quantifying the impact of transport infras...Integrated transportation and land use studies are of major interest to planners because they consider the interaction between transportation development and land use change. Quantifying the impact of transport infrastructure on land use change is necessary for evaluating the role of transportation development in the process of land use and land cover change in the urban-rural fringe. Taking Qixia District of Nanjing City, Jiangsu Province, China as a typical urban-rural fringe area, this paper analyzes the patterns and charac- teristics of land use change along three major transportation arteries using land use data from 2000 and 2008. We examine the spatial differentiation and gradient of land use pattern around railway, expressway, and highway corridors to investigate whether land use change in the urban-rural fringe is related to distance from transportation arteries and to clarify the varying impacts of different forms of transport infrastructure on land use patterns. We find that construction land generally tends to be located close to major transportation arteries, and that railways have the most obvious influence on land use change in the urban-rural fringe, while the impact of expressways was not significant. We conclude that there exists a causal relationship between the presence of transportation arteries and land use change in the urban-rural fringe, but this relationship varies across different types of linear transnort infrastrncnlre.展开更多
Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carb...Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carbon emissions by Logarithmic Mean Divisia Index（LMDI） model. The main conclusions are as follows： 1） Total anthropogenic carbon emission of Nanjing increased from 1.22928 ×10^7 t in 2000 to 3.06939 × 10^7 t in 2009, in which the carbon emission of Inhabitation, mining ＆ manufacturing land accounted for 93% of the total. 2） The average land use carbon emission intensity of Nanjing in 2009 was 46.63 t/ha, in which carbon emission intensity of Inhabitation, mining ＆ manufacturing land was the highest（200.52 t/ha）, which was much higher than that of other land use types. 3） The average carbon source intensity in Nanjing was 16 times of the average carbon sink intensity（2.83 t/ha） in 2009, indicating that Nanjing was confronted with serious carbon deficit and huge carbon cycle pressure. 4） Land use area per unit GDP was an inhibitory factor for the increase of carbon emissions, while the other factors were all contributing factors. 5） Carbon emission effect evaluation should be introduced into land use activities to formulate low-carbon land use strategies in regional development.展开更多
After the Kyoto Protocol was implemented,carbon leakage exerts great influences on international trade and economy.Trade creates a mechanism for consumers to shift environmental pollution associated with their consump...After the Kyoto Protocol was implemented,carbon leakage exerts great influences on international trade and economy.Trade creates a mechanism for consumers to shift environmental pollution associated with their consumption to other countries.China has overtaken the U.S.as the world's biggest CO2 emitter since 2006.As China's second largest trade partner,the U.S.has the biggest trade deficit with China which has aroused a lot of disputes between the two parties.But so far the assessments of the trade imbalance of China-U.S.have paid little attention to environmental impacts associated with the trade imbalance.Applied an input-output approach,the article estimates the amount of CO2 embodied in China-U.S.trade during 1997-2007.It was found that through trade with China,the U.S.reduced its CO2 emissions compared with a non-trade scenario.Due to the greater carbon-intensity and relatively less efficient production processes of Chinese industry,China-U.S.trade resulted in more CO2 emissions in China and the world.In the end,the article gives some suggestions:it is equal and sustainable that the international accounting methodologies should be improved,for CO2 emissions responsibility must be designed to account for the dynamic nature of international trade.展开更多
Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragme...Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragmentation, but few studies have focused on the fragmentation of leisure activities. This study was intended to extend the extant literature by: 1) analysing the spatio-temporal fragmentation of physical and virtual leisure activities by using a dataset collected in Nanjing, China, and 2) evaluating the reasons of leisure activity fragmentation, as well as the potential spatial effect of activity fragmentation. The results indicated that virtual leisure activities are more fragmented than physical leisure activities, but the fragmentation of physical and virtual leisure activities varies on weekday and weekend, as well as in various locations and urban districts. In addition, the results suggested that sociodemographic factors and information and communication technology(ICT) variables distinctly affect the fragmentation of leisure activities. Meanwhile, the fragmentation of virtual leisure activities may enhance the transformation of traditional urban space by reallocating leisure activity times and locations.展开更多
Economic clusters have been a central focus of current urban and regional research, policies and practices. However, a methodology to identify and analyze policy-relevant economic cluster dynamics is still not well de...Economic clusters have been a central focus of current urban and regional research, policies and practices. However, a methodology to identify and analyze policy-relevant economic cluster dynamics is still not well developed. Based on input-output(I-O) data of 1987, 1992, 1997, 2002 and 2007 of Beijing, this article presents an adapted principle component analysis for identifying the evolution of local economic cluster patterns. This research addresses the changes of economic interaction of industries with complementary and common activities over time. The identified clusters provide an insight into the reality of economic development in a diversifying urban economy: the increasing importance of services and the growing interaction between service and manufacturing industries. Our method therefore provides the analysts with a better understanding of the emergence, disappearance and development of economic clusters citywide. The results could be used to assist monitoring urban economic development and designing more practical urban economic strategies.展开更多
China's transition from a planned economy to a market economy has resulted in many changes in its urban structure and society and provided an opportunity for a quasi-longitudinal case study on the relationship bet...China's transition from a planned economy to a market economy has resulted in many changes in its urban structure and society and provided an opportunity for a quasi-longitudinal case study on the relationship between the built environment and activity-travel behavior.This paper draws upon data from an activity diary survey conducted in Beijing in 2007.The survey sample comprised 652 residents living in Danwei(work unit),commodity housing,and affordable housing neighborhoods.On the basis of the three-dimensional geo-visualization analysis of the space-time path and statistical multivariate regression models of daily travel and leisure time,it was found that both residential spatial factors and socio-demographics influence residents' daily behaviors.The findings show that Danwei residents have less daily travel time than those who live in commodity housing,but people living in affordable housing endure the longest travel time.Daily leisure time is associated more with individual attributes.We argue that although China's transition is currently gradual,the Danwei system may continue to play significant roles in daily life,and it might provide a valuable model for neighborhood spatial planning.展开更多
Emergence of Chinese economy together with the current Livestock Revolution in Asia have led to an increase of meat demands, specially pork that is reflected in the growth of commercial pig farms in peri-urban areas o...Emergence of Chinese economy together with the current Livestock Revolution in Asia have led to an increase of meat demands, specially pork that is reflected in the growth of commercial pig farms in peri-urban areas of Beijing, capital of People＇s Republic of China. In the framework of the International Research Training Group and of the Sino-Project Recycling of Organic Residues from Agricultural and Municipal Origin in China, the status quo of a large pig farm is researched. The first phase of the project was focused on a detailed description of the nutrients and trace elements contained in the main inputs （water, feed） and outputs （manure, wastewater） of the pig farm. The compliance with the Chinese national standards or often referred to as GB standards （in Chinese ＂GuoBiao＂） and, current German recommendations were included. The analysis of nutrients and trace minerals followed the natural structure of the pig life cycle, i.e., gestation, farrowing, weaning and fattening. The main results showed that the pig drinking water met the recommendations for livestock drinking water, ground water and human drinking water. Concentrations of Zn, Cu, Mn and As in the pig feeds samples displayed higher values compared to the Chinese and German recommendations. Average values of trace elements in the pig manure did not surpass the Chinese and German recommendations of biowastes, however, some manure samples showed excessive concentrations of Cd, Cu and Zn. Likewise, Pb, Cd, Cr, Cu and Zn concentrations in the wastewater surpassed the recommendations for irrigation water.展开更多
The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two ce...The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two centers. Taking Beijing-Tianjin region of China, which is a distinct dual-nuclei metropolitan area in the world, as an example and choosing Landsat-5 TM image in 2005, population, etc. as the data, this paper devotes to comprehending and illustrating a model of Cassini growth of population between the two metropolitan cities through the research of spatial population distribution pattern, aided with RS and GIS techniques. Main technical processes include Kriging interpolation of the population data and character simulation of the Cassini ovals. According to the calculation of a/b, a key characteristic index of Cassini growth model, the spatial structures of population distribution were given. When a/b〈 1, it is a curve with two separated loops with a population density more than 3000 persons/km^2. When a/b=1, it is a lemniscate curve with a population density about 3000 persons/km^2. When 1〈a/b〈 √2, it is a dog-bone shaped concave curve with a population density between 500-3000 persons/km^2. When a/b= √2, it is an oblate curve with a population density about 500 persons/km^2. When a/b〉 √2, there is an oval-shaped convex curve with a population density less than 500 persons/km^2. The results show that owing to the combined action and influence of the regional dual-nuclei, the population distribution of Beijing-Tianjin region is in accord with Cassini model significantly. Therefore, there is Cassini growth of population between the two metropolitan cities in Beijing-Tianjin region. In addition, the process of Cassini growth has extraordinarily instructive significance for judging the development stages of the dual-nuclei metropolitan areas.展开更多
基金Under the auspices of Knowledge Innovation Frontier Project of Institute of Soil Science,Chinese Academy of Sciences(No.ISSASIP0716 )the National Nature Science Foundation of China ( No.40701070,40571065)
文摘Hue-Saturation-Intensity （HSI） color model, a psychologically appealing color model, was employed to visualize uncertainty represented by relative prediction error based on the case of spatial prediction of pH of topsoil in the peri-urban Beijing. A two-dimensional legend was designed to accompany the visualization-vertical axis （hues） for visualizing the predicted values and horizontal axis （whiteness） for visualizing the prediction error. Moreover, different ways of visualizing uncertainty were briefly reviewed in this paper. This case study indicated that visualization of both predictions and prediction uncertainty offered a possibility to enhance visual exploration of the data uncertainty and to compare different prediction methods or predictions of totally different variables. The whitish region of the visualization map can be simply interpreted as unsatisfactory prediction results, where may need additional samples or more suitable prediction models for a better prediction results.
文摘上海中加贸易有限公司是欧洲专业的高端品牌纺织设备代理商,涵盖了从纺纱、织造、染色和后整理几乎所有领域。经过二十多年的不懈努力,公司现已获得数十家国际著名品牌供应商在中国市场的授权全权代理,同时专业的销售和服务团队也得到了国内广大用户的认可、支持与厚爱。代理的品牌包括意大利的LAFER、CORGHI、MCS、KD、LORIS BELLINI、LA WER、FLAINOX、DETTIN、PLM、SAL V ADE、PUGI、ZANCANER、ITB、COLOSIO、AUTOTEX以及德国的BRUCKNER、DORNIER,日本村田等。
基金National Natural Science Foundation of China(NNSFC3 9970 0 97)
文摘The present paper deals with the description of a new collembolan species, Homidia fascia, sp. nov., It shares some characters with H. tibetensis Chen & Zhong, 1998, however, can be distinguished from the latter by color pattern, labial setae L 1 and R 2, posterior macrochaetae on Abd. IV and relative position of line connecting macrochaetae Pr & Ed to median furrow on ventral tube.
基金Under the auspices of Key Project of National Natural Science Foundation of China (No. 40435013, 40301014)
文摘Taking Nanjing as a case, the paper explains the spatial behavior differences existing in the information technology use among different groups of residents and households, by virtue of analyzing the survey data of urban households in the 11 districts of Nanjing, from the social, spatial, life and other non-technical angles. Also it makes various analyses and evaluation quantitatively and qualitatively on the social and spatial effect of information technology. The results show that the new technology is changing the social spatial behaviors of urban residents. New behavioral spaces of urban family such as telecommuting, email and QQ have begun to emerge. With the help of Internet, the communication scope of families has expanded greatly, and more new forms of publicizing community information have begun to emerge. Telecommunication contact forms have been developing swiftly, and their frequencies of contact have been increasing dramatically.
基金Supported by The 863 National High Technology Research and Development Program of China,No.2006A02Z453the National Natural Science Foundation of China,No.30570063
文摘AIM： To investigate the genetic characteristics and pathogenicity of hepatitis E virus （HEV） and assess the potential risk factors for sporadic hepatitis E.
基金Under the auspices of Key Direction in Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-421)National Natural Science Foundation of China (No.40925003)
文摘Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in the rural areas of China.The purpose of this study is to evaluate the effect of these land use changes on the soil properties,nu-trient absorption rate,and nutrient use economic efficiency ratio in an agricultural area of Beijing.Specifically,the cropland,the orchard and the vegetable field were examined.Results of this study suggest that land use and farming management practices significantly affect the content of soil organic carbon (SOC),total nitrogen (TN),total phos-phorus (TP),and available phosphorus in the surface layer of 0-25 cm (p<0.05) in the Yanqing Basin,northwestern Beijing.Soil nutrients in each agricultural land use type decrease rapidly with the increasing soil depth.Orchard and vegetable field tend to have higher soil nutrients than the cropland does.However,the soil nutrient-absorption rate (NAR) of the orchard and vegetable field is lower than that of the cropland,even though orchard and vegetable field may provide much higher economic benefit.While increasing SOC,TN,and TP in the orchard and vegetable field by intensive farming may be a valuable option to improve soil quality,potential increase in the risk of nutrient loss,or agricultural non-point source pollution can be a tradeoff if the intensive practices are not managed appropriately.
基金Under the auspices of European Commission under 7th Framework Programme (No ECUBS–230824)
文摘The institutional environment in China has quite evidently changed during modern socio-economic transitions.Driven both by local government and by marketing force,urban social space was redistributed after the reform of urban land and real estate policies.Urban renewal makes for wide differential rent and therefore gentrification is occurring in China.This paper analyzes the background and institutional environment of gentrification in China,and further discusses the process,characteristics and evolutionary mechanisms in the case of Nanjing,through investigation of the attributes of 1075 residential communities built during the 1998-2008 at a macro level,and interviewing the residents and analyzing questionnaires in 6 different and typical communities at a micro level.As a socio-spatial course of two-way interaction,gentrification is divided into 3 stages of incubation,occurrence and fast development,according to the time of landmark events and policy reform on the leasehold of land in Nanjing during socio-economic transition.In terms of the socio-spatial characteristics of gentrification in Nanjing,the gentrification process under the trajectory of urban renewal makes urban social space present a new circle-layer structure;the rise of quite a number of gated communities results in the fragmentation of social space and privatization of public space;the management mode of modern communities and the change of life style have aggravated the indifference of neighborhood relationship of gentrified communities.Based on the empirical evidence of this study,this paper indicates that gentrification is quite different between China and western countries with respect to spatio-temporal order,dominant forces,paths of realization and spatial expression,and it further reveals the dynamic mechanism of gentrification developing in China at the present stage.
基金Under the auspices of National Natural Science Foundation of China(No.40871255)Scientific Research Foundation of Graduate School of Nanjing University(No.2010CL12)
文摘Integrated transportation and land use studies are of major interest to planners because they consider the interaction between transportation development and land use change. Quantifying the impact of transport infrastructure on land use change is necessary for evaluating the role of transportation development in the process of land use and land cover change in the urban-rural fringe. Taking Qixia District of Nanjing City, Jiangsu Province, China as a typical urban-rural fringe area, this paper analyzes the patterns and charac- teristics of land use change along three major transportation arteries using land use data from 2000 and 2008. We examine the spatial differentiation and gradient of land use pattern around railway, expressway, and highway corridors to investigate whether land use change in the urban-rural fringe is related to distance from transportation arteries and to clarify the varying impacts of different forms of transport infrastructure on land use patterns. We find that construction land generally tends to be located close to major transportation arteries, and that railways have the most obvious influence on land use change in the urban-rural fringe, while the impact of expressways was not significant. We conclude that there exists a causal relationship between the presence of transportation arteries and land use change in the urban-rural fringe, but this relationship varies across different types of linear transnort infrastrncnlre.
基金Under the auspices of National Natural Science Foundation of China(No.41301633)National Social Science Foundation of China(No.10ZD&030)+1 种基金Postdoctoral Science Foundation of China(No.2012M511243,2013T60518)Clean Development Mechanism Foundation of China(No.1214073,2012065)
文摘Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carbon emissions by Logarithmic Mean Divisia Index（LMDI） model. The main conclusions are as follows： 1） Total anthropogenic carbon emission of Nanjing increased from 1.22928 ×10^7 t in 2000 to 3.06939 × 10^7 t in 2009, in which the carbon emission of Inhabitation, mining ＆ manufacturing land accounted for 93% of the total. 2） The average land use carbon emission intensity of Nanjing in 2009 was 46.63 t/ha, in which carbon emission intensity of Inhabitation, mining ＆ manufacturing land was the highest（200.52 t/ha）, which was much higher than that of other land use types. 3） The average carbon source intensity in Nanjing was 16 times of the average carbon sink intensity（2.83 t/ha） in 2009, indicating that Nanjing was confronted with serious carbon deficit and huge carbon cycle pressure. 4） Land use area per unit GDP was an inhibitory factor for the increase of carbon emissions, while the other factors were all contributing factors. 5） Carbon emission effect evaluation should be introduced into land use activities to formulate low-carbon land use strategies in regional development.
文摘After the Kyoto Protocol was implemented,carbon leakage exerts great influences on international trade and economy.Trade creates a mechanism for consumers to shift environmental pollution associated with their consumption to other countries.China has overtaken the U.S.as the world's biggest CO2 emitter since 2006.As China's second largest trade partner,the U.S.has the biggest trade deficit with China which has aroused a lot of disputes between the two parties.But so far the assessments of the trade imbalance of China-U.S.have paid little attention to environmental impacts associated with the trade imbalance.Applied an input-output approach,the article estimates the amount of CO2 embodied in China-U.S.trade during 1997-2007.It was found that through trade with China,the U.S.reduced its CO2 emissions compared with a non-trade scenario.Due to the greater carbon-intensity and relatively less efficient production processes of Chinese industry,China-U.S.trade resulted in more CO2 emissions in China and the world.In the end,the article gives some suggestions:it is equal and sustainable that the international accounting methodologies should be improved,for CO2 emissions responsibility must be designed to account for the dynamic nature of international trade.
基金Under the auspices of National Natural Science Foundation of China(No.41571146,41301166)
文摘Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragmentation, but few studies have focused on the fragmentation of leisure activities. This study was intended to extend the extant literature by: 1) analysing the spatio-temporal fragmentation of physical and virtual leisure activities by using a dataset collected in Nanjing, China, and 2) evaluating the reasons of leisure activity fragmentation, as well as the potential spatial effect of activity fragmentation. The results indicated that virtual leisure activities are more fragmented than physical leisure activities, but the fragmentation of physical and virtual leisure activities varies on weekday and weekend, as well as in various locations and urban districts. In addition, the results suggested that sociodemographic factors and information and communication technology(ICT) variables distinctly affect the fragmentation of leisure activities. Meanwhile, the fragmentation of virtual leisure activities may enhance the transformation of traditional urban space by reallocating leisure activity times and locations.
基金Under the auspices of National Natural Science Foundation of China(No.41371008)
文摘Economic clusters have been a central focus of current urban and regional research, policies and practices. However, a methodology to identify and analyze policy-relevant economic cluster dynamics is still not well developed. Based on input-output(I-O) data of 1987, 1992, 1997, 2002 and 2007 of Beijing, this article presents an adapted principle component analysis for identifying the evolution of local economic cluster patterns. This research addresses the changes of economic interaction of industries with complementary and common activities over time. The identified clusters provide an insight into the reality of economic development in a diversifying urban economy: the increasing importance of services and the growing interaction between service and manufacturing industries. Our method therefore provides the analysts with a better understanding of the emergence, disappearance and development of economic clusters citywide. The results could be used to assist monitoring urban economic development and designing more practical urban economic strategies.
基金Under the auspices of National Natural Science Foundation of China(No.40671058,41071102)National'TwelfthFive-Year'Plan for Science and Technology Support(No.2012BAJ 05B04)
文摘China's transition from a planned economy to a market economy has resulted in many changes in its urban structure and society and provided an opportunity for a quasi-longitudinal case study on the relationship between the built environment and activity-travel behavior.This paper draws upon data from an activity diary survey conducted in Beijing in 2007.The survey sample comprised 652 residents living in Danwei(work unit),commodity housing,and affordable housing neighborhoods.On the basis of the three-dimensional geo-visualization analysis of the space-time path and statistical multivariate regression models of daily travel and leisure time,it was found that both residential spatial factors and socio-demographics influence residents' daily behaviors.The findings show that Danwei residents have less daily travel time than those who live in commodity housing,but people living in affordable housing endure the longest travel time.Daily leisure time is associated more with individual attributes.We argue that although China's transition is currently gradual,the Danwei system may continue to play significant roles in daily life,and it might provide a valuable model for neighborhood spatial planning.
文摘Emergence of Chinese economy together with the current Livestock Revolution in Asia have led to an increase of meat demands, specially pork that is reflected in the growth of commercial pig farms in peri-urban areas of Beijing, capital of People＇s Republic of China. In the framework of the International Research Training Group and of the Sino-Project Recycling of Organic Residues from Agricultural and Municipal Origin in China, the status quo of a large pig farm is researched. The first phase of the project was focused on a detailed description of the nutrients and trace elements contained in the main inputs （water, feed） and outputs （manure, wastewater） of the pig farm. The compliance with the Chinese national standards or often referred to as GB standards （in Chinese ＂GuoBiao＂） and, current German recommendations were included. The analysis of nutrients and trace minerals followed the natural structure of the pig life cycle, i.e., gestation, farrowing, weaning and fattening. The main results showed that the pig drinking water met the recommendations for livestock drinking water, ground water and human drinking water. Concentrations of Zn, Cu, Mn and As in the pig feeds samples displayed higher values compared to the Chinese and German recommendations. Average values of trace elements in the pig manure did not surpass the Chinese and German recommendations of biowastes, however, some manure samples showed excessive concentrations of Cd, Cu and Zn. Likewise, Pb, Cd, Cr, Cu and Zn concentrations in the wastewater surpassed the recommendations for irrigation water.
基金Under the auspices of National High-Tech Research and Development Program of China(863 Program)(No. 2007AAl22235)National Natural Science Foundation ofChina(No.40471058)
文摘The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two centers. Taking Beijing-Tianjin region of China, which is a distinct dual-nuclei metropolitan area in the world, as an example and choosing Landsat-5 TM image in 2005, population, etc. as the data, this paper devotes to comprehending and illustrating a model of Cassini growth of population between the two metropolitan cities through the research of spatial population distribution pattern, aided with RS and GIS techniques. Main technical processes include Kriging interpolation of the population data and character simulation of the Cassini ovals. According to the calculation of a/b, a key characteristic index of Cassini growth model, the spatial structures of population distribution were given. When a/b〈 1, it is a curve with two separated loops with a population density more than 3000 persons/km^2. When a/b=1, it is a lemniscate curve with a population density about 3000 persons/km^2. When 1〈a/b〈 √2, it is a dog-bone shaped concave curve with a population density between 500-3000 persons/km^2. When a/b= √2, it is an oblate curve with a population density about 500 persons/km^2. When a/b〉 √2, there is an oval-shaped convex curve with a population density less than 500 persons/km^2. The results show that owing to the combined action and influence of the regional dual-nuclei, the population distribution of Beijing-Tianjin region is in accord with Cassini model significantly. Therefore, there is Cassini growth of population between the two metropolitan cities in Beijing-Tianjin region. In addition, the process of Cassini growth has extraordinarily instructive significance for judging the development stages of the dual-nuclei metropolitan areas.
