Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook, this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting ...Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook, this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting factors. The results show that: 1) During 1980 to 2007, total grain production increased from 3.20 ~ 108 t to 5.02 x 108 t in China, with annual increasing rate of 1.68%. From the regional disparities, most of the regions present increasing trend of total grain production except for several regions with higher level of economic development; 2) Grain sown area decreased from 1.17 × 108 ha in 1980 to 1.06 x 108 ha in 2007, which has negative effect on total grain production; 3) The increase of grain yield per unit area caused by land use intensity changes contributed to the increase of total grain yield greatly. However, as the land use intensity showed that farmers pay more attention to labor-saving input but not yield-increasing input, the less enthusiasm of farmers in grain production may become an important constraint on fu- ture grain production increase in China; 4) Based on the results, this paper proposed different land management poli- cies in different regions, for example, the government should protect cultivated land, promote large scale production. As to the less developed regions, the government should pay more attention to agricultural subsidies to promote farm- ers' enthusiasm in grain production.展开更多
Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable,...Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable, this paper conducts SBM model to evaluate the aquaculture efficiency based on the data of 16 aquaculture-developed provinces in China from 2004 to 2011. The results show the efficiency in China has not changed much in recent years with the efficiency values mainly between 0.39 and 0.53, and the efficiency of marine-aquaculture-dominated provinces is generally higher than that of freshwater-aquaculture-dominated ones. To analyze the difference under the efficiency, the panel Tobit model is used with education level factor, training factor, technology extension factor, technical level factor, scale factor and species factor as the efficiency influencing factors. The results show that technology extension factor and technical level factor have significant positive influence.展开更多
The coastal zone is an area characterized by intense interaction between land and sea, high sensitivity to regional environmental changes, and concentrated human activities. Little research has investigated vegetation...The coastal zone is an area characterized by intense interaction between land and sea, high sensitivity to regional environmental changes, and concentrated human activities. Little research has investigated vegetation cover changes in coastal zones resulting from climate change and land-use change, with a lack of knowledge about the driving mechanism. Normalized diff erence vegetation index(NDVI) can be used as an indicator for change of the coastal environment. In this study, we analyzed the interannual changes and spatial distribution of NDVI in the coastal zone around Jiaozhou Bay in Qingdao, a coastal city undergoing rapid urbanization in northeast China. The underlying causes of NDVI variations were discussed in the context of climate change and land-use change. Results showed that the spatio-temporal distribution of NDVI displayed high spatial variability in the study area and showed a typical trend of gradually increasing from coastal to inland regions. The significant increase area of NDVI was mainly found in newly added construction land, extending along the coastline towards the inland. Land vegetation cover demonstrated a certain response relationship to sea-land climate change and land-based activities. The impact of land-based human activities was slightly greater than that of sea-land climate change for land vegetation cover. The results indicate that promoting ecological policies can build an ecological security framework of vegetation suitable for the resource characteristics of coastal cities. The framework will buf fer the negative ef fects of sea-land climate change and land-based human activities on vegetation cover and thereby achieve the balance of regional development and ecological benefits in the coastal zone.展开更多
Urbanization is a comprehensive concept, a trinity process that population urbanization, economic urbanization and space urbanization, is based on the interactions and mutual influences among the in which, people are ...Urbanization is a comprehensive concept, a trinity process that population urbanization, economic urbanization and space urbanization, is based on the interactions and mutual influences among the in which, people are the central and leading players in this process, while economic activities serve as the driving force and space is the carrier-the physical or material setting as well as the product. So the coordination among these processes is crucial for a country or region's sustainable development. China is experiencing rapid growth of cities and a surge in urban population, with the basic national condition of many people and little land, which calls for a systematic study of the issue of coordinated urbanization from theoretical, methodological and practical perspectives. Based on the concept of urbanization and non-coordination of urbanization, this article built a quantitative method to identify and evaluate the urbanization and non-coordination of urbanization, and made an empirical analysis in China between 2000 and 2008. The results show that the non-coordination overall level of China's urbanization declined during the study period, because population urbanization, economic urbanization, and space urbanization exhibited different trajectories of change. This study also reveals that performance assessment system, household registration system, and urban land expropriation system, etc., are the main affecting factors. At the end, we put forward some suggestions to achieve sustainable development of China's urbanization from the aspects of improving the local government's obiective function, imolementing the urban plalming svstem, enforcing public particination asnects and so on.展开更多
This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured ...This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured the CO 2 emission performance of 28 provinces and autonomous regions in China from 1996 to 2007;with the convergence theory and panel data regression model,the authors analyze the regional differences and the influencing factors.It is found that the performance of CO 2 emissions in China has been continuously improved mainly due to the technological progress,and the average improvement rate is 3.25%,with a cumulative improvement rate of 40.86%.In addition,the CO 2 emission performance varies across four regions.As a whole,the performance score of eastern China is the highest.The northeastern and central China has relatively lower performance scores,and the western China is relatively backward.The regional differences are decreasing,and the performance of CO 2 emissions is convergent.The influence of some factors on the performance of CO 2 emissions is significant,such as the level of economic development,the level of industrial structure,energy intensity,and ownership structure.The influence of some factors,such as opening-up to the outside world,on the performance of CO 2 emissions is not significant..展开更多
This data article describes the dataset from a national cross-sectional questionnaire survey on Chinese internal migrants in 2017.The survey was part of the Chinese Migrants Dynamic Survey,which is an annually conduct...This data article describes the dataset from a national cross-sectional questionnaire survey on Chinese internal migrants in 2017.The survey was part of the Chinese Migrants Dynamic Survey,which is an annually conducted large-scale national questionnaire survey on internal migrants.The respondents in the described dataset were migrants and registered local residents aged over 15 years old.A multistage stratified probability-proportionalto-size(PPS) sampling method based on the 2016 annual report data of China Migrant Population was adopted.The questionnaire was designed to collect demographic information of respondents and their family members,intention of migration or settlement,health status,health services accessibility,social integration,and epidemic influencing factors of common diseases,including hypertension,type 2 diabetes,diarrhea,fever,rash,icterus,conjunctival redness,cold,and other illnesses or injuries.The sample population in this survey include 13,998 internal migrants and 14,000 registered local residents from eight domestic cities/prefecture/districts across China.It is the most widely covering and highly representative dataset on common diseases and influencing factors of internal migrants in China.The dataset can be used to study common diseases and influencing factors among floating Chinese population.It provides data support for government to improve healthcare accessibility and the equity of public health services for internal migrants in China.展开更多
AIM: To investigate the incidence and mortality of gastric cancer (GC) in Zhuanghe region, northeast China and the influencing factors for their changing trends.METHODS: All new cancer cases and deaths registered ...AIM: To investigate the incidence and mortality of gastric cancer (GC) in Zhuanghe region, northeast China and the influencing factors for their changing trends.METHODS: All new cancer cases and deaths registered from 2005 to 2010 in Zhuanghe County were reviewed. The annual GC cases, constituent ratio, crude rates,age-standardized rates, their sex and age distribution and temporal trends were assessed. The method of annual percentage change (APC) was used to estimate the trends of GC.RESULTS: Altogether 2634 new cases of GC and 1722 related deaths were registered, which accounted for 21.04% and 19.13% of all cancer-related incidence and deaths, respectively. The age-standardized incidence rate steadily decreased from 57.48 in 2005 to 44.53 in 2010 per 10^5 males, and from 18.13 to 14.70 per 10s females, resulting in a APC of -5.81% for males and -2.89% for females over the entire period. The magnitude of APC in GC mortality amounted to -11.09% and -15.23%, respectively, as the agestandardized mortality rate steadily decreased from 42.08 in 2005 to 23.71 in 2010 per 10^5 males, and from 23.86 to 10.78 per 10^5 females. Females had a significantly lower incidence (a male/female ratio 2.80, P 〈 0.001) and mortality (a male/female ratio 2.30, P 〈 0.001). In both genders, the peak incidence and mortality occurred in the 80-84 years age group. The age-standardized mortality/incidence ratio also decreased from the peak of 0.73 in 2005 to 0.53 in 2010 for males, and from 1.32 to 0.73 for females.CONCLUSION: Encouraging declines of incidence and mortality of GC were observed in Zhuanghe region between 2005 and 2010, possibly due to the economic development and efficient GC control strategies.展开更多
Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated...Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated,trip purposes of private car travel are mainly commute and business affairs with a more flexible trip in the urban core area.And trip intensities are concentrated in a certain extent,with trip frequency being lower in the urban core area than the peripheral area.In addition,the trip time has two significant peaks occurring in the morning and afternoon,and one trough in the midday.And trip spatial distribution is mainly within commute with both residence and employment in urban area and inward commute with residence in suburban area while employment in urban area.Both kinds of commutes direct to the urban area.The study also shows that the characteristics of private car travel are principally influenced by two aspects:travelers' attributes and urban characteristics.The main travelers' social and economic attributes influenced it include the gender,education attainment,age,driving experience and per capita monthly household income.The urban characteristics influenced it mainly cover the land use pattern,public traffic facilities and spatial attributes of residential environment.展开更多
High PM_(2.5) concentrations and frequent air pollution episodes during late autumn and winter in Jilin Province have attracted attention in recent years. To describe the spatial and temporal variations of PM_(2.5) co...High PM_(2.5) concentrations and frequent air pollution episodes during late autumn and winter in Jilin Province have attracted attention in recent years. To describe the spatial and temporal variations of PM_(2.5) concentrations and identify the decisive influencing factors, a large amount of continuous daily PM_(2.5) concentration data collected from 33 monitoring stations over 2-year period from 2015 to 2016 were analyzed. Meanwhile, the relationships were investigated between PM_(2.5) concentrations and the land cover, socioeconomic and meteorological factors from the macroscopic perspective using multiple linear regressions(MLR) approach. PM_(2.5) concentrations across Jilin Province averaged 49 μg/m^3, nearly 1.5 times of the Chinese annual average standard, and exhibited seasonal patterns with generally higher levels during late autumn and over the long winter than the other seasons. Jilin Province could be divided into three kinds of sub-regions according to 2-year average PM_(2.5) concentration of each city. Most of the spatial variation in PM_(2.5) levels could be explained by forest land area, cultivated land area, urban greening rate, coal consumption and soot emissions of cement manufacturing. In addition, daily PM_(2.5) concentrations had negative correlation with daily precipitation and positive correlation with air pressure for each city, and the spread and dilution effect of wind speed on PM_(2.5) was more obvious at mountainous area in Jilin Province. These results indicated that coal consumption, cement manufacturing and straw burning were the most important emission sources for the high PM_(2.5) levels, while afforestation and urban greening could mitigate particulate air pollution. Meanwhile, the individual meteorological factors such as precipitation, air pressure, wind speed and temperature could influence local PM_(2.5) concentration indirectly.展开更多
To analyze the positive influencing factors of Chinese telecom operators' EVA(Economic Value Added),this paper selects fifteen indicators based on the enterprise features of telecom operators and telecommunication...To analyze the positive influencing factors of Chinese telecom operators' EVA(Economic Value Added),this paper selects fifteen indicators based on the enterprise features of telecom operators and telecommunications industry characteristics,and then classifies these indicators into the following factors:operation scale,profitability,solvency and asset management ability by factor analysis.This paper also gives the priorities of these four factors by regression analysis,of which the operation scale is the most important factor.The research results point out a clear method for the telecom operatorsto increase their EVA in order to meet the performance appraisal from State-owned Assets Supervision and Administration Commission of the State Council.展开更多
The important role of spatial scale in exploring the geography of poverty as well as its policy implications has been noticed but with limited knowledge. To improve such limited understanding, we mainly investigated t...The important role of spatial scale in exploring the geography of poverty as well as its policy implications has been noticed but with limited knowledge. To improve such limited understanding, we mainly investigated the spatial patterns and influencing factors of rural poverty(indicated by poor population and poverty incidence) at three different administrative levels in the Liupan Mountain Region, one of the fourteen poorest regions in China. Our results show that from a global perspective, poor areas are clustered significantly at the county-, township-, and village-level, and more greatly at a lower level. Locally, there is spatial mismatch among poverty hotspots detected not only by the same indicator at different levels but also by different indicators at the same level. A scale effect can be found in the influencing factors of rural poverty. That is, the number of significant factors increases, but the degree of their association with poverty incidence decreases at a lower level. Such scale effect indicates that poverty incidence at lower levels may be affected by more complex factors, including not only the new local ones but also the already appeared non-local ones at higher levels. However, the natural conditions tend to play a scale-independent role to poverty incidence. In response to such scale-dependent patterns and factors, anti-poverty policies can be 1) a multilevel monitoring system to reduce incomplete or even misleading single-level information and understanding; 2) the village-based targeting strategy to increase the targeting efficiency and alleviate the mentioned spatial mismatch; 3) more flexible strategies responding to the local impoverishing factors, and 4) different task emphasises for multilevel policymakers to achieve the common goal of poverty reduction.展开更多
The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner ...The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner method by laboratory and pot experiments. Results showed that the content of fixed ammoniumin the plough horizons ranged from 88.3 mg kg-1 to 388.1 mg kg-1, with 273.2 ± 77.7 mg kg-1 on average,accounting for 11.2% of total soil N on average. Content of fixed ammonium decreased in the order of newlylacustrine clayey paddy soil > alluvial sandy paddy soil > purple clayey paddy soil > newly alluvial sandypaddy soil > yellow clayey paddy soil > reddish-yellow clayey paddy soil > granitic sandy paddy soil. Therewere four distribution patterns of fixed ammonium in the profiles to 1-m depth, i.e., increase with the depth,decrease with increasing depth, no distinct change with the depth, and abrupt increase or decrease in somehorizon. Percentage of fixed ammonium in total N increased with the depth in most of the soils. Fixationof NH4+ by soil was higher at 30 ℃ than at 20 ℃ and 40 ℃, and continuous submergence benefited thefixation of NH4+ in newly alluvial sandy paddy soil, purple clayey paddy soil and alluvial sandy paddy soil,while alternating wetting and drying contributed to the fixation of NH4+ in yellow clayey paddy soil mostly.Fixed ammonium content in the test paddy soils was significantly correlated with < 0.01 mm clay content(P < 0.05), but not with < 0.001 mm clay content, total N, organic N and organic matter. Fixed ammoniumcontent varied with rice growth stages. Application of N fertilizer promoted fixation of NH4+ by soil, and Nuptake by rice plant promoted release of fixed ammonium from the soil. Recently fixed ammonium in paddysoil after N fertilizer application was nearly 100% available to rice plant, while native fixed ammonium wasonly partly available, varying with the soil type and rice type.展开更多
This paper first estimates the overall return on capital in China between 1978 and 2013. It then identifies the determinants of return on capital by analyzing provincial panel data and breaks down the causes of swerve...This paper first estimates the overall return on capital in China between 1978 and 2013. It then identifies the determinants of return on capital by analyzing provincial panel data and breaks down the causes of swerves in capital return after the eruption of the global financial crisis in 2008. It finds that: (1) there is significant inertia in the return on capital," (2) government intervention has significantly negative impact on capital return; (3) a significantly negative correlation is observed between investment rate and return on capital," and (4) the increases in the shares of secondary and tertiary industries in the economy have significantly positive impact on return on capital. This paper concludes that the growth in investment rate and the expansion of government size are both important contributors to the recent decline in China's return on capital since the financial crisis.展开更多
China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires ...China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires of 11 villages in 2 counties and Tobit model,this paper analyzes the geographical differences and influencing factors of energy consumption for non-production purposes of rural households living in different terrain conditions.This research finds that:(1) Coal takes up the main part of energy consumption in valley areas and coal consumption is mainly affected by per capita cultivated land area,household income,proportion of rural household energy expenditure in total expenditure,coal price,and family population size.Firewood takes up the main part of energy consumption in high mountain areas and firewood consumption is mainly affected by per capita firewood forest area,distance to purchase coal,household income,electricity price,and coal price.(2) Only when the distance is greater than 20 kilometers,that is the average distance of rural households living in middle mountain areas(1,600m^1,800m) to purchase coal,the transportation condition has a significant impact on coal consumption.(3) In high mountain areas,prices of coal and electricity are the main factors influencing energy consumption choice of rural households.Too high prices of coal and electricity would to some extent lead rural households to choose firewood as the main energy consumption type.Compared to coal,rural households prefer to choose electricity.展开更多
At present, the aging situation of China's population is becoming more and more serious. By the end of 2016, there were 231 million people over the age of 60 in China, accounting for 16.7% of the total population. Ab...At present, the aging situation of China's population is becoming more and more serious. By the end of 2016, there were 231 million people over the age of 60 in China, accounting for 16.7% of the total population. About 150 million people aged 65 and over make up 10.8 percent of the total population. China is expected to enter the peak period of population aging by 2035. Therefore, the government as a single pension service main body management pattern already can not adapt to our country entered the aging society, mobilize and fostering social organizations to participate in the pension services is to build perfect endowment service system, satisfy people pension service demand model of a kind of indispensable. In view of the development of social organizations has just started in our country, there exist many problems and difficulties, so this article USES the ISM method, for social organizations to participate in research and analyze influence factors of pension services, and then find out the social organization in the process of participation in pension service problems, put forward effective solutions.展开更多
In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull"...In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies.展开更多
The Poyang Lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and...The Poyang Lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and mitigation. The present study identified the characteristics variations of historical floods in the Poyang Lake and their tendencies based on the Mann-Kendall(M-K) test, and also investigated the related affecting factors, both from climate and human activities. The results revealed that the highest flood stages, duration as well as hazard coefficient of floods showed a long-term increasing linear trend during the last 60 years with the M-K statistic of 1.49, 1.60 and 1.50, respectively. And, a slightly increasing linear trend in the timing of the highest stages indicated the floods occurred later and later during the last six decades. The rainfall during the flood season and subsequent discharges of the Changjiang(Yangtze) River and runoff from the Poyang Lake Basin were mainly responsible for the severe flood situation in the Poyang Lake in the 1990 s. In addition, the intensive human activities, including land reclamation and levee construction, also played a supplementary role in increasing severity of major floods. While, the fewer floods in the Poyang Lake after 2000 can be attributed to not only the less rainfall over the Poyang Lake Basin and low discharges of the Changjiang River during flood periods, but also the stronger influences of human activity which increased the floodwater storage of the Poyang Lake than before.展开更多
The middle class in metropolitan Chinese cities has become an important social group. With the rapid development of urbanization and constant advancement of suburbanization, the middle class has increasingly come to i...The middle class in metropolitan Chinese cities has become an important social group. With the rapid development of urbanization and constant advancement of suburbanization, the middle class has increasingly come to influence city traffic. Research into middle-class commuting activities thus has practical significance for improving traffic congestion and reducing the commuting burden in metropolitan cities. Based on a dataset formed by 816 completed surveys, this paper analyzes the commuting mode, time and distance of middle-class residents in Guangzhou City using the descriptive statistical method. The results indicate that private cars are the main commuting mode, followed by public transport. Meanwhile, middle-class residents mainly undertake medium-short time and medium-short distance commuting. The study subsequently uses multilevel logistic regression and multiple linear regression models to analyze the factors that influence commuting mode choice, time and distance. The gender, age, number of family cars, housing source and jobs-housing balance are the most important factors influencing commuting mode choice; housing, population density, jobs-housing balance and commuting mode significantly affect commuting time; and transport accessibility, jobs-housing balance and commuting mode are the notable factors affecting commuting distance. Finally, this paper analyzes what is affecting the commuting activities of middle-class residents and determines the differences in commuting activity characteristics and influence factors between middle-class and ordinary residents. Policy suggestions to improve urban planning and urban management are also proposed.展开更多
Runoff change and trend of the Naoli River Basin were studied through the time series analysis using the data from the hydrological and meteorological stations. Time series of hydrological data were from 1957 to 2009 ...Runoff change and trend of the Naoli River Basin were studied through the time series analysis using the data from the hydrological and meteorological stations. Time series of hydrological data were from 1957 to 2009 for Bao′an station, from 1955 to 2009 for Baoqing station, from 1956 to 2009 for Caizuizi station and from 1978 to 2009 for Hongqiling station. The influences of climate change and human activities on runoff change were investigated, and the causes of hydrological regime change were revealed. The seasonal runoff distribution of the Naoli River was extremely uneven, and the annual change was great. Overall, the annual runoff showed a significant decreasing trend. The annual runoff of Bao′an, Baoqing, and Caizuizi stations in 2009 decreased by 64.1%, 76.3%, and 84.3%, respectively, compared with their beginning data recorded. The wet and dry years of the Naoli River have changed in the study period. The frequency of wet year occurrence decreased and lasted longer, whereas that of dry year occurrence increased. The frequency of dry year occurrence increased from 25.0%-27.8% to 83.9%-87.5%. The years before the 1970s were mostly wet, whereas those after the 1970s were mostly dry. Precipitation reduction and land use changes contributed to the decrease in annual runoff. Rising temperature and water project construction have also contributed important effects on the runoff change of the Naoli River.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 40971062)China Postdoctoral ScienceFundation (No. 20100480441)
文摘Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook, this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting factors. The results show that: 1) During 1980 to 2007, total grain production increased from 3.20 ~ 108 t to 5.02 x 108 t in China, with annual increasing rate of 1.68%. From the regional disparities, most of the regions present increasing trend of total grain production except for several regions with higher level of economic development; 2) Grain sown area decreased from 1.17 × 108 ha in 1980 to 1.06 x 108 ha in 2007, which has negative effect on total grain production; 3) The increase of grain yield per unit area caused by land use intensity changes contributed to the increase of total grain yield greatly. However, as the land use intensity showed that farmers pay more attention to labor-saving input but not yield-increasing input, the less enthusiasm of farmers in grain production may become an important constraint on fu- ture grain production increase in China; 4) Based on the results, this paper proposed different land management poli- cies in different regions, for example, the government should protect cultivated land, promote large scale production. As to the less developed regions, the government should pay more attention to agricultural subsidies to promote farm- ers' enthusiasm in grain production.
基金supported by the Major State Basic Research Development Program of China: the Research on the Key Technology of Clean and High Efficient Mariculture Pond (Grant Nos. 2011BAD 13B03)Promotive Research Fund for Excellent Young and Middle-Aged Scientists of Shandong Province: High Efficiency and Low Carbon Development Research of Shandong Mariculture Industry (Grant Nos. BS2012HZ 024)the Research of Chinese Mariculture Industry High Efficiency and Low Carbon Development Model Implementation Mechanism Funded by the Marine Development Institute of Ocean University of China Humanities and Social Science Key Research Base of Ministry of Education (Grant Nos. 2012JDZS02)
文摘Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable, this paper conducts SBM model to evaluate the aquaculture efficiency based on the data of 16 aquaculture-developed provinces in China from 2004 to 2011. The results show the efficiency in China has not changed much in recent years with the efficiency values mainly between 0.39 and 0.53, and the efficiency of marine-aquaculture-dominated provinces is generally higher than that of freshwater-aquaculture-dominated ones. To analyze the difference under the efficiency, the panel Tobit model is used with education level factor, training factor, technology extension factor, technical level factor, scale factor and species factor as the efficiency influencing factors. The results show that technology extension factor and technical level factor have significant positive influence.
基金Supported by the National Natural Science Foundation of China(No.41201569)the Natural Science Foundation of Shandong Province(No.ZR2011DQ003)the Qingdao Municipal Science&Technology Program(No.12-1-4-1-(15)-jch)
文摘The coastal zone is an area characterized by intense interaction between land and sea, high sensitivity to regional environmental changes, and concentrated human activities. Little research has investigated vegetation cover changes in coastal zones resulting from climate change and land-use change, with a lack of knowledge about the driving mechanism. Normalized diff erence vegetation index(NDVI) can be used as an indicator for change of the coastal environment. In this study, we analyzed the interannual changes and spatial distribution of NDVI in the coastal zone around Jiaozhou Bay in Qingdao, a coastal city undergoing rapid urbanization in northeast China. The underlying causes of NDVI variations were discussed in the context of climate change and land-use change. Results showed that the spatio-temporal distribution of NDVI displayed high spatial variability in the study area and showed a typical trend of gradually increasing from coastal to inland regions. The significant increase area of NDVI was mainly found in newly added construction land, extending along the coastline towards the inland. Land vegetation cover demonstrated a certain response relationship to sea-land climate change and land-based activities. The impact of land-based human activities was slightly greater than that of sea-land climate change for land vegetation cover. The results indicate that promoting ecological policies can build an ecological security framework of vegetation suitable for the resource characteristics of coastal cities. The framework will buf fer the negative ef fects of sea-land climate change and land-based human activities on vegetation cover and thereby achieve the balance of regional development and ecological benefits in the coastal zone.
基金Under the auspices of National Natural Science Foundation of China(No.41071109)Fundamental Research Funds for the Central University(No.10SSXT137)
文摘Urbanization is a comprehensive concept, a trinity process that population urbanization, economic urbanization and space urbanization, is based on the interactions and mutual influences among the in which, people are the central and leading players in this process, while economic activities serve as the driving force and space is the carrier-the physical or material setting as well as the product. So the coordination among these processes is crucial for a country or region's sustainable development. China is experiencing rapid growth of cities and a surge in urban population, with the basic national condition of many people and little land, which calls for a systematic study of the issue of coordinated urbanization from theoretical, methodological and practical perspectives. Based on the concept of urbanization and non-coordination of urbanization, this article built a quantitative method to identify and evaluate the urbanization and non-coordination of urbanization, and made an empirical analysis in China between 2000 and 2008. The results show that the non-coordination overall level of China's urbanization declined during the study period, because population urbanization, economic urbanization, and space urbanization exhibited different trajectories of change. This study also reveals that performance assessment system, household registration system, and urban land expropriation system, etc., are the main affecting factors. At the end, we put forward some suggestions to achieve sustainable development of China's urbanization from the aspects of improving the local government's obiective function, imolementing the urban plalming svstem, enforcing public particination asnects and so on.
基金financial support provided by the National Social Science Foundation of China (Grant No. 08 &ZD046)National Natural Science Foundation of China (Grant No.70903031 and 41071348)
文摘This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured the CO 2 emission performance of 28 provinces and autonomous regions in China from 1996 to 2007;with the convergence theory and panel data regression model,the authors analyze the regional differences and the influencing factors.It is found that the performance of CO 2 emissions in China has been continuously improved mainly due to the technological progress,and the average improvement rate is 3.25%,with a cumulative improvement rate of 40.86%.In addition,the CO 2 emission performance varies across four regions.As a whole,the performance score of eastern China is the highest.The northeastern and central China has relatively lower performance scores,and the western China is relatively backward.The regional differences are decreasing,and the performance of CO 2 emissions is convergent.The influence of some factors on the performance of CO 2 emissions is significant,such as the level of economic development,the level of industrial structure,energy intensity,and ownership structure.The influence of some factors,such as opening-up to the outside world,on the performance of CO 2 emissions is not significant..
文摘This data article describes the dataset from a national cross-sectional questionnaire survey on Chinese internal migrants in 2017.The survey was part of the Chinese Migrants Dynamic Survey,which is an annually conducted large-scale national questionnaire survey on internal migrants.The respondents in the described dataset were migrants and registered local residents aged over 15 years old.A multistage stratified probability-proportionalto-size(PPS) sampling method based on the 2016 annual report data of China Migrant Population was adopted.The questionnaire was designed to collect demographic information of respondents and their family members,intention of migration or settlement,health status,health services accessibility,social integration,and epidemic influencing factors of common diseases,including hypertension,type 2 diabetes,diarrhea,fever,rash,icterus,conjunctival redness,cold,and other illnesses or injuries.The sample population in this survey include 13,998 internal migrants and 14,000 registered local residents from eight domestic cities/prefecture/districts across China.It is the most widely covering and highly representative dataset on common diseases and influencing factors of internal migrants in China.The dataset can be used to study common diseases and influencing factors among floating Chinese population.It provides data support for government to improve healthcare accessibility and the equity of public health services for internal migrants in China.
基金Supported by Grants from the Tenth Five-Year Program for National Scientific Key Project of China,No.2004BA703B06-2973 National Basic Research Development Program of China,No.2010CB529304the funds for scientific research fromthe Financial Department of Liaoning Province,China,No.2008-621
文摘AIM: To investigate the incidence and mortality of gastric cancer (GC) in Zhuanghe region, northeast China and the influencing factors for their changing trends.METHODS: All new cancer cases and deaths registered from 2005 to 2010 in Zhuanghe County were reviewed. The annual GC cases, constituent ratio, crude rates,age-standardized rates, their sex and age distribution and temporal trends were assessed. The method of annual percentage change (APC) was used to estimate the trends of GC.RESULTS: Altogether 2634 new cases of GC and 1722 related deaths were registered, which accounted for 21.04% and 19.13% of all cancer-related incidence and deaths, respectively. The age-standardized incidence rate steadily decreased from 57.48 in 2005 to 44.53 in 2010 per 10^5 males, and from 18.13 to 14.70 per 10s females, resulting in a APC of -5.81% for males and -2.89% for females over the entire period. The magnitude of APC in GC mortality amounted to -11.09% and -15.23%, respectively, as the agestandardized mortality rate steadily decreased from 42.08 in 2005 to 23.71 in 2010 per 10^5 males, and from 23.86 to 10.78 per 10^5 females. Females had a significantly lower incidence (a male/female ratio 2.80, P 〈 0.001) and mortality (a male/female ratio 2.30, P 〈 0.001). In both genders, the peak incidence and mortality occurred in the 80-84 years age group. The age-standardized mortality/incidence ratio also decreased from the peak of 0.73 in 2005 to 0.53 in 2010 for males, and from 1.32 to 0.73 for females.CONCLUSION: Encouraging declines of incidence and mortality of GC were observed in Zhuanghe region between 2005 and 2010, possibly due to the economic development and efficient GC control strategies.
基金Under the auspices of National Natural Science Foundation of China (No 40571052,40301014)
文摘Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated,trip purposes of private car travel are mainly commute and business affairs with a more flexible trip in the urban core area.And trip intensities are concentrated in a certain extent,with trip frequency being lower in the urban core area than the peripheral area.In addition,the trip time has two significant peaks occurring in the morning and afternoon,and one trough in the midday.And trip spatial distribution is mainly within commute with both residence and employment in urban area and inward commute with residence in suburban area while employment in urban area.Both kinds of commutes direct to the urban area.The study also shows that the characteristics of private car travel are principally influenced by two aspects:travelers' attributes and urban characteristics.The main travelers' social and economic attributes influenced it include the gender,education attainment,age,driving experience and per capita monthly household income.The urban characteristics influenced it mainly cover the land use pattern,public traffic facilities and spatial attributes of residential environment.
基金Under the auspices of National Natural Science Foundation of China(No.41601607,41771138,41771161)Strategic Planning Project from Institute of Northeast Geography and Agroecology(IGA),Chinese Academy of Sciences(No.Y6H2091001-3)
文摘High PM_(2.5) concentrations and frequent air pollution episodes during late autumn and winter in Jilin Province have attracted attention in recent years. To describe the spatial and temporal variations of PM_(2.5) concentrations and identify the decisive influencing factors, a large amount of continuous daily PM_(2.5) concentration data collected from 33 monitoring stations over 2-year period from 2015 to 2016 were analyzed. Meanwhile, the relationships were investigated between PM_(2.5) concentrations and the land cover, socioeconomic and meteorological factors from the macroscopic perspective using multiple linear regressions(MLR) approach. PM_(2.5) concentrations across Jilin Province averaged 49 μg/m^3, nearly 1.5 times of the Chinese annual average standard, and exhibited seasonal patterns with generally higher levels during late autumn and over the long winter than the other seasons. Jilin Province could be divided into three kinds of sub-regions according to 2-year average PM_(2.5) concentration of each city. Most of the spatial variation in PM_(2.5) levels could be explained by forest land area, cultivated land area, urban greening rate, coal consumption and soot emissions of cement manufacturing. In addition, daily PM_(2.5) concentrations had negative correlation with daily precipitation and positive correlation with air pressure for each city, and the spread and dilution effect of wind speed on PM_(2.5) was more obvious at mountainous area in Jilin Province. These results indicated that coal consumption, cement manufacturing and straw burning were the most important emission sources for the high PM_(2.5) levels, while afforestation and urban greening could mitigate particulate air pollution. Meanwhile, the individual meteorological factors such as precipitation, air pressure, wind speed and temperature could influence local PM_(2.5) concentration indirectly.
文摘To analyze the positive influencing factors of Chinese telecom operators' EVA(Economic Value Added),this paper selects fifteen indicators based on the enterprise features of telecom operators and telecommunications industry characteristics,and then classifies these indicators into the following factors:operation scale,profitability,solvency and asset management ability by factor analysis.This paper also gives the priorities of these four factors by regression analysis,of which the operation scale is the most important factor.The research results point out a clear method for the telecom operatorsto increase their EVA in order to meet the performance appraisal from State-owned Assets Supervision and Administration Commission of the State Council.
基金Under the auspices of National Natural Science Foundation of China(No.41401204,41471462)Fundamental Research Funds for the Central Universities(No.lzujbky-2013-128)
文摘The important role of spatial scale in exploring the geography of poverty as well as its policy implications has been noticed but with limited knowledge. To improve such limited understanding, we mainly investigated the spatial patterns and influencing factors of rural poverty(indicated by poor population and poverty incidence) at three different administrative levels in the Liupan Mountain Region, one of the fourteen poorest regions in China. Our results show that from a global perspective, poor areas are clustered significantly at the county-, township-, and village-level, and more greatly at a lower level. Locally, there is spatial mismatch among poverty hotspots detected not only by the same indicator at different levels but also by different indicators at the same level. A scale effect can be found in the influencing factors of rural poverty. That is, the number of significant factors increases, but the degree of their association with poverty incidence decreases at a lower level. Such scale effect indicates that poverty incidence at lower levels may be affected by more complex factors, including not only the new local ones but also the already appeared non-local ones at higher levels. However, the natural conditions tend to play a scale-independent role to poverty incidence. In response to such scale-dependent patterns and factors, anti-poverty policies can be 1) a multilevel monitoring system to reduce incomplete or even misleading single-level information and understanding; 2) the village-based targeting strategy to increase the targeting efficiency and alleviate the mentioned spatial mismatch; 3) more flexible strategies responding to the local impoverishing factors, and 4) different task emphasises for multilevel policymakers to achieve the common goal of poverty reduction.
基金Froject supported by the Scientific Research Foundation of Hunan Province(No.20012-2000C168).
文摘The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner method by laboratory and pot experiments. Results showed that the content of fixed ammoniumin the plough horizons ranged from 88.3 mg kg-1 to 388.1 mg kg-1, with 273.2 ± 77.7 mg kg-1 on average,accounting for 11.2% of total soil N on average. Content of fixed ammonium decreased in the order of newlylacustrine clayey paddy soil > alluvial sandy paddy soil > purple clayey paddy soil > newly alluvial sandypaddy soil > yellow clayey paddy soil > reddish-yellow clayey paddy soil > granitic sandy paddy soil. Therewere four distribution patterns of fixed ammonium in the profiles to 1-m depth, i.e., increase with the depth,decrease with increasing depth, no distinct change with the depth, and abrupt increase or decrease in somehorizon. Percentage of fixed ammonium in total N increased with the depth in most of the soils. Fixationof NH4+ by soil was higher at 30 ℃ than at 20 ℃ and 40 ℃, and continuous submergence benefited thefixation of NH4+ in newly alluvial sandy paddy soil, purple clayey paddy soil and alluvial sandy paddy soil,while alternating wetting and drying contributed to the fixation of NH4+ in yellow clayey paddy soil mostly.Fixed ammonium content in the test paddy soils was significantly correlated with < 0.01 mm clay content(P < 0.05), but not with < 0.001 mm clay content, total N, organic N and organic matter. Fixed ammoniumcontent varied with rice growth stages. Application of N fertilizer promoted fixation of NH4+ by soil, and Nuptake by rice plant promoted release of fixed ammonium from the soil. Recently fixed ammonium in paddysoil after N fertilizer application was nearly 100% available to rice plant, while native fixed ammonium wasonly partly available, varying with the soil type and rice type.
基金the Natural Social Science Foundation of China research fund(Grant No.10zd&007)the Ministry of Education research fund(Grant No.12YJC790269)the Natural Science Foundation of China research fund(Grant No.71103212) for financial support
文摘This paper first estimates the overall return on capital in China between 1978 and 2013. It then identifies the determinants of return on capital by analyzing provincial panel data and breaks down the causes of swerves in capital return after the eruption of the global financial crisis in 2008. It finds that: (1) there is significant inertia in the return on capital," (2) government intervention has significantly negative impact on capital return; (3) a significantly negative correlation is observed between investment rate and return on capital," and (4) the increases in the shares of secondary and tertiary industries in the economy have significantly positive impact on return on capital. This paper concludes that the growth in investment rate and the expansion of government size are both important contributors to the recent decline in China's return on capital since the financial crisis.
基金support provided by National Natural Sciences Foundation of China (No. 41271146)National Key Technology R&D Program (No. 2008BAH31B01)
文摘China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires of 11 villages in 2 counties and Tobit model,this paper analyzes the geographical differences and influencing factors of energy consumption for non-production purposes of rural households living in different terrain conditions.This research finds that:(1) Coal takes up the main part of energy consumption in valley areas and coal consumption is mainly affected by per capita cultivated land area,household income,proportion of rural household energy expenditure in total expenditure,coal price,and family population size.Firewood takes up the main part of energy consumption in high mountain areas and firewood consumption is mainly affected by per capita firewood forest area,distance to purchase coal,household income,electricity price,and coal price.(2) Only when the distance is greater than 20 kilometers,that is the average distance of rural households living in middle mountain areas(1,600m^1,800m) to purchase coal,the transportation condition has a significant impact on coal consumption.(3) In high mountain areas,prices of coal and electricity are the main factors influencing energy consumption choice of rural households.Too high prices of coal and electricity would to some extent lead rural households to choose firewood as the main energy consumption type.Compared to coal,rural households prefer to choose electricity.
文摘At present, the aging situation of China's population is becoming more and more serious. By the end of 2016, there were 231 million people over the age of 60 in China, accounting for 16.7% of the total population. About 150 million people aged 65 and over make up 10.8 percent of the total population. China is expected to enter the peak period of population aging by 2035. Therefore, the government as a single pension service main body management pattern already can not adapt to our country entered the aging society, mobilize and fostering social organizations to participate in the pension services is to build perfect endowment service system, satisfy people pension service demand model of a kind of indispensable. In view of the development of social organizations has just started in our country, there exist many problems and difficulties, so this article USES the ISM method, for social organizations to participate in research and analyze influence factors of pension services, and then find out the social organization in the process of participation in pension service problems, put forward effective solutions.
基金financial supports from the National Natural Science Foundation of China (Grant Nos. 41571527, 41301193, 41101552,41401198)Main Direction Program (KZCX2-EW317)West Light Foundation of the Chinese Academy of Sciences (2013Yuhui)
文摘In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies.
基金Under the auspices of National Basic Research Program of China(No.2012CB417003)National Natural Science Foundation of China(No.41101024)
文摘The Poyang Lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and mitigation. The present study identified the characteristics variations of historical floods in the Poyang Lake and their tendencies based on the Mann-Kendall(M-K) test, and also investigated the related affecting factors, both from climate and human activities. The results revealed that the highest flood stages, duration as well as hazard coefficient of floods showed a long-term increasing linear trend during the last 60 years with the M-K statistic of 1.49, 1.60 and 1.50, respectively. And, a slightly increasing linear trend in the timing of the highest stages indicated the floods occurred later and later during the last six decades. The rainfall during the flood season and subsequent discharges of the Changjiang(Yangtze) River and runoff from the Poyang Lake Basin were mainly responsible for the severe flood situation in the Poyang Lake in the 1990 s. In addition, the intensive human activities, including land reclamation and levee construction, also played a supplementary role in increasing severity of major floods. While, the fewer floods in the Poyang Lake after 2000 can be attributed to not only the less rainfall over the Poyang Lake Basin and low discharges of the Changjiang River during flood periods, but also the stronger influences of human activity which increased the floodwater storage of the Poyang Lake than before.
基金Under the auspices of National Natural Science Foundation of China(No.41271182)
文摘The middle class in metropolitan Chinese cities has become an important social group. With the rapid development of urbanization and constant advancement of suburbanization, the middle class has increasingly come to influence city traffic. Research into middle-class commuting activities thus has practical significance for improving traffic congestion and reducing the commuting burden in metropolitan cities. Based on a dataset formed by 816 completed surveys, this paper analyzes the commuting mode, time and distance of middle-class residents in Guangzhou City using the descriptive statistical method. The results indicate that private cars are the main commuting mode, followed by public transport. Meanwhile, middle-class residents mainly undertake medium-short time and medium-short distance commuting. The study subsequently uses multilevel logistic regression and multiple linear regression models to analyze the factors that influence commuting mode choice, time and distance. The gender, age, number of family cars, housing source and jobs-housing balance are the most important factors influencing commuting mode choice; housing, population density, jobs-housing balance and commuting mode significantly affect commuting time; and transport accessibility, jobs-housing balance and commuting mode are the notable factors affecting commuting distance. Finally, this paper analyzes what is affecting the commuting activities of middle-class residents and determines the differences in commuting activity characteristics and influence factors between middle-class and ordinary residents. Policy suggestions to improve urban planning and urban management are also proposed.
基金Under the auspices of National Natural Science Foundation of China (No. 40830535, 41001110, 41101092, 41171092)National Basic Research Program of China (No. 2010CB951304)the CAS/SAFEA (Chinese Academy of Sciences/State Administration of Foreign Experts Affairs) International Partnership Program for Creative Research Teams, Eleventh Five-Year' Key Technological Projects of Heilongjiang Province Farm Bureau (No. HNK10A-10-01, HNK10A-10-03)
文摘Runoff change and trend of the Naoli River Basin were studied through the time series analysis using the data from the hydrological and meteorological stations. Time series of hydrological data were from 1957 to 2009 for Bao′an station, from 1955 to 2009 for Baoqing station, from 1956 to 2009 for Caizuizi station and from 1978 to 2009 for Hongqiling station. The influences of climate change and human activities on runoff change were investigated, and the causes of hydrological regime change were revealed. The seasonal runoff distribution of the Naoli River was extremely uneven, and the annual change was great. Overall, the annual runoff showed a significant decreasing trend. The annual runoff of Bao′an, Baoqing, and Caizuizi stations in 2009 decreased by 64.1%, 76.3%, and 84.3%, respectively, compared with their beginning data recorded. The wet and dry years of the Naoli River have changed in the study period. The frequency of wet year occurrence decreased and lasted longer, whereas that of dry year occurrence increased. The frequency of dry year occurrence increased from 25.0%-27.8% to 83.9%-87.5%. The years before the 1970s were mostly wet, whereas those after the 1970s were mostly dry. Precipitation reduction and land use changes contributed to the decrease in annual runoff. Rising temperature and water project construction have also contributed important effects on the runoff change of the Naoli River.