"Space" is the place where people take social and economic activities,as well as the carrier supporting any public life style and rights and acts.Urban and rural places are the two main parts that comprise t..."Space" is the place where people take social and economic activities,as well as the carrier supporting any public life style and rights and acts.Urban and rural places are the two main parts that comprise the regional economic system,and only when they are developed harmoniously can the overall economic optimization and social welfare maximization come true.On basis of analyzing the experience and mechanism of urban and rural spaces of London,New York and Tokyo 3 typical international metropolitan area and learning from their development experience,the study has proposed development strategies for the integration of urban-rural space of Xi'an City according to its current development situation.展开更多
Environmental and ecological problems in the urban-rural integration were analyzed, characteristics of urban green space system introduced, such as excellent landscape eco-structure, distinctive historical and humanis...Environmental and ecological problems in the urban-rural integration were analyzed, characteristics of urban green space system introduced, such as excellent landscape eco-structure, distinctive historical and humanistic features, and diversified natural landscape resources, and also challenges pointed out. Evolution, overall spatial structure and conservation concept of conservation-minded urban green space system planning were elaborated, on the basis of which the evaluation system of conservation-minded urban green space system was studied, and it was proposed that mutual relationship between impact factors of compound value and qualitative evaluation factors should be taken into consideration as a whole in evaluating conservation effects of green space system. Quantitative evaluation indexes and qualitative evaluation measures were analyzed, an objective and precise evaluation system for the conservation-minded urban green space system was established by combining qualitative and quantitative analysis to improve ecological environment during the urbanization, and fully show planning concepts of conservation-minded green space system.展开更多
Equal access to social infrastructures is a fundamental prerequisite for sustainable development,but has long been a great challenge worldwide.Previous studies have primarily focused on the accessibility to social inf...Equal access to social infrastructures is a fundamental prerequisite for sustainable development,but has long been a great challenge worldwide.Previous studies have primarily focused on the accessibility to social infras-tructures in urban areas across various scales,with less attention to rural areas,where inequality can be more severe.Particularly,few have investigated the disparities of accessibility to social infrastructures between urban and rural areas.Here,using the Changsha-Zhuzhou-Xiangtan urban agglomeration,China,as an example,we investigated the inequality of accessibility in both urban and rural areas,and further compared the urban-rural difference.Accessibility was measured by travel time of residents to infrastructures.We selected four types of social infrastructures including supermarkets,bus stops,primary schools,and health care,which were funda-mentally important to both urban and rural residents.We found large disparities in accessibility between urban and rural areas,ranging from 20 min to 2 h.Rural residents had to spend one to two more hours to bus stops than urban residents,and 20 min more to the other three types of infrastructures.Furthermore,accessibility to multiple infrastructures showed greater urban-rural differences.Rural residents in more than half of the towns had no access to any infrastructure within 15 min,while more than 60%of the urban residents could access to all infrastructures within 15 min.Our results revealed quantitative accessibility gap between urban and rural areas and underscored the necessity of social infrastructures planning to address such disparities.展开更多
There are significant differences between urban and rural bed-and-breakfasts(B&Bs)in terms of customer positioning,economic strength and spatial carrier.Accurately identifying the differences in spatial characteri...There are significant differences between urban and rural bed-and-breakfasts(B&Bs)in terms of customer positioning,economic strength and spatial carrier.Accurately identifying the differences in spatial characteristics and influencing factors of each type,is essential for creating urban and rural B&B agglomeration areas.This study used density-based spatial clustering of applications with noise(DBSCAN)and the multi-scale geographically weighted regression(MGWR)model to explore similarities and differences in the spatial distribution patterns and influencing factors for urban and rural B&Bs on the Jiaodong Peninsula of China from 2010 to 2022.The results showed that:1)both urban and rural B&Bs in Jiaodong Peninsula went through three stages:a slow start from 2010 to 2015,rapid development from 2015 to 2019,and hindered development from 2019 to 2022.However,urban B&Bs demonstrated a higher development speed and agglomeration intensity,leading to an increasingly evident trend of uneven development between the two sectors.2)The clustering scale of both urban and rural B&Bs continued to expand in terms of quantity and volume.Urban B&B clusters characterized by a limited number,but a higher likelihood of transitioning from low-level to high-level clusters.While the number of rural B&B clusters steadily increased over time,their clustering scale was comparatively lower than that of urban B&Bs,and they lacked the presence of high-level clustering.3)In terms of development direction,urban B&B clusters exhibited a relatively stable pattern and evolved into high-level clustering centers within the main urban areas.Conversely,rural B&Bs exhibited a more pronounced spatial diffusion effect,with clusters showing a trend of multi-center development along the coastline.4)Transport emerged as a common influencing factor for both urban and rural B&Bs,with the density of road network having the strongest explanatory power for their spatial distribution.In terms of differences,population agglomeration had a positive impact on the distribution of urban B&Bs and a negative effect on the distribution of rural B&Bs.Rural B&Bs clustering was more influenced by tourism resources compared with urban B&Bs,but increasing tourist stay duration remains an urgent issue to be addressed.The findings of this study could provide a more precise basis for government planning and management of urban and rural B&B agglomeration areas.展开更多
The environmental impact issues,such as global warming and expansion of the urban zone,seem more serious and have become the biggest defining challenges of the 21st century.Climate change can lead to water shortages,d...The environmental impact issues,such as global warming and expansion of the urban zone,seem more serious and have become the biggest defining challenges of the 21st century.Climate change can lead to water shortages,desertification,land degradation,air pollution,rising sea levels,accelerated deforestation,and exacerbated economic pressures.Global urban growth greatly impacts changes in sociability,humanity,and the environment of the Earth.The human presence,especially in cities,seriously affects resource use and waste disposal,and they are consuming natural resources faster than the planet can sustain during urbanization,changing how people live.China,with a population of 1.3 billion,has seen tens of millions of people living in the countryside migrate to cities,especially megacities,since the 1980s.As a result of its decision to industrialize and urbanize to boost the economy,China has become the world’s second-largest consumer of energy.In recent years,China’s government has quickly recognized the lessons of“limits to growth”and has taken action by initiating the construction process in Dongtan,Shanghai,China.They are making efforts to build urban-rural integration communities to promote sustainable development.Based on a literature review focusing on Dongtan,research questions are raised according to the research objective:(1)What are the challenges of sustainable development in urban-rural integration?(2)What practices has Dongtan implemented for sustainable development,or how is sustainable development being applied to Dongtan?(3)What are the social,political,environmental,and economic concerns regarding the sustainable development of Dongtan?The sustainable urban-rural integration concerns the ecological,economic,environmental,and psychological aspects of urban-rural integration design and management.The overall objective is to promote sustainable development in economic,social,ecological,and spatial dimensions.It will be a liveable,complete community that makes economic,environmental,and social sense locally while also contributing to national and global sustainable development.It will serve as a compelling model for how to build sustainable urban-rural integration worldwide.展开更多
Firstly,this paper reviews and analyzes historic background of urban-rural integration of Chongqing,and the evolution and trend of urban and rural dual economic structure.On the basis of previous researches,it selects...Firstly,this paper reviews and analyzes historic background of urban-rural integration of Chongqing,and the evolution and trend of urban and rural dual economic structure.On the basis of previous researches,it selects factors and variables influencing urban and rural dual economic structure,and establishes an econometric model.By state space Kalman filtering method,it analyzes dynamic influence of factors upon urban-rural dual economic intensity.According to empirical conclusion,it puts forward corresponding policy recommendations for promoting integrated urban and rural economic development of Chongqing.展开更多
The connotation of urban-rural integration,its construction courses,construction modes in China and abroad are introduced in this study,the problems emerging from the urban-rural integration practices are analyzed,and...The connotation of urban-rural integration,its construction courses,construction modes in China and abroad are introduced in this study,the problems emerging from the urban-rural integration practices are analyzed,and strategies for the urban-rural integration in China are proposed.展开更多
目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,...目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。展开更多
Urban-rural integration is important for urbanization and strengthening of urban and rural development in China. Since the third session of the 16th National Committee, the model is still at experimental stage, althou...Urban-rural integration is important for urbanization and strengthening of urban and rural development in China. Since the third session of the 16th National Committee, the model is still at experimental stage, although with some progress. Hence, it is necessary to make a summary on some typical experience of urban-ru- ral integration, in order to provide references for further exploration.展开更多
The urban and rural areas are regarded as two major components of the regional economic system. Only through joint balanced development of the two can we achieve overall economic optimization and social welfare maximi...The urban and rural areas are regarded as two major components of the regional economic system. Only through joint balanced development of the two can we achieve overall economic optimization and social welfare maximization. But the great social division of labor has separated urban areas from rural areas,which casts the shadow of city-oriented theory on cooperative relations between urban and rural areas. Mutual separation between urban and rural settlements and independent development trigger off a range of social problems. We must undertake guidance through rational development path of urban-rural integration,to eliminate the phenomenon of urban-rural dual structure,and promote the sustainable development of population,resources and environment in urban and rural areas as soon as possible.展开更多
Human activity and urbanization result in urban-rural environmental gradients. Understanding effect of the gradients on soil properties is necessary for management of the soils around urban areas. In this study, soil ...Human activity and urbanization result in urban-rural environmental gradients. Understanding effect of the gradients on soil properties is necessary for management of the soils around urban areas. In this study, soil quality of some vegetable fields was characterized along an urban-rural gradient in Shaoxing County, Zhejiang Province. Fifteen soil physical and chemical properties were evaluated by using principal component analysis.Results showed that there was a great variation in the soil quality along the gradient. From rural to urban zones, soil organic matter, water-stable aggregates, cation exchangeable capacity (CEC), total N and P, and available K increased, whereas soil pH value decreased. In addition, Pb, Cu, Ni, Co, Zn and Cr in the soils tended to be accumulated toward the urban zone. Sequential chemical extraction showed that mobility of all the heavy metals in the soils tended to increase from the rural to the urban zones. The variation of soil properties accounted for by the first principal component was significantly explained by the difference in application rates of municipal wastes.展开更多
China is a country with a long history of agricultural development,the tr adition of bureaucratic administra-tion and economic management system s for the social development.In its t ransition from traditional society...China is a country with a long history of agricultural development,the tr adition of bureaucratic administra-tion and economic management system s for the social development.In its t ransition from traditional society to modern soci-ety during the past 50years,the rela tions between rural areas and urban a reas have been kept abnormal if considered from the point of view of the modernized co untries.Today,China still has its more than 70percent of population,bu t limited capital,lower technology and underdeveloped culture,in the rural areas.This unbalance forms not only the o bstacles to China’s modernization of social development,but also the barriers to th e society,economy and environment sustainable devel-opment.This paper focuses on the dis cussion about the coordinate develo pment of the relations between rural and urban in the past 50years,and the authors hold that only has the abnormal relation between the two areas been corrected,could China’s future development of natio nal economy be successful.展开更多
The general law of regional spatial evolution is researched.In the process of the evolution of four stages,namely the early stage of traditional agriculture and industrialization,the middle stage of industrialization,...The general law of regional spatial evolution is researched.In the process of the evolution of four stages,namely the early stage of traditional agriculture and industrialization,the middle stage of industrialization,the later stage of industrialization and post-industrialization,the types of space are homogenized space,polarized space,pole-axis space and integrated space respectively;the choosing of the spatial location is influenced by economy,society and environment,and the spatial structure extends along with three-dimensional space.Based on the fact that China's urban-rural spatial structure evolution develops rapidly,and the outstanding characteristics of dual structure becomes the main obstacle to urban-rural balanced development,the thesis poses the countermeasures of China's urban-rural spatial integrated balanced development.It points out that the healthy development of socio-economy is the external environment of realizing urban-rural spatial integration;the urban-rural coordinated planning is the prerequisite of realizing urban-rural spatial integration;fulfilling the governmental function is the key to realizing urban-rural spatial integration;promoting agricultural industrialization is the approach to realizing urban-rural spatial integration;perfecting social security system is the basis of realizing urban-rural spatial integration.展开更多
Through reviewing domestic and overseas literatures about the definition of urban-rural fringe,it can be found that the combination of qualitative and quantitative definition methods has become a dominant one.This pap...Through reviewing domestic and overseas literatures about the definition of urban-rural fringe,it can be found that the combination of qualitative and quantitative definition methods has become a dominant one.This paper makes out the principle and basis,uses the data of villages and towns,and establishes an index system from three angles:population,land use and landscape.And then the gravitational model is applied to define the urban-rural fringe with Beijing as an example.展开更多
螺旋藻(Spirulina)藻蓝蛋白具有独特的理化特性及生理功能,是药物、食品和化妆品的天然原料,具有较大的开发潜力。为探讨螺旋藻藻蓝蛋白的研究现状与发展前景,对中国知网和Web of Science数据库中1990—2023年发表的文献进行检索并筛选...螺旋藻(Spirulina)藻蓝蛋白具有独特的理化特性及生理功能,是药物、食品和化妆品的天然原料,具有较大的开发潜力。为探讨螺旋藻藻蓝蛋白的研究现状与发展前景,对中国知网和Web of Science数据库中1990—2023年发表的文献进行检索并筛选,使用Cite Space软件对文章发文量、研究团队及研究热点进行图谱分析。综合分析可知,国内年发文量偏少,呈平稳趋势;国外年发文量持续上升,尤其近几年发文量迅速增长,且发文量超过了100篇;国外研究热点集中于藻蓝蛋白在食品、医药行业的应用方面,而国内研究热点集中在提取纯化、稳定性、功能活性的研究与应用,下一步应结合研究现状开发适合规模化生产的提取纯化工艺,进一步加强藻蓝蛋白研究的广度与深度;国内外研究群体主要是高校的相关生物技术学院或研究机构等,总体来讲,学者间存在较为密切的合作,但研究机构间尚未形成紧密的合作关系,在地域上比较分散,各大高校和研究机构应突破地区或机构间的各种限制,促进该研究领域的深度融合和快速发展,深入挖掘藻蓝蛋白在各个领域的潜在应用。展开更多
Understanding the effects of land use changes on the spatiotemporal variation of soil organic carbon (SOC) can provide guidance for low carbon and sustainable agriculture. In this paper, based on the large-scale dat...Understanding the effects of land use changes on the spatiotemporal variation of soil organic carbon (SOC) can provide guidance for low carbon and sustainable agriculture. In this paper, based on the large-scale datasets of soil surveys in 1982 and 2009 for Pinggu District -- an urban-rural ecotone of Beijing, China, the effects of land use and land use changes on both temporal variation and spatial variation of SOC were analyzed. Results showed that from 1982 to 2009 in Pinggu District, the following land use change mainly occurred: Grain cropland converted to orchard or vegetable land, and grassland converted to forestland. The SOC content decreased in region where the land use type changed to grain cropland (e.g., vegetable land to grain cropland decreased by 0.7 g kg-1; orchard to grain cropland decreased by 0.2 g kg-l). In contrast, the SOC content increased in region where the land use type changed to either orchard (excluding forestland) or forestland (e.g., grain cropland to orchard and forestland increased by 2.7 and 2.4 g kg-1, respectively; grassland to orchard and forestland increased by 4.8 and 4.9 g kg-1, respectively). The organic carbon accumulation capacity per unit mass of the soil increased in the following order: grain cropland soil〈vegetable land/grassland soil〈orchard soil〈forestland soil. Therefore, to both secure supply of agricultural products and develop low carbon agriculture in a modern city, orchard has proven to be a good choice for land using.展开更多
Developing rural vocational education is of great significance to urban-rural integration: developing rural vocational education is helpful to cultivating new farmers for construction of new socialist countryside,favo...Developing rural vocational education is of great significance to urban-rural integration: developing rural vocational education is helpful to cultivating new farmers for construction of new socialist countryside,favorable to improving farmers' ability of finding jobs and starting undertaking, and beneficial to transfer of rural surplus labor and acceleration of urbanization. Restrictions on development rural vocational education mainly include: low value cognition of society and social assessment of rural vocational education; out of balance of cost and expected return of rural vocational education; the quality of supply of rural vocational education failure to satisfy demand of socio-economic development; imperfect rural vocational education system. In view of these,following countermeasures and suggestions are put forward: strengthen propaganda and guidance to build environment of public opinion for rural vocational education; push forward rural vocational compulsory education system to lay social foundation for rural vocational education; reinforce policy support to assist in building rural vocational education system; improve education system to build overall framework of rural vocational education; perfect laws and regulations to establish system and norm for development of rural vocational education.展开更多
基金Supported by Key Research Fund of Center for Information Industry Development in Shaanxi ProvinceIndustrial Economics Foundation of Provincial and Ministerial Key Disciplines+1 种基金Shaanxi Provincial Social Science Foundation(12D166)Project of Shaanxi Provincial Department of Education(2013JK0142)
文摘"Space" is the place where people take social and economic activities,as well as the carrier supporting any public life style and rights and acts.Urban and rural places are the two main parts that comprise the regional economic system,and only when they are developed harmoniously can the overall economic optimization and social welfare maximization come true.On basis of analyzing the experience and mechanism of urban and rural spaces of London,New York and Tokyo 3 typical international metropolitan area and learning from their development experience,the study has proposed development strategies for the integration of urban-rural space of Xi'an City according to its current development situation.
文摘Environmental and ecological problems in the urban-rural integration were analyzed, characteristics of urban green space system introduced, such as excellent landscape eco-structure, distinctive historical and humanistic features, and diversified natural landscape resources, and also challenges pointed out. Evolution, overall spatial structure and conservation concept of conservation-minded urban green space system planning were elaborated, on the basis of which the evaluation system of conservation-minded urban green space system was studied, and it was proposed that mutual relationship between impact factors of compound value and qualitative evaluation factors should be taken into consideration as a whole in evaluating conservation effects of green space system. Quantitative evaluation indexes and qualitative evaluation measures were analyzed, an objective and precise evaluation system for the conservation-minded urban green space system was established by combining qualitative and quantitative analysis to improve ecological environment during the urbanization, and fully show planning concepts of conservation-minded green space system.
基金supported by funding from the National Natural Science Foundation of China(Grant No.U21A2010)the National Science Fund for Distinguished Young Scholars(Grant No.42225104)the National Key Research and Development Program(Grant No.2022YFF130110O).
文摘Equal access to social infrastructures is a fundamental prerequisite for sustainable development,but has long been a great challenge worldwide.Previous studies have primarily focused on the accessibility to social infras-tructures in urban areas across various scales,with less attention to rural areas,where inequality can be more severe.Particularly,few have investigated the disparities of accessibility to social infrastructures between urban and rural areas.Here,using the Changsha-Zhuzhou-Xiangtan urban agglomeration,China,as an example,we investigated the inequality of accessibility in both urban and rural areas,and further compared the urban-rural difference.Accessibility was measured by travel time of residents to infrastructures.We selected four types of social infrastructures including supermarkets,bus stops,primary schools,and health care,which were funda-mentally important to both urban and rural residents.We found large disparities in accessibility between urban and rural areas,ranging from 20 min to 2 h.Rural residents had to spend one to two more hours to bus stops than urban residents,and 20 min more to the other three types of infrastructures.Furthermore,accessibility to multiple infrastructures showed greater urban-rural differences.Rural residents in more than half of the towns had no access to any infrastructure within 15 min,while more than 60%of the urban residents could access to all infrastructures within 15 min.Our results revealed quantitative accessibility gap between urban and rural areas and underscored the necessity of social infrastructures planning to address such disparities.
基金Under the auspices of National Social Science Foundation of China (No.21BJY202)。
文摘There are significant differences between urban and rural bed-and-breakfasts(B&Bs)in terms of customer positioning,economic strength and spatial carrier.Accurately identifying the differences in spatial characteristics and influencing factors of each type,is essential for creating urban and rural B&B agglomeration areas.This study used density-based spatial clustering of applications with noise(DBSCAN)and the multi-scale geographically weighted regression(MGWR)model to explore similarities and differences in the spatial distribution patterns and influencing factors for urban and rural B&Bs on the Jiaodong Peninsula of China from 2010 to 2022.The results showed that:1)both urban and rural B&Bs in Jiaodong Peninsula went through three stages:a slow start from 2010 to 2015,rapid development from 2015 to 2019,and hindered development from 2019 to 2022.However,urban B&Bs demonstrated a higher development speed and agglomeration intensity,leading to an increasingly evident trend of uneven development between the two sectors.2)The clustering scale of both urban and rural B&Bs continued to expand in terms of quantity and volume.Urban B&B clusters characterized by a limited number,but a higher likelihood of transitioning from low-level to high-level clusters.While the number of rural B&B clusters steadily increased over time,their clustering scale was comparatively lower than that of urban B&Bs,and they lacked the presence of high-level clustering.3)In terms of development direction,urban B&B clusters exhibited a relatively stable pattern and evolved into high-level clustering centers within the main urban areas.Conversely,rural B&Bs exhibited a more pronounced spatial diffusion effect,with clusters showing a trend of multi-center development along the coastline.4)Transport emerged as a common influencing factor for both urban and rural B&Bs,with the density of road network having the strongest explanatory power for their spatial distribution.In terms of differences,population agglomeration had a positive impact on the distribution of urban B&Bs and a negative effect on the distribution of rural B&Bs.Rural B&Bs clustering was more influenced by tourism resources compared with urban B&Bs,but increasing tourist stay duration remains an urgent issue to be addressed.The findings of this study could provide a more precise basis for government planning and management of urban and rural B&B agglomeration areas.
文摘The environmental impact issues,such as global warming and expansion of the urban zone,seem more serious and have become the biggest defining challenges of the 21st century.Climate change can lead to water shortages,desertification,land degradation,air pollution,rising sea levels,accelerated deforestation,and exacerbated economic pressures.Global urban growth greatly impacts changes in sociability,humanity,and the environment of the Earth.The human presence,especially in cities,seriously affects resource use and waste disposal,and they are consuming natural resources faster than the planet can sustain during urbanization,changing how people live.China,with a population of 1.3 billion,has seen tens of millions of people living in the countryside migrate to cities,especially megacities,since the 1980s.As a result of its decision to industrialize and urbanize to boost the economy,China has become the world’s second-largest consumer of energy.In recent years,China’s government has quickly recognized the lessons of“limits to growth”and has taken action by initiating the construction process in Dongtan,Shanghai,China.They are making efforts to build urban-rural integration communities to promote sustainable development.Based on a literature review focusing on Dongtan,research questions are raised according to the research objective:(1)What are the challenges of sustainable development in urban-rural integration?(2)What practices has Dongtan implemented for sustainable development,or how is sustainable development being applied to Dongtan?(3)What are the social,political,environmental,and economic concerns regarding the sustainable development of Dongtan?The sustainable urban-rural integration concerns the ecological,economic,environmental,and psychological aspects of urban-rural integration design and management.The overall objective is to promote sustainable development in economic,social,ecological,and spatial dimensions.It will be a liveable,complete community that makes economic,environmental,and social sense locally while also contributing to national and global sustainable development.It will serve as a compelling model for how to build sustainable urban-rural integration worldwide.
基金Supported by Social Science Planning Project of Chongqing(2010YBJJ13)the Fundamental Research Funds for the Central Universities(XDJK2010C103)Ph.D Foundation Project of Southwest University(SWU1209303)
文摘Firstly,this paper reviews and analyzes historic background of urban-rural integration of Chongqing,and the evolution and trend of urban and rural dual economic structure.On the basis of previous researches,it selects factors and variables influencing urban and rural dual economic structure,and establishes an econometric model.By state space Kalman filtering method,it analyzes dynamic influence of factors upon urban-rural dual economic intensity.According to empirical conclusion,it puts forward corresponding policy recommendations for promoting integrated urban and rural economic development of Chongqing.
文摘The connotation of urban-rural integration,its construction courses,construction modes in China and abroad are introduced in this study,the problems emerging from the urban-rural integration practices are analyzed,and strategies for the urban-rural integration in China are proposed.
文摘目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。
基金Supported by National Social Science Fund Youth Project(12CJL073)Ministry of education of Humanities and Social Sciences Research Youth Project(11YJC790272)+1 种基金the Young Backbone Teachers Project of Henan Province(2012GGJS-167)the Bidding Decision Project of Government in Henan Province(2012B518)~~
文摘Urban-rural integration is important for urbanization and strengthening of urban and rural development in China. Since the third session of the 16th National Committee, the model is still at experimental stage, although with some progress. Hence, it is necessary to make a summary on some typical experience of urban-ru- ral integration, in order to provide references for further exploration.
基金Supported by Key Research Base Foundation of Research Center for Information Industry Development of Shaanxi ProvinceProject of Shaanxi Provincial Department of Education ( 11JK0053)
文摘The urban and rural areas are regarded as two major components of the regional economic system. Only through joint balanced development of the two can we achieve overall economic optimization and social welfare maximization. But the great social division of labor has separated urban areas from rural areas,which casts the shadow of city-oriented theory on cooperative relations between urban and rural areas. Mutual separation between urban and rural settlements and independent development trigger off a range of social problems. We must undertake guidance through rational development path of urban-rural integration,to eliminate the phenomenon of urban-rural dual structure,and promote the sustainable development of population,resources and environment in urban and rural areas as soon as possible.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No. 1999011809).
文摘Human activity and urbanization result in urban-rural environmental gradients. Understanding effect of the gradients on soil properties is necessary for management of the soils around urban areas. In this study, soil quality of some vegetable fields was characterized along an urban-rural gradient in Shaoxing County, Zhejiang Province. Fifteen soil physical and chemical properties were evaluated by using principal component analysis.Results showed that there was a great variation in the soil quality along the gradient. From rural to urban zones, soil organic matter, water-stable aggregates, cation exchangeable capacity (CEC), total N and P, and available K increased, whereas soil pH value decreased. In addition, Pb, Cu, Ni, Co, Zn and Cr in the soils tended to be accumulated toward the urban zone. Sequential chemical extraction showed that mobility of all the heavy metals in the soils tended to increase from the rural to the urban zones. The variation of soil properties accounted for by the first principal component was significantly explained by the difference in application rates of municipal wastes.
文摘China is a country with a long history of agricultural development,the tr adition of bureaucratic administra-tion and economic management system s for the social development.In its t ransition from traditional society to modern soci-ety during the past 50years,the rela tions between rural areas and urban a reas have been kept abnormal if considered from the point of view of the modernized co untries.Today,China still has its more than 70percent of population,bu t limited capital,lower technology and underdeveloped culture,in the rural areas.This unbalance forms not only the o bstacles to China’s modernization of social development,but also the barriers to th e society,economy and environment sustainable devel-opment.This paper focuses on the dis cussion about the coordinate develo pment of the relations between rural and urban in the past 50years,and the authors hold that only has the abnormal relation between the two areas been corrected,could China’s future development of natio nal economy be successful.
基金Supported by the Key Research Base Program of Information Industrial Development Center of Shaanxi Province
文摘The general law of regional spatial evolution is researched.In the process of the evolution of four stages,namely the early stage of traditional agriculture and industrialization,the middle stage of industrialization,the later stage of industrialization and post-industrialization,the types of space are homogenized space,polarized space,pole-axis space and integrated space respectively;the choosing of the spatial location is influenced by economy,society and environment,and the spatial structure extends along with three-dimensional space.Based on the fact that China's urban-rural spatial structure evolution develops rapidly,and the outstanding characteristics of dual structure becomes the main obstacle to urban-rural balanced development,the thesis poses the countermeasures of China's urban-rural spatial integrated balanced development.It points out that the healthy development of socio-economy is the external environment of realizing urban-rural spatial integration;the urban-rural coordinated planning is the prerequisite of realizing urban-rural spatial integration;fulfilling the governmental function is the key to realizing urban-rural spatial integration;promoting agricultural industrialization is the approach to realizing urban-rural spatial integration;perfecting social security system is the basis of realizing urban-rural spatial integration.
文摘Through reviewing domestic and overseas literatures about the definition of urban-rural fringe,it can be found that the combination of qualitative and quantitative definition methods has become a dominant one.This paper makes out the principle and basis,uses the data of villages and towns,and establishes an index system from three angles:population,land use and landscape.And then the gravitational model is applied to define the urban-rural fringe with Beijing as an example.
文摘螺旋藻(Spirulina)藻蓝蛋白具有独特的理化特性及生理功能,是药物、食品和化妆品的天然原料,具有较大的开发潜力。为探讨螺旋藻藻蓝蛋白的研究现状与发展前景,对中国知网和Web of Science数据库中1990—2023年发表的文献进行检索并筛选,使用Cite Space软件对文章发文量、研究团队及研究热点进行图谱分析。综合分析可知,国内年发文量偏少,呈平稳趋势;国外年发文量持续上升,尤其近几年发文量迅速增长,且发文量超过了100篇;国外研究热点集中于藻蓝蛋白在食品、医药行业的应用方面,而国内研究热点集中在提取纯化、稳定性、功能活性的研究与应用,下一步应结合研究现状开发适合规模化生产的提取纯化工艺,进一步加强藻蓝蛋白研究的广度与深度;国内外研究群体主要是高校的相关生物技术学院或研究机构等,总体来讲,学者间存在较为密切的合作,但研究机构间尚未形成紧密的合作关系,在地域上比较分散,各大高校和研究机构应突破地区或机构间的各种限制,促进该研究领域的深度融合和快速发展,深入挖掘藻蓝蛋白在各个领域的潜在应用。
基金supported by the Hundred Talent Program of the Chinese Academy of Sciences(Huang Wenjiang)the Innovation“135”Program from Chinese Academy of Sciences(Y3SG0100CX)the Science&Technology Basic Research Program of China(2014FY210100)
文摘Understanding the effects of land use changes on the spatiotemporal variation of soil organic carbon (SOC) can provide guidance for low carbon and sustainable agriculture. In this paper, based on the large-scale datasets of soil surveys in 1982 and 2009 for Pinggu District -- an urban-rural ecotone of Beijing, China, the effects of land use and land use changes on both temporal variation and spatial variation of SOC were analyzed. Results showed that from 1982 to 2009 in Pinggu District, the following land use change mainly occurred: Grain cropland converted to orchard or vegetable land, and grassland converted to forestland. The SOC content decreased in region where the land use type changed to grain cropland (e.g., vegetable land to grain cropland decreased by 0.7 g kg-1; orchard to grain cropland decreased by 0.2 g kg-l). In contrast, the SOC content increased in region where the land use type changed to either orchard (excluding forestland) or forestland (e.g., grain cropland to orchard and forestland increased by 2.7 and 2.4 g kg-1, respectively; grassland to orchard and forestland increased by 4.8 and 4.9 g kg-1, respectively). The organic carbon accumulation capacity per unit mass of the soil increased in the following order: grain cropland soil〈vegetable land/grassland soil〈orchard soil〈forestland soil. Therefore, to both secure supply of agricultural products and develop low carbon agriculture in a modern city, orchard has proven to be a good choice for land using.
文摘Developing rural vocational education is of great significance to urban-rural integration: developing rural vocational education is helpful to cultivating new farmers for construction of new socialist countryside,favorable to improving farmers' ability of finding jobs and starting undertaking, and beneficial to transfer of rural surplus labor and acceleration of urbanization. Restrictions on development rural vocational education mainly include: low value cognition of society and social assessment of rural vocational education; out of balance of cost and expected return of rural vocational education; the quality of supply of rural vocational education failure to satisfy demand of socio-economic development; imperfect rural vocational education system. In view of these,following countermeasures and suggestions are put forward: strengthen propaganda and guidance to build environment of public opinion for rural vocational education; push forward rural vocational compulsory education system to lay social foundation for rural vocational education; reinforce policy support to assist in building rural vocational education system; improve education system to build overall framework of rural vocational education; perfect laws and regulations to establish system and norm for development of rural vocational education.