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1.
不同空间尺度的江苏省区域经济差异研究   总被引:2,自引:0,他引:2  
运用基尼系数、空间自相关等方法分析改革开放以来县域和地级市空间尺度下的江苏省区域经济差异变化及其空间机制。研究表明:改革开放以来江苏省县域和地级市尺度的区域经济差异在2008年前均呈扩大趋势,以后差距缩小,且县域尺度大于地级市尺度。在县域和地级市尺度上江苏省区域经济差异均存在明显的空间正相关关系,且不断增强,在县域尺度空间集聚更强。在地级市水平上,苏北的低水平集聚是其产生区域差异的主要原因,而在县域尺度上则苏南的高水平集聚是江苏区域差异主要原因。针对江苏省区域经济差异重点关注县域尺度的区域差异,在地级市尺度上侧重提升落后地区发展水平,而在县域空间尺度上以促进高水平地区的空间扩散为主。  相似文献   

2.
1990年以来江苏省外商直接投资空间格局动态演化研究   总被引:1,自引:0,他引:1  
江苏省自1990年以来外向型经济的快速发展推动着外商直接投资区域空间格局的演变.采用1990-2006年江苏省各县、市(市辖区)FDI数据,首先计算、分析了各区域单元FDI总量的变化与特征,描述了区域FDI发展的不平衡性,进而采用全局空间自相关与局部空间自相关理论,定量表示出江苏省自1990年以来FDI空间格局的动态演化过程及趋势.结果表明:江苏省FDI增量主要集中在苏南地区,苏北与苏南FDI的差距进一步拉大;区域单元实际利用外资的过程存在较强的空间自相关性,自1999年以来空间自相关性有所增强;FDI呈现显著的空间集聚模式,并且集聚态势越来越显著;以苏州市辖区、无锡市辖区为核心的苏南地方,成为江苏省FDI发展的核心区域,而苏北与苏中大部分区域,则沦为FDI发展的外围地带.  相似文献   

3.
江苏省乡村性的县域差异时空分析   总被引:5,自引:0,他引:5  
基于城乡一体化的思想构建乡村性指数(RI),运用熵值法确定2001~2012年乡村性指数的权重,以乡村性指数为变量,运用差异系数对江苏省乡村性县域差异的演变过程与空间格局进行定量分析。结果表明:2001年以来,江苏省乡村性随着城市化水平的提高呈现不断减弱的趋势,县域乡村性在2001~2007~2012年表现为总体缩小基础上的先缩小后扩大的演变格局。县域乡村性各子系统发展不平衡,主要表现为土地利用差异,人口发展、经济发展和基础设施差异相对较小。在空间上,县域乡村性呈现由苏北苏中地区向环太湖和宁镇地区不断极化的过程。其中苏南地区以向下收敛为主;苏北地区以向上收敛为主;苏中地区以向上发散为主。  相似文献   

4.
改革开放以来,吉林省进入工业化和城市化的快速发展时期,城市布局集群化现象明显。传统的空间分析方法很难深入刻画城镇体系空间格局的时空演变过程。因此,运用Kernel空间密度分析方法,就改革开放以来吉林省城市集聚区的空间演进过程进行系统研究。结果显示:①1986-2007年间,吉林省城市空间分布集中表现为4个城市群组集聚区;②吉林省城市集聚核心区为长、吉两市;③1986-2007年间,吉林省城市空间格局在中东部方向的拓展较为明显,而东部和西部城市空间分布密度变化不明显,其省域空间分布具有中东部偏密集/东、西部较稀疏的空间格局特征;④吉林省城市分布空间的节点结构呈现多空间层次的结构特征。  相似文献   

5.
聚落规模和空间结构的研究历来是地理学的研究热点,分形理论越来越多地被应用于聚落的定量研究,而相对于城镇体系分形研究,乡村聚落体系的分形研究是一块"短板"。为定量对比分析苏南地区与皖北地区的聚落体系的分形特征,以ArcGIS9.3软件为平台,在县域尺度上选取镇江丹阳市和宿州埇桥区平原地区团聚状聚落体系为研究对象,通过计算豪斯道夫维数对比分析了聚落体系规模分布的分形特征差异,通过计算关联维数和集聚维数,从聚落要素的空间相关性和聚落随机集聚的向心性两方面,分析了聚落体系空间结构的分形特征差异,对聚落体系的空间集聚性的多级分形特征差异作了重点探讨。结果表明:丹阳市和埇桥区规模分布分形的判定系数R2分别为0.966和0.962、空间结构的相关系数R2在0.990左右,表明苏南地区和皖北地区团聚状聚落体系在规模分布和空间结构上都具有比较明显的分形特征,表现出自相似结构,且皖北地区聚落体系处低水平发展阶段;苏南地区和皖北地区团聚状聚落体系的空间集聚性存在多级分形的特征,苏南地区的城市的集聚性强于皖北地区,而镇(乡)和中心村的集聚性(分维数D平均值为2.162和2.029)则明显小于皖北地区(分维数D平均值为1.916和1.592);平原地区聚落体系的分形特征与其城市化阶段密切相关。因此,在以后的工作中可以利用分形思想进行聚落体系规划,有效地利用地理空间资源,优化区域聚落体系结构。  相似文献   

6.
近30年来江苏省农村居民点时空格局演变及集约利用变化   总被引:3,自引:0,他引:3  
基于江苏省6个时点的土地利用动态监测数据,分别从土地利用动态度、核密度估计、景观格局指数等空间探索性分析以及集约利用评价出发,对江苏省1987~2015年农村居民点时空格局动态演变进行分析。结果显示:(1)江苏省各市农村居民点用地从1987~2015年处于不断的扩张中,并呈波动增长态势,而居民点用地规模变化速度以苏中和苏南地区最快。(2)从农村居民点用地变动的转入和转出来看,1987~2015年农村居民点用地转入58.63万hm2,其中84.79%来源于耕地,占用耕地的比例表现为苏北>苏南>苏中;农村居民点用地转出28.36万hm 2,其中54.26%转变为城镇用地和40.88%复垦为耕地,苏北以复垦为耕地为主,苏中和苏南以转为城镇用地为主。(3)从农村居民点空间分布来看,核密度空间分异明显,呈“多核心”集聚分布,整体呈现“西密东疏”的空间格局特征,另外近30年江苏省农村居民点平均斑块面积呈增长趋势,且斑块形状越发规则,居民点聚集指数呈上升趋势。(4)从集约利用评价结果来看,农村居民点集约利用级别表现为:苏南>苏中>苏北,呈“由高到低”的集约利用梯度。总体来看,近30年来江苏省农村居民点空间格局演变趋于规则和集聚,集约利用程度区域差异明显。应根据居民点布局区域特点及集约利用差异,在推进宅基地“三权分置”和村庄空间规划的基础上,优化土地资源空间配置,提高宅基地利用效率,促进城乡融合发展和乡村振兴。  相似文献   

7.
人口分布的空间演变是人口发展过程中在时间和空间上的表现形式,人口的集聚与扩散是诠释区域人口空间分布格局与形态的重要方面.对其研究有助于揭示人口分布现状的本质、理解区域空间结构特征及演变趋势.本研究运用局部空间自相关方法,并结合GIS技术,以县域为基本单元,人口密度为衡量指标,对西藏"一江两河"地区1990-2008年间人口分布空间格局的演变进行了分析.分析结果表明,"一江两河"地区各县市(区)人口总量和密度均有明显增长,人口分布总体上呈现出不断集中的态势.局部自相关分析揭示"一江两河"地区开始显现以拉萨市和日喀则市为中心的两个显著的人口高密度区,显示出该区域人口分布的多中心空间结构特征.对以拉萨市、日喀则市和乃东县为中心的区域密度函数进行拟合.多中心区域密度函数的估计结果显示,"一江两河"地区空间发展正逐步由20世纪90年代单中心(拉萨市城关区)阶段,向目前的多中心向心集聚阶段转变,除拉萨市城关区外,日喀则市和乃东县集聚能力开始显现.  相似文献   

8.
采用Landsat TM/ETM遥感解译数据,综合运用定性与定量方法,分析江苏省1985~2015年建设用地扩张的时空演变特征、类型与模式,通过多元回归和地理探测器方法探索江苏省和各地级市建设用地扩张的时空驱动因子及驱动机制。结果表明:(1)江苏省建设用地扩张幅度空间上呈现苏南>苏中>苏北的特征,建设用地扩张速率时间上呈现先上升后下降的趋势,2005~2010年是快速扩张期。(2)江苏省建设用地扩张呈空间自相关和明显的集聚分布。扩张密度分布呈现以江苏沿江地区为高值中心,沿海及苏北地区为低值连片区的空间分异现象。高-高值区主要分布在城市中心区。(3)江苏省已形成沿长江的城市发展轴带和空间集约的都市连绵区,呈现外延型的空间扩张模式。江苏省建设用地扩张的协调性和稳定性,均出现苏南>苏北的地理空间格局,可分为 4种类型:协调稳定型、不协调稳定型、协调波动型、不协调波动型。(4)建设用地扩张主导时间驱动因子是产业结构转型、人口增长、居民生活水平提高和投资增长,第二、三产业比重是扩张的核心时间驱动因素,工业化是驱动建设用地扩张的重要动力。GDP和人口密度是建设用地扩张的主导空间驱动因子。  相似文献   

9.
基于中国省域2007~2016年面板数据,重构了城乡一体化水平评价指标体系,运用熵值法对中国城乡一体化水平进行了测度,并通过趋势面分析、空间自相关、门槛模型研究了中国各个省市城乡一体化水平的时空格局演变特征与影响因素。研究发现:中国城乡一体化水平在"城乡空间、城乡经济、城乡社会、城乡文化、城乡生态"5个维度中稳步上升,区域差异呈现出"两升一降"的"N"型变化趋势;地区间发展不平衡,即在东西方向上存在较为稳定的"东高西低"的空间趋势,在南北方向上存在"两端低中间高"的空间趋势;城乡一体化水平全局上表现出空间集聚特征,局部上城乡一体化水平热点区和次热点区主要集中在中国的东部地区和东南沿海的省市,冷点区主要集中在中部和西部地区;城乡收入差距和政府行为均对城乡一体化水平具有显著的双门槛效应。  相似文献   

10.
推动养老服务业区域协调发展是实现养老服务业高质量发展的基础。运用综合指标评价法、泰尔指数及ESDA等方法,对2005~2015年江苏省县域养老服务业时空演变格局和空间关联性进行分析,并采用空间计量模型探讨其驱动因素。结果表明:(1)江苏省养老服务业发展水平总体较低且不均衡,呈现"南高北低"的显著差异;(2)区域差异呈"扩大-缩小-扩大-缩小"的"M"字型演变趋势,区域内差异大于区域间差异;(3)江苏省不同县域间养老服务业空间关联性显著为正,出现了发展水平相似县域相邻分布的空间集聚效应,空间集聚格局呈现稳态的南北差异;(4)人口老龄化、经济发展水平、城镇化水平、市场力量、产业结构、养老保障水平以及政府政策等多种因素对江苏省养老服务业发展格局和区域差异产生了不同程度的影响。  相似文献   

11.
十一五期间中央环境保护专项资金下达近91亿元,为我国环境污染防治和监管基础能力建设提供了强有力的资金保障。随着财政资金使用改革的不断深入,财政部和环保部对中央环境保护专项资金的管理已从过去以评审为中心转变为以绩效为中心,无论在资金投向、分配方式、过程管理、绩效评估等方面都紧密围绕环境绩效这一中心开展。本文在对十一五期间中央环境保护专项资金资金分配总体情况总结归纳的基础上,分析了资金分配方式制约绩效发挥的主要问题,以改革创新资金分配方式、提高环境绩效为目的,对中央统筹法、项目申报法、因素分配法等三种分配方式提出了若干改革优化的建议。  相似文献   

12.
The results of more than 1 yr of air monitoring inside and outside of five homes in each of two communities are presented for SO2, NO2, mass respirable particles, SO4, Al, Br, Cl, Mn, Na, and V. Outdoor measurements across the home site in each city are consistent with proximity to outdoor sources. Looking across indoor residential sites in each city, the home appears to alter outdoor concentrations in several ways. Indoor level of SO2, SO4, Mn, and V are lower than those measured outdoors. These constituents are thought generally to result from outdoor sources. The other constituents studied are at times found in excess within homes. In some cases the source or sources of excess concentration of a particular constituent could be identified; often, however, the source of excess indoor concentration could not be identified.  相似文献   

13.
Abstract

Refrigerants used in refrigerators are an important source of ozone depleting substances released into the atmosphere, and can have a significantly negative effect on the hole in the ozone layer. But most emission of refrigerants is man-made, unreasonable and needless. Since in most emission cases the refrigerants are contained in the refrigerators, we can retrieve them by some technique that changes the ‘manual emission’ into manual retrieving. To promote the retrieval action and diminish the pollution, society can use economic, administrative and technical countermeasures, which can create a ‘good-cycle’ both ‘harnessing pollution and earning income simultaneously’, reinforce the motive of retrieving, and retrieve most proportion of refrigerants used by all refrigerators. This ‘good-cycle’ method can be easily promoted, and also a valuable way to promote other forms of environmental protection. The three countermeasures have almost no social cost, even no cost at all.  相似文献   

14.
Refrigerants used in refrigerators are an important source of ozone depleting substances released into the atmosphere, and can have a significantly negative effect on the hole in the ozone layer. But most-emission of refrigerants is man-made, unreasonable and needless. Since in most emission cases the refrigerants are contained in the refrigerators, we can retrieve them by some technique that changes the 'manual emission' into manual retrieving. To promote the retrieval action and diminish the pollution, society can use economic, administrative and technical countermeasures, which can create a 'good-cycle' both 'harnessing pollution and earning income simultaneously', reinforce the motive of retrieving, and retrieve most proportion of refrigerants used by'all refrigerators. This 'good-cycle' method can be easily promoted, and also a valuable way to promote other forms of environmental protection. The three countermeasures have almost no social cost, even no cost at all.  相似文献   

15.
The proposed conversion from gasoline powered automobiles to diesel powered vehicels has prompted the Environmental Protection Agency to evaluate the potential health effects associated with exposure to diesel emissions. At present, there is no direct epidemiological link between this exposure and human health. Therefore, a research program was constructed to compare the health effects associated with diesel emissions with those from other emission sources for which epidemiological information was available. The emission sources chosen were cigarette smoke, roofing tar, and coke oven. An additional comparative emission source which was a gasoline catalyst engine. Respirable particles from a variety of combustion sources have the potential of being carcinogenic and mutagenic. The objective of these studies was to determine the relative biological activity of the organic material adsorbed on these particles in both in vitro mutagenesis and in vitro and in vivo bioassays. The organic extracts from the following series of emission sources were quantitatively bioassayed in a matrix of tests for their carcinogenic and mutagenic activity: (1) a light-duty Oldsmobile diesel 350 engine; (2) a heavy-duty Caterpillar diesel engine; (3) a light-duty Nissan engine; (4) a Volkswagen Rabbit diesel engine; (5) cigarette smoke; (6) roofing tar; (7) coke oven; and (8) a gasoline catalyst Mustang. The test matrix consisted of the following bioassay: reverse mutation in Salmonella typhimurium; mitotic recombination in Saccharomyces cerevisiae; DNA damage in Syrian hamster embryo cells (SHE); sister chromatid exchange in CHO cells; gene mutation in L5178Y mouse lymphoma cells, Balb/c 3T3 mouse embryo fibroblasts and CHO cells; viral enhancement of SHE cells; oncogenic transformation in Balb/c 3T3 cells; and skin tumor initiation in SENCAR and C57 black mice. The results of this test matrix are discussed.  相似文献   

16.
The widespread use of brominated flame-retarded products in the last two decades has resulted in an increasing presence of bromine in thermal processes such as waste combustion and accidental fires. Brominated and brominated-chlorinated dibenzodioxins and dibenzofurans (PBDDs/PBDFs, PXDDs/PXDFs) are micropollutants of concern arising from such processes. The present review aims to evaluate the relevance of these compound classes in actual thermal processes. Four categories of thermal processes are discussed in this respect according to their potential for PBDD/PBDF and PXDD/PXDF generation: thermal stress, pyrolysis/gasification, insufficient combustion conditions and controlled combustion conditions. Under thermal stress situations, as they may occur in production or recycling processes, PBDDs/PBDFs precursors like polybrominated diphenylethers (PBDE) can have a relevant potential for PBDD/PBDF formation via a simple elimination. Under insufficient combustion conditions as they are present in, e.g. accidental fires and uncontrolled burning as well as gasification/pyrolysis processes, considerable amounts of PBDDs/PBDFs can be formed from BFRs, preferably via the precursor pathway. In contrast, under controlled combustion conditions, BFRs and PBDDs/PBDFs can be destroyed with high efficiency. The relevance of de novo synthesis of PXDDs/PXDFs is discussed for this condition.Providing a basis for the understanding of PXDD/PXDF formation in actual thermal processes, the present paper also summarises the formation pathways of brominated and brominated-chlorinated PXDDs/PXDFs from brominated flame retardants (BFRs) investigated during laboratory thermolysis experiments. Relevant mechanistic steps for PBDD/PBDF formation from brominated precursors are discussed including elimination reactions, condensation steps and debromination/hydrogenation reactions.In addition, chlorination/bromination and halogen exchange reactions are briefly discussed with respect for their relevance on the final distribution of PBDDs/PBDFs, mixed chlorinated PXDDs/PXDFs and PCDDs/PCDFs resulting from thermal processes.  相似文献   

17.
Harbour seals (Phoca vitulina) and harbour porpoises (Phocoena phocoena) are top predators in the North Sea and consequently accumulate a variety of pollutants in their tissues. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and their hydroxylated metabolites (HO-PCBs and HO-PBDEs) were measured in serum of wild harbour seals (n = 47) and captive harbour porpoises (n = 21). Both species exhibit long life spans and do not have extreme situations, such as complete fasting during periods of lactation, in their annual cycles. For PCBs, concentrations in adult males were slightly higher than in juveniles and lowest in juvenile females. For PBDEs, juveniles have higher levels than adult males and females, probably as a consequence of lactational transfer. However, differences between these age–gender groups were not statistical significant, indicating that individual variation was limited within each species, even without knowing the feeding status of the animals. Body condition, particularly emaciation, has a major influence on the levels of chlorinated and brominated contaminants in serum. Profiles of PCBs were CB 153 > CB 138 > CB 187 > CB 180 and CB 153 > CB 138 > CB 149 > CB 187 > CB 180 for harbour seals and porpoises respectively. For PBDEs, BDE 47 was the predominant congener followed by BDE 100 and 99 in both species. In harbour seals, concentrations of sum PCBs (median: 39,200 pg/ml) were more than 200 times higher than levels of sum PBDEs (median: 130 pg/ml) and almost 10 times higher than concentrations of sum HO-PCBs (4350 pg/ml). In harbour porpoises, concentrations of sum PCBs (median: 24,300 pg/ml) were about 20 times higher than concentrations of PBDEs (median: 1300 pg/ml). HO-PCBs were detected in only 4 harbour porpoises and this at very low concentrations. Naturally-produced MeO-PBDEs were only found in harbour porpoises at concentrations ranging from 120 to 810 pg/ml. HO-PBDEs were not found in any species. In general, harbour seals accumulate less compounds and have mostly lower concentrations than harbour porpoises possibly as a result of a better developed metabolism.  相似文献   

18.
Fate and transport of pathogens in lakes and reservoirs   总被引:3,自引:0,他引:3  
Outbreaks of water-borne disease via public water supplies continue to be reported in developed countries even though there is increased awareness of, and treatment for, pathogen contamination. Pathogen episodes in lakes and reservoirs are often associated with rain events, and the riverine inflow is considered to be major source of pathogens. Consequently, the behaviour of these inflows is of particular importance in determining pathogen transport and distribution. Inflows are controlled by their density relative to that of the lake, such that warm inflows will flow over the surface of the lake as a buoyant surface flow and cold, dense inflows will sink beneath the lake water where they will flow along the bathymetry towards the deepest point. The fate of pathogens is determined by loss processes including settling and inactivation by temperature, UV and grazing. The general trend is for the insertion timescale to be shortest, followed by sedimentation losses and temperature inactivity. The fate of Cryptosporidium due to UV light inactivation can occur at opposite ends of the scale, depending on the location of the oocysts in the water column and the extinction coefficient for UV light. For this reason, the extinction coefficient for UV light appears to be a vitally important parameter for determining the risk of Cryptosporidium contamination. For risk assessment of pathogens in supply reservoirs, it is important to understand the role of hydrodynamics in determining the timescale of transport to the off-take relative to the timescale of inactivation. The characteristics of the riverine intrusion must also be considered when designing a sampling program for pathogens. A risk management framework is presented that accounts for pathogen fate and transport for reservoirs.  相似文献   

19.
中国地表权、地下权概念、应用模式及相关问题分析   总被引:2,自引:0,他引:2  
文章通过对地表权、地下权相关法律概念的梳理,指出地表权、地下权概念界定的复杂性,借鉴《商业词典》对地表权和地下权的定义,探讨了在中国矿产资源一元所有制及土地二元所有制并存的情形下,地表权与地下权的应用模式、相关产权界定及存在的问题。文章分三种情形对二者的应用模式进行了探讨,指出:地表权与地下权相分离的模式是符合中国国情的一种合理选择,但是在具体实践中却存在农村集体作为土地拥有者的地位没有得到应有的尊重、矿业权主体行政审批问题严重、矿产资源的国家所有权权益没有得到应有的体现、矿产资源开发中的环境产权界定不清晰等问题;在探讨中指出两个启迪性的思路:一是使农村集体参与矿产资源开发收益分成模式;二是在现有的征地制度下,理顺价格机制,建立有效的土地流转市场,在土地使用权转让中,给予土地所有者以价格补偿。文章进一步对矿产资源开发中的土地所有权界定、税费问题、土地价格补偿及环境产权分配给予相应的分析并给出建议。  相似文献   

20.
探矿权资产化、证券化是我国改革探矿业投融资体制,解决探矿业资金瓶颈问题的关键。本文从制度建设、机构投资者的发展状况等方面分析了我国初步推行探矿权资产化、证券化的有利条件.指出了探矿权资产化、证券化的三种模式。并以基金模式和股权模式为例提出了实施探矿权资产化、证券化的步骤设想。  相似文献   

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