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1.
“泛珠三角”区域政府间合作为广东东西两翼加速经济发展带来了机遇,通过分析两翼在泛珠三角区域中的地位、经济发展面临的挑战与机遇;提出了泛珠三角背景下两翼实现经济跨越式发展的思路.  相似文献   

2.
Electrical Conductivity Measurement(ECM) from ice core is a representative index for atmospheric environmental change.The pH value and ECM from three shallow ice cores(each 3.85 m,231 ice samples total) on Glacier No.1 at the headwater of Urumqi River,Glacier No.48 in Kuitun area,and Miaoergou Glacier in Hami area in the eastern Tianshan Mountains,western China,were measured and analyzed for atmospheric environment records research.Ice core record shows that the changing trend of pH and ECM in three sites in recent years is different:ECM in Kuitun increases with the ice depth change,but ECM in Hami and Urumqi Glacier No.1 ice cores show a decreasing trend.Average ECM value in Hami is much larger than other two sites,just as the dust concentration and ions concentration are also very high in this site.ECM records in all three sites are mainly affected by aerosol mineral dust of Central Asia,and correlative coefficients of ECM and mineral ions such as Ca2+,Mg2+,Na+ are all significantly high.The pH value and ECM are also significantly high correlative coefficients in the eastern Tianshan Mountains.Comparison between the eastern Tianshan Mountains and other sites in western China,and Polar Regions,shows that the difference of ECM can very well reflect the spatial difference of worldwide atmospheric environment.  相似文献   

3.
Electrical Conductivity Measurement (ECM) from ice core is a representative index for atmospheric environmental change. The pH value and ECM from three shallow ice cores (each 3.85 m, 231 ice samples total) on Glacier No.1 at the headwater of Urumqi River, Gla-cier No.48 in Kuitun area, and Miaoergou Glacier in Hami area in the eastern Tianshan Mountains, western China, were measured and analyzed for atmospheric environment re-cords research. Ice core record shows that the changing trend of pH and ECM in three sites in recent years is different: ECM in Kuitun increases with the ice depth change, but ECM in Hami and Urumqi Glacier No.1 ice cores show a decreasing trend. Average ECM value in Hami is much larger than other two sites, just as the dust concentration and ions concentra-tion are also very high in this site. ECM records in all three sites are mainly affected by aerosol mineral dust of Central Asia, and correlative coefficients of ECM and mineral ions such as Ca2+, Mg2+, Na+ are all significantly high. The pH value and ECM are also significantly high correlative coefficients in the eastern Tianshan Mountains. Comparison between the eastern Tianshan Mountains and other sites in western China, and Polar Regions, shows that the difference of ECM can very well reflect the spatial difference of worldwide atmospheric environment.  相似文献   

4.
中国各省区对外开放度比较研究   总被引:16,自引:1,他引:15  
改革开放以来,中国对外开放水平不断提高,但各地区之间差异显著。关于我国对外开放度的测定已引起学术界的重视,但对经济开放度的区域差异研究很少。文章采用1990年和2000年的统计资料对中国各省区对外开放度进行测定和比较分析,结果表明1990年以来各省区对外开放度普遍有了明显的提高,对外开放度的排序有了一些变化,但总体格局没有改变。各省区之间对外开放度存在巨大差异,不仅东、中、西三大地带之间差异显著,而且区域内部也存在明显差异。最后,根据对外开放度的时空差异特征对各省区进行分类,并得出若干结论和启示。  相似文献   

5.
阿尼玛卿山地祁连圆柏径向生长对气候的响应   总被引:2,自引:0,他引:2  
通过对阿尼玛卿山地5 个坡面20 个祁连圆柏树轮宽度标准年表的分析, 发现公共区间内各树木年轮宽度标准年表中的信噪比SNR 和样本总解释量EPS 值都较高, 说明年表中都含有较强的环境信息; 树轮宽度年表之间的平均相关为0.35 (大多达到95%的置信程度), 具有较好的区域一致性。聚类分析使树木年轮宽度年表分成东、西两大部分, 而年表的第一主分量显示出: 西部树轮的指数序列明显长于东部即树木生长有自西向东扩展的趋势, 并且东、西区域树木生长变化的特征年变化具有同步性。东、西树轮宽度年表中第一主分量和第二主分量与气候因子的相关和响应都表现出一定的相似性, 但第二主分量对气候因子响应的差异性更显著。西部树木生长PCI 的主要限制因子是温度, 尤其当年春末夏初及前一年秋季温度影响最大, 同样降水也起着重要的作用, 西部树木生长PC2 的主要限制因子是降水量; 而东部树木生长PC1 主要受降水的制约, 第二主分量PC2 的响应分析显示出气候的滞后影响(树木前期生长) 是非常重要的限制因子。  相似文献   

6.
盖美  秦冰  郑秀霞 《地理研究》2021,40(9):2572-2590
绿色发展与动能转换之间联系密切,研究根据二者内涵构建综合评价指标体系,基于耦合协调相对发展度模型、空间自相关、重心和标准差椭圆模型分析中国31个省市(不含港澳台)2008—2018年两系统耦合协调的时空格局演变特征,得出以下结论:① 绿色发展和动能转换综合指数均呈波动上升趋势,但空间异质性显著,东部沿海地区水平最高。② 各省绿色发展与动能转换的耦合协调度逐年提升,逐步形成东部沿海地区为轴带向中西部地区扩散的“川”字阶梯型发展格局。③ 绿色发展与动能转换的耦合协调度具有显著的空间正相关性,位于“低-低”类型区域的省份最多,高值和低值区域趋于两极集聚分布。④ 2008—2018年耦合协调度的重心主要向西南方向迁移,耦合协调度呈向西南方向分散的态势。东、中、西部地区绿色发展与动能转换耦合协调的空间格局演变特征存在差异,东部地区呈西南方向迁移的分散态势,中部地区呈西南方向迁移的集聚态势,西部地区呈东南方向迁移的集聚态势。  相似文献   

7.
古镇是中国物质文化和精神文化的重要载体,也是发展古镇旅游的物质基础。近年来,古镇研究受到学界高度重视,但涉及古镇型旅游地空间分布的研究却鲜有所见。运用ArcGIS9.3分析软件、不平衡指数和地理集中指数,分析中国古镇型旅游地的整体分布特征及其在东、中、西部的区域分布特征。研究表明:中国古镇型旅游地整体分布不均衡,主要集中在东部和西部地区。区域内部分布也不均衡,东部地区主要集中在浙江、江苏两省;西部地区主要集中在贵州、四川、云南3省;中部地区主要集中在安徽省。影响其空间分布的因素主要是旅游资源禀赋、区位条件、区域经济发展水平、交通可达性和文化发展脉络。  相似文献   

8.
中国北方地区40年来湿润指数和气候干湿带界线的变化   总被引:63,自引:6,他引:57  
本文研究了中国北方地区 196 1~ 2 0 0 0年 4 0年间气候干湿带界线分布和 10年际变化。 4 0年来中国北方地区 ,在东经 10 0°以东地区 ,半干旱区和半湿润区的分界线不断波动向东推进 ,2 0世纪 90年代比 6 0年代向东和向南扩展 ,半干旱区面积扩大 ,半湿润区面积缩小 ,气候趋向干旱化 ;东经 10 0°以西地区 ,极端干旱区面积在缩小 ,湿润指数有增大趋势。如果把温度和湿润指数相结合 ,东经 10 0°以东的黄淮海区和黄土高原区为持续的干暖型 ;东经 10 0°以西的西北地区 ,则由干暖型向湿暖型转变 :河西走廊和东疆盆地转型的时间发生在 2 0世纪 70年代初 ,北疆山地绿洲荒漠地区转型的时间发生 2 0世纪 80年代中期前后。气候干湿带界线的变化取决于降水和潜在蒸发的变化速率。 4 0年来 ,在东经 10 0°以东地区 ,降水和潜在蒸发都呈下降趋势 ,但降水减少速率大于潜在蒸发下降速率 ;在东经 10 0°以西地区变湿的原因 ,研究认为除了降水有所增加外 ,潜在蒸发也在下降 ,而且潜在蒸发下降速率的绝对值大于降水增加速率。  相似文献   

9.
天山东部冰芯pH值和电导率的大气环境空间差异   总被引:2,自引:1,他引:1  
冰芯电导率是大气环境变化的替代性指标.对我国天山东部三个研究点奎屯哈希勒根48号冰川、乌鲁木齐河源1号冰川以及哈密庙儿沟平顶冰川粒雪芯中pH值和电导率的近期环境记录进行了分析研究.结果显示,三个研究点粒雪芯反映的近期pH值和电导率变化趋势不同:奎屯电导率随冰芯深度增加表现出升高趋势,哈密庙尔沟平顶冰川和乌鲁木齐河源1号冰川随冰芯深度增加表现出一定下降趋势;冰芯电导率平均值在哈密庙儿沟冰川最大,而其他两个点相对较小,这与矿物粉尘浓度和离子浓度的分布一致;雪冰电导率与粉尘及离子相关性分析表明,电导率主要受中亚粉尘活动影响,同时与Ca2+、Mg2+、Na+等相关性很高.通过比较显示,天山东部与我国西部其他研究点以及极地雪冰电导率的差异可以很好地反映大气环境的空间差异.  相似文献   

10.
Teleseismic P waves passing through low-wave-speed bodies in the mantle are refracted, causing anomalies in their propagation directions that can be measured by seismometer arrays. Waves from earthquakes in the eastern Pacific and western North America arriving at the NORSAR array in Norway and at seismic stations in Scotland pass beneath the Iceland region at depths of ∼ 1000–2000 km. Waves arriving at NORSAR have anomalous arrival azimuths consistent with a low-wave-speed body at a depth of ∼ 1500 km beneath the Iceland–Faeroe ridge with a maximum diameter of ∼250 km and a maximum wave-speed contrast of ∼ 1.5 per cent. This agrees well with whole-mantle tomography results, which image a low-wave-speed body at this location with a diameter of ∼ 500 km and a wave-speed anomaly of ∼ 0.5 per cent, bearing in mind that whole-mantle tomography, because of its limited resolution, broadens and weakens small anomalies. The observations cannot resolve the location of the body, and the anomaly could be caused in whole or in part by larger bodies farther away, for example by a body imaged beneath Greenland by whole-mantle tomography.  相似文献   

11.
中国主要城市入境旅游网络结构演变分析   总被引:2,自引:2,他引:0  
基于旅游经济联系模型,运用GIS技术手段,构建中国入境旅游城市的旅游经济联系网络,并对1997年和2010年的Top1、Top5和Top10网络的结构演变特征进行研究。研究发现:① 整体网络规模在缩小,但是最大联系强度和平均联系强度却明显增长,且最大联系强度一直出现在广州和深圳之间;② 整体网络结构处于核心极化阶段,总体呈现“东部强,中西弱”的“L”型分布,一级节点城市北京、上海和广州的集聚作用显著,且进一步增强;③ 旅游城市联系以东部区内联系为主,东部地区城市的集聚作用愈加明显,中部和西部地区城市的集聚作用在减弱;④ 中国入境旅游城市可分为三大体系,形成三极多核的空间格局。  相似文献   

12.
产业结构升级是欠发达地区经济跨越式发展的重要标志。运用More值、Lilien指数、产业结构超前系数、偏离度和趋同性指数对广东欠发达地区2001年~2013年度产业结构速率、方向和效益进行了定量分析,结果发现:自2000年以来,广东欠发达地区产业结构呈现出升级速率快;以二、三产业,劳动密集型行业为主要升级方向;产业结构偏离度高;协同协调发展不够;产业结构趋同等总体特征,以及升级速率粤东快于粤西粤北,升级方向粤东第二产业粤西粤北二、三产业,粤东粤北资源密集型行业、粤西劳动密集型行业超前,产业结构适应协调程度粤东高于粤北、粤西等空间差异特征。  相似文献   

13.
Results of the first detailed study of the climate proxy record in the loess-palaeosol sequence at Xining-one of the few palaeoclimate sites in the currently arid western Loess Plateau of China-illustrate the importance of making many types of rock-magnetic measurements other than susceptibility. A multiparameter approach yielded confirmation that here, as elsewhere in the Loess Plateau, the susceptibility enhancement in palaeosols was caused primarily by ultrafine magnetite and maghaemite. Nevertheless, magnetic enhancement was caused not exclusively by changes in relative grain size, but also by variations in concentration and mineralogy of the magnetic fraction.
The effects of concentration variations were removed through normalization of susceptibility and anhysteretic remanence with saturation magnetization and saturation remanence, respectively. the resulting signal was ascribed more confidently to variation in magnetic grain size, which in turn was interpreted as a better proxy of pedogenesis than simple susceptibility. Variations in magnetic mineralogy were also determined to constrain interpretations further. the data were then used to discuss climate history at Xining. Finally, results from Xining were compared with other western sites and contrasted with eastern sites.
In summary: (1) data is presented from a new Loess Plateau site which also appears to yield a global climate signal; (2) a demonstration is made of a more rock-magnetically robust way to separate concentration, composition and grain-size controls on susceptibility and other magnetic parameters; and (3) models are provided for inter-regional comparisons of palaeoclimate proxy records.  相似文献   

14.
王若宇  刘晔  薛德升 《热带地理》2018,38(2):184-195
基于第五(2000年)、六次(2010年)全国人口普查数据和社会经济统计数据,利用综合空间评价方法和耦合协调度模型,探讨中国341个地级及以上行政单元的人才优势度与经济发展的空间差异特征,并系统分析两者间的耦合协调关系。结果表明:1)中国经济发展的地区差异明显,2000―2010年大部分地区的经济发展水平处于上升的趋势并呈现出“大范围扩散、小范围集聚”的趋势。2)中国人才优势度存在明显的空间差异,呈现以北上广深为绝对高地,以其余直辖市、省会城市和计划单列市为相对高地,其余地区为低地的空间结构。2000―2010年人才优势度的空间差异日益突出,表现为东部地区与中西部地区之间的差距以及同一省份内省会城市与非省会城市之间的差距进一步拉大。3)基于耦合协调度系统评价,把所有地区划分为以下3种类型:高耦合度-高协调度地区、高耦合度-低协调度地区、低耦合度-中协调度地区。2000―2010年东部地区“高耦合度-高协调度”趋势加剧,中西部地区“高耦合度-低协调度”趋势加剧。  相似文献   

15.
吉林省城市空间结构及地方中心城市腹地范围界定   总被引:1,自引:1,他引:0  
将经济流与交通流相结合,运用社会网络分析法,分析了吉林省城市空间联系网络特征,选出吉林省地方中心城市,根据各市(县)间的综合联系程度界定地方中心城市的腹地。结果显示:① 吉林省的经济、公路和铁路3个网络联系密度均偏低,长春市处于各网络中的核心地位,全省范围内各网络联系程度差异较大;② 从综合联系网络来看,中部与其他地区的联系较为密切,东部和西部地区联系较弱;中部地区内的2个凝聚子群间联系有待加强,吉林省中部地区一体化发展任重道远,产业协调发展是未来的发展方向;南部地区内部的联系应进一步提升,促进南部轴线的发展;③ 结合吉林省47个市(县)的点度中心度、点入度和点出度值及实际发展需要,将长春市、吉林市、四平市、辽源市、通化市、延吉市和白城市作为吉林省的地方中心城市,其中,长春市的辐射带动能力最大,白城市最低;延吉市与敦化市应组团发展,成为东部地区的发展核心,共同带动东部地区发展;白城市应增强自身的中心性和辐射带动能力,充分发挥西部门户城市作用。  相似文献   

16.
秦巴山地植物南北变化与过渡模式研究   总被引:1,自引:0,他引:1  
秦岭—大巴山是中国重要的南北地理分界线和生态过渡带,建立秦巴山地南北方向上植物种类组成及重要值的详细变化序列和过渡模式,对于深入认识中国南北过渡带的过渡性、复杂性及暖温带与亚热带分界线具有十分重要的科学意义。本文通过野外实地调查获取秦巴山地东、中、西部3条南北穿越样线163个采样点的植被序列数据,分析了物种丰富度、相对重要值及优势种多度的纬向变化,并将亚热带与温带物种相对重要值的差值(SND-RIV)用于表现南北方物种的优势程度,以分析和归纳植物的空间变化模式。结果表明:① 东部(三门峡—宜昌)、中部(西安—达州)、西部(天水—广元)亚热带物种丰富度及相对重要值自北向南递增,温带物种自北向南递减。东部温带物种丰富度及相对重要值在神农架和伏牛山由于海拔高度的影响出现两个峰值,中部亚热带物种在大巴山地区最高,西部亚热带物种在陇南以南超过温带物种;② 东部南北方物种的交错过渡带最宽,约180 km;中部大约在秦岭南坡至大巴山北坡之间,约100 km;西部交错过渡带偏南,约50~60 km。③ 东、中、西部山地植物纬向过渡模式和驱动因子有明显差异。东、西部自南向北亚热带物种的减少主要与年均降水量减少有关,年平均气温影响较小;中部年平均气温的作用比湿润指数稍大。本文揭示了秦巴山地东、中、西部植物的南北变化及过渡模式,提升了对中国南北过渡带复杂性和多样性的科学认识。  相似文献   

17.
杨忍  徐茜  余昌达 《地理科学》2016,36(7):1017-1026
利用综合评价、耦合协调度、空间滞后模型(SLR)等模型,对2000~2010年的中国分县农村综合发展水平及2010年的分县道路交通优势度进行综合测度,解析其两者的空间耦合协同特征,并探索道路交通对农村发展的影响机制。结果表明: 2000~2010年,中国分县的农村综合发展水平的东、中、西差异格局未突破,农村综合发展水平整体提升了33.20%。东部地区的农村发展进入优化整合提升阶段,中、西部地区在政策、产业转移、城镇化、工业化等驱动下农村综合水平提升较快,乡村多维空间历经转型重构。 2010年,县域道路交通优势度呈现出典型的“点-轴”的地域结构特征,存在东、中、西部和交通枢纽中心地与外围地区之间的地域差异,其与农村发展水平耦合协同性整体较差,处于轻度失调以下状态占县(区)总数的88.25%,西部地区协调度普遍低于0.40,交通发展与农村发展协同性较好地域集中于东部沿海地域和道路交通优势极核及轴带的县(区)。道路交通等级、密度、可介入性等影响农村综合发展。道路密度对农村发展正向影响较大,国道、省道、县道沿途邻近可进入性强,对农村综合发展有积极促进作用;高速公路和铁路有景观生态学“廓道”性质,空间上起连通作用,结构的不可穿越性,封闭性影响可介入性,高速公路的出入口和火车站空间布局对农村发展影响显得尤为重要。地级市交通中心地对农村发展带动影响明显,大城市的强聚集能力易促成周边县区的农村发展“灯下黑”的地域结构特征。道路交通设施建设的等级、阶段对农村发展的传导效应及区域交通建设的超前或滞后的科学判断核心理论,将是人文经济地理学及乡村地理学亟待关注的重要领域。  相似文献   

18.
宋彭生 《盐湖研究》2000,8(4):70-74
西部的资源赋存并不丰富。对全国经济发展有巨大意义的关键性资源并不多 ,由资源特性和经济发展的趋势决定了东部地区对西部地区资源的依赖降低 ,对于西部长期以资源开发为重点的发展模式所造成的多种疾患 ,以及目前国内外资源环境形势 ,提出西部注重开发技术、知识资源 ,培育特色产业 ,大力发展旅游业和建立国家资源安全战略的西部开发资源战略  相似文献   

19.
Field studies and petrographic examinations of core samples and of the bedrock of the floor of the Qattara Depression, Egypt, indicate that salt weathering predominates in its western part in marked contrast to its eastern part. The eastern part of the depression is covered with more than 120-cm-thick, moist sands with sporadic occurrence of halite and gypsum due to the low salinity of the groundwater table. At the western part of the depression, the strongly saline, sodium chloride nature of the groundwater table favors crystallization of halite (and sometimes gypsum) at or near the surface of the outcropping bedrock of the Moghra clastics and/or Dabaa shale. Crystallization of halite and/or gypsum generates increased pressure that leads to mechanical disintegration of the bedrock into fine-grained debris. Features related to disintegration include blistering of the rock surface, splitting, spalling and/or granular disintegration.Alternation of dry and wet cycles favor halite crystallization, mechanical disintegration of the outcropping bedrock and dissolution of the halite cement, which exposes fine-grained debris to wind deflation. Removal of the debris from the floor of the depression leads to the accumulation of lunettes and other dunes in the downwind direction.Therefore, salt weathering provides fine-grained debris that are easily removed by deflation, which accounts for the topographically lower level of the western part of the depression (134 m below sea level (b.s.l.)). In contrast, the presence of moist sediments at the eastern part of the depression inhibits deflation and encourages sedimentation by adhesion of wind-blown sand to the damp surface of the sabkha at an elevation of 45 m below sea level.The disintegration of the bedrock of the Qattara Depression by salt weathering has been in effect since the onset of aridity in northern Egypt in Quaternary time. Whereas the initial excavation of the depression started in Late Miocene or Pliocene time by fluvial erosion, karstic process, mass-wasting and wind deflation.  相似文献   

20.
Over the past two decades in China, stress on the environment has increased continuously. This paper will assess the change in environmental quality over time, and its spatial variation using data from the statistical yearbooks of 31 provincial administrative regions in 1990, 1995, 2000, 2005, and 2010. These books provide a general assessment of the environment at the provincial level, and the three major economic regions from western to eastern China. By using the geographic information system (GIS) and SPSS, we analyzed the changing trend of China's eco-environment and calculated the changing trajectory in the gravity center of the eco-environmental quality. We conclude the following. (1) From 1990 to 2010, the rate of deterioration of the environment went down. We argue that the cause of this trend was neither the result as "the deterioration trend was under control" noticed by the government departments concerned, nor "the deterioration rate of the environment was increasingly intensified" suggested by many researchers. (2) Since 1990, the general environment has been worsening in China, but it was improved in some regions; however, the ecological deficit is still expanding and will last for a long time. (3) From western to eastern China, the deterioration rate of environmental quality was slowed down. The reasons include a good natural environment, a developed regional economy, and technology and finance in eastern China. (4) After extensive economic development in China, there are imbalances of population, economy, society, and the environment in the 31 provincial regions. The governments at all levels should play an important role in research and protecting the environment. In addition, it is imperative to implement positive measures such as controlling population, improving the environment, and promoting smart development to balance the socio-ecological system.  相似文献   

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