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11.
<正>在20世纪60年代前期进行的经济调整过程中,中国共产党和政府采取了许多特殊而有效的措施,完成了国民经济调整的任务,度过了困难时期。在调整后期,中国试图在经济管理体制上找出一条新路,改变统得过多过死的局面。为了照顾特殊地区的发展,1965年先后设置了安达特区和攀枝花特区,成为这个时期计划工作中的亮点。一、开发大庆油田与设立安达特区  相似文献   
12.
Granitoid (pegmatite and aplite) veins in metamorphic rocks and intrusive syenites of central Dronning Maud Land, Antarctica, are flanked by conspicuous light‐coloured alteration halos, which represent the damage zone of fracture propagation. The damage zone is characterized by a high density of sealed or healed microcracks, about 1 order of magnitude above background. Fluid inclusions along healed microcracks in quartz of both pegmatite and alteration halos are inspected by optical and scanning electron microscopy, and their composition is analysed by microthermometry and quadrupole mass spectrometry. The similar inclusion record in the granitoid vein and in the damaged host rock indicates the derivation of the fluids from the hydrous melt phase. The aqueous inclusions bear abundant daughter crystals, mainly silicates, and may represent a hydrous melt. The volatile composition is variable in the system H2O–CO2, with mostly subordinate amounts of N2. Phase separation with partitioning of CO2 into the fluid phase coexisting with the hydrous melt, and possibly immiscibility in the subsolidus range, govern fluid evolution during cooling. The variable CO2/N2 ratio suggests mixing with fluids from an external source in the host rock and vigorous circulation at an early stage of high transient permeability. Experiments have shown that healing of microcracks at high temperatures is a matter of hours to weeks, hence similar in time scale to the cooling of the cm‐ to dm‐thick granitoid veins. In this case, rapid cooling and concomitant crack healing in a system undergoing phase separation causes a broad compositional variability of the inclusions due to necking down, and the underpressure developing in closed compartments precludes a meaningful thermobarometric interpretation.  相似文献   
13.
本文通过对西递村、束河古镇两个典型旅游村落的调查发现,村落中不同游览区的游客数量差异较大,80%以上游客到达的主要游览区域面积占村落建成区的比例分别约为29%和35.6%,由此提出村落的主要游览区域面积可控制在45%以内。对此,本文从游客常规线路、游客观赏行为、游客疲劳限度、游客寻路和从众心理五个方面进行分析,指出村落的主要游览区域范围不会因为游客的增加而扩大,并得出了应减少无序无用开发、挖掘主要游览区价值、保持非主要游览区氛围三点启示。  相似文献   
14.
苏州工业园区旅游发展的问题及对策研究   总被引:1,自引:0,他引:1  
近年来,随着国内外环境的变化,开发区已经从单一经济功能的产业园区向具有综合城市功能的新城转型。旅游业作为产业链较长、容纳就业人口较多的第三产业,在开发区转型发展中起着重要作用。本文对苏州工业园区旅游发展现状进行了研究,指出其现阶段存在的主要问题有旅游新品牌形象难以树立、旅游服务倾向高端群体、旅游项目收益不理想和企业参与旅游业发展的热情不高等,并尝试针对这些问题提出相应的对策措施,以期为研究区及其它处于相似境地的开发区旅游业发展提供借鉴和参考。  相似文献   
15.
成渝经济区县域经济差异的空间分析   总被引:4,自引:0,他引:4  
彭颖  陆玉麒 《人文地理》2010,25(5):97-102
借助ARCGIS软件中ESDA分析模块和统计功能,并与传统统计方法加权变异系数相结合,以县域为研究单元,以人均GDP和GDP为测度指标,初步探索了1999-2008年成渝经济区县域经济差异的空间格局变化。结果表明,成渝经济区县域经济总体差异呈逐渐扩大趋势,经济发展水平、经济增长能力和经济密度的空间特征三者的空间格局基本吻合,形成以成都市区和重庆市区为核心的圈状空间结构,且这种格局在不断的强化;高速公路发展轴经济带动作用不明显,广大地区经济仍处于落后状态;现发展阶段,核心区的极化作用占主导,区域经济发展极不平衡。  相似文献   
16.
淮海经济区城市空间影响范围与城市经济区划分   总被引:3,自引:0,他引:3  
运用因子分析法求取淮海经济区20个地级市的综合实力指数及等级划分。根据城市综合实力指数和等级划分,选取4个一级城市作为中心城市,然后运用断裂点公式计算中心城市与邻近城市的空间影响距离。再根据空间影响距离划分各中心城市经济影响区范围。最后以城市经济影响区为基础,综合考虑各城市的区域特征、发展潜力、现有经济规划、历史习惯和人文特征,确定城市经济区界限。研究淮海经济区城市经济区形成和划分的目的是指明各城市在整个区域内劳动地域分工中的地位,了解城市经济发展现状和主要特点。  相似文献   
17.
    
X. Zhou  T. J. Burbey 《Geofluids》2014,14(2):174-188
The initiation of hydraulic fractures during fluid injection in deep formations can be either engineered or induced unintentionally. Upon injection of CO2, the pore fluids in deep formations can be changed from oil/saline water to CO2 or CO2 dominated. The type of fluid is important not only because the fluid must fracture the rock, but also because rocks saturated with different pore fluids behave differently. We investigated the influence of fluid properties on fracture propagation behavior by using the cohesive zone model in conjunction with a poroelasticity model. Simulation results indicate that the pore pressure fields are very different for different pore fluids even when the initial field conditions and injection schemes (rate and time) are kept the same. Low viscosity fluids with properties of supercritical CO2 will create relatively thin and much shorter fractures in comparison with fluids exhibiting properties of water under similar injection schemes. Two significant times are recognized during fracture propagation: the time at which a crack ceases opening and the later time point at which a crack ceases propagating. These times are very different for different fluids. Both fluid compressibility and viscosity influence fracture propagation, with viscosity being the more important property. Viscosity can greatly affect hydraulic conductivity and the leak‐off coefficient. This analysis assumes the in‐situ pore fluid and injected fluid are the same and the pore space is 100% saturated by that fluid at the beginning of the simulation.  相似文献   
18.
    
Oxygen is a key parameter in the degradation of archaeological material, but little is known of its dynamics in situ. In this study, 10 optical oxygen sensors placed in a 2 m deep test pit in the cultural deposits at Bryggen in Bergen have monitored oxygen concentrations every half hour for more than a year. It is shown that there is a significant spatial and temporal variation in the oxygen concentration, which is correlated to measured soil characteristics, precipitation, soil water content and degradation of organic material. In these deposits oxygen typically occurs when the air content of the soil exceeds 10–15% vol, while oxygen dissolved in infiltrating rainwater is of less importance for the supply of oxygen in the unsaturated zone.  相似文献   
19.
福建文化地域格局的演变及其机制   总被引:1,自引:2,他引:1  
林拓 《人文地理》2001,16(3):57-61
本文通过福建文化地域格局演变主体过程的还原,揭示其阶段性特征及内在机制,进而澄清某些长期困扰研究进展的传统看法,并提出一些新的学术观念。  相似文献   
20.
藏北无人区是野生动物的天然保护区,那里繁衍生息着许多高原特有的珍稀动物。在无人区的动物种类中,最大的群落要数藏羚羊、藏野驴和野牦牛三种。它们是动物王国里名声显赫的“三大家族”。  相似文献   
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