跨学科视角下“地缘政治”概念及其研究范式

分析1982—2019年中国核心学术刊物和著作,梳理地理学和政治学对于“地缘政治”概念和研究范式的不同理解。研究发现：① 地理学和政治学有很多相似之处,包括对“地缘战略”等概念的关注,对“大国安全与崛起”等议题的探讨,以及在分析框架中对案例和质性分析方法的强调等;② 地理学和政治学有各具特色,地理学衍生“地缘环境”等概念,政治学也衍生“地缘安全”等概念;地理学在议题上更具空间和系统思维,对海洋地缘政治等话题更偏好,而政治学更强调时事性,侧重于分析时事政治及其地缘政治逻辑等;在分析框架上,地理学受计量革命的影响深远,对质性和定量分析都有所关注,而政治学对案例分析和质性分析的依赖度更高。这些发现说明了当前学科分工并没有改变地理学中的“地缘政治”概念和政治学中的“地缘政治”概念源出一脉的事实,同时也发现,其中的差异正是学科壁垒形成关键所在。     

Vegetation and climate history of Anggertu Lake in the Tengger Desert over the last millennium

Reconstructing climate change of the last millennium is important to understand the current relationship between human-social activities and natural environmental changes. Pollen assemblages, losson-ignition(LOIo rg at 550°C), and grain size data collected from sediment core AGE15 A from the center of Anggertu lake(eastern Tengger Desert, Inner Mongolia) were used to reconstruct the regional vegetation and climate history of the last millennium. Desert or steppe desert, dominated by A rtemisia and Amaranthaceae, expanded around this region during the period of 988–1437 AD indicating a generally dry climate condition with two short humid periods(1003–1082 AD and 1388–1437 AD). These two wet periods were characterized by relatively high vegetation cover and bioproductivity, as reflected by high pollen concentrations and LOIo rg values. Increases in steppe and meadow vegetation communities(Poaceae, Cyperaceae) and vegetation cover during 1437–2015 AD suggest a wetting trend, which was also deduced from a gradual trend towards fine grains and higher lake biological productivity as reflected by LOIo rg values. An unstable lacustrine environment was identified via frequent fluctuations in pollen concentration and grain size after 1842 AD. This study also recorded a relatively dry Medieval Warm Period(MWP, 1082–1388 AD) and a wet Little Ice Age(LIA, 1437–1842 AD). Increased Amaranthaceae and high abundance of Poaceae may be related to overgrazing and agricultural activities that took place during those time periods. The evolution of vegetation in the lake region was influenced by climate change and human activities. These results could provide more fundamental support for studies of the environmental evolution of the Tengger Desert.     

Effect of Wetland Reclamation on Soil Organic Carbon Stability in Peat Mire Soil Around Xingkai Lake in Northeast China

Content and density of soil organic carbon(SOC) and labile and stable SOC fractions in peat mire soil in wetland, soybean field and rice paddy field reclaimed from the wetland around Xingkai Lake in Northeast China were studied. Studies were designed to investigate the impact of reclamation of wetland for soybean and rice farming on stability of SOC. After reclamation, SOC content and density in the top 0–30 cm soil layer decreased, and SOC content and density in soybean field were higher than that in paddy field. Content and density of labile SOC fractions also decreased, and density of labile SOC fractions and their ratios with SOC in soybean field were lower than that observed in paddy field. In the 0–30 cm soil layer, densities of labile SOC fractions, namely, dissolved organic carbon(DOC), microbial biomass carbon(MBC), readily oxidized carbon(ROC) and readily mineralized carbon(RMC), in both soybean field and paddy field were all found to be lower than those in wetland by 34.00% and 13.83%, 51.74% and 35.13%, 62.24% and 59.00%, and 64.24% and 17.86%, respectively. After reclamation, SOC density of micro-aggregates( 0.25 mm) as a stable SOC fraction and its ratio with SOC in 0–5, 5–10, 10–20 and 20–30 cm soil layers increased. SOC density of micro-aggregates in the 0–30 cm soil layer in soybean field was 50.83% higher than that in paddy field. Due to reclamation, SOC density and labile SOC fraction density decreased, but after reclamation, most SOC was stored in a more complex and stable form. Soybean farming is more friendly for sustainable SOC residence in the soils than rice farming.     

移动目标空间拓扑关系的度量描述

针对传统9交模型对移动目标空间拓扑关系表达及量化描述的不足,基于格网化思想,提出了度量参数量化描述的方法。首先对移动目标和参考目标进行格网化,划分为固定大小的格网阵列;然后利用9交模型确定空间目标间拓扑关系的形式化描述;最后引入内部分量、边界分量、外部分量3种度量参数对移动目标空间拓扑关系进行度量化描述。试验证明,该方法计算简单、直观,能更加有效地度量移动目标间的拓扑关系。     

国外海底犁式开沟机技术进展

总结了国外海底犁式开沟机技术进展,海底犁式开沟机可分为"V"型开沟犁和矩形开沟犁两种,"V"型开沟犁开沟截面面积较大,沟槽截面形状为V型,适合与海底管道埋设,其回填方式有专门回填犁回填和回填模块回填两种。矩形开沟犁开沟面积较小,截面狭长且为矩形,多适用于海底电缆埋设。其土壤排出方式有垂向排土和侧向挤压排土两种,沟槽靠重力自动回填。犁式开沟机开沟速度快,造价相对较低,目前正在朝大型化、模块化发展。开沟犁的关键技术包括犁式开沟机的开沟阻力减小方法以及在崎岖海底地形上开沟时的开沟深度稳定性等,这也是目前研究的重点。对国外犁式开沟机技术的总结,对开沟犁设计和海上施工作业有一定指导意义。     

多源数据中尺度涡三维结构分析方法研究

作为重要的海洋中尺度现象之一,中尺度涡的研究受到人们的关注和重视。随着数值模式的进一步发展、卫星资料的累积、时间更长以及更多更有效的海上实测数据的取得,使得综合利用实测资料、卫星遥感资料、再分析/数值预报产品等数据源,对中尺度涡进行自动识别与三维结构分析成为中尺度涡研究的主要方向之一。在前期对卫星遥感资料中尺度涡自动检测算法进行研究的基础上,开展多源资料中尺度涡三维结构分析方法研究,以表面漂流浮标运动轨迹为中尺度涡的判定依据,综合利用高度计观测、红外遥感观测、以及再分析/数值预报产品分析中尺度涡三维结构信息,在此基础上,提出中尺度涡研究的发展方向,为全面分析中尺度涡的时空特性提供技术途径,为中尺度涡的动力机制研究奠定基础。     

青海共和盆地地应力状态与断层稳定性分析

青海共和盆地地质构造条件复杂,断层十分发育,区域内既有地热、太阳能、矿产等资源丰富,存在龙羊峡水库诱发地震环境背景.因此,分析青海共和盆地地应力特征与地质结构易滑性对于青海东部地区防震减灾具有重要意义.对盆地及附近区域内19个钻孔、65条水压致裂数据和44条应力解除实测数据进行统计分析,并基于断层摩擦强度理论、Byer...     

隧道下穿码头群桩基础的离心模型试验研究

在地下隧道施工中遇到既有桩的情况并不少见,尽管近年来隧道-土-桩相互作用引起了广泛关注,但以往的研究主要集中在小规模隧道开挖引起的桩的反应上.通过三维离心模型试验,研究了双管大型隧道开挖引起的群桩变形机理.由于隧道开挖引起的应力释放,群桩的实测沉降随隧道的推进几乎呈线性增加.监测点距新建隧道较短,导致群桩沉降较大.单隧...     

生态环境类电子地图集的研究与开发

针对生态环境类电子地图集这种新型的专题性电子地图集在信息构成和功能上的特殊性,首先,研究和确定了它的主题定位和功能定位,提出集信息可视化和空间分析、虚拟仿真等功能于一体的理念。其次,提出并构建了生态环境类电子地图集的新颖的数据模型,第三,研究并阐述了该类电子地图集的专题图型和表达方法,第四,设计并实现了这种电子地图集的体系结构和技术系统,通过丰富的电子地图实例阐述本文的技术和方法创新点。     

东昆仑山昆仑河纵剖面形貌分析及构造涵义

青藏高原东昆仑北部地区新构造活动强烈, 存在一系列活动断层, 控制了该地区的地貌格局和水系的发育.其中大部分活动断层是已经确定下来的, 还有一些活动断层还处在定性推测阶段.引进河流长度-坡度参数(以下简称“SL参数”) 和Hack剖面2个能够有效反映区域新构造活动的地质参数, 对昆仑河纵剖面坡度变化进行详细刻画和研究, 并对昆仑河河流阶地进行空间对比分析.研究结果表明, 昆仑河河流的Hack剖面与SL参数存在形貌上的对应关系, SL参数的突变主要是受断裂构造活动控制; 证实了昆仑河-野牛沟断裂和东昆中断裂第四纪以来存在构造活动性; 第四纪以来强烈的构造差异隆升作用控制了东昆仑地区的地貌水系发育格局, 并将产生更深远的影响.