中国自下而上城市化的发展及其机制

改革开放以来的实践证明,中国确定存在着二元城市化模式,而农村城市化在中国整个城市化过程中已经和正在起着重要作用。作者在肯定了小城镇为主休的农村城市化的作用下,从城市化启动力的角度指出,这各发生在农村地域,由地方政府和农民群体力量推动的城市化是一种自下而上的城市化过程,具有明显的中国特色。文章并由此分析了自下而上城市化的发展阶段探讨了其在国家方针政策指导影响的政府、农民、外部力量共同作用下的运行机制     

Small towns resisting urban decay through residential attractiveness. Findings from Denmark

Small towns are often considered as losing out in the current trend towards urban development. However, research from around Europe shows a great diversity of small town development, including successful development trajectories despite geographical disadvantages. Investigations into this are predominately done in the context of economic development and urban systems, but such approaches fail to explain why a number of small towns that are not centrally located near a metropolitan region are not in decay. This paper examines how the restructuring of retail and service sectors, demographic composition, residential migration, social organisation and community engagement form and affect small town (1000–5000 inhabitants) development patterns in Denmark and specific place-based endowments. The study is carried out with mixed methods, comprising a quantitative analysis of development trends, complemented by qualitative case studies in six small towns. Our findings show how favourable development paths are a combination of a positive development in population, provision of daily commodities and attractive housing, and a high number of local voluntary social organisations. Introducing the concept of ‘residential urbanism’, the paper discusses the extent to which a residentially driven urban development can compensate for the generally unfavourable regional development context.     

小流域水土保持效益的灰色预测分析：以鹿马岔实验区为例

水土保持效益指标是一个多目标、多因素的动态灰色控制系统，其时间序列的动态变化可以用灰色控制理论中的灰色模型进行定理分析与预测。根据对鹿马岔小流域产业结构和经济潜力的分析，其预测值是可信的，从而证明了灰色系统理论是小流域水土保持综合治理效益预测实现模型化、定量化的有效方法之一。     

水土保持系列专题制图研究

介绍了水土保持图的基本概念,结合实际工作总结出了计算机技术支持下的水土保持系列专题制图技术思路,以邙山小流域为例对水土保持制系列制图进行了具体实践,给出了部分水土保持专题图示例,对今后进行水土保持制图研究具有一定的指导意义.     

模拟流域地貌发育过程的空间数据获取与分析

运用数字摄影测量与GIS技术对人工模拟降雨条件下小流域模型地貌发育过程进行了动态监测研究,获得了小流域模型不同发育阶段地貌形态高精度、高分辨率的DEM数据、等高线、纵横剖面等数据,计算出了流域模型各种地貌形态参数,并利用GIS技术进行流域发育过程的空间形态进行了可视化和空间分析.研究表明,数字摄影测量与GIS技术可准确快速获取流域地貌形态的相关参数及小流域土壤侵蚀的空间定量分布,对于黄土高原小流域降雨侵蚀产沙过程与地貌形态特征定量作用关系研究及小流域土壤侵蚀预报模型建立具有重要科学意义.     

产业群理论与小城镇特色产业园区建设

文章对产业群理论及其研究进展进行了分析，对我国已经出现的产业群类型进行了总结，并阐述了产业群重要类型之一的小城镇特色产业群的重要性。认为，建设小城镇特色产业园区，是政府应用产业群理论，引导推动小城镇特色产业群健康发展的重要举措。最后，针对特色产业园区建设提出了几点建议。     

中国城镇人口“镇化”发展的时空分异

将中国人口城镇化细分为城镇人口“镇化”与“城化”,采用“镇化水平”和“镇化贡献率”两个指标,从不同空间尺度及主体功能区视角,系统分析1982-2015年中国城镇人口镇化发展的时空分异及影响因素。主要结论包括：① 中国的城镇人口“镇化水平”和“镇化贡献率”在不断提升。2015年镇化水平为41.8%,2010-2015年期间镇化贡献率为55.1%。② 中国城镇人口镇化呈现显著的时空分异特征。镇化主导型县市主要分布在中西部地区,占全国国土面积的70%以上;城化主导型县市主要集中分布在沿海城市群地区,在全国国土面积中所占比例较小。③ 展望未来,中国城镇人口的镇化贡献率和镇化水平将稳中趋缓,应加强探索出基于主体功能区域分异的差异化小城镇发展模式。     

大城市边缘区中小城市规划建设可持续发展探讨—以广州增城市为例

大城市边缘区中小城市的规划建设有其特殊性，特殊的区位和特殊的功能定位决定它的规划建设必须走可持续发展的路子，文中对广州市边缘区增城市城市规划建设可持续发展的现状、背景契机、制约性和对策措施方面进行了初步的探讨。     

Unravelling runoff processes in Andean basins in northern Ecuador through hydrological signatures

Streamflow is the runoff response integrated in space and time over a complex system involving climatic and catchment physiographic factors. In the Andes, accelerating runoff process understanding is hampered by the inability to quantify heterogeneity of surface and subsurface catchment properties. Here, we present a statistical approach based on regression models and correlation analysis that links hydrological signatures and catchment properties to unveil processes in a set of volcanic mountain catchments (latitude 0°30'N) in Ecuador. The catchments represent form and function diversity in the same hydrological unit. We found that despite of similar atmospheric-water inputs the water yield in the north-east region is about 5× larger than in the south-west region and their flow regimes are asymmetric. The soil-bedrock interface and lithology exert a first-order control on hydrologic partitioning, and this allowed us to hypothesize two hydrological mechanisms. Firstly, in the north-east region, the perennial streamflow is associated with seasonal rainfall patterns, and subsequent drainage processes taking place at the surface and subsurface level. The amount of streamflow is related to landform characteristics, high canopy density and root development of forest as well as water holding capacity of organic soils. From a mechanistic standpoint, the low concentration time, steep slopes and shallow infiltration limited by high-consolidated deposits of sedimentary and volcanics suggest a lateral movement of the flow. Secondly, in the south-west region the streamflow regime is mostly groundwater-dependent and it becomes seasonally enhanced by rainfall. Larger seasonal variations of precipitation and temperature result into enhanced evapotranspiration in the drier months, limiting shallow soil infiltration. Under the soil layers, highly permeable pyroclastic deposits and andesitic lavas promote deep percolation. The results highlight the degree of dissimilarity of hydrological processes in Andean settings, but unravelling their complexity seems plausible using streamflow signatures and causal explanatory models.     

基于涡轮-转阀驱动的小直径水力振荡减阻器设计研究

小直径水平钻井在钻探中应用广泛,可以有效提高效率,降低成本。但钻柱与井壁之间存在较大的摩阻,导致出现托压现象,影响钻压传递,进而严重影响钻进效率。本文研究了一种基于涡轮-转阀驱动的小直径水力振荡减阻技术,通过振荡器的轴向振动,降低钻柱在钻井过程中所受阻力,提高钻进效率。文章从振动减阻器的研究现状、结构设计和实验结果等方面做了系统分析,得到实验结论:当泵排量相同时,振动频率越小,振幅越大,此时转速对压降影响较小。在转速保持不变的情况下,泵排量越大,振幅越大,且压降明显增加。这一研究成果可为该技术的发展提供一定参考。