基于CDIO理念的“大地测量学基础”课程教学设计的实践与探讨     

林鹏  裴媛媛 《测绘与空间地理信息》2022,(2)

基于CDIO理念,对"大地测量学基础"课程教学设计进行了探讨与实践,并以坐标转换中的原理作为教学片段内容展示了具体的实践过程。根据课前设计的问题情景引导学生主动思考,达到了调动学生积极性的目的,提高了课堂教学质量,取得了良好的教学效果。  相似文献   

2021年度自然科学基金申请书关键词透视地理科学研究前沿热点与发展方向     

高阳  熊巨华  吴浩  张中浩  刘建宝  李鑫 《地理科学》2022,42(1):15-30

地理科学是提升人类对地球表层认知、探索人地关系、解决资源、环境、发展所面临的复杂问题的重要支撑。引领科学发展,支撑领域人才队伍的建设与培育,是国家自然科学基金委员会的使命与职责。追踪地理科学领域前沿,优化学科布局并开展战略引导是基金委地理科学学科工作的重要任务。以2021年国家自然科学基金地理科学领域4 479项申请书为样本,运用词云分析方法,对申请书的关键词进行统计分析,剖析了地理科学及各分支学科的研究热点。结果表明：“深度学习”“气候变化”“生态系统服务”“高光谱遥感”“青藏高原”“可持续发展”等是2021年地理科学研究内容与方法的热点关键词。在分支学科间交叉融合方面,信息地理学与人文地理学的共现关键词主要有“空间分析模型”“地理信息系统”“遥感”“机器学习”等;自然地理学与人文地理学的共现关键词主要有“生态系统服务”“土地利用”“土地利用变化”“可持续发展”“情景分析”等;自然地理学与信息地理学的共现关键词主要有“遥感监测”“尺度效应”“机器学习”“数字土壤制图”等。未来,国家自然科学基金委员会将从关键词设置、学科间交叉融合等途径入手,进一步从战略层面优化地理科学研究布局,引导科学家聚焦地理学基础理论与热点前沿问题,服务碳中和、乡村振兴等国家重大战略需求。  相似文献   

Foundation design considerations for a pile supported critical facility     

Thomas W. Houston  Carl J. Costantino  Quazi Hossain  N. Earl Stone 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):1169-1174

A large reinforced concrete structure supported on piles extending to bedrock is evaluated using a seismic soil–structure interaction analysis. The physical structure, the supporting pile system, analysis model and analytical methodology used are described. Important considerations in the design of the foundation pile system using the seismic analysis loadings and deformations are discussed.  相似文献   

云南中甸香格里拉大酒店项目岩土工程分析     

高伏芳 《云南地质》2012,(1):93-95

经资料整理、数理统计以及参照地区经验,认为场地工程性能一般,应采用桩基础或进行地基处理,提出合理岩土工程参数及地基处理方法、建议。  相似文献   

2005年度地理学基金项目评审及成果分析     

宋长青  冷疏影  张立新  刘黎明  黄永梅  高红山 《地球科学进展》2005,20(12):1337-1342

介绍了国家自然科学基金2005年度地理学项目受理、评审与资助的总体情况;分析了2005年在研的地理学基金项目执行情况,着重剖析了2002年批准项目的成果产出数量与水平;阐述了2004年底结题的地理学基金项目取得的突出进展。  相似文献   

Flow resistance of one-line emergent vegetation along the floodplain edge of a compound open channel     

Xin Sun  Koji Shiono 《Advances in water resources》2009

Experiments have been conducted in straight compound channels with and without one-line emergent vegetation along the floodplain edge, in which stream-wise velocities and boundary shear stresses have been measured. The experimental results show that the velocity distribution in the vegetation case is considerably different from that in the no vegetation case and the boundary shear stress is also significantly reduced by the additional flow resistance caused by the vegetation at a similar relative water depth. The apparent shear stress distribution which has been calculated with the boundary shear stress and weight component in the vegetation case is totally different from that in the no-vegetation case. New formulae for friction factors for the with and without vegetation cases are developed using vegetation density and flow parameters. The drag force caused by the vegetation is obtained for two different vegetation density cases and the magnitude of its effect on total flow resistance is then investigated. The force balance method is used to predict discharge and this is compared with the discharge predicted by the new formula. A further analysis of the selection of vegetation spacing is carried out, determining its effect on stage-discharge.  相似文献   

Improvement of the Lateral Distribution Method based on the mixing layer theory     

《Advances in water resources》2014

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Olivine intergranular plasticity at mantle pressures and temperatures     

Paul Raterron  Caroline Bollinger  Sébastien Merkel 《Comptes Rendus Geoscience》2019,351(2-3):80-85

The ductile behavior of olivine-rich rocks is critical to constrain thermal convection in the Earth's upper mantle. Classical olivine flow laws for dislocation or diffusion creep fail to explain the fast post-seismic surface displacements observed by GPS, which requires a much weaker lithosphere than predicted by classical laws. Here we compare the plasticity of olivine aggregates deformed experimentally at mantle pressures and temperatures to that of single crystals and demonstrate that, depending on conditions of stress and temperature, strain accommodated through grain-to-grain interactions – here called intergranular strain – can be orders of magnitude larger than intracrystalline strain, which significantly weakens olivine strength. This result, extrapolated along mantle geotherms, suggests that intergranular plasticity could be dominant in most of the upper mantle. Consequently, the strength of olivine-rich aggregates in the upper mantle may be significantly lower than predicted by flow laws based on intracrystalline plasticity models.  相似文献   

Bar structure in an arid ephemeral stream     

Marwan A. Hassan  Philip M. Marren  Uri Schwartz 《Sedimentary Geology》2009,221(1-4):57-70

This study describes the structure of gravel bars in Nahal Zin, an ephemeral stream in the Negev desert. The internal structure of the bars was examined along trenches and in shallow pits. Gravel sheets and unit bars form during transporting flow events in the main channel, on intra-bar channels and near bar heads. Unit bars are dominated by the Go facies. Compound bars develop from accretion around, and modification of, unit bars. Compound bars are active under the current flow regime and the average depth of the fill layer is about 35 cm. The structure of compound bars is dominated by Gm (massive), containing large amounts of sand. The second most common facies is clast-supported, openwork, and well sorted sediments of the Go (pebbles) facies. Bar formation, and the development of the range of facies evident in the bars is controlled by sediment supply, particularly the high volumes of sand-sized sediment, the passage of gravel sheets and bedforms during floods, and the lateral and vertical instability of the channel. Repeated scour and fill events have produced a diverse arrangement of facies, with numerous erosional contacts between depositional units. Lateral and downstream shifts in the pattern of scour and fill due to flow and antecedent conditions shape the channel morphology and bar internal structure. Ephemeral river bars differ from those of humid and proglacial rivers in terms of the dominant facies present, the arrangement of the facies within the bars, and the sedimentary structures developed within the depositional units and on the bar surface.  相似文献   

城市地理信息系统空间基础数据建设探讨   总被引：11，自引：1，他引：11  

黄林进  甘雪梅 《现代测绘》2003,26(4):38-39

本文通过分析城市地理信息系统基础数据的主要组成、基础数据的数据特性和数据结构，提出了常用数据格式(如DGN、DXF等)到ARC／INFO数据格式转换、入库的技术实现路线，为GIS基础数据的生产、更新雏护和应用提供了一种方法和思路。  相似文献