基于SLAM技术的地下空间三维实景建设关键技术研究     

吕华新  陈玲  骆小龙  杨帆 《测绘地理信息》2022,47(3):83-86

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基于SLAM技术的地下空间三维实景建设关键技术研究     

吕华新  陈玲  骆小龙  杨帆 《测绘地理信息》2022,47(3):83-86

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栅格型新安江模型在赣江流域的应用          下载免费PDF全文

山红翠  任立良  周瑜佳 《水文》2014,34(4):28-31

以赣江流域峡山站以上为研究区域,利用栅格型数字高程数据,提取数字流域水系及其空间拓扑关系,在此基础上建立数字水文模型。赣江上游峡山站以上集水区域包含21198个空间分辨率为30s的栅格,采用就近移植法将降水数据及蒸发数据插值到每个栅格上,计算峡山站的径流过程。日模型中选取1978~1985年为参数率定期,1986~1987年为参数验证期,以多年径流量误差最小为目标函数。次洪模型中采用前16场洪水用于参数率定,后6场用于模拟验证,以洪水总量、洪峰流量、峰现时间按许可误差统计合格率最高和确定性系数最大为目标函数。结果显示,率定期16场洪水中14场合格,验证期6场洪水均合格,表明栅格型新安江模型模拟效果良好。  相似文献   

耐高温（230 ℃）饱和盐水钻井液技术研究          下载免费PDF全文

陶士先  张丽君  单文军 《探矿工程》2014,41(1):21-26

我国未来深部大陆科学钻探计划深度为13000 m,温度梯度按3．0℃/100 m计算,井底温度将达到390℃以上,钻井液将面临超高温高压环境,钻井液技术将面临严峻考验。为此,开展了超高温钻井液的预研究,利用抗盐粘土、抗高温降滤失剂、抗高温解絮凝剂、抗高温保护剂等,研制了可用于230℃高温环境的饱和盐水钻井液配方。室内评价试验表明,用该配方配制的耐高温钻井液经230℃、16 h高温滚动老化后,具有良好的流动性能,高温高压失水量（210℃、3．45 MPa）＜35 mL/30 min。  相似文献   

鄱阳湖环湖区生态系统服务价值时空变化及权衡协同关系   总被引：1，自引：0，他引：1  

温玉玲  张小林  魏佳豪  王晓龙  蔡永久 《地理科学》2022,42(7):1229-1238

基于修订的当量因子表,结合1988—2020年7期土地利用数据,运用GIS数据处理和空间分析等方法探究了鄱阳湖环湖区生态系统服务价值的时空演变特征,同时引入生态系统服务权衡协同度模型对食物生产、水文调节、土壤保持等7项生态服务功能进行权衡与协同分析。结果表明：① 1988—2020年鄱阳湖环湖区生态系统服务价值从577.95亿元增至592.50亿元,呈先增后减再增的波动变化特征。② 生态系统服务价值的空间分布表现为明显的不均衡性,ESV显著减少的区域为南昌市区、九江市区以及其它各区县的城镇建成区,生态系统服务价值增加的区域均匀分布在研究区东北和西北地区以及靠近研究区外侧的东南和西南地区。③ 协同关系为生态系统服务之间的主导关系,权衡关系较少且主要存在于食物生产与其他服务之间。  相似文献   

Erosions on the southern Tibetan Plateau: Evidence from in-situ cosmogenic nuclides 10Be and 26Al in fluvial sediments     

ZHANG Xiaolong  XU Sheng  CUI Lifeng  ZHANG Maoliang  ZHAO Zhiqi  LIU Congqiang 《地理学报(英文版)》2022,32(2):333-357

Investigating topographic and climatic controls on erosion at variable spatial and temporal scales is essential to our understanding of the topographic evolution of the orogen.In this work,we quantified millennial-scale erosion rates deduced from cosmogenic 10Be and 26Al concentrations in 15 fluvial sediments from the mainstream and major tributaries of the Yarlung Zangbo River draining the southern Tibetan Plateau (TP).The measured ratios of 26Al/10Be range from 6.33 ± 0.29 to 8.96 ± 0.37,suggesting steady-state erosion processes.The resulted erosion rates vary from 20.60 ± 1.79 to 154.00 ± 13.60 m Myr-1,being spatially low in the upstream areas of the Gyaca knickpoint and high in the downstream areas.By examining the relationships between the erosion rate and topographic or climatic indices,we found that both topography and climate play significant roles in the erosion process for basins in the upstream areas of the Gyaca knickpoint.However,topography dominantly controls the erosion processes in the downstream areas of the Gyaca knickpoint,whereas variations in precipitation have only a second-order control.The marginal Himalayas and the Yarlung Zangbo River Basin (YZRB) yielded significantly higher erosion rates than the central plateau,which indicated that the landscape of the central plateau surface is remarkably stable and is being intensively consumed at its boundaries through river headward erosion.In addition,our 10Be erosion rates are comparable to present-day hydrologic erosion rates in most cases,suggesting either weak human activities or long-term steady-state erosion in this area.  相似文献   

火力发电厂大型接地网与防雷检测实践     

李小龙 《内蒙古气象》2014,(5)

通过火力发电厂大型接地网与防雷检测实践,对气象部门涉足较少的电力生产企业防雷检测进行了有益的探索。文章介绍了火力发电厂生产系统流程和结构特点,以及电力系统安全作业要求,确定了重点检测区域、检测方法、检测标准和检测周期要求。为火力发电厂大型接地网防雷检测工作提供参考。  相似文献   

A multi‐proxy sediment record of late Holocene and recent climate change from a lake near Ny‐Ålesund,Svalbard     

SHAN JIANG  XIAODONG LIU  JING SUN  LINXI YUAN  LIGUANG SUN  YUHONG WANG 《Boreas: An International Journal of Quaternary Research》2011,40(3):468-480

Jiang, S., Liu, X., Sun, J., Yuan, L., Sun, L. & Wang, Y. 2011: A multi‐proxy sediment record of late Holocene and recent climate change from a lake near Ny‐Ålesund, Svalbard. Boreas, Vol. 40, pp. 468–480. 10.1111/j.1502‐3885.2010.00198.x. ISSN 0300‐9483 The Arctic constitutes a unique and important environment with a significant role in the dynamics and evolution of the earth system. Arctic lake sediments, which accumulate slowly over time, contain abundant information about the biological communities that lived within the water body, as well as in the surrounding catchment. In this study, we collected a sediment core from Ny‐Ålesund, Svalbard, performed multi‐proxy analyses on sediment pigments, mineral magnetic susceptibility, various sediment quality (i. e. organic matter content, CaCO₃ content, carbon and nitrogen isotope), and diatom composition, and reconstructed the history of ecosystem responses to environmental variations, especially regarding aquatic productivity and lake catchment surface processes. Ny‐Ålesund has undergone distinct ecological and climatic changes. During the Little Ice Age, the cold climate was unfavourable for the growth of lake algae, and therefore the lake primary productivity declined. After about AD 1890 and during the 20th century, the warming climate and reduced ice cover led to rapid lithological change and growth of lake algae, enhanced lake primary productivity, and increased input of nutrients derived from increased chemical weathering into the lake. The lake ecosystem on Ny‐Ålesund has had rapid responses to climatic and environmental changes in the Arctic.  相似文献   

辽西金羊盆地南部髫髻山组陆相火山岩及旋回层序划分     

潘明臣  刘文海  单学东  敖光  付民秋  刘基超  王岩 《国土资源》2000,(2)

辽西金羊盆地（金岭寺－羊山盆地）南部髫髻山组陆相火山岩发育，为一套以中性为主的基性、中基性、中性火山岩组合。火山岩碱度主要为钙碱性。火山岩形成环境为活动大陆边缘区，这与本区所处大地构造位置相吻合。根据当前火山岩的研究现状，尝试性地对该盆地髫髻山组火山岩进行了火山喷发旋回层序的划分，共划分了四级火山喷发旋回层序。其中 A-A′剖面Ⅰ级 1个，Ⅱ级 5个，Ⅲ级 17个，Ⅳ级 21个； B-B′剖面Ⅰ级 1个，Ⅱ级 5个，Ⅲ级 18个，Ⅳ级 24个。  相似文献   

海洋石油工程服务管理研究     

单小麟  高喜峰 《海洋技术学报》2008,27(3)

海洋石油工程具有高投资、高风险、高技术含量等特点.海洋石油工程是项复杂的系统工程,提高服务管理水平,对于保证施工、建造、拖航及安装设置过程的安全,提高效率,进而提高竞争力极为重要.文中提出了海洋石油工程服务管理的系列理论与方法,并提出海洋石油工程服务管理中应注意的事项,为此类工程项目管理提供合理建议.  相似文献