青藏高原（格尔木-亚东）冰缘现象及其气候意义     

刘擎  李宜垠  孙才奇  聂振宇  杨玮琳  崔之久  刘耕年 《冰川冻土》2021,43(3):690-700

冰缘地貌与沉积是冰冻圈环境变化的载体,对其开展深入研究对了解青藏高原地表过程与过去气候变化,具有重要意义。基于青藏高原（格尔木-亚东）冰缘地貌和沉积野外记录和实验分析,获得以下认识：格尔木在LGM时多年冻土至少下限到达海拔2 900 m,年均气温降至< -4 ℃,比现在至少低9 ℃,气候寒冷干燥;冰消期和全新世存在极端干冷的气候事件,可能存在地面温度< -10 ℃的冬季迅速降温气候期。楚玛尔、那曲谷露和纳木错的冰楔假型分别记录了末次冰期冷期多年冻土扩张,亚东古砂楔记录了早全新世冷事件。西藏羊八井泥炭沉积剖面孢粉和测年揭示,该区自新仙女木事件以来经历了严寒（12.8~9.8 ka）、暖湿（9.8~5.0 ka）、干冷（5.0 ka至今）的气候阶段。青藏高原（格尔木-亚东）广泛发育的冻融褶皱、成层坡积、风沙沉积等,是古环境重建的重要佐证,具有刻画冷暖-干湿的意义。  相似文献   

缅甸某船坞抽水试验井局部失稳原因及预防对策          下载免费PDF全文

章荣国  梅奇  刘擎 《探矿工程》2006,33(6):46-48

缅甸某干船坞工程在抽水试验井施工过程中发生井壁局部失稳事故，有地下水动力作用的自然因素，又有桩基础挤土效应、压密注浆等人为诱发因素。通过现场观测和分析，在利用地下水动力作用方向的基础上，采取了改善泥浆性能、预先释放挤土应力等措施后，井壁无失稳现象出现。经抽水试验验证，成井效果良好。  相似文献   

东洞庭湖湖陆风特征分析     

杨伟  刘擎  王威  张巧明  方阳 《气象科学进展》2020,10(3)

  相似文献   

地理信息行业数据人员的六大发展方向     

刘擎 《中国测绘》2013,(6):58-59

从业已经超过10年,对于数据工作了解较多,接触的专长之人也较多,毕竟本人是数据类专业出身：面对新的的投身行业者和应届毕业生刚入行时,比较迷茫、浮躁,数据工作比较枯燥、单调、乏味、繁复、回报低,如何挺过入行适应期和行业工作低潮期,是很多人在思索的问题。  相似文献   

振弦式剖面沉降仪在软基堤坝施工监测中的应用   总被引：6，自引：0，他引：6  

吴建  刘擎 《岩土工程技术》2002,(4):195-197

4651型振弦式剖面沉降仪是一种地基变形监测仪器,能直观、全面地量测地基观测剖面上各点的沉降.结合工程实例介绍其基本原理、试验方法、资料整理及其运用于堤坝施工监测的优越性.  相似文献   

珠江广州河段微表层与次表层水环境质量比较(英文)   总被引：1，自引：0，他引：1  

刘擎  胡晓娟  蒋江峦  张俊逸  吴志辉  杨宇峰 《地理学报(英文版)》2014,24(3):475-491

The water quality in the surface microlayer(SML) and subsurface water(SSW) in the Guangzhou segment of Pearl River, a eutrophic urban river section in China, were analyzed. The spatial and temporal dynamics of nutrient concentrations, heavy metals and bacteria were examined from two sampling sites in monthly samples throughout 2010. The mean concentrations of total nitrogen, ammonia, nitrate and nitrite were higher than 7.0 mg/L, 3.1 mg/L, 1.1 mg/L and 0.3 mg/L, while total phosphorus and orthophosphate were 0.5 mg/L and 0.1 mg/L, respectively. These results indicated that the water quality was rich in minerals and eutrophic. The mean concentrations of Mn and Fe were higher than 0.013 mg/L; and Ni, Cr and Pb were higher than 0.001 mg/L. The mean concentrations were in the order of Mn Fe Ni Pb Cr. The concentrations of heavy metals in the Guangzhou segment were lower than the limit of the surface water quality standards in China and the World Health Organization(WHO), but higher than the median values in the world's freshwater. The density of bacteria ranged from 3.30×105 to 5.23×106 cells/mL, and the amount of cultivable heterotrophic bacteria ranged from 1.30×10 3 to 1.89×10 6 cfu/mL. Fecal coliform levels were beyond the V class of China water quality standard. The SML was enriched in nutrients, heavy metals and bacteria, with the maximum enrichment factor of 3.84 for nutrients, 8.00 for heavy metals, and 3.04 for bacteria, suggesting that the water quality of the SML of the Guangzhou segment of the Pearl River was more serious than in the SSW.  相似文献