MW5型潜水电磁打捞器在桩孔施工中的应用     

阮广招  陈亨顺 《福建地质》1997,16(3):143-147

通过工程实例，介绍了应用潜水电磁铁处理桩孔施工中掉铁件事故的方法及操作要领，它具有实用价值。  相似文献   

三明市农业气候资源概况   总被引：2，自引：0，他引：2  

蒋宗孝  阮锡章  伍毓柏  李文 《气象科技》2004,32(Z1):68-72

通过分析三明市光照、水分、热量的时空分布特征及其与农作物发育生长的关系 ,指出 :三明市的农业气候资源丰富 ,其中 10℃以上活动积温为 6 6 77 9～ 5 2 4 0 2℃年 ,降水量为 14 4 0～ 182 5mm ,主要分布在 3～ 9月 (约占全年降水量的 80 %～ 85 % ) ,且随纬度、海拔高度的增加而增加 ,太阳总辐射量为 5 5 1～ 6 13MJ/m2 ,年变化为单峰型 ,2月最小、7月最大。  相似文献   

2002年秋季山东省干旱遥感监测分析   总被引：2，自引：0，他引：2  

赵玉金  赵红  刘文  刘欣  张璇  薛晓萍 《国土资源遥感》2004,15(1):65-67,77

利用极轨气象卫星遥感资料对2002年山东省秋季干旱进行监测和服务,其监测方法主要采用热惯量法。为了提高土壤水分模式的计算精度,将全省分为4个区域,对利用卫星资料反演的地表温度日较差进行植被指数等环境因素订正。在地理信息系统支持下,比较准确地计算出农田受旱面积,效果良好。  相似文献   

A New Generation Earth Mantle Model from Global Adjoint Tomography     

Youyi Ruan  Wenjie Lei  Matthieu Lefebvre  Ryan Modrak  James Smith  Ridvan Orsvuran  Ebru Bozdag  Judith Hill  Norbert Podhorszki  Dave Pugmire  Jeroen Tromp 《《地质学报》英文版》2018,92(Z1):140-140

  相似文献   

An insight into the surface velocity of Inylchek Glacier and its effect on Lake Merzbacher during 2006–2016 with Landsat time-series imagery     

Shiyong Yan  Yi Li  Zhiguo Li  Guang Liu  Zhixing Ruan  Zian Li 《Environmental Earth Sciences》2018,77(23):773

Mountain glacier is one of the extremely sensitive indicators for climate change, and its surface motion distribution and corresponding variation are valuable information for understanding ice mass exchange and glacier dynamics. This paper presents the long-term ice velocity distributions of Inylchek Glacier in the Tianshan region by pixel-tracking algorithm with time-series Landsat imagery acquired during 2006–2016. Then the monitored ice motion fields of Inylchek Glacier were carefully analyzed and revealed a generally similar spatial distribution characteristic. Most of the ice of the North Inylchek Glacier remains in a stagnant state except for the upstream part, but a relatively high velocity of 20–40 cm/day with an RMSE of 3 cm/day was observed on most part of the South Inylchek Glacier, except for the slow-moving glacier terminus. We also state the glacier dynamics around Lake Merzbacher and their possible effect on its glacier lake outburst flood (GLOF) risk. Besides, the surface velocity distribution on South Inylchek Glacier surface during the ablation period from 2014 to 2016 was also established and also compared with annual velocity. The corresponding difference yields that there is a positive relation between ice motion and temperature variation. Therefore, the time-series ice surface motion yielded by the Landsat imagery thus could provide us an efficient and low-cost way to analyze the current state and changes in glaciers, thanks to the continuous and regular spaceborne observations provided by the Landsat satellites.  相似文献   

东北黑土水土流失特点   总被引：39，自引：4，他引：35  

张晓平  梁爱珍  申艳  李文凤  张学林  王玉玺  解运杰  刘凤飞  杨学明 《地理科学》2006,26(6):687-692

东北黑土区是中国的主要粮食生产基地。黑土水土流失和肥力退化一直是东北农业持续发展必须面对的问题。文章以黑土为对象,分析了水土流失的方式和特点。黑土流失面积虽大,但侵蚀的土壤物质大部分没有进入河道,而是在黑土景观的低洼部位堆积下来,形成侵蚀和堆积共存的土壤物质再分布景观特征。合理的农业管理措施,如等高耕作和保护性耕作可以在很大程度上控制黑土侵蚀,保持和恢复黑土肥力。  相似文献   

电阻率二维神经网络反演   总被引：32，自引：4，他引：28       下载免费PDF全文

徐海浪  吴小平 《地球物理学报》2006,49(2):584-589

由于非线性特性地球物理反演一直以来都是一个比较困难的问题. 近十年来,非线性反演方法如人工神经网络、遗传算法在地球物理数据解释中得到越来越多的应用,但目前基本仍限于一维反演问题. 对于二维反问题,反演参数较多,神经网络反演运用较少. 本文利用BP神经网络优化方法,实现了电阻率二维非线性反演. 与传统线性化的迭代反演比较,神经网络反演能够克服传统方法的不足、获得更好的反演结果.  相似文献   

潮汐测量与验潮技术的发展   总被引：10，自引：0，他引：10  

阮锐 《海洋技术学报》2001,20(3):68-71

潮汐是由各天体作用于地球上的引潮力所产生，不仅海洋中有潮汐，大气圈和地球固体部分也同样存在着潮汐。海道测量中的潮汐测量仅指海洋潮汐测量仅指海洋潮汐测量，潮汐测量的手段很多，主要包括采用水尺；浮子式、引压钟式、声学式、压力式验潮仪验潮。而GPS验潮及潮汐遥感测量等技术研究国内外正在开展。所有这些验潮技术各有自己的特点。  相似文献   

扇贝多肽在体外对免疫细胞活性的影响及其抗紫外线的氧化损伤作用   总被引：9，自引：2，他引：9  

刘晓萍  王玉贞  韩彦弢  于业军  王跃军  王春波 《海洋与湖沼》2001,32(4):414-419

采用噻唑盐（MTT）比色方法研究在紫外线辐射损伤条件下扇贝多肽对免疫细胞的保护作用，并探讨扇贝多肽对胸腺细胞和脾细胞活性的影响，结果表明，扇贝多肽具有抗紫外线氧化损伤的作用，可减轻或抑制紫外线对胸腺细胞和脾细胞的氧化损伤，并且呈剂量依赖性，扇贝多肽在0.5%-10.0%的浓度范围内，其抗氧化能力随浓度的增高而增强，在正常条件下可显著增强免疫细胞的活性，并且可拮抗雌激素对免疫细胞的抑制作用。提示扇贝多肽不仅具有抗氧化损伤作用，而且具有免疫增强使用。  相似文献   

Bibliometric Analysis of Global Research Progress on Coastal Flooding 1995–2016     

Chao Gao  Tian Ruan 《中国地理科学(英文版)》2018,28(6):998-1008

Global research progress on coastal flooding was studied using a bibliometric evaluation of publications listed in the Web of Science extended scientific citation index. There was substantial growth in coastal flooding research output, with increasing publications, a higher collaboration index, and more references during the 1995–2016 period. The USA has taken a dominant position in coastal flooding research, with the US Geological Survey leading the publications ranking. Research collaborations at institutional scales have become more important than those at global scales. International collaborative publications consistently drew more citations than those from a single country. Furthermore, coastal flooding research included combinations of multi-disciplinary categories, including ‘Geology' and ‘Environmental Sciences Ecology'. The most important coastal flooding research sites were wetlands and estuaries. While numerical modeling and 3 S(Remote sensing, RS; Geography information systems, GIS; Global positioning systems, GPS) technology were the most commonly used methods for studying coastal flooding, Lidar gained in popularity. The vulnerability and adaptation of coastal environments, their resilience after flooding, and ecosystem services function showed increases in interest.  相似文献