移动目标监控系统在西部测图中的开发应用   总被引：1，自引：0，他引：1  

张福浩  仇阿根  刘纪平 《测绘科学》2009,34(2)

西部测图项目是国家重点项目,该项目测绘的区域自然条件复杂,属于无人居住区,对于参加该项目野外测绘的人员的安全,是一个重要而又艰巨的任务,移动目标监控系统就是充分利用已有的卫星定位技术和网络技术,提供车辆与人员的定位、指挥中心对车辆与人员的监控,确保车辆与人员的实时监控,提供安全保证,本文详细介绍了西部测图安全监控系统的原理、架构、技术路线和功能。  相似文献   

Ecological controls on biogeochemical lfuxes in the western Antarctic Peninsula studied with an inverse foodweb model     

Hugh W Ducklow  S C Doney  S F Sailley 《极地研究(英文版)》2015,(2)

Sea ice in the western Antarctic Peninsula (WAP) region is both highly variable and rapidly changing. In the Palmer Station region, the ice season duration has decreased by 92 d since 1978. The sea-ice...  相似文献   

基于最佳用途的土地用途有偿管制机制探索     

赵淑芹 《国土资源情报》2014,(2):41-45

当前基于现状用途的管制存在管制方式偏行政化、管制手段无偿化导致农村集体土地收益偏向国有、非农产业和城市分配,重塑用途管制制度已显示出迫切性。本文探索基于最佳用途,通过"用途差"和"用途差"交易实现土地用途有偿管制的机制,认为通过用途有偿管制机制不仅可以保护农用地,特别是耕地资源,保障土地资源的可持续利用。而且,可激活土地资源价值,特别是有助于农用地资源资产、资本化,缩小农村、农业和农民家庭资产与收入与城镇的差距。  相似文献   

8000-year history of palaeoproductivity in a large boreal lake     

Arto Itkonen  Virpi Marttila  Jarno Meriläinen  Veli-Pekka Salonen 《Journal of Paleolimnology》1999,21(3):271-294

An 8000-year record of palaeoproductivity, based on the chemical and chironomid stratigraphies from Lake Päijänne, S. Finland, was assessed with respect to known morphometric, climatic and anthropogenic events. A gradual trend of dystrophication and an associated decrease in aquatic production was detected during the Holocene, with the following exceptions: (1) high diatom and chironomid production around 8000-6000 cal yr BP, (2) eutrophication around 2000 cal yr BP, and (3) an anthropogenic signal during the last few decades.The changes in chironomid assemblages, before the past few decades, have mainly been shifts in concentration, but not in species composition. Variation in chironomid production was mainly explained by the accumulations of biogenic silicon, carbon and organic matter. Nutrient availability seems to be important in controlling biogenic silicon, which we use to infer past diatom production. The high production ca. 8000-6000 cal yr BP and the fluctuation in chironomid influx after ca. 2000 cal yr BP, however, were probably caused by the proposed warm/dry and cold/wet conditions during these times, respectively. These results highlight the sensitivity of boreal shield lake ecosystems to climatic forcing. In contrast, the pronounced change in the morphometry of the basin around 7000 cal yr BP had little effect on the trophic state of the lake. The human-induced trophic change during the past few decades has affected the Lake Päijänne ecosystem to an extent never experienced before during the last 8000-years.  相似文献   

河南登封白坪铝土矿的古地貌控制   总被引：2，自引：0，他引：2  

葛宝勋  李凯琦 《煤田地质与勘探》1992,20(4):1-5

用趋势面分析法恢复登封白坪G层铝土矿沉积时的古地形;用相关分析法研究了古地形对含铝岩系厚度、植物分布、钛率以及矿体分布、矿石质量、矿石结构的控制作用,提出了古隆起控矿的观点。在成矿机理与找矿方法方面也提出了新看法。   相似文献   

蒙皂石伊利石化反应机理和框架性行为模式   总被引：1，自引：0，他引：1       下载免费PDF全文

邬金华  许仕策 《地质科学》1999,34(4):498-505

对珠江口盆地两口钻井95个泥质岩样粘土矿物X衍射分析资料的定量研究表明,若反应是以消耗蒙皂石为代价形成伊利石,则反应符合溶解-沉淀机理,但除此以外,蒙皂石还可以净溶解或新增伊利石层的方式加大I/S比。蒙皂石在渐进成岩过程中的框架性行为模式具有三级控制,按顺序分别由温度、基本离子成分和动力学因素控制特定温度段内蒙皂石行为过程的起始和终结、行为过程的方式和行为过程的速率和程度。渐进成岩过程中I/S比的变化主要与第三级控制有关,而游离状蒙皂石和伊-蒙混层粘土的含量变化则是第二三两级共同控制的结果。  相似文献   

Salinity problem of groundwater in the Wadi Tharad Basin, Saudi Arabia     

Mahmoud S. Alyamani 《GeoJournal》1999,48(4):291-297

In Wadi Tharad the groundwater has been subjected to hydrochemical study to identify the process (s) that led to the formation of relatively highly saline water in shallow alluvial aquifer. The chemical analyses results show that the groundwater salinity was highly variable and randomly distributed along the wadi course. This variation could be attributed to intensive evaporation on effluent prone surface irrigation water that led to precipitation of evaporates (e.g., calcite, dolomite, gypsum and probably halite). The intensive irrigation practice through mineral dissolution recharged the groundwater with a marked increase in the salinity. The local hydrogeological condition is also involved in determining the risk of the groundwater salinity as a consequence of irrigation practice. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

MORPHOLOGICAL VAMABILITY OF THE UPPER MISSISSIPPI RIVER     

Annie G. BHOWMIK 《国际泥沙研究》1999,(2)

1INTRODUCTIONTheUpperMississippiRiver(U-MR)extendsfromCairo,Illinois,totheheadwaiersoftheMississippiRiver(MR)nearLakeltascainMinnesota.Theentirerivercanbedividedintotwomajorreachesf1)theUpperMississippiRiverfromheadwaierstoCairo,Illinois,totheconfluenceoftheOhioRiverwiththeMississippiRiver,and2)theLowerMississippiRiver(LMR)fromCairo,Illinois,totheGulfofMexico.FigureIshowsthisdivision,includingabreakdownoftheentireriverintofive(5)segmentswhichwillbedescribedinasubsequentsectio…  相似文献   

试论煤层气藏概念与成藏要素     

时保宏  赵靖舟  权海奇 《煤田地质与勘探》2005,33(1):22-25

通过对前人煤层气藏概念的调研和对煤层气性质及成藏要素的研究, 认为: 煤层气藏是在压力封闭作用下, 吸附煤层气达到相当数量的煤岩体或煤层, 是煤层气聚集和煤层气勘探开发的基本地质单元。煤层气藏的成藏要素主要包括煤层条件、压力封闭和保存条件。煤层条件是煤层气藏形成的物质基础, 压力封闭是煤层气藏的必要条件, 保存条件是煤层气藏从形成到现今能够存在的前提。   相似文献   

福建武夷山龙井坑铅锌矿地质特征及找矿远景分析     

魏隆海 《福建地质》2009,28(3):193-199

武夷山龙井坑铅锌矿（化）体贮存于逆冲推覆构造带中,受其控制,矿（化）体产出特征取决于推覆构造带的规模和形状。通过对矿区成矿地质条件及地球物化异常特征等的分析,初步认为属中低温热液型矿床。  相似文献