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61.
以512矿床为例,研究了砂岩铀矿体铀、钍含量及其放射性同位素分布规律,由此讨论铀矿体的定位条件。结果表明:①在整个层间氧化带中岩石的钍含量变化不大,表现出钍化学性质的不易被淋洗、迁移、富集的惰性特征;②铀含量从强氧化带到弱氧化带直至矿化带逐渐升高,由矿化带到还原带逐渐降低,铀含量分带性反映了氧化环境铀溶解迁移、还原环境水解沉淀的过程;③铀含量大于100μg/g是砂岩铀矿体的定位条件;④放射性同位素比值作为铀矿体定位条件因矿体所处时期不同而不同;后期矿体放射性同位素定位条件为1≤234U/238U≤2,0≤230Th/238U≤0·2,234U/230Th>1;前期铀矿体放射性同位素定位的标准为0·75≤234U/238U≤1,0·5≤230Th/238U≤1。 相似文献
62.
水资源系统网络图是流域水资源配置及调度模型的基础.但对大型流域而言,网络图构建复杂且容易犯错.为了解决该问题,本文提出一种基于数字高程模型(DEM)的水资源网络图构建方法.该方法借鉴分布式水文模型中子流域划分的思想,根据DEM数据自动绘制地表水网络中的天然水流关系.同时该算法也可以自动构建各个计算单元的地下水开采补给网络,再通过人工添加供水网络就可以完成整个水资源系统网络图的构建.该方法已成功应用于海河流域.该方法可以推进水资源系统网络图构建的科学性,及水资源系统网络图绘制工具的软件化水平,进而促进水资源配置及调度模型系统的推广与应用. 相似文献
63.
Ioannis Nalbantis Ino Papageorgaki Panayiotis Sioras Charalambos Ioannidis 《水文研究》2017,31(9):1760-1775
The impact of uncertainty in ground elevation on the extent of areas that are inundated due to flooding is investigated. Land surface is represented through a Digital Surface Model (DSM). The effect of uncertainty in DSM is compared to that of the uncertainty due to rainfall. The Monte Carlo method is used to quantify the uncertainty. A typical photogrammetric procedure and conventional maps are used to obtain a reference DSM, later altered to provide DSMs of lower accuracy. Also, data from the Shuttle Radar Topography Mission are used. Floods are simulated in two stages. In the first stage, flood hydrographs for typical return periods are synthesized using generated storm hyetographs, the Soil Conservation Service–Curve Number method for effective rainfall, and the Soil Conservation Service synthetic unit hydrograph. In the second stage, hydrographs are routed via a one‐dimensional hydraulic model. Uncertainty in DSM is considered only in the second stage. Data from two real‐world basins in Greece are used. To characterize the inundated area, we employ the 90% quantile of the inundation extent and inundation topwidth for peak water level at specific river cross‐sections. For topwidths, apart from point estimates, also interval estimates are acquired using the bootstrap method. The effect of DSM uncertainty is compared to that for rainfall. Low uncertainty in DSM is found to widen the inundated area; whereas, the opposite occurred with high uncertainty. SRTM data proved unsuitable for our test basins and modelling context. 相似文献
64.
从应用角度出发,结合MapGIS软件属性录入功能,以土地调查工作为例,阐述如何利用MapGIS软件录入图斑属性,重点讨论如何对属性录入的过程进行检查,并开发出相应的补充辅助模块. 相似文献
65.
多宝山矿田铜山铜矿资源潜力及深部勘查方向 总被引:1,自引:0,他引:1
目前,多宝山矿田铜山铜矿深部勘查尚面临成矿后断层对矿体的切割和错动等问题,该问题严重制约着对该矿床成因的认识及深部勘查方向的选择。铜山断层是破坏铜山铜矿主矿体的主要成矿后断层,其走向为东西向,倾向南,是沿北东10°~12°方向推覆的一条压性断层。研究表明铜山断层由南向北推移的断距在东部1096勘探线为750m,西部1072勘探线断距则为1060m;由于东、西两端推应力的差异性产生东西方向的水平分力,致使断层上盘由西向东水平位移200~250m。铜山Ⅰ、Ⅱ、Ⅲ号主矿体均被铜山断层所切断,其中断层上盘Ⅰ号矿体的部分和Ⅲ号矿体的全部因被抬升已被剥蚀,本文重点讨论Ⅰ、Ⅱ号矿体在断层下盘的赋存部位。分析推测表明,铜山 Ⅰx号矿体在断层下盘赋存在1048~1084线,埋深950m以下;Ⅱx号矿体赋存在断层下盘1036~1104线,埋深1150m。通过对铜山断层下盘推测的Ⅰx、Ⅱx矿体和部分已控制的Ⅲ、Ⅴ(Ⅳ)、Ⅵ号矿体进行资源量预测,铜山铜矿总预测资源量约为铜金属390万t,预测深度为1700m。建议铜山铜矿后期勘查工作重点勘查范围界定在1048线至1096线,勘查深度在900~1700m。 相似文献
66.
地热能是一种安全、清洁、稳定的可再生能源,广东阳江地区的地热资源开发潜力巨大,但研究程度较低。热红外遥感技术能够高效地圈定地热异常区并对隐伏断裂进行预测,笔者等选取研究区landsat8遥感数据,通过分析地表温度、地热异常点及人类活动的关系,利用大气校正方法对该区潜在的地热异常进行了预测。在排除人为热影响下得到高温地热异常区9处,排除湖泊水域以及海拔的影响下得到低温地热异常区4处。在此基础上,利用地表温度与归一化植被指数计算研究区的温度植被干旱指数值(TVDI),预测可能存在的隐伏断裂23 处。最后结合岩性、断裂构造有效地圈定了5处地热靶区,主要分布在研究区西南区域和新洲镇附近。研究结果有助于预测阳江地区具有开发前景的地热异常区、识别圈定具有勘探意义的靶区以及预测隐伏断裂,对该区后续地热资源的进一步研究具有重要的意义。 相似文献
67.
《China Geology》2018,1(3):415-424
Since 2011, certain advances have been made through the resource investigation, metallogenesis research, mining supervision and environmental protection of ion-adsorption type rare earth element (REE) deposit in South China. Firstly, some progress has been made in REE prospecting in Jiangxi, Guangdong, Guangxi and Yunnan. REE deposits are not only found within the weathering crusts of granites and felsic volcanic rocks, but also within the weathering crusts of epimetamorphic rocks and basic magmatic rocks. Secondly, the methods of exploration, delineating ore bodies and calculation of reserves have been improved, which intuitively reflect the thickness, REE composition and value of weathering crust. Thirdly, the relationship between REEs and weathering degree and the rule of distribution, migration and enrichment of REEs in the weathering profile was summarized through the analysis of big data, which can predict the metallogenetic horizon of REEs. Fourthly, a method for quick, accurate and dynamic investigation of the REE deposit has been established by using high resolution remote sensing technology. Finally, the relation between the production status of REE mines and water pollution has been revealed based on long-term hydrochemical monitoring data of rivers and wells in mines and surrounding areas. 相似文献
68.
69.
基于专家证据权重法的成矿远景区划与评价--以东昆仑地区金矿为例 总被引:7,自引:0,他引:7
在介绍专家证据权重法的基础上,将东昆仑地区的基础地质、区域成矿规律及典型矿床研究等方面取得的认识(知识系统)与证据权重法结合,提出并建立了一个基于专家证据权重法的矿产资源定量预测评价系统,该系统在根据知识系统对各证据因子赋权重的过程中体现了地质专家的思想.应用专家证据权重法对东昆仑地区金矿的成矿概率进行了定量计算,并进行了金矿成矿远景区划.研究结果表明远景区内预测含矿单元的后验概率二重积分的大小可代表远景区的总体成矿潜力,据此将各远景区进行分级排队,由高到低划分为A、B、C 3级. 相似文献
70.
The modernisation of local government has attempted to reinvent central-local government relations by offering freedoms and flexibilities to facilitate the governance of local issues. At the same time, a shift to outcome focussed targets as a new form of governmental rationality allows central government to delimit these opportunities. Drawing on aspects of governmentality and actor-network theory, the paper explores the tensions between these modes of government. It argues that outcome focussed targets circumscribe the limits of local governance by offering a despatialised technology of government. Using a case study of Local Public Service Agreements, the paper highlights the problems 10 English rural local authorities have experienced in their attempts to construct and negotiate a series of local policy targets with central government. The paper shows how the spatial limitations of statistical governance conspire against the construction of targets which reflect local policy priorities. In conclusion we consider the extent to which these limitations are a deliberate act of control and consider the implications for agency within networks of governmentality. 相似文献