首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   138篇
  免费   24篇
  国内免费   80篇
测绘学   6篇
地球物理   18篇
地质学   200篇
海洋学   7篇
综合类   8篇
自然地理   3篇
  2024年   2篇
  2023年   4篇
  2022年   5篇
  2021年   4篇
  2020年   9篇
  2019年   4篇
  2018年   11篇
  2017年   3篇
  2016年   16篇
  2015年   9篇
  2014年   10篇
  2013年   22篇
  2012年   9篇
  2011年   14篇
  2010年   8篇
  2009年   11篇
  2008年   8篇
  2007年   11篇
  2006年   19篇
  2005年   9篇
  2004年   11篇
  2003年   5篇
  2001年   8篇
  2000年   5篇
  1999年   6篇
  1998年   6篇
  1997年   6篇
  1996年   2篇
  1995年   3篇
  1993年   1篇
  1989年   1篇
排序方式: 共有242条查询结果,搜索用时 483 毫秒
41.
A pressure cell apparatus has been developed in this research work to study the long-term hydro-mechanical behaviour of cemented paste backfill (CPB) cured under applied stress. The samples are cured for 7, 28, 90 and 150 days and the evolution of their mechanical, hydraulic, physical and microstructural properties is studied. Also, the suction, temperature and electrical conductivity are monitored for a period of 150 days of curing. The testing and monitoring programmes are conducted in undrained conditions, with and without pressure application. The obtained results show that the curing stress affects the hydro-mechanical behaviour of CPB for up to 28 days. Within this curing period, the CPB exhibits enhanced hydro-mechanical performance. However, application of sustained excessive curing stress onto the CPB samples induces the propagation of microcracks in the backfill structure, thus causing lower mechanical strength and higher fluid permeability at the more advanced ages. Furthermore, the mineralogical and chemical compositions of the tailings (e.g., sulfidic tailings) can significantly alter the mechanical strength properties (uniaxial compressive strength and elastic modulus) and the permeability of the CPB. The evolution of coupled factors and characteristics of the CPB at an early age control and influence its long-term behaviour and performance.  相似文献   
42.
Little is known about the impacts of mine waste disposal, including deep-sea tailings, on tropical marine environments and this study presents the first account of this impact on deepwater fish communities. The Lihir gold mine in Papua New Guinea has deposited both excavated overburden and processed tailings slurry into the coastal environment since 1997. The abundances of fish species and trace metal concentrations in their tissues were compared between sites adjacent to and away from the mine. In this study (1999-2002), 975 fish of 98 species were caught. Significantly fewer fish were caught close to the mine than in neighbouring regions; the highest numbers were in regions distant from the mine. The catch rates of nine of the 17 most abundant species were lowest, and in three species were highest, close to the mine. There appears to be limited contamination in fish tissues caused by trace metals disposed as mine waste. Although arsenic (several species) and mercury (one species) were found in concentrations above Australian food standards. However, as in the baseline (pre-mine) sampling, it appears they are accumulating these metals mostly from naturally-occurring sources rather than the mine waste.  相似文献   
43.
从源项调查的目的、意义、基本内容和主要方法等方面进行了研究,分析了国内该方面研究工作的主要动态,指出了目前源项调查工作存在的主要问题,并对退役治理工作提出了合理的建议。  相似文献   
44.
对人矿床进行地质-工艺评价,开发利用这一巨大的潜在资源,是现阶段矿业生产发展的一项迫切的新任务。以葫芦塘尾矿库为例,通过三维模拟技术对尾矿库型人工矿床的形态、产状、储量、品位及其变化进行了定量模拟和评价;同时开展了人工矿床的技术评价和经济评价。通过对尾矿开发成本构成以及精锡成本影响因素的定量分析,得出了提高经济效益的最佳对策。  相似文献   
45.
Iron-hydroxide-rich and plant litter-containing sediments from natural sites contaminated with uranium mine tailing leachates were examined for their ability to adsorb arsenic. The samples with high contents of iron hydroxides (Fetotal concentration, >300 g kg−1) exhibited remarkable fixation of arsenic (up to 40 g As kg−1). This value corresponded approximately to the supersaturation point for natural iron hydroxides under the present conditions, and it was significantly lower than the value found for synthetic iron hydroxides. There was a strong correlation (R=0.8999) between the concentration of iron and that of arsenic at low arsenic contents, indicating adsorption on strong binding sites. Although all the samples had noticeable contents of organic carbon (plant litter), calcium, and manganese, no obvious effect of these elements on arsenic fixation could be detected. The amount of iron hydroxides was found the only fixation-controlling parameter immediately below a leaching water source.  相似文献   
46.
随着地表找矿难度的日益加大,目前的找矿目标应从以地表找矿为主转到地下找矿为主,这就需要有更高层次的找矿哲学作指导来提高找矿的成功率。紫金矿业合理利用废弃的毛石充分体现了找矿哲学思想,这样做提高了企业效益,再通过联合经营使资源枯竭型矿山企业走上可持续发展之路。  相似文献   
47.
铀水冶尾矿库地下水流特征与模拟分析:以某矿为例   总被引:4,自引:1,他引:3  
铀水冶尾矿库中地下水流动特征控制了核素向周围环境扩散与迁移。本文以某矿山谷型尾矿库为例,运用二维有限元模拟了库内地下水分布及流动,结合水文地质条件进行了分析与讨论。  相似文献   
48.
四川若尔盖巴西金矿堆浸尾矿提金工艺研究   总被引:1,自引:0,他引:1  
四川若尔盖巴西金矿堆浸属矿金平均品位 2 .5 5× 10 -6,为了进一步回收尾矿中的金 ,用氰化法、硫脲法、溴法、硫代硫酸盐法、石硫合剂法 5种方法进行了提金试验和制粒氰化法提金试验 ,在此基础上提出了回收该尾矿中金的最佳方案  相似文献   
49.
Three cores from Traunsee were investigated and compared with respect to diatom stratigraphy concerning dating of incursions into and rate of accumulation of industrial tailings in the profundal zone.
  相似文献   
50.
姜波  李俊锋  张渊 《世界地质》2004,23(3):309-312
经对尾矿中绢云母试验研究,确定尾矿中回收绢云母的工艺采用先粗选后浮选的方法,同时加入捕收剂BK,抑制剂B—1和B—2,使绢云母的纯度达到98%,尾矿中绢云母产出率为6%。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号