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41.
地热回灌是实现地热资源可持续开发的有力措施,在世界各国已获得广泛应用,在地热资源的保护、减少资源浪费、延长地热井寿命以及减少环境污染等方面具有重要意义.天津是我国开展地热回灌比较成熟的地区之一,截至2019年底,天津市基岩裂隙型热储回灌率已达79.61%.大规模集中采灌条件下热储层渗流场的变化以及是否会影响热储温度已成为热储系统研究的前沿课题.本文以天津市东丽湖地区为例,选取1,5-萘磺酸钠作为示踪剂,在2018~2019年供暖期集中采灌期间开展了群井示踪试验,结果显示,供暖期内地热井开采量(或回灌量)、水温没有明显变化,水位除受正常采灌影响外没有明显变化,热储系统基本处于稳定状态;试验中示踪剂回收率极低,开采井和回灌井之间水力联系较差,有限的优势通道中的最大流速为448.42 m/d,优势通道的方向主要集中于北东向,与区内主要控热断裂沧东断裂及其次生断裂的发育方向一致;在现状开发利用模式下,不会造成该热储层温度的显著变化.这些认识对于指导北方古潜山碳酸盐岩热储的科学开发利用具有一定的现实意义. 相似文献
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Variation characteristics of heavy metals and nutrients in the core sediments of Taihu Lake and their pollution history 总被引:1,自引:0,他引:1
The sedimentary environment change, trophic evolution and heavy metals pollution history of the northern Taihu Lake in the last 100 years are studied according to the sedimentary geochemical proxies of the core sediments, such as grain size, nutrients, heavy metals, diatom, etc. The nutrients in the sediments depended mainly on the lake internal circulation and the heavy metals were from natural geogenic sources before the 1920s, which were not influenced by human activities generally, and grain size was one of the key factors influencing heavy metals content in the sediments. The alternation of manner and strength of human activities in Taihu Lake catchment before and after the 1920s made the lake sediments coarser, and hence heavy metals and TP content decreased contrasted with that before the 1920s. TP content in sediments and water increased from the 1950s to late 1970s due to anthropogenic pollutants discharge, and the lake belonging to mesotrophic state. TN and TOC content and C/N ratio increased due to the increasing external pollutants into Taihu Lake by human activities, TP content also increased obviously in water and sediments, and the diatom association was dominated by eutrophic species since the late 1970s, indicating the eutrophication state of Taihu Lake in this period. Meanwhile the increasing in heavy metals content, such as Cu, Mn, Ni, Pb and Zn, and their proportion of valid fractions in the sediments indicates that they all result from human pollutants since the late 1970s. The heavy metals in the surface sediments have certain potential biological toxicity due to the higher SEM/AVS ratio. 相似文献
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工程地质测试技术与方法 总被引:2,自引:0,他引:2
张苏民 《水文地质工程地质》1993,20(1):38-41
本文分别论述了室内试验,原位测试,资料整理及数值分析方法、地基加固4个方面所取得的进展,并指出存在问题及努力的方向 相似文献
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Diatom assemblages and quantitative reconstruction for paleosalinity from a sediment core of Chencuo Lake,southern Tibet 总被引:3,自引:0,他引:3
Changing salinity in lakes and especially in closed lakes depends mainly on the balance between precipitation, runoff and evaporation in arid and semi-arid areas, hence influencing lake levels di-rectly[1-4]. Past salinity has been recovered by a vari-ety of environmental indicators from lake sediments such as diatoms, chironomids, ostracoda, isotopes of ostracoda shells, geochemistry, and isotopes of authi-cabonates[3,5—10]. Recently, with extensive data-base study on diatom-salinity transfe… 相似文献
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A 2.8 Ma record of environmental evolution and tectonic events inferred from the Cuoe core in the middle of Tibetan Plateau 总被引:1,自引:0,他引:1
Ji?ShenEmail author Houyuan?Lü Sumin?Wang Shiyue?Chen Xiangdong?Yang Yanhong?Wu Zhaoyu?Zhu 《中国科学D辑(英文版)》2004,47(11):1025-1034
Based on a multi-proxy investigation into the deep core of the Cuoe Lake in the middle of Tibetan Plateau, a 2.8 Ma paleoclimatic
and paleoenvironmental evolution is reconstructed. The result of magnetic stratum indicates that the lake basin was formed
at about 2.8 MaBP, while the multi-proxy analyses of lithology, grain size, magnetic susceptibility and geochemical elements
reveal that there have been three major environmental evolution stages and at least two intensive uplifts of the Tibetan Plateau
in the lake basin area, i.e. during 2.8-2.5 MaBP, the lake basin came into being as a result of the disaggregation of the
planation surface and rapid rising of the Tibetan Plateau. During 2.5-0.8 MaBP, with gradual uplift of the Tibetan Plateau,
the environment of this area was more effectively controlled by the climatic cycle of the alternative glacial-interglacial
stages. After 0.8 MaBP, the middle part of the Plateau accelerated its uplift and entered cryoshere. 相似文献
50.
ClimateconditionsintheLastGlacialMaximum(LGM)wereremarkablydifferentfromthepresentones.LGMglobalmeantemperaturewas5℃-10℃dropbutprecipitationdecreasescommonly.LGMhasbecomethekeyphasetoreconstructtheearthenvironmentalfield,retrieveextremecoldclimatecondit… 相似文献