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981.
L. Li D. A. Barry C. Cunningham F. Stagnitti J. -Y. Parlange 《Advances in water resources》2000,23(8):176
Previous studies on tidal dynamics of coastal aquifers have focussed on the inland propagation of oceanic tides in the cross-shore direction, a configuration that is essentially one-dimensional. Aquifers at natural coasts can also be influenced by tidal waves in nearby estuaries, resulting in a more complex behaviour of head fluctuations in the aquifers. We present an analytical solution to the two-dimensional depth-averaged groundwater flow equation for a semi-infinite aquifer subject to oscillating head conditions at the boundaries. The solution describes the tidal dynamics of a coastal aquifer that is adjacent to a cross-shore estuary. Both the effects of oceanic and estuarine tides on the aquifer are included in the solution. The analytical prediction of the head fluctuations is verified by comparison with numerical solutions computed using a standard finite-difference method. An essential feature of the present analytical solution is the interaction between the cross- and along-shore tidal waves in the aquifer area near the estuary’s entry. As the distance from the estuary or coastline increases, the wave interaction is weakened and the aquifer response is reduced, respectively, to the one-dimensional solution for oceanic tides or the solution of Sun (Sun H. A two-dimensional analytical solution of groundwater response to tidal loading in an estuary, Water Resour Res 1997;33:1429–35) for two-dimensional non-interacting tidal waves. 相似文献
982.
吉林省通榆、乾安县承压地下水氟污染的原因及其防治对策 总被引:3,自引:0,他引:3
本文针对吉林省通榆、乾安县潜水高区下部第四系承压地下水氟含量升高,引起氟地主病重新抬头的环境水千文地质问题,分析了氟升高的原因,主要是研发第四系承压地下水的过程中含水层顶板的大规模破坏,使高氟潜水下窜,污染了深层压水所致。对防治对策进行了探讨,提示人们在水资源开发过程中应保护开采层的地球化学环境,从违背自然的主观意识所造成的恶果中肖取教训。 相似文献
983.
984.
985.
地下水资源是陕西实施西部大开发战略的重要保证 总被引:2,自引:0,他引:2
陕西在西部大开发中具有重要地位和良好前景。陕西是一个缺水省份,但存在着地下水赋存的良好地质-水文地质条件,地下水资源是陕西实施西部大开发战略的重要保证。面对西部大开发的新形势,依法加大陕西地下水资源勘查开发力度,把地下水资源勘查开发同其它基础建设要放在同等重要位置。组建专业委员会研讨地下水资源勘查开发问题。 相似文献
986.
S. Harrison J. Molson H. Abercrombie J. Barker D. Rudolph R. Aravena 《Hydrogeology Journal》2000,8(6):608-622
Discovery of high contents of methane gas in coals of the Mist Mountain Formation in the Elk River valley, southeastern British
Columbia, Canada, has led to increased exploration activity for coal-seam gas (CSG). CSG production requires groundwater abstraction
to depressurize the coal beds and to facilitate methane flow to the production wells. Groundwater abstraction will have hydrodynamic
effects on the flow system, and an understanding of the groundwater flow system is needed to evaluate these effects. The purpose
of this paper is to describe the groundwater flow system in the area by means of a groundwater flow model and interpretation
of hydrochemical and isotopic analyses of groundwater and surface water.
Groundwater flow for the Weary Creek exploration area is modeled in two vertical sections. The model domains, based on classic
upland–lowland conceptual flow models, are approximately 10,000 m long and 4,000 m deep. Each consists of a fixed water-table
boundary and no-flow boundaries along the traces of major faults. Steady-state groundwater flow is calibrated to hydraulic-head,
streamflow, and groundwater-recharge data. Simulated steady-state velocity fields define regional and local flow components
consistent with the conceptual model.
The results are consistent with regional trends in δ2H, δ18O, tritium, and TDS, which define two distinct groundwater groups (A and B) and a third of intermediate composition. An active,
shallow, local flow component (group A) is recharged in beds cropping out along subdued ridges; this component discharges
as seeps along lower and mid-slope positions in the southern part of the study area. The waters are tritiated, relatively
enriched in δ2H and δ18O, and have low TDS. A deeper regional flow component (group B), which originates at a higher altitude and which discharges
to the Elk River valley bottom, is characterized by non-tritiated groundwater with relatively depleted δ2H and δ18O, and higher TDS.
Groundwater contributes less than 10% of the total direct flow to the Elk River, as indicated by flow measurements and by
the absence of group A and group B characteristics in the river water. Thus it is hypothesized that groundwater extraction
during CSG production will have little impact on the river. The groundwater flow model developed in this work is used in a
companion paper to further test this hypothesis.
Electronic Publication 相似文献
987.
Groundwater targeting in a hard-rock terrain using fracture-pattern modeling, Niva River basin, Andhra Pradesh, India 总被引:1,自引:0,他引:1
In hard-rock terrain, due to the lack of primary porosity in the bedrock, joints, fault zones, and weathered zones are the
sources for groundwater occurrence and movement. To study the groundwater potential in the hard-rock terrain and drought-prone
area in the Niva River basin, southern Andhra Pradesh state, India, Landsat 5 photographic data were used to prepare an integrated
hydrogeomorphology map. Larsson's integrated deformation model was applied to identify the various fracture systems, to pinpoint
those younger tensile fracture sets that are the main groundwater reservoirs, and to understand the importance of fracture
density in groundwater prospecting. N35°–55°E fractures were identified as tensile and N35°–55°W fractures as both tensile
and shear in the study area. Apparently, these fractures are the youngest open fractures. Wherever N35°–55°E and N35°–55°W
fracture densities are high, weathered-zone thickness is greater, water-table fluctuations are small, and well yields are
high. Groundwater-potential zones were delineated and classified as very good, good to very good, moderate to good, and poor.
Electronic Publication 相似文献
988.
济宁市地下水与地面沉降三维有限元模拟 总被引:1,自引:0,他引:1
在分析济宁市水文地质条件的基础上 ,对引起地面沉降诸因素进行了分析 ,并建立了地面沉降量与地下水位变幅之间的相关关系。集中过量开采地下水是引起济宁市地面沉降的主要原因。在此基础上 ,建立了准三维地下水流模型和一维地面沉降模型。通过水力联系建立地下水与地面沉降耦合数值模型 ,运用有限元法对地下水渗流场和地面沉降量进行模拟 ,并对 2 0 0 0年和 2 0 10年地面沉降进行了预测 相似文献
989.
广西岩溶地下水资源及允许开采量的探讨 总被引:4,自引:2,他引:2
广西岩溶地下水资源十分丰富,前人用枯水迳流模数法计算的地下水允许开采量为148.11亿m3 /a,但该法未能充分考虑广西岩溶区雨季补给量大及地下岩溶储存空间大的特性,使评价结果偏于保守。本文从地下水开发利用的经济、技术及生态的约束性条件出发,并参考已有水源地的有关参数,提出了评估地下水允许开采量的方法,使地下水允许开采量评价结果比前人有了较大的提高。 相似文献
990.