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991.
Karst aquifers represent one of the main sources of water supply in Serbia. Wide distributions of karstic areas, abundant
reserves, and excellent quality of karst groundwater have been the reasons for its extensive use in water supply systems throughout
the country. In Serbia, 70 karstic sources have been tapped for centralized water supply, with the assessed minimal capacity
exceeding 4.5 m3/s. Most of the large cities of Eastern and Western Serbia currently use karst groundwater for water supply; however, due
to unstable flow regime when only natural springflow is tapped, numerous problems arise during the recession period (summer–autumn).
During the last two decades, after favorable conditions had been confirmed through hydrogeological survey and feasibility
studies, several newly constructed systems for artificial control of karst aquifers (mostly in Eastern Serbia) resulted in
significantly improved water supply. 相似文献
992.
993.
《煤矿床水文地质、工程地质及环境地质勘查评价标准》和《煤矿防治水规定》中各给出了一个突水系数计算公式,分别称为公式(1)和公式(2)。比较发现,两个计算公式在参数的选择、规定的正常块段的l临界突水系数、安全系数、使用的方便程度4方面是不同的,并逐一进行了分析。然后以山西省临县新民煤矿1井田9号煤层的开采为例,进行了突水系数的计算。结果表明,采用公式(1)计算出的突水系数大于采用公式(2)计算出的突水系数;采用公式(1)计算,井田范围内9号煤开采全部处在带压开采临界区内;采用公式(2)计算,井田南部有一部分范围9号煤开采处在带压开采安全区内,井田北部大部分范围9号煤开采处在带压开采临界区内。最后指出.在计算突水系数时,水文地质条件简单、含水层富水性较弱、补给条件差的矿区,选择公式(1);水文地质条件复杂、含水层富水性较强、补给条件好的矿区.可以选择公式(2)。 相似文献
994.
995.
This paper proposed a series of simple equations to calculate the head difference at the two sides of waterproof curtain. The barrier effect of waterproof curtain is considered from two situations with respect to without barrier case: (i) groundwater head difference below the barrier and (ii) groundwater head difference by convergence into the opening. The solution for the first situation can be derived from hydraulic analyses and the second situation can be obtained using a numerical analysis. The final groundwater head difference is the sum of these two situation according to the superposition principal. In the proposed equations, the head difference is expressed as a function of the inserted depth of the barrier into confined aquifer, the ratio of the hydraulic conductivity of the aquifer, the thickness of the aquifer, and hydraulic gradient under normal conditions. Finally, the proposed equation was applied to a field case to verify the validity of the proposed approach. Compared with the field data, the results show that the proposed method is reasonable. 相似文献
996.
地下流体的抽取所引起的地面沉降的预测依赖于所选理论模型中参数的量化。本文所建立的逆问题模型中涉及到压缩承压含水系统中5个控制地面沉降的参数:压缩弱透水层的垂向水力传导系数K'、塑性贮水率S'skv和弹性贮水率S'ske、含水层的贮水率S'S和弱透水层的前期最大固结压力p'max0。逆问题模型由Newton-Raphson调整算法和Helm有限差分一维固结模型构成(COMPAC),其中固结模型可用其他模型替代。文中用一个理想压缩承压含水系统对该逆问题模型进行检验,检验结果显示该模型能求解出理想压缩承压含水系统的K'、S'skv、S'ske、S'S和p'max0的近似值,其中p'max0和S'skv是控制计算沉降量的两个最主要的参数。每个监测点计算压缩量的平均相对误差为7.8%,该误差仅由调整算法产生。该逆问题模型应用于上海F9地面沉降监测点上部承压含水系统参数的求解和变形量的预测,所求解出的K'、S'skv、S'ske、S'S和p'max0的近似值分别为8.58×10-4 m/a、3.50×10-4 1/m、6.39×10-6 1/m、1.19×10-5 1/m和-2.50m、每个观测点计算压缩量的平均相对误差为13.7%。误差的来源除了调整算法外,还包括地下水位、压缩变形的观测误差以及模型概化所产生的误差。 相似文献
997.
The Direct Current resistivity method was applied to the consolidated coastal Plioquaternary aquifer of Mamora plain, located on the Atlantic coast of Morocco. The aim is to determine the depth of the base of the saturated zone in the aquifer and to help in imaging lateral and vertical distribution of groundwater salinity. The geoelectric survey showed four geoelectric formations with the following electrical resistivities from top to bottom: 20–80, 200–2000, 200–300 and 5–70 Ohm m. The latter designates the basement of the aquifer constituted of marls and sandy marls. The mean resistivity of 250 Ohm m designates the aquifer formation. It decreases to less than 25% of its initial values for the soundings near the shore, reflecting the oceanic impact on the aquifer formation resistivity. The contour map shows that the basement of the saturated zone in the aquifer is deeper in the Northwest near the Sebou River estuary with values up to 70 m below sea level. This results in a larger thickness of the saturated zone of the aquifer leading to a consequent hydraulic potential. On the other hand, it has been deduced that the extent of marine intrusion inside the continent can be governed by human activities, natural properties and substratum geometry of the aquifer as well as by ecological factors. An optimal network of electrical soundings has been proposed for the monitoring of saltwater intrusion. 相似文献
998.
阜新盆地东梁区地热资源赋存条件分析 总被引:6,自引:0,他引:6
根据东梁区DR-1与DR-2地热井及以往地质资料,对控制本区地热资源的赋存条件(热储层、控热构造及盖层)作了研究后认为,该区的地热资源主要受控于热储构造、热储层裂隙的发育程度和盖层条件,而热储层裂隙的发育程度及与含水层的水力联系,又决定了本区地下热水的开发潜能。 相似文献
999.
本文通过对太行山前平原地下调蓄的水文地质及水文条件、库容评价原则与方法和类型的分析,阐明了其地下调蓄能力及可利用性,给出了综合评价结果:石景山-大兴靶区、石家庄-晋县靶区和邢台靶区可作为南水北调地下调蓄首选目标,房山-容城靶区、望都 - 定县-新乐靶区和磁县-安阳靶区可作为南水北调地下调蓄的主要备选场所,邯郸靶区和辉县-新乡靶区适宜作为井灌小型地下调蓄场所. 相似文献
1000.
Colloids are known to transport contaminants over long distances in natural media. Despite this potentially harmful effect,
very few studies have been undertaken in subsurface aquifers. This paper presents the first results of a study of natural
colloids and particles in a karstic aquifer. The site was chosen for its coverage by clay layers and peat which deliver various
and numerous particle types in water. The methodological part describes three methods used for size determination and sample
fractionation of surface water and spring water. These methods have been adapted for the treatment of multiple samples due
to the rapid discharge variation typical of karstic aquifers. The analysis of many particle size distributions (PSD) shows
that they can be described by a Pareto law. The variation of the slope of the PSD at the spring is mainly dependent on discharge.
This behavior is interpreted as a washing of the karstic drains during the first phase of high flow events. Fractionation
of the samples allowed application of various characterization techniques to particle size classes. X-ray diffraction (XRD)
patterns showed that most of the mineral particles originated from Quaternary deposits and limestones. However the use of
scanning electron micrsocopy with energy-dispersive spectrometer (SEM-EDS) detailed the composition of individual particles
and revealed particles not found by XRD. These techniques also showed the high complexity of the natural particles and the
important place of coprecipitation in their formation. Consequences on the fluxes of particulate matter and its potential
role as a carrier of contaminants are discussed.
Received: 28 October 1996 · Accepted: 7 July 1997 相似文献