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991.
地质灾害危险性评价研究——以四川省青川县为例 总被引:3,自引:0,他引:3
我国是一个地质灾害多发的国家。20世纪90年中期,每年造成1000多人死亡,经济损失高达200多亿元。地质灾害危险性评价是地质灾害调查的重要内容,也是风险管理及减灾管理的基础,它为管理部门制定出相应的减灾对策并为部署实施有效的减灾工程提供了科学依据。文章首先介绍了国内外地质灾害危险性评价方法的研究现状,通过对比,指出现阶段我国地质灾害危险性评价中的不足;结合实际工作经验,运用危险性评价指标对比法建立了简单有效的地质灾害危险性评价体系。以四川省青川县地质灾害调查为例,对该县地质灾害进行了危险性评价,为地质灾害易发区划分及防治分区提供了依据。 相似文献
992.
Miguel A. Snchez Alberto Foyo Carmen Tomillo Eneko Iriarte 《Engineering Geology》2007,94(3-4):180-200
Altamira Cave occurs in a carbonate sequence-dated as middle to upper Cenomanian, being characterized by tabular bedding. This sequence has been studied in detail and mapped in an attempt to delimit the beds in which the cave was formed. The cave forms part of a karstic complex developed in the Altamira Formation, which consists of eight stratigraphic units characterized by karstic forms and landslides as the main geomorphologic elements. The strong relationship between sinkholes and faults within the area was also revealed, with sinkholes of oval morphology aligned along the faults. Inside the cave, the subhorizontal bedding is intersected by subvertical joints, generating geometrical blocks prone to falling down. This is the main process of the present evolution of the cave in addition to the dissolution and precipitation of carbonates in local zones. We used this geological characterization as the basis for the definition of protection areas around prehistoric caves, applied in this article to the Altamira Cave. Landslides, water flow towards the cave, rock falls within cave and karstic features are the main geological risks affecting the karstic complex. Two semi-quantitative indexes were proposed, the Natural Risk Index (NRI) and Safety Factor (SF), with the main aim of determining the risk level in different zones of the study area. The information provided by geological studies as well as the results obtained using the proposed indexes allowed definition suitable protection areas around the cave. 相似文献
993.
Christian D. Klose 《Natural Hazards》2007,43(3):303-317
Since the last eruption of the Fossa crater in 1888–1890, intense volcanic degassing has been remaining on Vulcano Island
of Sicily (Italy). Toxic sulfur dioxide (SO2) of the solfataric action in this area represents, when inhaled, a permanent natural hazard harming humans. Approximately
500 permanent residents live and 15,000 tourists visit during the summer time the Porto village in the North of Vulcano Island.
A cross-disciplinary fuzzy logic risk assessment has been conducted to evaluate health risks of human individuals exposed
to higher SO2-concentrations C over certain exposure times t. The simple approach, based on fuzzy set theory, explains health risks semantically by words rather than by numbers. Advantages
of this approach are, first, experts, non-experts, decision makers, or the public are able to understand and communicate risk
degrees by words without using numbers. Second, in comparison to other risk definitions, the risk is not equal to the vulnerability;
it is based on the hazard (SO2-gas clouds) and vulnerability (health effects) in combination. Third, risk levels can be still estimated even when limited
or no statistical information is available, e.g., high SO2-concentrations or long exposure times. Moreover, human health risks were determined for C−t-scenarios based on threshold values of the European Union and the World Health Organization. Independently, two additional
methods were used to determine the proportions of the population who are exposed to levels of SO2 at which health effects may be expected and also safety zones for civil protection around the degassing fields. In conclusion,
SO2-gas concentrations in many parts of Vulcano Island go beyond the proclaimed alert threshold of the European Union and the
World Health Organization. For example, the results show that sensitive individuals, such as asthmatics, young children, or
elderly people, should not be exposed at any time to the degassing areas in Porto di Levante and at the NE-rim of the Fossa
crater. In contrast, healthy non-sensitive individuals should be exposed less than 10 min to the SO2-clouds at these degassing areas, while hiking on the crater rim. 相似文献
994.
Rock Wedge Stability Analysis Using System Reliability Methods 总被引:5,自引:1,他引:5
Summary We present a system reliability approach to rock wedge stability analysis. Different failure modes are considered, and a disjoint
cut-set formulation is employed – with each cut-set corresponding to a different failure mode – to explore the system aspects
of the problem, so that the reliability of the system is assessed by computing the probability of failure of the slope under
each failure mode. An example case is used to demonstrate different approaches to compute the reliability of the slope design.
Our results show that an approximation to the “exact” probability of failure – given by Monte Carlo simulation results – may
be obtained using a first order approximation to the failure domain, and that linear programming techniques may be used to
obtain bounds of the probability of failure. Furthermore, we identify the most likely failure mode, and we explore the sensitivity
of the computed probabilities to changes in the random variables considered. The results indicate that the reliability results
are quite sensitive to the geometry of the wedge. Changes in water conditions are also found to have a significant impact
on the computed probabilities, while changes in unit weight of the rock have a considerably smaller effect on the reliability. 相似文献
995.
介绍了大庆油田工程有限公司在管道完整性管理信息化系统建设方面的成果,重点介绍3维GIS技术在完整性管理中的应用,以3维GIS作为工具进行工程地质灾害风险分析与预测的实现方法。 相似文献
996.
Estimating the confidence of earthquake damage scenarios: examples from a logic tree approach 总被引:1,自引:0,他引:1
Earthquake loss estimation is now becoming an important tool in mitigation planning, where the loss modeling usually is based
on a parameterized mathematical representation of the damage problem. In parallel with the development and improvement of
such models, the question of sensitivity to parameters that carry uncertainties becomes increasingly important. We have to
this end applied the capacity spectrum method (CSM) as described in FEMA HAZUS-MH. Multi-hazard Loss Estimation Methodology, Earthquake Model, Advanced Engineering Building Module. Federal Emergency Management Agency, United States (2003), and investigated the effects of selected parameters. The results demonstrate that loss scenarios may easily vary by as
much as a factor of two because of simple parameter variations. Of particular importance for the uncertainty is the construction quality of the structure. These results represent a warning against simple acceptance of unbounded damage scenarios and strongly
support the development of computational methods in which parameter uncertainties are propagated through the computations
to facilitate confidence bounds for the damage scenarios. 相似文献
997.
Advances in sensor techniques, digital acquisition, communication and computing allowed establishment of the field of real-time
seismology (Kanamori et al., 1997) and the design of earthquake information systems that provide rapid information on ground motion and potential damage
in an area for which a ground motion estimation data base is available and where the inventory of buildings and infrastructure
and its vulnerability to shaking is known. We discuss a system for the Romanian capital of Bucharest, where an early warning
system with about 30 seconds lead time, shake maps and a sophisticated damage estimation tool for Bucharest have been developed
in the frame of the Collaborative Research Center on Strong Earthquakes (). 相似文献
998.
Communicating human health risks associated with disinfection by-products in drinking water supplies: a fuzzy-based approach 总被引:1,自引:2,他引:1
Rehan Sadiq Manuel J. Rodriguez Syed A. Imran Homayoun Najjaran 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(4):341-353
Chlorine used for the disinfection of water supplies can react with naturally occurring organic compounds and form potentially
harmful disinfection by-products (DBPs). A risk index for two regulated groups of chlorinated DBPs—trihalomethanes (THMs)
and haloacetic acids (HAAs), using fuzzy C-means (FCM) clustering algorithm and fuzzy rule-based modeling is proposed for risk communication. The proposed index evaluates
the cancer and non-cancer risks individually for THMs and HAAs using the FCM algorithm. Subsequently, two different fuzzy
rule-bases were used to evaluate the overall risk-index based on cancer and non-cancer risks. The overall risk-index will
provide drinking water utilities with an effective communication tool for communicating aggregated water quality compliance.
Simulated DBP occurrence data obtained from the City of Quebec, Canada, is used to demonstrate the application of this methodology. 相似文献
999.
根据靖江王城古建筑物的特点、分布情况及所处的地理环境特征,结合雷击风险评估结果,对不同的保护物划分防雷类别,提出了雷电保护方案。 相似文献
1000.
A probabilistic model is presented to obtain a realistic estimate of earthquake insurance rates for reinforced concrete buildings in Turkey. The model integrates information on seismic hazard and information on expected earthquake damage on engineering facilities in a systematic way, yielding to estimates of earthquake insurance premiums. In order to demonstrate the application of the proposed probabilistic method, earthquake insurance rates are computed for reinforced concrete buildings constructed in five cities located in different seismic zones of Turkey. The resulting rates are compared with the rates currently charged by the insurance companies. The earthquake insurance rates are observed to be sensitive to the assumptions on seismic hazard and damage probability matrices and to increase significantly with increasing violation of the code requirements. 相似文献