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101.
一次较成功的中期地震概率预测实例 总被引:1,自引:0,他引:1
1988年底依据地震活动性资料,运用MYCIN不精确推理方法,提出了1989年及稍长时间的中国大陆中期地震趋势预测概率图,这是一次较成功的中期地震概率预测实例。 相似文献
102.
通过对山西境内地震序列的分析计算,得出一个适合山西地区地震活动的概率模型。并以此模型对1989年前后的地震活动进行了计算,给出1989年以来山西地震频繁活动的理论依据,对今后的地震活动进行了预测。 相似文献
103.
Vindell Hsu Charles E. Helsley Eduard Berg David A. Novelo-Casanova 《Pure and Applied Geophysics》1984,122(6):878-893
A close correlation in spatial distribution of local seismic activity and energy release patterns before and after the 1979 Petatlan, Mexico earthquake suggests heterogeneity within the fault plane of this major low-angle thrust event associated with subduction along the Middle America Trench. A simple two-asperity model is proposed to account for the complexity. Foreshocks and aftershocks of the neighboring 1981 Playa Azul earthquake showed a similar pattern. As both events occurred at the junction of the Orozco Fracture Zone and the Middle America Trench, we speculate that the observed complex fault plane is caused by subduction of the rugged ocean floor of the Orozco Fracture Zone. Short-term precursory seismicity prior to the Petatlan earthquake can be explained by using the asperity model and migration of a slip front from the south-east to the north-west across the main shock source region. 相似文献
104.
S. J. Gibowicz 《Pure and Applied Geophysics》1986,124(4-5):611-658
This review was prepared as an opening lecture for the International Symposium on Physics of Fracturing and Seismic Energy Release, held at the Castle of Liblice near Prague from October 28 to November 1, 1985, and organized by the Geophysical Institute of the Czechoslovak Academy of Sciences. The review attempts to classify and synthesize results of recent studies in fracture mechanics and earthquake source physics. The following topics are discussed: recent developments in fracture mechanics, earthquake source modeling, heterogeneous fault planes, foreshocks and aftershocks, faults and fractals, and moment tensor solutions. This rather broad range of topics prevents presentation of a complete list of all relevant works, though over one hundred and seventy references are cited. 相似文献
105.
本文叙述了地震活动的综合概率预报方法,并对宁夏及青海地区(35°00’-41°00’N,100°00’-107°40’E)1970年以来的地震活动资料进行了统计计算,对1992年-1993年该区地震活动进行了综合预报效能检验。并据此对该区1994年-1995年的地震趋势做了估计。 相似文献
106.
中国大陆原地复发强震的基本特征及其预测 总被引:7,自引:3,他引:7
在印度板块与欧亚块相碰撞形成的喜马拉雅弧板块边界力作用下,中国大陆有自己独特的现代构造运动和地震活动基本格架。格架是两组近似于对数螺线的现代构造滑移线,即最大剪切应力和剪切应变集中释放的区,带。在这种格架控制下,强震和大震在原地或基本在原地重复发生是中国大陆地震活动的重要特征。本文还提出了i-f-j复发轮回模式和估计当前轮回强震复发时间的概率分布以及计算未来强震复发概率分式。为中,长期预测原地复发 相似文献
107.
本文根据极值理论建立了烈度超越给定值Ij的平均重现期公式,根据最大熵原理建立了未来T年烈度超越给定值Ij的概率和烈度超越给定值Ij的平均重现期之间的关系式。利用1022─1993年的地震资料,计算了临汾(36.10°N,111.50°E)周围4级以上地震在临汾造成的烈度,绘制了未来100年临汾的烈度超越概率曲线(地震危险性曲线)。结果表明,计算场地烈度的极值理论方法可作为地震危险性分析的综合概率法的补充和验证。 相似文献
108.
A Preliminary Study on the Probabilistic Estimation of Deaths from Future Earthquakes in North China
During the period from 1800 to 1989,the degree of fatalities(?from earthquakes in North China(Lat.34.0°-42.0°N,Long.107.5°-125.0°E)varied exponentially with the frequency of earthquake events(N),namely:N=37.71 exp(-0.72?(E-logD,D:deaths).For the periods from 1988 to 1998 and from 1999 to 2009,the probabilities for earthquakes to cause one thousand or more deaths in North China are estimated to be 0.37 and 0.50,respectively,by using the Gumbel's extreme value theory. 相似文献
109.
Our results illustrate the performance of at-site and regional GEV/PWM flood quantile estimators in regions with different coefficients of variation, degrees of regional heterogeneity, record lengths, and number of sites. Analytic approximations of bias and variance are employed. For realistic GEV distributions and short records, the index-flood quantile estimator performs better than a 2-parameter GEV/PWM quantile estimator with a regional shape parameter, or a 3-parameter at-site GEV/PWM quantile estimator, in both humid and especially in arid regions, as long as the degree of regional heterogeneity is moderate. As regional heterogeneity or record lengths increases, 2-parameter estimators quickly dominate. Flood frequency models that assign probabilities larger than 2% to negative flows are unrealistic; experiments employing such distributions provide questionable results. This appraisal generally demonstrates the value of regionalizing estimators of the shape of a flood distribution, and sometimes the coefficient of variation. 相似文献
110.
Herak Marijan Herak Davorka Markušić Snježana Ivančić Ines 《Studia Geophysica et Geodaetica》2001,45(3):251-266
The rate of aftershock occurrence after the M6 Ston-Slano (Croatia) earthquake is modeled as the Epidemic Type Aftershock Sequence (ETAS). Increase of the modeled cumulative number of aftershocks with time was fitted to observations by the least-squares criterion using the combined grid-search and Monte-Carlo approach. This enabled not only the estimation of the most probable ETAS parameters, but also the determination of their confidence limits, as well as the estimation of the bias between them. It has been found that the bias is significant for some of the parameter pairs, regardless of the threshold magnitude assumed. Residual analyses revealed that all strong aftershocks (M
L
4.5) occurred during the periods of normal to high aftershock activity. There were two periods of quiescence in the sequence, both of which were followed by a strong aftershock. 相似文献