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201.
利用Shamway和Der的多道最大或然性反褶积原理,讨论了从单台三分量远震P波波形中分离接收函数径向与垂向分量复谱比的方法.根据Tarantola的波形反演理论发展了接收函数复谱比的非线性反演方法.本文的反演方法除了拟合接收函数的复谱比之外,还需拟合时间域中接收函数垂向与径向分量的初至振幅比.合成波形数据反演的结果表明本文方法的反演结果不依赖初始模型.利用该方法和CDSN台网兰州台记录的宽频带远震P波波形数据,研究了该台站的接收函数及其随方位角的变化.接收函数复谱比非线性反演给出了该台站下方140km深度岩石层的S波速度结构,得到兰州台下方地壳厚度为54ks,岩石层厚度为94km. 相似文献
202.
本文在证明场址的地震影响烈度的频次与相应的烈度值星对数线性关系的基础上,利用最大似然法,以山西南部(35.5°~38°N,111°~113°E)和四川西部(26°~29°N,101°~103°E)为例,求出各场址的β,λ和Imax,得出各场址的烈度危险性分析曲线,并用“逻辑树”方法对各场址的危险性结果进行不确定校正,由此得到二区域的烈度区划图。结果表明,这种方法是可行的,尤其是针对呈现过烈度异常的区域,本方法的结果更能显示其特殊性。 相似文献
203.
应用混合极值理论及最大似然法估计东南沿海各地震区的地震危险性 总被引:1,自引:0,他引:1
将东南沿海地区划分为7个地震区带,利用历史及现代地震资料,动用混合极值理论及最大似然法分析了各个地震区带的地震危险性,并采用预测检验的方法确定了各个地震区带的危险阈值,对各地震区未来两年的中小地震及未来5年的中强地震的危险性分别给出了定量估计。 相似文献
204.
Daniel Rabinowitz 《Mathematical Geology》1991,23(2):257-274
Inference about deposits left to be discovered in a partially explored oil field that require only assumptions about the randomness in the exploration procedure are considered. Unbiased estimators, estimators based on partial likelihood methods and confidence procedures are proposed. 相似文献
205.
Cluster models for earthquakes: Regional comparisons 总被引:2,自引:0,他引:2
L. Adamopoulos 《Mathematical Geology》1976,8(4):463-475
Four clustering models are fitted by means of a spectral-likelihoodmethod to series of earthquakes in each of 14 seismic regions. It is concluded that from these models only the Neymann—Scott process, containing both short- and long-term components, is satisfactory for all regions. By inspecting the parameters of this model the consistency of results between regions of similar geological type is studied and the characteristics of different types of region are compared. 相似文献
206.
The paper deals with the probability estimates of temperature extremes (annual temperature maxima and heat waves) in the Czech Republic. Two statistical methods of probability estimations are compared; one based on the stochastic modelling of time series of the daily maximum temperature (TMAX) using the first-order autoregressive (AR(1)) model, the other consisting in fitting the extreme value distribution to the sample of annual temperature peaks.The AR(1) model is able to reproduce the main characteristics of heat waves, though the estimated probabilities should be treated as upper limits because of deficiencies in simulating the temperature variability inherent to the AR(1) model. Theoretical extreme value distributions do not yield good results when applied to maximum annual lengths of heat waves and periods of tropical days (TMAX 30°C), but it is the best method for estimating the probability and recurrence time of annual one-day temperature extremes. However, there are some difficulties in the application: the use of the two-parameter Gumbel distribution and the three-parameter generalized extreme value (GEV) distribution may lead to different results, particularly for long return periods. The resulting values also depend on the chosen procedure of parameter estimation. Based on our findings, the shape parameter testing for the GEV distribution and the L moments technique for parameter estimation may be recommended.The application of the appropriate statistical tools indicates that the heat wave and particularly the long period of consecutive tropical days in 1994 were probably a more rare event than the record-breaking temperatures in July 1983 exceeding 40°C. An improvement of the probability estimate of the 1994 heat wave may be expected from a more sophisticated model of the temperature series. 相似文献
207.
利用极大似然反褶积提取鲁棒性地震子波的方法进行了研究,并讨论了极大似然反褶积的稳健性。理论分析表明,在理想条件下极大似然反褶积是无偏估计,而且还是一致估计,这一结论可以由所提取的地震子波得到验证。实际地震资料的处理结果分析表明,极大似然反褶积具有很好的稳健性。应当指出,为保证地震子波的鲁棒性,极大似然反褶积子渡时窗应尽量满足统计条件,以提高极大似然反褶积的稳健性。 相似文献
208.
GUAN Shuwei WANG Xin YANG Shufeng HE Dengfa & ZHAO Weidong . Research Institute of Petroleum Exploration Development Beijing China . Department of Geosciences Zhejiang University Hangzhou China . Tarim Oilfield Company Korla China 《中国科学D辑(英文版)》2005,48(7)
The concept of displacement transfer[1] was initially utilized by Dahlstrom (1970) to explain the relation- ships of overlapping thrusts in the Canadian Rockies wherein the displacement on one thrust is transferred to another, but the total displacement is still held con- stant along trend. Displacement transfer, which may exist in compressional[2] as well as tensile environ-ments[3], is a familiar kinematic mechanism that keeps the magnitude of deformation steady along trend in the linear str… 相似文献
209.
210.
T. N. Kaseke M. E. Thompson 《Stochastic Environmental Research and Risk Assessment (SERRA)》1997,11(1):1-16
Abstract: Linear continuous time stochastic Nash cascade conceptual models for runoff are developed. The runoff is modeled
as a simple system of linear stochastic differential equations driven by white Gaussian and marked point process noises. In
the case of d reservoirs, the outputs of these reservoirs form a d dimensional vector Markov process, of which only the dth
coordinate process is observed, usually at a discrete sample of time points. The dth coordinate process is not Markovian.
Thus runoff is a partially observed Markov process if it is modeled using the stochastic Nash cascade model. We consider how
to estimate the parameters in such models. In principle, maximum likelihood estimation for the complete process parameters
can be carried out directly or through some form of the EM (estimation and maximization) algorithm or variation thereof, applied
to the observed process data. In this research we consider a direct approximate likelihood approach and a filtering approach
to an algorithm of EM type, as developed in Thompson and Kaseke (1994). These two methods are applied to some real life runoff
data from a catchment in Wales, England. We also consider a special case of the martingale estimating function approach on
the runoff model in the presence of rainfall. Finally, some simulations of the runoff process are given based on the estimated
parameters. 相似文献