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排序方式: 共有345条查询结果,搜索用时 31 毫秒
81.
台湾集集和华北大同地震序列的定量模型分析 总被引:4,自引:0,他引:4
介绍了传染型余震序列(ETAS)模型的基本原理和发展概况,并利用该模型分析了1999年开始的台湾集集地震序列(主震Ms7.6)和1989年开始的大同地震序列(主震为Ms5.7)。通过分析计算,得到了二个序列的ETAS参数向量,并结合各自的孕震环境和机制分析了二个地震序列的异同和序列衰减规律。 相似文献
82.
Hans-Dieter Vosteen Volker Rath Andreas Schmidt-Mumm Christoph Clauser 《Tectonophysics》2004,386(1-2):81-95
The thermal regime and the distribution of heat flow at the base of sedimentary basins is fundamental to the understanding of the process of basin evolution and the associated mobilization and migration of hydrocarbon and other fluids. For the Northeastern-German sedimentary basin, available information on structure, temperature, and thermal properties along a seismic DEKORP reflection profile allow high resolution 2-D forward and inverse simulations. This approach is attractive in situations where much information is available, if only with considerable uncertainty. In particular, this allows to introduce “soft” information into the analysis. In our case, forward simulations yield initial a priori estimates of the parameters while inversion calculations yield a posteriori estimates of the parameters and their uncertainty. The a priori parameters as well as their assumed uncertainty are input for a Bayesian parameter estimation scheme. In respect to the Northeastern-German sedimentary basin, the inverse analysis postulates a significant and characteristic a posteriori variation of thermal conductivity of the Zechstein unit along the entire profile as well as a generally large a posteriori thermal conductivity of the (pre-Permian) basement in the northern part of the basin. For inverse calculations, we used two alternative scenarios: One assumes the thermal conductivity of the Zechstein unit to be homogeneous along the profile while the other allows a lateral variation. A posteriori heat flow across the base of the model varies from 40 to 60 and 50 to 65 mW m−2 for models in which values for thermal conductivity and radiogenic heat generation rate were either based on literature values or direct measurements, respectively. 相似文献
83.
Including prior information in the estimation of effective soil parameters in unsaturated zone modelling 总被引:2,自引:0,他引:2
In this paper we propose a methodology to include prior information in the estimation of effective soil parameters for modelling the soil moisture content in the unsaturated zone. Laboratory measurements on undisturbed soil cores were used to estimate the moisture retention curve and hydraulic conductivity curve parameters. The soil moisture content was measured at 25 locations along three transects and at three different depths (surface, 30 and 60 cm) on an 80×20 m hillslope for the year 2001. Soil cores were collected in 84 locations situated in three profile pits along the hillslope. For the estimation of the effective soil hydraulic parameters the joint probability distribution of measured parameter values was used as prior information. A two-horizon single column 1D MIKE SHE model based on Richards' equation was set-up for nine soil moisture measurement locations along the middle transect of the hillslope. The goal of the model is to simulate the soil moisture profile at each location. The shuffled complex evolution (SCE) algorithm has been applied to estimate effective model parameters using either wide parameter ranges, referred to as the ‘no-prior’ case, or the joint probability distribution of measured parameter values as prior information (‘prior’ case). When the prior information is incorporated in the SCE optimisation the goodness-of-fit of the model predictions is only slightly worse compared to when no-prior information is incorporated. However, the effective parameter estimates are more realistic when the prior information is incorporated. For both the no-prior and prior case the generalised likelihood uncertainty estimation procedure (GLUE) was subsequently used to estimate the uncertainty bounds (UB) on the model predictions. When incorporating the prior information more parameter sets were accepted for the estimation of the predictive uncertainty and the parameter values were more realistic. Moreover, UB better enclosed the observations. Thus, incorporating prior information in GLUE reduces the amount of model evaluations needed to obtain sufficient behavioural parameter sets. The results indicate the importance of prior information in the SCE and GLUE parameter estimation strategies. 相似文献
84.
G.R. Dargahi-Noubary 《Soil Dynamics and Earthquake Engineering》1998,17(5):297-309
A statistical method is proposed for estimation of the corner frequency. It is based on inference for a stochastic model whose short-term behavior resembles the established source time functions. Properties of the estimates are investigated and some numerical examples are presented. A discussion concerning earthquake–explosion discrimination and the way corner frequency can be related to the rate of zero-crossings is also included. The paper is concluded with some numerical examples. 相似文献
85.
山东蓝宝石中包裹体的研究 总被引:4,自引:1,他引:4
山东蓝宝石中含有不同类型的包裹体,其中固态包裹体主要有镁铁尖晶石、普通辉石、钾长石、铌铁金红石和磁铁矿等。山东蓝宝石以及大部分固态包裹体中皆含有稀有元素铌或钽。 相似文献
86.
证明了主成分估计实质上是附着条件的参数平差,并根据此性质结合算例分析了主成分估计的局限性,提出了改进方法。 相似文献
87.
渭北中部奥陶系岩溶水资源合理开发和利用探讨 总被引:1,自引:0,他引:1
陕西省渭北中部奥灰岩溶水资源丰富,但由于岩溶水资源分布不均,因而存在着从宏观角度规划水资源与合理开发利用的问题。据最新野外调查资料,就目前岩溶水的开发利用现状、潜力及存在的问题进行了分析与探讨,并提出了相应的解决对策,对本地区国民经济的持续稳定发展具有一定的借鉴意义。 相似文献
88.
西昆仑—塔里木—天山岩石圈深地震探测综述 总被引:40,自引:6,他引:40
沿新疆地学断面走廊域实施了3种深地震探测方法:近垂直深地震反射剖面、宽角反射与折射深地震测深剖面和移动式宽频地震观测,揭露出西屁仑-塔里木-天山岩石圈的结构与横向变化,发现了塔里木大陆地块与青藏高原西北部西昆仑造山带碰撞的地震学证据,揭示出天山与塔里木、天山与准噶尔,以及昆仑山与塔里木之间的岩石圈尺度盆山耦合关系。阶段成果发表后引起国内外学者广泛注意,本文结合相关资料对这些新成果进行了系统综述,旨在对比研究青藏高原南北两缘不同的碰撞变形之深部过程。 相似文献
89.
90.
Tight oil siltstones are rocks with complex structure at pore scale and are characterized by low porosity and low permeability at macroscale. The production of tight oil siltstone reservoirs can be increased by hydraulic fracturing. For optimal fracking results, it is desirable to map the ability to fracture based on seismic data prior to fracturing. Brittleness is currently thought to be a key parameter for evaluating the ability to fracture. To link seismic information to the brittleness distribution, a rock physics model is required. Currently, there exists no commonly accepted rock physics model for tight oil siltstones. Based on the observed correlation between porosity and mineral composition and known microstructure of tight oil siltstone in Daqing oilfield of Songliao basin, we develop a rock physics model by combining the Voigt–Reuss–Hill average, self-consistent approximation and differential effective medium theory. This rock physics model allows us to explore the dependence of the brittleness on porosity, mineral composition, microcrack volume fraction and microcrack aspect ratio. The results show that, as quartz content increases and feldspar content decreases, Young's modulus tends to increase and Poisson ratio decreases. This is taken as a signature of higher brittleness. Using well log data and seismic inversion results, we demonstrate the versatility of the rock physics template for brittleness prediction. 相似文献