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61.
62.
Pao-Shan?YuEmail author Shien-Tsung?Chen Chia-Jung?Chen Tao-Chang?Yang 《Natural Hazards》2005,34(2):131-150
This study applies the fuzzy multi-objective approach to forecast short-term (around 24 h) typhoon rainfall, which can be implemented without much background meteorological knowledge. The physical characteristics of 40 typhoons, including route, central pressure, central velocity and cyclonic radius, were used as the data set. The fuzzy multi-objective method mined information from the database to forecast both the depth and pattern of rainfall, which were then combined to estimate a cumulative rainfall curve. The results of calibration with reference to 40 historical typhoon events and the results of validation using another five typhoon events indicate that the proposed model has the potential to forecast short-term cumulative rainfall curves if more variables can be included and more historical typhoon events can be collected to enlarge the database. 相似文献
63.
Prospects for forecasting climate variability over the tropical Indian Ocean sector, specifically extreme positive events of the Indian Dipole Mode (IDM), with lead times of a season or more are investigated using the NASA Seasonal-to-Interannual Prediction Project (NSIPP) coupled-model system. The coupled system presents biases in its climatology over the Indian Ocean sector, which include (i) warmest sea-surface temperatures (SSTs) occurring in the central equatorial basin rather than on the eastside with the eastern (western) tropical SSTs up to 1 °C too cool (warm), (ii) a too northwest lying InterTropical Convergence Zonal over the ocean in boreal fall, (iii) a thermocline shallower (deeper) than observed west of Sumatra-Java (north of Madagascar), (iv) a delay of about a month in the onset (cessation) of the southwest (southeast) monsoon in the west (east) in boreal spring (fall). These biases affect the effectiveness of the SST-clouds-shortwave radiation negative feedback, the sensitivity of SST to wind-stress perturbations, and the character of equatorial coupled ocean-atmosphere modes. Despite these biases, ensemble hindcasts of the SST anomalies averaged over the eastern and western poles of the IDM for the decade 1993–2002, which included extreme positive events in 1994 and 1997/1998, are encouragingly good at 3-months lead. The onset of the 1997/1998-event is delayed by about a month, though the peak and decay are correctly timed. At 6-months lead-time, the forecast at the eastern pole deteriorates with either positive or negative false alarms generated each boreal fall. The forecast at the western pole remains good. 相似文献
64.
2011年6—8月T639、ECMWF及日本模式中期预报性能检验 总被引:1,自引:2,他引:1
为更好地应用数值模式中期预报产品,对2011年6—8月T639模式进行天气学检验,并与ECMWF、日本模式进行了对比分析。结果表明:三家模式均对亚洲中高纬环流形势的调整和演变具有较好的预报性能。综合来看,ECMWF模式对大尺度环流形势、影响天气系统及要素的预报最接近实况;日本模式和T639模式稍差,稳定性也不如ECMWF模式。对1109号台风梅花(MUIFA)的路径及强度预报,三家模式的预报效果均不理想,T639模式对"梅花"登陆后的预报与零场较接近,而ECMWF模式及日本模式预报相对较差。 相似文献
65.
利用新疆北疆地区不同草地类型上观测的草地可食产量、环境与遥感资料等,使用3S技术进行了相关分析和遥感估产及预报,建立了地面光学和线性或非线性遥感估产及产量预报模型,在实际估产和产量预测中加以应用、检验,并给出了生态学解释。 相似文献
66.
变形监测信息管理系统的设计与实现 总被引:1,自引:0,他引:1
介绍了GIS数据管理与图形显示的优势、组件技术,设计了变形监测数据管理系统平台,实现了变形监测数据的智能化管理、分析与预测. 相似文献
67.
This paper evaluates the feasibility of using an artificial neural network (ANN) methodology for estimating the groundwater levels in some piezometers placed in an aquifer in north‐western Iran. This aquifer is multilayer and has a high groundwater level in urban areas. Spatiotemporal groundwater level simulation in a multilayer aquifer is regarded as difficult in hydrogeology due to the complexity of the different aquifer materials. In the present research the performance of different neural networks for groundwater level forecasting is examined in order to identify an optimal ANN architecture that can simulate the piezometers water levels. Six different types of network architectures and training algorithms are investigated and compared in terms of model prediction efficiency and accuracy. The results of different experiments show that accurate predictions can be achieved with a standard feedforward neural network trained usung the Levenberg–Marquardt algorithm. The structure and spatial regressions of the ANN parameters (weights and biases) are then used for spatiotemporal model presentation. The efficiency of the spatio‐temporal ANN (STANN) model is compared with two hybrid neural‐geostatistics (NG) and multivariate time series‐geostatistics (TSG) models. It is found in this study that the ANNs provide the most accurate predictions in comparison with the other models. Based on the nonlinear intrinsic ANN approach, the developed STANN model gives acceptable results for the Tabriz multilayer aquifer. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
69.
70.
2008年6-8月T639、ECMWF及日本模式中期预报性能检验 总被引:2,自引:0,他引:2
为更好地应用T639模式中期预报产品,对2008年6-8月T639 模式进行天气学检验,并与ECMWF、日本模式进行了对比分析.结果表明:3种模式均对亚洲中高纬环流形势的调整和演变具有较好的预报性能.综合来看,ECMWF模式对各系统及要素的预报最接近实况;日本模式和T639模式稍差,稳定性不如ECMWF模式;特别是T639模式对0808号台风凤凰(FUNG-WONG)路径及强度的预报与实况差异较大,而ECMWF及日本模式预报相对准确. 相似文献