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51.
53.
Natural Hazards - Tsunamis occur not only in marine settings but also in lacustrine environments. Most of the lacustrine tsunamis are caused by seismically- or aseismically-triggered mass... 相似文献
54.
西南区域中尺度数值模式预报性能及其与天气过程关系初探 总被引:2,自引:1,他引:1
本文以探空站和自动站实测资料为检验参考,通过主客观检验GRAPES和WRF模式在西南地区的初始分析场和预报场,一定程度揭示出模式在西南地区的初值质量、动力框架性能和降水参数化效果。GRAPES在西南地区的位势高度、风速、风向初值质量都不同程度好于WRF,但进入预报阶段,GRAPES位势高度、温度均方根误差以比WRF更高的斜率随时效增长,GRAPES对西南地区的500 hPa高度场预报呈现系统性偏低,而WRF对西南地区高度预报的正误差概率比较高;分类天气过程检验表明,GRAPES对低涡、切变过程的初始分析质量好于WRF,但进入预报阶段,WRF对低槽、低涡和切变三类天气过程的低值系统预报正确率都高于GRAPES,这一定程度反映出WRF的模式性能好于GRAPES;分类天气过程降水预报检验表明,低涡过程降水预报难于低槽过程。GRAPES对低涡过程的降水预报能力较低,WRF预报能力最低的是切变过程。这与模式对分类天气过程中低值系统预报能力一致,这一定程度表明两个模式的降水参数化效果水平相当。 相似文献
55.
A comparison has been made between the predictions of the theory for radial variations of both Alfvénic fluctuations and solar wind proton temperatures proposed by Tu (1987, 1988) and the statistical results of hourly averaged plasma and magnetic field data observed by Helios 1 and 2 from launch through 1980 for different solar wind speed regimes. The comparison shows that for speed ranges between 500–800 km s-1, the radial variation of the proton temperature between 0.3 and 1 AU can be explained by heating from the cascade energy determined by the radial variation of the total variance of magnetic field vector. The explanation of the radial variations of both temperature and the total variance of magnetic fields for speed ranges less than 400 km s -1 is less clear.This project was supported by National Natural Science Foundation of China for Tu's part of the work. 相似文献
56.
通过对龙永煤田童子岩组煤系顶部鲕状带"鲕粒"赋存规律及其矿物学特征、宏观特征、围岩特征的野外研究及镜下观察,分析了"鲕粒"的成因及其岩相意义,为龙永煤田童子岩组顶部地层提供了对比依据. 相似文献
57.
Formation of an Interactive User-Oriented Forecasting System: Experience from Hydrological Application in Linyi, Eastern China 总被引:1,自引:0,他引:1
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YAN Zhongwei HAN Jiarui JIAO Meiyan CHEN Jing YE Qian ZHAO Linn TU Kai 《Acta Meteorologica Sinica》2012,26(1):13-25
Having provided an overview of the ideas of developing user-oriented interactive forecast system (UIFS) emerging in recent years,the authors proposed an idealized framework of the new-generation meteorological system,which includes the initial user-end module for configuring the forecast target,the physical predictive and downscaling components,and an incessant assessing module in association with decision-making at the user-end.A case study was carried out with a focus on applying the TIGGE (THORPEX Interactive Grand Global Ensemble;THORPEX stands for The Observing System Research and Predictability Experiment) precipitation forecasts for the hydrological users in Linyi,a region richest in rivers and reservoirs in eastern China.The preliminary results exhibited great potential of improvement in applications of weather forecasts by combining the user-end information.Although the TIGGE results provided by existing national/international operating models were independent from the user-end,the case study enlightened ways of establishing an iteratively self-improving UIFS involving user-orientation throughout the forecast process. 相似文献
58.
利用GRAPES—meso模式和T213资料,对2007年7月18日发生在我国四川盆地和华东地区一次大暴雨过程进行多组数值试验,以分析侧边界资料、驱动资料的垂直分辨率、模式积分区域、云物理参数及边界参数对GRAPES—nleso模式降水预报影响。试验结果表明:(1)侧边界资料对模式降水预报结果影响较小,驱动GRAPES—meso的全球模式产品质量提高,降水预报结果越好;(2)驱动资料垂直分辨率的高低对降水预报结果影响较大,分辨率越高,预报能力越强,反之越弱;(3)模式积分区域对降水预报结果也有明显影响,区域越大,降水预报未必总是最好;(4)物理过程和边界参数试验表明,WSM6方案与KFeta方案组合的24小时降水预报与实况更接近。 相似文献
59.
The origin of the solar wind is a long-standing issue in both observational and theoretical studies. To understand how and
where in the solar atmosphere the mass and energy of the solar wind are supplied is very important. Previous observation suggests
a scenario in which the fast solar wind originates at heights above 5 Mm in the magnetically open funnel, a process that is
accompanied by downward flow below 5 Mm, whereby the mass and energy are supplied through reconnection between the open funnel
and adjacent closed loops. Based on this scenario, we develop a fluid model to study the solar wind generation under the assumption
that mass and energy are deposited in the open funnel at 5 Mm. The mass supply rate is estimated from the mass loss rate as
given by the emptying of the side loops as a result of their assumed reconnection with the open funnel. Similarly, the energy
input rate is consistent with the energy release rate as estimated from the energy flux associated with the reconnection between
the open magnetic funnel and the closed magnetic loops. Following the observations, we not only simulate the plasma flowing
upward to form the solar wind but also calculate the downward flow back to the lower atmosphere. This model is a first attempt
to study physically the proposed scenario of solar wind origin and gives a new physical illustration of the possible initial
deposition and consequent transportation of mass and energy in the coronal funnel. 相似文献
60.