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121.
Based on the temperature of the black body (TBB), station observed and NCEP reanalysis data, the impacts of the eastward propagation of convective cloud systems over the Tibetan Plateau on the southwest vortex (SWV) formation that occurred at 1800 UTC on 29 June 2003 are analyzed by using the Zwack-Okossi (Z-O) equation to diagnose the thermal and dynamic processes. It is found that, in summer, severe convective activities often occur over the Tibetan Plateau due to the abundant supply of moisture. The convective cloud near the east edge of the plateau could move eastward with a short-wave trough in the westerly. The divergent center that is induced by latent heat release, which is associated with severe convective activities, moves out with the convective cloud and contributes to the low level decompression which is favorable for the formation of plateau edge cyclogenesis (PEC). The Z-O equation indicates that, in this case, the latent heat release and convergence are the two most important factors for SWV formation, which amounts to about 42% and 15% of the term TOTAL, respectively. It is implied that the thermal process effect was more important than the dynamic process during SWV formation. 相似文献
122.
Reservoirs impose many negative impacts on riverine ecosystems. To balance human and ecosystem needs, we propose a reservoir operation method that combines reservoir operating rule curves with the regulated minimum water release policy to meet the environmental flow requirements of riverine ecosystems. Based on the relative positions of the reservoir and the water intakes, we consider three scenarios: water used for human needs (including industrial, domestic and agricultural) is directly withdrawn from (1) the reservoir; (2) both reservoirs and downstream river channels and (3) downstream river. The proposed method offers two advantages over traditional methods: First, it can be applied to finding the optimal reservoir operating rule curves with the consideration of environmental flow requirement, which is beneficial to the sustainable water uses. Second, it avoids a problem with traditional approaches, which prescribe the minimum environmental flow requirements as the regulated minimum environmental flow releases from reservoirs, implicitly giving lower priority to the riverine ecosystem. Our method instead determines the optimal regulated minimum releases of water to sustain environmental flows while more effectively balancing human and ecosystem needs. To demonstrate practical use of the model, we present a case study for operation of the Tanghe reservoir in China's Tang river basin for the three above‐mentioned scenarios. The results demonstrate that this approach will help the reservoir's managers satisfy both human and environmental requirements. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
123.
基于GIS的重点污染源管理信息查询与分布系统设计的实现 总被引:3,自引:0,他引:3
系统应用地理信息系统(GIS)技术、数据库技术、多媒体技术、Internet/Intranet技术,实现对污染源空间信息和非空间信息的综舍管理。直现地表现各类污染源的分布特点、总量特征及其排放污染物的动态变化。并通过网络实现污染源信息网上发布。本文概要介绍了系统的组成、结构、数据库以及系统的功能及其实现。 相似文献
124.
卸荷工程岩体与传统的加载岩体的力学条件有着本质的区别,其非线性特征更为明显,卸荷工程岩体的研究是一个崭新的领域,对卸荷岩体的工程地质特征、力学参数的确定、本构关系及卸荷岩体释放荷载的计算方面进行了初步的探讨。 相似文献
125.
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127.
李兴才 《地震学报(英文版)》1994,7(3):409-414
Promotingeffectsof1975HaichengforeshocksontheoccurrenceofthemainshockXing-CaiLI(李兴才)(InstituteofGeophysics,StateSetismologica... 相似文献
128.
Vasile Marza Juraci Carvalho Lucas Barros Cristiano Chimpliganond 《Journal of Seismology》2003,7(1):89-98
An analysis and discussion of the main features and effects of the 1999global seismicity based especially on the inferred patterns of strong(Mw 7) earthquakes using NEIC/USGS data is presented.Based on the above data and their statistical features (see also Table 1)one may state that from the point of view of occurrence rate (number/yr)the 1999 global seismicity was fairly regular, but from the moment (orenergy) release standpoint it is well under the long-term average. The spacepartition was again rather typical and time distribution was quasi-Poissonian,noteworthy, the 1999 worldwide seismicity had an anomalously high deathtoll, to be discussed later. Two main new insights are brought by ouranalysis: (i) a (mega)quiescence along the whole south American segmentof circum-Pacific earthquake belt, which was inferred and rated asanomalous while it was underway and which, in retrospect, ended with thegreat (Mw = 8.4 HRV) 2001 Arequipa (Peru) event; (ii) an intriguingmonotonous rate decrease within only magnitude class 5.0 to 5.9 duringthe analyzed period (i.e., 1990–1999). 相似文献
129.
SHILing 《地球空间信息科学学报》2005,8(2):148-151
Parallel machine problems with a single server and release times are generahzatlons ot classical parallel machine problems. Before processing, each job must be loaded on a machine, which takes a certain release times and a certain setup times. All thesesetups have to be done by a single server, which can handle at most one job at a time. In this paper, we continue studying the complexity result for parallel machine problem with a single and release times. New complexity results are derived for special cases. 相似文献
130.
Long-term seismic activity prior to the December 26, 2004, off the west coast of northern Sumatra, Indonesia, M
W=9.0 earthquake was investigated using the Harvard CMT catalogue. It is observed that before this great earthquake, there
exists an accelerating moment release (AMR) process with the temporal scale of a quarter century and the spatial scale of
1 500 km. Within this spatial range, the M
W=9.0 event falls into the piece-wise power-law-like frequency-magnitude distribution. Therefore, in the perspective of the
critical-point-like model of earthquake preparation, the failure to forecast/predict the approaching and/or the size of this
earthquake is not due to the physically intrinsic unpredictability of earthquakes.
Foundation item: Ministry of Science and Technology Project (2004CB418406).
Contribution No. 05FE3010, Institute of Geophysics, China Earthquake Administration. 相似文献