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701.
井周流场,水跃值与井内水位降深的关系 总被引:2,自引:0,他引:2
徐至进 《水文地质工程地质》1993,20(6):24-27,52
本文以单井稳定流抽水为例,从井固流场与地下水向集水井幅射流的涌水量方程入手,阐明井结构,井周泥浆堵塞和井内水位降深的关系。证明了水跃值是井周泥浆堵塞降深与井周三维流域或紊流引起的二次项降深(简称“井损“)之代数和,并得出了水跃值不同组成部分随井内降深变化而变化的规律。从而提出了消除水跃值,利用裘布依涌水量方程进行水文地质参数计算。 相似文献
702.
A new semi-empirical formula for evaluating the residual strain of soils under earthquake loading is presented in this paper based on the incremental method and the increment model proposed by the authors. When the incident loading is uniform, the results calculated by the new formula are nearly the same as those by the existing formula. For excitation of the random earthquake loading, the results calculated by the new formula are compared to the results obtained by dynamic triaxial tests. The dynamic triaxial tests had been performed considering different seismic waves, confining stresses,consolidation ratios, and types of cohesive soils. The comparison between the calculated and tested results indicate that the presented formula can efficiently and practically describe the time-dependent process of the soil residual strains under actual seismic loads. 相似文献
703.
Soil behaviour under dynamic loading conditions: experimental procedures and statistical trends 总被引:1,自引:1,他引:0
G.?ChristakosEmail author 《Stochastic Environmental Research and Risk Assessment (SERRA)》2003,17(3):175-190
Soil behaviour under dynamic conditions is a crucial component of several studies concerned with the environmental effects of earthquakes, risk assessment and geological hazards. This work presents experimental procedures for studying soil behaviour under repeated loading and examines the role of uncertain parameters in the expected soil performance. Laboratory techniques are used to obtain stress controlled cyclic triaxial soil measurements, and a series of test programs are performed in order to study general statistical trends in the response of soils under simulated earthquake conditions, to investigate the processes causing soil failure, and to examine factors that may influence the results obtained in the laboratory.This work has been supported by grants from the National Institute of Environmental Health Sciences (Grant no. P42-ES05948 and P30-ES10126) and the Army Research Office (DAAG55-98-1-0289). 相似文献
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Gravity observations from superconducting gravimeters are used to observe loading effects from shallow-water tides on the Japanese east and west coasts. Non-linear third-diurnal and higher-frequency shallow-water tides are identified in the tide-gauge observations from these coastal areas. The most energetic constituents in the tide gauge observations are also seen in the gravity observations due to their loading effects on the deformation of the Earth. Even though the shallow-water tides at the Japanese east coast have an amplitude of only a few millimetres, they are still able to generate a loading signal at gravity sites located several hundred kilometres inland. In particular, the S3, S4 and S5 solar tides occur in both gravity and tide gauge observations. It is indicated that in other shelf regions with large shallow water tides, the shallow water loading signals account for a significant signal, which should be taken into account.Acknowledgement The authors would like to thank the Hydrographic and Oceanographic Department (Japan Coast Guard), Japan Meteorological Agency and Hokkaido Development Agency for access to the tide-gauge data. Also, the Global Geodynamic Project Information System and Data Center (GGP-ISDC) is acknowledged for providing the gravity data. 相似文献
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Introduction With the development of science and technology, the accuracy of gravity measurement is im-proved. The gravity observation with FG5 gravimeter has reached accuracy of μ magnitude. And the high accurate superconducting gravimeter can detect the tiny signal of 10?2 μ magnitude in frequency domain. With the high-accuracy gravity observation on Earth′s surface, the Earth′s tidal parameters can be determined precisely. And the observations can also be used to invert the struc-ture… 相似文献
709.
1 INTERNAL HYDRAULIC JUMPS AND LOCAL WATER ENTRAINMENT Traveling and stationary internal hydraulic jumps in two-layer flow can occur in the following situations (Fig. 1). When a stratified fluid flows over an obstacle created by a sudden blockage, the layer of increased depth within the heavier fluid will propagate upstream as a traveling hydraulic jump. When the heavier fluid overtops the obstacle it will flow along the downstream face of the obstacle as a supercritical flow… 相似文献
710.