全文获取类型
收费全文 | 101篇 |
免费 | 0篇 |
国内免费 | 8篇 |
专业分类
大气科学 | 2篇 |
地球物理 | 57篇 |
地质学 | 47篇 |
综合类 | 2篇 |
自然地理 | 1篇 |
出版年
2022年 | 1篇 |
2019年 | 2篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 26篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 3篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 6篇 |
1971年 | 3篇 |
1970年 | 4篇 |
1966年 | 1篇 |
排序方式: 共有109条查询结果,搜索用时 31 毫秒
1.
The paper presents the 3D finite element simulation of tidal flow and Sediment transport in the estuarine region of the Haihe river. The proposed model adopts sigma-transformation of the hydrodynamic and sediment transport equations. The hydrodynamic and sediment transport models are verified in case of a simple test problem for which analytical solutions are available. Finally the models are applied to muddy Haihe river estuary of North China and it is claimed that hydrodynamic and sediment transport models give a reliable comparison with the observed field data. However, there are certain discrepancies, and some reasonable questions regarding the present state-of-art, in the modeling of three-dimensional multilevel hydrodynamics and sediment transport, which are provided below for answer. 相似文献
2.
Space weather prediction involves advance forecasting of the magnitude and onset time of major geomagnetic storms on Earth. In this paper, we discuss the development of an artificial neural network-based model to study the precursor leading to intense and moderate geomagnetic storms, following halo coronal mass ejection (CME) and related interplanetary (IP) events. IP inputs were considered within a 5-day time window after the commencement of storm. The artificial neural network (ANN) model training, testing and validation datasets were constructed based on 110 halo CMEs (both full and partial halo and their properties) observed during the ascending phase of the 24th solar cycle between 2009 and 2014. The geomagnetic storm occurrence rate from halo CMEs is estimated at a probability of 79%, by this model. 相似文献
3.
S. SINGH 《Geophysical Prospecting》1986,34(4):492-507
A field study was undertaken to evaluate the effectiveness of the high frequency seismic reflection technique for mapping of shallow and irregular bedrock. Bedrock reflections were obtained using a hammer source with both in-line and common offset field layouts. The recording equipment included 12-channel enhancement seismographs, 28 Hz vertical geo-phones and a microcomputer. The latter increased the overall versatility of the seismic system. Field sites for this study are typical of the geological settings of the tin mining areas of Malaysia. The topographical ‘lows’ of the irregular bedrock control the localization of tin ore. The subsurface geology consists of a thin low velocity layer (± 300 m/s) overlying the compact overburden (± 1700 m/s) which in turn lies on bedrock. This paper discusses various criteria for designing an optimum window for obtaining usable reflections between the first arrival and the leading edge of the ground roll cone. Detailed mapping of the overburden and the bedrock interface by the reflection method can be useful in delineating areas for exploratory drilling and for optimum planning of mining operations. 相似文献
4.
Summary A number of resistivity profiles over quartz reefs have been taken using Wenner and Schlumberger configurations around Dhanbad in order tofind the potential of these for water accumulation. These reefs give rise to both resistivity highs and lows as compared to the background. The results are discussed in the light of known theories. Some suitable sites for water accumulation have been delineated. 相似文献
5.
Summary Least square criterion has been introduced to specify the order of isostatic compensation of mountains. The hydrostatic stability of the mountains is of basic significance in plate tectonics. However different concepts of isostasy differ in the evaluation of its order. An elegant and rapid technique is developed which extends the symmetric matrix method of root estimation byNegi andGarde [1]3) to provide a stability test through the mathematical expectation of the root increment. Application is illustrated for Rocky Mountains, United States. 相似文献
6.
Jagdeo Singh 《Pure and Applied Geophysics》1971,85(1):269-282
Summary Thermal demagnetization of large number of samples form the Isle of Mull have been carried out. The rocks belong to the Tertiary age. The results indicate that the rocks have been magnetized in the prevalling geomagnetic field at the time of formation. Some of the rocks indicate movement during cooling. 相似文献
7.
8.
The use of Very High Frequency measurements applied to the detection of the variation in dielectric constant as a precursor to earthquakes is examined. It is concluded that such a technique is feasible and that the installation of source and sensor in separate deep boreholes provides a suitable environment for this type of study. The boreholes could also be used for a considerable range of other types of instrumentation. 相似文献
9.
10.