全文获取类型
收费全文 | 11057篇 |
免费 | 2324篇 |
国内免费 | 2530篇 |
专业分类
测绘学 | 1492篇 |
大气科学 | 205篇 |
地球物理 | 968篇 |
地质学 | 10673篇 |
海洋学 | 795篇 |
天文学 | 70篇 |
综合类 | 1043篇 |
自然地理 | 665篇 |
出版年
2024年 | 88篇 |
2023年 | 276篇 |
2022年 | 537篇 |
2021年 | 630篇 |
2020年 | 536篇 |
2019年 | 543篇 |
2018年 | 397篇 |
2017年 | 485篇 |
2016年 | 573篇 |
2015年 | 654篇 |
2014年 | 940篇 |
2013年 | 661篇 |
2012年 | 817篇 |
2011年 | 801篇 |
2010年 | 737篇 |
2009年 | 700篇 |
2008年 | 633篇 |
2007年 | 772篇 |
2006年 | 718篇 |
2005年 | 615篇 |
2004年 | 554篇 |
2003年 | 480篇 |
2002年 | 388篇 |
2001年 | 380篇 |
2000年 | 321篇 |
1999年 | 320篇 |
1998年 | 276篇 |
1997年 | 227篇 |
1996年 | 200篇 |
1995年 | 163篇 |
1994年 | 121篇 |
1993年 | 98篇 |
1992年 | 89篇 |
1991年 | 53篇 |
1990年 | 33篇 |
1989年 | 34篇 |
1988年 | 8篇 |
1987年 | 18篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1972年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
731.
论述航运局综合楼地基所在处的地形地貌、水文地质、工程地质条件;分析地基基础盲目施工诱发造成建筑场地工程地质灾害和危及周国民居安全的原因,提出防治措施,合理施工,治理塌陷,并取得较好效益。 相似文献
732.
733.
734.
The mechanical model for plane strain, time-harmonic seismic wave propagation problems in cracked, multi-layered geological regions with surface topography and non-parallel interfaces was described in the first part of this work. Here, this model is used to investigate the response of such a region to the presence of traveling elastic waves generated by a seismic source. The computational methodology that was developed in the first part is based on a combination of both the regular (displacement-based) and the hypersingular (traction-based) Boundary Integral Equation Method (BIEM). First, the accuracy and convergence characteristics of this hybrid BIEM are studied. Then, a series of problems involving four different configurations of a reference geological deposit with both interface and internal cracks are solved, for a loading that is due to a seismically-induced pressure wave propagating upwards from the underlying rigid half-plane. The purpose of the numerical study is to investigate the influence of various key parameters of the problem, such as frequency and incidence angle of the incoming wave, size of the surface relief, location and size of the buried cracks, interaction effects between cracks and finally the presence of layers, on both the scattered displacement field and the stress concentration field. 相似文献
735.
An integrated geophysical survey which combines vertical seismic profile method, shallow reflection seismic method, electric
sounding, soil temperature measurement and radioactive gas measurement was used to investigate Zhaoshuling landslide in the
new site of Badong County and to assess the stability of the landslide. By rational use of these methods together with borehole
geological profile and other geological information, the spatial distribution of the landslide body, the formations and structures
within and without the landslide body were determined and the stability of the landslide was also assessed, thus making great
contribution to the successful and rational investigation and assessment of the landslide. 相似文献
736.
737.
陆相红层盆地1:5万区调中的遥感应用研究 总被引:3,自引:0,他引:3
本文采用遥感地质方法,对陆相红层盆地的沉积岩相、沉积体系界面、盆地充填序列、岩相变化以及地层格架影像特征进行了识别研究,取得了较好效果,为遥感在红层盆地1:5万区调中的应用,开辟了新思路。 相似文献
738.
739.
V. Pereyra 《Pure and Applied Geophysics》1996,148(3-4):345-386
We describe an integrated forward and inverse three-dimensional modeling system that can deal with complex geological structures. The system has been designed to handle large-scale problems by using a distributed approach. It uses seismic ray tracing for forward simulation, time-to-depth mapping, and nonlinear travel-time inversion.A novel decomposition method is our tool to attack large-scale problems in a parallel approach. The system is fully implemented and we demonstrate its performance with synthetic examples.This research was partially supported by the National Science Foundation under SBIR Grant III-9300992. 相似文献
740.
1995年3月19日,新疆和硕县那音克乡发生Ms5.0级地震。震前,乌鲁木齐地区地下水中溶解气体Ar、CH4、CO2、H2S等和库尔勒地区的断层气Rn相继出现明显的异常。异常具有短期临震性质,主要表现为短期趋势升高,临震突跳。 相似文献