全文获取类型
收费全文 | 4328篇 |
免费 | 871篇 |
国内免费 | 419篇 |
专业分类
测绘学 | 1516篇 |
大气科学 | 103篇 |
地球物理 | 651篇 |
地质学 | 2170篇 |
海洋学 | 530篇 |
天文学 | 66篇 |
综合类 | 320篇 |
自然地理 | 262篇 |
出版年
2024年 | 6篇 |
2023年 | 56篇 |
2022年 | 198篇 |
2021年 | 290篇 |
2020年 | 275篇 |
2019年 | 223篇 |
2018年 | 112篇 |
2017年 | 209篇 |
2016年 | 169篇 |
2015年 | 201篇 |
2014年 | 336篇 |
2013年 | 272篇 |
2012年 | 322篇 |
2011年 | 300篇 |
2010年 | 212篇 |
2009年 | 210篇 |
2008年 | 251篇 |
2007年 | 288篇 |
2006年 | 245篇 |
2005年 | 177篇 |
2004年 | 190篇 |
2003年 | 166篇 |
2002年 | 136篇 |
2001年 | 95篇 |
2000年 | 93篇 |
1999年 | 102篇 |
1998年 | 81篇 |
1997年 | 79篇 |
1996年 | 75篇 |
1995年 | 61篇 |
1994年 | 41篇 |
1993年 | 36篇 |
1992年 | 26篇 |
1991年 | 18篇 |
1990年 | 16篇 |
1989年 | 14篇 |
1988年 | 4篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有5618条查询结果,搜索用时 93 毫秒
1.
Richard J. Pike 《The Professional geographer》1987,39(2):131-145
Extraterrestrial geography has become a reality, as we move from Earth's moon to the planets. A broad-scale regional physiography is being established on twenty planets and satellites through remote sensing techniques. Spacecraft images yield most of the information on Solar System landscapes. Topographic measurements are extracted by monoscopic image-processing, stereophotogrammetry, and radar analysis. Invisible parts of the spectrum furnish non-topographic data. 相似文献
2.
本文在已有数据处理方法的基础上,利用近代数值逼近理论,给出了从时空域角度描述地壳垂直运动过程的一种具体的函数解析形式。最后给出了一个实际算例。 相似文献
3.
C.S. Botzler J. Snigula R. Bender N. Drory G. Feulner G.J. Hill U. Hopp C. Maraston C. Mendes de Oliveira 《Astrophysics and Space Science》2003,284(2):393-396
The Munich Near-IR Cluster Survey (MUNICS) is a wide-area, medium-deep, photometric survey selected in the K' band. The project's
main scientific aims are the identification of galaxy clusters up to redshifts of unity and the selection of a large sample
of field early-type galaxies up to z < 1.5 for evolutionary studies. We created a Large Scale Structure catalog, using a new structure finding technique specialized
for photometric datasets, that we developed on the basis of a friends-of-friends algorithm. We tested the plausibility of
the resulting galaxy group and cluster catalog with the help of Color-Magnitude Diagrams (CMD), as well as a likelihood- and
Voronoi-approach.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
张众服 《大地测量与地球动力学》1996,(4)
利用三峡地区多年的地形变观测资料,分析了该区的地形变特征。结果表明,各断层活动性甚微或基本不活动,区域地壳相对稳定 相似文献
5.
RTK技术在杭州湾跨海大桥桥位地形测绘中的应用 总被引:1,自引:0,他引:1
介绍了RTK技术在杭州湾跨海大桥桥位地形测绘中的应用,并对其定位结果进行了精度比较与分析,结果表明:RTK定位测量的点位精度可达厘米级,各点位之间不存在误差积累,与全站仪等测量手段取得的结果符合得较好,可以用来代替二三级导线控制测量和等外水准等测量方法;流动站与基准站的距离在10km范围以内时,应用RTK技术对近岸水下地形进行测量具有方便、快捷、精度高等特点,但当此距离超过10km时,其精度则难以保证。杭州湾跨海大桥施工时应用RTK技术进行定位、高程测量,可提高工作效率和成果的质量。 相似文献
6.
7.
本文概述了建国以来我国海洋地质调查与研究工作取得的丰硕成果。论述区域地质调查在海洋地质基础工作和未来海洋开发中的战略意义,介绍了国内外海洋区域地质调查的现状,对开展这项调查的可行性条件,以及进行1/100万海洋区域地质调查的项目内容、技术方法和提交成果等提出了设想和建议。 相似文献
8.
9.
10.
We have examined wind-induced circulation in the Sea of Okhotsk using a barotropic model that contains realistic topography
with a resolution of 9.25 km. The monthly wind stress field calculated from daily European Centre for Medium-Range Weather
Forecasting (ECMWF) Re-Analysis data is used as the forcing, and the integration is carried out for 20 days until the circulation
attains an almost steady state. In the case of November (a representative for the winter season from October to March), southward
currents of velocity 0.1–0.3 m s−1 occur along the bottom contours off the east of Sakhalin Island. The currents are mostly confined to the shelf (shallower
than 200 m) and extend as far south as the Hokkaido coast. In the July case (a representative for the summer season from April
to September), significant currents do not occur, even in the shallow shelves. The simulated southward current over the east
Sakhalin shelf appears to correspond to the near-shore branch of the East Sakhalin Current (ESC), which was observed with
the surface drifters. These seasonal variations simulated in our experiments are consistent with the observations of the ESC.
Dynamically, the simulated ESC is interpreted as the arrested topographic wave (ATW), which is the coastally trapped flow
driven by steady alongshore wind stress. The volume transport of the simulated ESC over the shelf reaches about 1.0 Sv (1
Sv = 106 m3s−1) in the winter season, which is determined by the integrated onshore Ekman transport in the direction from which shelf waves
propagate.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献