全文获取类型
| 收费全文 | 8070篇 |
| 免费 | 1215篇 |
| 国内免费 | 1726篇 |
专业分类
| 测绘学 | 109篇 |
| 大气科学 | 244篇 |
| 地球物理 | 893篇 |
| 地质学 | 4741篇 |
| 海洋学 | 1214篇 |
| 天文学 | 2134篇 |
| 综合类 | 365篇 |
| 自然地理 | 1311篇 |
出版年
| 2024年 | 32篇 |
| 2023年 | 109篇 |
| 2022年 | 323篇 |
| 2021年 | 340篇 |
| 2020年 | 318篇 |
| 2019年 | 334篇 |
| 2018年 | 305篇 |
| 2017年 | 295篇 |
| 2016年 | 282篇 |
| 2015年 | 345篇 |
| 2014年 | 347篇 |
| 2013年 | 416篇 |
| 2012年 | 372篇 |
| 2011年 | 389篇 |
| 2010年 | 333篇 |
| 2009年 | 595篇 |
| 2008年 | 490篇 |
| 2007年 | 538篇 |
| 2006年 | 588篇 |
| 2005年 | 447篇 |
| 2004年 | 454篇 |
| 2003年 | 486篇 |
| 2002年 | 396篇 |
| 2001年 | 334篇 |
| 2000年 | 339篇 |
| 1999年 | 291篇 |
| 1998年 | 312篇 |
| 1997年 | 208篇 |
| 1996年 | 149篇 |
| 1995年 | 149篇 |
| 1994年 | 148篇 |
| 1993年 | 96篇 |
| 1992年 | 98篇 |
| 1991年 | 54篇 |
| 1990年 | 54篇 |
| 1989年 | 27篇 |
| 1988年 | 22篇 |
| 1987年 | 29篇 |
| 1986年 | 15篇 |
| 1985年 | 15篇 |
| 1984年 | 25篇 |
| 1983年 | 32篇 |
| 1982年 | 33篇 |
| 1981年 | 40篇 |
| 1980年 | 2篇 |
| 1979年 | 1篇 |
| 1977年 | 1篇 |
| 1954年 | 3篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
51.
52.
The biomass of macro- and interstitial fauna on clean and wrack-covered beaches in Western Australia
Anton McLachlan 《Estuarine, Coastal and Shelf Science》1985,21(4):587-599
The benthic faunal spectrum including bacteria, protozoans, meiofauna, wrack epifauna and macrofauna, was quantitatively surveyed on two modally reflective, moderate energy, Western Australian beaches. The more exposed beach had coarser sand, no intertidal macrofauna and a poor interstitial fauna. The less exposed beach had a large deposit of wrack totalling 161 kg m?1 dry mass concentrated on the lower shore. The amphipod Allorchestes compressa was abundant in the fresh wrack comprising most of the macrofauna. There were also fairly abundant small epifauna on the wrack. Dry biomass of macrofauna, epifauna, meiofauna, protozoans and bacteria was 0, 0, 15, 4 and 180 g m?1 on the more exposed beach and 160, 3, 112, 9 and 901 g m?1 on the less exposed beach with wrack. On the latter beach there was an inverse correlation between meiofaunal densities and the densities of protozoans and bacteria, suggesting grazing by the former on the latter. On both beaches meiofauna was concentrated in the mid- to upper beach, protozoans near the surface and bacteria in the mid- to lower beach. It is estimated that bacteria are responsible for most of the secondary production on both beaches. 相似文献
53.
We investigate the evolution of rotation period and spindown age of a pulsar whose surface magnetic field undergoes a phase
of growth. Application of these results to the Crab pulsar strongly indicates that its parameters cannot be accounted for
by the field growth theories. 相似文献
54.
55.
56.
57.
We present a new model for the chemical evolution of elliptical galaxies taking into account SN feedback, detailed nucleosynthesis
and galactic winds. We discuss the effect of galactic winds on the chemical enrichment of the ICM and compute the energy per
particle injected by the galaxies into the ICM.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
58.
Stellar population synthesis at the resolution of 2003 总被引：2，自引：0，他引：2
59.
60.