全文获取类型
收费全文 | 465篇 |
免费 | 22篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 13篇 |
大气科学 | 99篇 |
地球物理 | 96篇 |
地质学 | 150篇 |
海洋学 | 33篇 |
天文学 | 60篇 |
综合类 | 2篇 |
自然地理 | 35篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 13篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 15篇 |
2016年 | 25篇 |
2015年 | 9篇 |
2014年 | 22篇 |
2013年 | 45篇 |
2012年 | 18篇 |
2011年 | 19篇 |
2010年 | 22篇 |
2009年 | 25篇 |
2008年 | 14篇 |
2007年 | 18篇 |
2006年 | 15篇 |
2005年 | 20篇 |
2004年 | 19篇 |
2003年 | 9篇 |
2002年 | 3篇 |
2001年 | 12篇 |
2000年 | 14篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1975年 | 5篇 |
1972年 | 3篇 |
1962年 | 1篇 |
1892年 | 1篇 |
1887年 | 1篇 |
1885年 | 3篇 |
排序方式: 共有488条查询结果,搜索用时 656 毫秒
21.
M. Déqué R. G. Jones M. Wild F. Giorgi J. H. Christensen D. C. Hassell P. L. Vidale B. Rockel D. Jacob E. Kjellström M. de. Castro F. Kucharski B. van den Hurk 《Climate Dynamics》2005,25(6):653-670
Four high resolution atmospheric general circulation models (GCMs) have been integrated with the standard forcings of the
PRUDENCE experiment: IPCC-SRES A2 radiative forcing and Hadley Centre sea surface temperature and sea-ice extent. The response
over Europe, calculated as the difference between the 2071–2100 and the 1961–1990 means is compared with the same diagnostic
obtained with nine Regional Climate Models (RCM) all driven by the Hadley Centre atmospheric GCM. The seasonal mean response
for 2m temperature and precipitation is investigated. For temperature, GCMs and RCMs behave similarly, except that GCMs exhibit
a larger spread. However, during summer, the spread of the RCMs—in particular in terms of precipitation—is larger than that
of the GCMs. This indicates that the European summer climate is strongly controlled by parameterized physics and/or high-resolution
processes. The temperature response is larger than the systematic error. The situation is different for precipitation. The
model bias is twice as large as the climate response. The confidence in PRUDENCE results comes from the fact that the models
have a similar response to the IPCC-SRES A2 forcing, whereas their systematic errors are more spread. In addition, GCM precipitation
response is slightly but significantly different from that of the RCMs. 相似文献
22.
Carbon dioxide in magmas and implications for hydrothermal systems 总被引:21,自引:0,他引:21
Jacob B. Lowenstern 《Mineralium Deposita》2001,36(6):490-502
23.
Dr. H. Jacob 《International Journal of Earth Sciences》1962,51(2):530-546
Zusammenfassung Die Mazeral-Klassifikation von Torf und Weichbraunkohle muß tunlichst auf die Steinkohlen-Nomenklatur Bezug nehmen und nach gleichen bzw. ähnlichen Prinzipien erfolgen. Ferner hat sie technologischen Gesichtspunkten Rechnung zu tragen. Die vom Verfasser vorgeschlagene Nomenklatur wird diesen Anforderungen gerecht. Da Torfe und Weichbraunkohlen heterogener als Steinkohlen sind, ist eine stärkere Gliederung erforderlich. 5 Gruppen (Exinit, Xylinit, Detrinit, Dopplerinit und Inertinit) werden jeweils in 3 Untergruppen eingeteilt. Diese erfahren eine weitere Gliederung nach Mazeralen. Abschließend weist der Verfasser darauf hin, daß durch Kombination der Weichbraunkohlen- und Steinkohlen-Klassifikation auch den Belangen der Hartbraunkohlen-Petrographie Rechnung getragen werden kann. 相似文献
24.
25.
26.
27.
We study the orbital evolutions of various systems of planetary embryos in the transneptunian region, undergoing mutual scattering and perturbations from the giant planets. We show that about 15-20% of the original embryos should survive in the transneptunian region at the current epoch. The orbital dispersion of the surviving embryos depends on their individual mass, so that only lunar mass embryos could survive with semimajor axis smaller than 50 AU. In all cases, we show by a Monte Carlo model that at least one of the surviving embryos should have already been discovered by one of the most effective Kuiper-belt surveys. This implies that planetary embryos did not form in the transneptunian region (or have been removed by some external and unknown mechanism). Therefore, we conclude that the Kuiper belt was not excited by resident planetary embryos, unlike the asteroid belt. We also compute with the Monte Carlo model that a significant number (order 10) of Pluto-size bodies could exist only on very eccentric and long-periodic orbits, typical of the scattered disk, while the existence of about 30 bodies brighter than absolute magnitude 4 in the classical belt is compatible with the discovery of Varuna by the Spacewatch survey. 相似文献
28.
An intercomparison of regional climate simulations for Europe: assessing uncertainties in model projections 总被引:2,自引:0,他引:2
M. Déqué D. P. Rowell D. Lüthi F. Giorgi J. H. Christensen B. Rockel D. Jacob E. Kjellström M. de Castro B. van den Hurk 《Climatic change》2007,81(1):53-70
Ten regional climate models (RCM) have been integrated with the standard forcings of the PRUDENCE experiment: IPCC-SRES A2 radiative forcing and Hadley Centre boundary conditions. The response over Europe, calculated as the difference between the 2071–2100 and the 1961–1990 means can be viewed as an expected value about which various uncertainties exist. Uncertainties are measured here by variance in eight sub-European boxes. Four sources of uncertainty can be evaluated with the material provided by the PRUDENCE project. Sampling uncertainty is due to the fact that the model climate is estimated as an average over a finite number of years (30). Model uncertainty is due to the fact that the models use different techniques to discretize the equations and to represent sub-grid effects. Radiative uncertainty is due to the fact that IPCC-SRES A2 is merely one hypothesis. Some RCMs have been run with another scenario of greenhouse gas concentration (IPCC-SRES B2). Boundary uncertainty is due to the fact that the regional models have been run under the constraint of the same global model. Some RCMs have been run with other boundary forcings. The contribution of the different sources varies according to the field, the region and the season, but the role of boundary forcing is generally greater than the role of the RCM, in particular for temperature. Maps of minimum expected 2m temperature and precipitation responses for the IPCC-A2 scenario show that, despite the above mentioned uncertainties, the signal from the PRUDENCE ensemble is significant. 相似文献
29.
30.
Vertical momentum fiuxes measured by analog covariance equipment and hot-wire anemometers inside a dense canopy of mature maize vary exponentially with height above the ground. An attenuation coefficient of about 4 is indicated.This work was supported by the US Energy Research and Development Administration.Part of the Energy Research and Development Administration's Multistate Atmospheric Power Production Pollution Study (MAP3S). 相似文献