全文获取类型
收费全文 | 1301篇 |
免费 | 31篇 |
国内免费 | 3篇 |
专业分类
测绘学 | 50篇 |
大气科学 | 64篇 |
地球物理 | 623篇 |
地质学 | 305篇 |
海洋学 | 25篇 |
天文学 | 240篇 |
综合类 | 3篇 |
自然地理 | 25篇 |
出版年
2018年 | 31篇 |
2017年 | 32篇 |
2016年 | 54篇 |
2015年 | 36篇 |
2014年 | 49篇 |
2013年 | 58篇 |
2012年 | 20篇 |
2011年 | 33篇 |
2010年 | 44篇 |
2009年 | 39篇 |
2008年 | 34篇 |
2007年 | 30篇 |
2006年 | 28篇 |
2005年 | 14篇 |
2004年 | 22篇 |
2003年 | 20篇 |
2002年 | 30篇 |
2001年 | 26篇 |
2000年 | 22篇 |
1999年 | 14篇 |
1998年 | 19篇 |
1997年 | 16篇 |
1996年 | 30篇 |
1995年 | 25篇 |
1994年 | 24篇 |
1993年 | 34篇 |
1992年 | 21篇 |
1991年 | 17篇 |
1990年 | 16篇 |
1989年 | 25篇 |
1988年 | 18篇 |
1987年 | 23篇 |
1986年 | 21篇 |
1985年 | 20篇 |
1984年 | 19篇 |
1983年 | 24篇 |
1982年 | 21篇 |
1981年 | 15篇 |
1980年 | 20篇 |
1979年 | 20篇 |
1978年 | 26篇 |
1977年 | 24篇 |
1976年 | 17篇 |
1975年 | 17篇 |
1974年 | 13篇 |
1973年 | 17篇 |
1972年 | 12篇 |
1971年 | 20篇 |
1970年 | 11篇 |
1969年 | 13篇 |
排序方式: 共有1335条查询结果,搜索用时 46 毫秒
31.
Nikola Stražičić 《GeoJournal》1996,38(4):445-453
Croatia, through its geographic position, is a Mediterranean/Adriatic and Central European/Danube state. As an Adriatic coastal state, it has a long maritime tradition, which is apparent in its well-developed shipping (2.4 million GT), the high-quality ship-building industry (among the top six in the world) and through its numerous sea ports, of which many were established in ancient times. The leading national port is Rijeka, which is at the same time an important transit port for Austria, Hungary, Slovakia and the Czech Republic.The exceptionally indented Croatian Adriatic coast with its attractive archipelagos and favorable climatic and oceanographic conditions in the coastal sea offers very advantageous conditions for comprehensive tourist utilization. This is particularly true of nautical tourism, which is complimented by a larger number of constructed and well-equipped yachting ports/marinas on the coast and islands. 相似文献
32.
The western part of the Bohemian Massif is characterized by repeated occurrences of intraplate earthquake swarms. To study surface deformations of this anomalous region, a network covering about 2000 square kilometres for repeated geodetic measurements was established in 1993 - 1994. The positions of the individual points of the network were carefully picked with respect to local tectonic structure and earthquake foci distribution. GPS and precise levelling measurements were performed 1-2 times a year. The GPS data were processed by Bernese GPS software.
No tendency to any displacement - either horizontal or vertical - of geological blocks was derived from the geodetic data for the period 1993 - 96. Only displacements of less than 5 mm/year in average could occur in the whole region in that period; larger displacements would have been revealed by our measurements. 相似文献
33.
Michael Pearlman Carey Noll Peter Dunn Julie Horvath Van Husson Paul Stevens Mark Torrence Hoai Vo Scott Wetzel 《Journal of Geodynamics》2005,40(4-5):470
The International Laser Ranging Service (ILRS) was established in September 1998 as a service within the IAG to support programs in geodetic, geophysical, and lunar research activities and to provide data products to the International Earth Rotation Service (IERS) in support of its prime objectives. Now in operation for 5 years, the ILRS develops: (1) the standards and specifications necessary for product consistency and (2) the priorities and tracking strategies required to maximize network efficiency. The service collects, merges, analyzes, archives and distributes satellite and lunar laser ranging data to satisfy a variety of scientific, engineering, and operational needs and encourages the application of new technologies to enhance the quality, quantity, and cost effectiveness of its data products. The ILRS works with: (1) the global network to improve station performance; (2) new satellite missions in the design and building of retroreflector targets to maximize data quality and quantity and (3) science programs to optimize scientific data yield. The ILRS Central Bureau maintains a comprehensive web site as the primary vehicle for the distribution of information within the ILRS community. The site, which can be accessed at: http://ilrs.gsfc.nasa.gov is also available at mirrored sites at the Communications Research Laboratory (CRL) in Tokyo and the European Data Center (EDC) in Munich.During the last 2 years, the ILRS has addressed very important challenges: (1) data from the field stations are now submitted hourly and made available immediately through the data centers for access by the user community; (2) tracking on low satellites has been significantly improved through the sub-daily issue of predictions, drag functions, and the real-time exchange of time biases; (3) analysis products are now submitted in SINEX format for compatibility with the other space geodesy techniques; (4) the Analysis Working Group is heavily engaged in Pilot Projects as it works toward an ILRS “standard” global solution and (5) SLR has significantly increased its participation in the International Terrestrial Reference Frame (ITRF) activity, which is important to the success of IGGOS. 相似文献
34.
35.
36.
37.
The response in floodplain respiration of an alpine river to experimental inundation under different temperature regimes
下载免费PDF全文
![点击此处可从《水文研究》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tatjana Simčič Nataša Mori Christian Hossli Christopher T. Robinson Michael Doering 《水文研究》2015,29(26):5438-5450
The respiratory potential [i.e. electron transport system activity (ETSA)] of soils and sediments from five floodplain habitats (channel, gravel, islands, riparian forest and grassland) of the Urbach River, Switzerland, and actual respiration rate (R) of the same samples exposed to experimental inundation were measured. Measurements were carried out at three incubation temperatures (4°C, 12°C and 20°C), and ETSA/R ratios (i.e. exploitation of the overall metabolic capacity) were investigated to better understand the effects of temperature and inundation on floodplain functional heterogeneity. Furthermore, ETSA/R ratios obtained during experimental inundation were compared with ETSA/R ratios from field measurements to investigate the exploitation in total metabolic potential at different conditions. Lowest ETSA and R were measured in samples from channel and gravel habitats, followed by those from islands. Substantially higher values were measured in soils from riparian forest and grassland. Both ETSA and R increased with increasing temperature in samples from all habitats, while the ETSA/R ratio decreased because of a rapid response in microbial community respiration to higher temperatures. The metabolic capacity exploitation (i.e. ETSA/R) during experimental inundation was lowest in predominantly terrestrial samples (riparian forest and grassland), indicating the weakest response to wetted conditions. Comparison of experimentally inundated and field conditions revealed that in rarely flooded soils, the metabolic capacity was less exploited during inundation than during non‐flooded conditions. The results suggest high sensitivity in floodplain respiration to changes in temperature and hydrological regime. ETSA/R ratios are considered good indicators of changes in metabolic activity of floodplain soils and sediments, and thus useful to estimate the impact of changes in hydrological regime or to evaluate success of floodplain restoration actions. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
38.
39.
40.