全文获取类型
收费全文 | 262篇 |
免费 | 15篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 9篇 |
大气科学 | 38篇 |
地球物理 | 55篇 |
地质学 | 70篇 |
海洋学 | 33篇 |
天文学 | 52篇 |
综合类 | 1篇 |
自然地理 | 21篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 12篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 14篇 |
2013年 | 21篇 |
2012年 | 19篇 |
2011年 | 18篇 |
2010年 | 14篇 |
2009年 | 15篇 |
2008年 | 12篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有279条查询结果,搜索用时 31 毫秒
81.
Deville Diego Sanchez Gustavo Barahona Sergio Yamashiro Carmen Oré-Chávez Daniel Bazán Roger Quiroz Umino Tetsuya 《Ocean Science Journal》2020,55(1):33-48
Ocean Science Journal - We evaluated the influence of areas with dissimilar upwelling intensity along the Humboldt Current System on the morphological variation of the economically important sea... 相似文献
82.
Cristina Portalés José Luis Lerma Santiago Navarro 《ISPRS Journal of Photogrammetry and Remote Sensing》2010,65(1):134-142
Close-range photogrammetry is based on the acquisition of imagery to make accurate measurements and, eventually, three-dimensional (3D) photo-realistic models. These models are a photogrammetric product per se. They are usually integrated into virtual reality scenarios where additional data such as sound, text or video can be introduced, leading to multimedia virtual environments. These environments allow users both to navigate and interact on different platforms such as desktop PCs, laptops and small hand-held devices (mobile phones or PDAs). In very recent years, a new technology derived from virtual reality has emerged: Augmented Reality (AR), which is based on mixing real and virtual environments to boost human interactions and real-life navigations. The synergy of AR and photogrammetry opens up new possibilities in the field of 3D data visualization, navigation and interaction far beyond the traditional static navigation and interaction in front of a computer screen.In this paper we introduce a low-cost outdoor mobile AR application to integrate buildings of different urban spaces. High-accuracy 3D photo-models derived from close-range photogrammetry are integrated in real (physical) urban worlds. The augmented environment that is presented herein requires for visualization a see-through video head mounted display (HMD), whereas user’s movement navigation is achieved in the real world with the help of an inertial navigation sensor. After introducing the basics of AR technology, the paper will deal with real-time orientation and tracking in combined physical and virtual city environments, merging close-range photogrammetry and AR. There are, however, some software and complex issues, which are discussed in the paper. 相似文献
83.
John M. Livingston Vladimir N. Kapustin Beat Schmid Philip B. Russell Patricia K. Quinn Timothy S. Bates Philip A. Durkee Peter J. Smith Volker Freudenthaler Matthias Wiegner Dave S. Covert Santiago Gassó Dean Hegg Donald R. Collins Richard C. Flagan John H. Seinfeld Vito Vitale Claudio Tomasi 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):594-619
84.
85.
The ANELFA scale for hailfall intensity is proposed on the model of the 6-class Fujita scale for tornadoes. It is based on more than three thousand point hailfalls measured by hailpads over a 16-year period in France. The class number of a hailfall is determined by the integer value of the largest measured hailstone diameter in cm, or by equivalence with current objects: A0 to A5 for pea, grape, pigeon's egg, walnut, hen's egg, orange. The class number is followed by a plus or minus sign if the ground is significantly more or less than half-covered by hailstones respectively. When the scale is applied to the ANELFA data, a log-normal distribution is found for the class distribution, allowing the frequency determination of the upper class ever observed until now at the hailpad stations. 相似文献
86.
87.
The world‐class Poderosa‐Pataz district is famous for its gold endowment in vertically and laterally extensive quartz‐sulphide veins. Precipitating mechanisms are investigated to determine why gold is so laterally and vertically distributed. Micro‐XRF and LA‐ICP‐MS element mapping of pyrites surrounding gold grains reveals systematic enrichment of As around or near visible gold accumulations. These As‐enriched zones define discordant rims and corridors overprinting pyrites. LA‐ICP‐MS spot analyses performed within and outside the As enrichment zones indicate that As is enriched on average by two orders of magnitude in association with gold. Secondary pyrite transformation by hydrothermal fluids with elevated As‐Au induced a change in the semiconducting properties of pyrite grains, resulting in the precipitation of visible gold particles at the interfaces of As‐enriched zones. The electrochemical precipitation mechanism acted as a filter to extract gold in solution regardless of variations in pressure and temperature, hence explaining the vertically and laterally extensive gold mineralization. 相似文献
88.
Paulina Montero Giovanni Daneri Humberto E. González Jose Luis Iriarte Fabián J. Tapia Lorena Lizárraga Nicolas Sanchez Oscar Pizarro 《Continental Shelf Research》2011,31(3-4):202-215
We characterized the seasonal cycle of productivity in Reloncaví Fjord (41°30′S), Chilean Patagonia. Seasonal surveys that included measurements of gross primary production, community respiration, bacterioplankton secondary production, and sedimentation rates along the fjord were combined with continuous records of water-column temperature variability and wind forcing, as well as satellite-derived data on regional patterns of wind stress, sea surface temperatures, and surface chlorophyll concentrations. The hydrography and perhaps fjord productivity respond to the timing and intensity of wind forcing over a larger region. Seasonal changes in the direction and intensity of winds, along with a late-winter improvement in light conditions, may determine the timing of phytoplankton blooms and potentially modulate productivity cycles in the region.Depth-integrated gross primary production estimates were higher (0.4–3.8 g C m?2 d?1) in the productive season (October, February, and May), and lower (0.1–0.2 g C m?2 d?1) in the non-productive season (August). These seasonal changes were also reflected in community respiration and bacterioplankton production rates, which ranged, respectively, from 0.3 to 4.8 g C m?2 d?1 and 0.05 to 0.4 g C m?2 d?1 during the productive and non-productive seasons and from 0.05 to 0.6 g C m?2 d?1 and 0.05 to 0.2 g C m?2 d?1 during the same two periods. We found a strong, significant correlation between gross primary production and community respiration (Spearman, r=0.95; p<0.001; n=12), which suggests a high degree of coupling between the synthesis of organic matter and its usage by the planktonic community. Similarly, strong correlations were found between bacterioplankton secondary production and both gross primary production (Spearman, r=0.7, p<0.05, n=9) and community respiration (Spearman, r=0.8, p<0.05, n=9), indicating that bacterioplankton may be processing an important fraction (8–59%) of the organic matter produced by phytoplankton in Reloncaví Fjord. In winter, bacterial carbon utilization as a percentage of gross primary production was >100%, suggesting the use of allochthonous carbon sources by bacterioplankton when the levels of gross primary production are low. Low primary production rates were associated with a greater contribution of small cells to autotrophic biomass, highlighting the importance of small-sized plankton and bacteria for carbon cycling and fluxes during the less productive winter months. Fecal pellet sedimentation was minimal during this period, also suggesting that most of the locally produced organic carbon is recycled within the microbial loop. During the productive season, on the other hand, the area exhibited a great potential to export organic matter, be it to higher trophic levels or vertically towards the bottom. 相似文献
89.
E. S. Krayenhoff J.-L. Santiago A. Martilli A. Christen T. R. Oke 《Boundary-Layer Meteorology》2015,156(2):157-189