全文获取类型
收费全文 | 154篇 |
免费 | 6篇 |
国内免费 | 9篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 16篇 |
地球物理 | 46篇 |
地质学 | 47篇 |
海洋学 | 31篇 |
天文学 | 16篇 |
综合类 | 4篇 |
自然地理 | 7篇 |
出版年
2022年 | 1篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 12篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 4篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2007年 | 9篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 9篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有169条查询结果,搜索用时 15 毫秒
71.
Degradation of crude oil in a contaminated tidal flat area and the resilience of bacterial community
Jaejin Lee Il Han Bo Ram Kang Seong Heon Kim Woo Jun Sul Tae Kwon Lee 《Marine pollution bulletin》2017,114(1):296-301
Crude oil spills, Hebei Spirit in South Korea, is considered as one of the worst environmental disasters of the region. Our understanding on activation of oil-degrading bacteria and resilience of microbial community in oil contaminated sites are limited due to scarcity of such event. In the present study, tidal flat sediment contaminated by the oil spill were investigated for duration of 13 months to identify temporal change in microbial community and functional genes responsible for PAH-degradation. The results showed predominance of previously known oil-degrading genera, such as Cycloclasticus, Alcanivorax, and Thalassolituus, displaying significant increase within first four months of the accident. The disturbance caused by the oil spill altered the microbial community and its functional structures, but they were almost restored to the original state after 13 months. Present study demonstrated high detoxification capacity of indigenous bacterial populations in the tidal flat sediments and its resilience of microbial community. 相似文献
72.
73.
The republic of El Salvador in Central America is an area of high seismic hazard where at least twelve destructive earthquakes have occurred this century alone. The principal sources of seismic hazard are earthquakes associated with the subduction of the Cocos plate in the Middle America Trench and upper-crustal earthquakes in the chain of Quaternary volcanoes that runs across the country parallel to the subduction trench. Hazard assessments for Central America have suggested almost uniform distribution of hazard throughout El Salvador. Seismic zonations for three successive building codes in El Salvador simply divide the country into two regions, with the higher hazard zone containing the volcanoes and the coastal areas. Historical records suggest that the greatest hazard is posed by the upper-crustal earthquakes concentrated on the volcanic centres which, although of smaller magnitude than the subduction events, are generally of shallow focus and coincide with the main population centres. These earthquakes have repeatedly caused intense damage over small areas in the vicinity of some of the main volcanoes. This study focuses on El Salvador to explore the capability of different approaches to hazard assessment to reflect significant variations of seismic hazard within small geographical areas. In the study, three 'zone-free' methods are employed as well as the Cornell–McGuire approach. The results of the assessments are compared and their implications for seismic zoning for construction and insurance purposes are discussed. 相似文献
74.
Kim Sangil Yoon Sang Chol Yoo Man Ho Park Kyung Woo Park Sang Rul Youn Seok-Hyun 《Ocean Science Journal》2019,54(1):129-139
Ocean Science Journal - Pyropia yezoensis cultured in the estuary of the Nakdong River in Korea is an important fisheries resource for the local economy. Over the past few decades, the... 相似文献
75.
Jong-Kuk Choi Joo-Hyung Ryu Yoon-Kyung Lee Hong-Rhyong Yoo Han Jun Woo Chang Hwan Kim 《Estuarine, Coastal and Shelf Science》2010
High spatial resolution satellite data (IKONOS) combined with in situ data was used to quantitatively estimate the spatial distribution of tidal flat characteristics for the Hwangdo tidal flat, Cheonsu Bay, Korea. The classification result was accurate in terms of a comparison with the in situ data, and the overall accuracy was 90.7%, which confirmed the validity of the classification. GIS analysis based on a probabilistic model was applied to a quantitative estimation of the relationship between each surface sediment facies and the spectral reflectance. Mud flat facies showed a high positive correlation (R2 = 0.91), and sand flat facies showed a high negative correlation (R2 = 1.00), which was a good reflection of the sedimentary characteristics of Hwangdo tidal flat. Relationships between each sediment facies and DEM also showed good agreement with the topographic characteristics in the study area. The study revealed that intertidal surface sediment classification using high resolution remote sensing imagery and in situ data successfully shows spectral and topographic characteristics of the study area. It was noted that spectral reflectance was affected by a combination of environmental factors, including grain size, topography, and remnant surface water. It is possible to determine the type of tidal flat through quantitative estimates of the spatial distribution of surface sediments according to their spectral reflectance. 相似文献
76.
Sung-Hoon Ji Kyung Woo Park Doo-Hyun Lim Chunsoo Kim Kyung Su Kim William Dershowitz 《Hydrogeology Journal》2012,20(7):1341-1353
The development and implementation of a hybrid discrete fracture network/equivalent porous medium (DFN/EPM) approach to groundwater flow at the Gyeong-Ju low- and intermediate-level radioactive waste (LILW) disposal site in the Republic of Korea is reported. The geometrical and hydrogeological properties of fractured zones, background fractures and rock matrix were derived from site characterization data and implemented as a DFN. Several DFN realizations, including the deterministic fractured zones and the stochastic background fractures, whose statistical properties were verified by comparison with in-situ fracture and hydraulic test data, were suggested, and they were then upscaled to continuums using a fracture tensor approach for site-scale flow simulations. The upscaled models were evaluated by comparison to in-situ pressure monitoring data, and then used to simulate post-closure hydrogeology for the LILW facility. Simulation results demonstrate the importance of careful characterization and implementation of fractured zones. The study highlighted the importance of reducing uncertainty regarding the properties and variability of natural background fractures, particularly in the immediate vicinity of repository emplacement. 相似文献
77.
An exploratory investigation was conducted to assess the present conditions and evaluate the potential impacts of mining activities on soil and water environments at the Shivee-Ovoo coalmine area in Mongolia. Water quality analysis was conducted on samples from mine dewatering boreholes, a tailings dam, and drinking water sources around the mine area. In drinking water supplies of the area, concentrations of Mg, Fe, and F exceeded the levels set in Mongolian and World Health Organization guidelines. Water type and the principal components analysis indicated that water from the mine area and from public water-supply wells originated from the same aquifer. However, the water quality differed in shallow wells and deep wells because of bedrock differences and geochemical weathering processes, rather than climate effects such as from evaporation. The discharged water poses medium to high salinity hazard for use in irrigation, suggesting the need to manage its use in sustainable agriculture or projects to prevent desertification. The particle size distribution and fractal dimension values of soils revealed the dominance of fine to medium sands, which have strong potential for desertification. X-ray photoelectron spectroscopy analysis showed that the soils currently pose no apparent threat for acid rock drainage. Consequently, the open-pit mining of the study area shows no obvious environmental impact at present in its vicinity. However, for sustainable development and expansion of the mine, environmental changes should be continuously monitored, with consideration of possible measures for waste recycling. 相似文献
78.
79.
To investigate the genotoxic effect of marine sediments on aquatic organism, sediment samples were collected from 13 sites along the coast of Gwangyang Bay (Korea). Concentrations of polycyclic aromatic hydrocarbons (PAHs) in sediments were determined and the relationship between exposure of flounder blood cells to sediment extracts and DNA single-strand breakage in the blood cells was examined using the comet assay. Levels of DNA damage were proportionally increased by exposure concentration and the highest sediment-associated DNA damage was observed at the station showing the highest PAHs contamination. DNA damage in blood cells exposed to five types of PAHs (benzo[a]pyrene, fluoranthene, anthracene, pyrene and phenanthrene) and in flounder (Paralichthys olivaceus) exposed to benzo[a]pyrene (BaP) for 0, 2 and 4 days were assessed by measuring comet tail length. The tail lengths of five PAHs-exposed groups at 50 and 100 ppb were significantly different from the non-exposed group, and the genotoxic effect of BaP correlated with both concentration and duration of exposure. Throughout the study, significant differences in DNA breakage were recorded between cells exposed to sediment extracts or PAHs and non-exposed control. This study demonstrated the comet assay as a successful tool in monitoring contamination of marine sediments and assessing genotoxicity of PAHs in marine organisms, either in vitro or in vivo. 相似文献
80.