全文获取类型
收费全文 | 1019篇 |
免费 | 38篇 |
国内免费 | 42篇 |
专业分类
测绘学 | 32篇 |
大气科学 | 20篇 |
地球物理 | 205篇 |
地质学 | 709篇 |
海洋学 | 49篇 |
天文学 | 51篇 |
综合类 | 9篇 |
自然地理 | 24篇 |
出版年
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 26篇 |
2020年 | 39篇 |
2019年 | 22篇 |
2018年 | 100篇 |
2017年 | 86篇 |
2016年 | 88篇 |
2015年 | 42篇 |
2014年 | 80篇 |
2013年 | 136篇 |
2012年 | 44篇 |
2011年 | 70篇 |
2010年 | 46篇 |
2009年 | 49篇 |
2008年 | 29篇 |
2007年 | 15篇 |
2006年 | 25篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 13篇 |
2002年 | 28篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1099条查询结果,搜索用时 15 毫秒
991.
Mohamed Deriche 《应用地球物理》2016,13(3):449-458
The accurate interpretation and analysis of seismic data heavily depends on the robustness of the algorithms used. We focus on the robust detection of salt domes from seismic surveys. We discuss a novel feature-ranking classification model for saltdome detection for seismic images using an optimal set of texture attributes. The proposed algorithm overcomes the limitations of existing texture attribute-based techniques, which heavily depend on the relevance of the attributes to the geological nature of salt domes and the number of attributes used for accurate detection. The algorithm combines the attributes from the Gray-Level Co-occurrence Matrix (GLCM), the Gabor filters, and the eigenstructure of the covariance matrix with feature ranking using the information content. The top-ranked attributes are combined to form the optimal feature set, which ensures that the algorithm works well even in the absence of strong reflectors along the salt-dome boundaries. Contrary to existing salt-dome detection techniques, the proposed algorithm is robust and computationally efficient, and works with small-sized feature sets. I used the Netherlands F3 block to evaluate the performance of the proposed algorithm. The experimental results suggest that the proposed workflow based on information theory can detect salt domes with accuracy superior to existing salt-dome detection techniques. 相似文献
992.
993.
994.
995.
996.
Ben Ameur W de Lapuente J El Megdiche Y Barhoumi B Trabelsi S Camps L Serret J Ramos-López D Gonzalez-Linares J Driss MR Borràs M 《Marine pollution bulletin》2012,64(2):241-251
The aim of the study was to evaluate the impact of environmental contaminants on oxidative stress, genotoxic and histopathologic biomarkers in liver of mullet (Mugil cephalus) and sea bass (Dicentrarchus labrax) collected from a polluted coastal lagoon (Bizerte Lagoon) in comparison to a reference site (the Mediterranean Sea). Antioxidant enzyme activities were lower in fish from the polluted site compared with fish from the reference site, suggesting deficiency of the antioxidant system to compensate for oxidative stress. DNA damage was higher in both fish species from the contaminated site indicating genotoxic effects. The liver histopathological analysis revealed alterations in fish from Bizerte Lagoon. Hepatocytes from both fish species featured extensive lipid-type vacuolation and membrane disruption. Results suggest that the selected biomarkers in both fish species are useful for the assessment of pollution impacts in coastal environments influenced by multiple pollution sources. 相似文献
997.
Stochastic modeling of the impact of meteorological conditions on road traffic accidents 总被引:1,自引:0,他引:1
Meshari Al-Harbi Mohamed F. Yassin Mohamed Bin Shams 《Stochastic Environmental Research and Risk Assessment (SERRA)》2012,26(5):739-750
Meteorological conditions have become one of the major factors that influence the frequency and severity of motor vehicle collisions in urban environments. In Kuwait, more than 60,000 accidents occur each year, and about 500 people are killed annually on the roads. This paper is intended to investigate the impact of meteorological conditions on traffic accidents in Kuwait. Stochastic models are developed to analyze and examine the influence of meteorological conditions on the level of road accidents. Normal and lognormal probability densities and their associated cumulative density functions are used to model the meteorological conditions in four different seasons. The results indicate that the most influential meteorological condition that causes accidents is temperature during the fall, spring, and winter seasons. In the summer, wind speed is identified as the most influential factor that accounts for the increased road accidents, with temperature as the second highest meteorological condition affecting accidents. Wind speed and humidity are also found to have significant influence on accident level, following temperature in the fall and winter seasons, respectively. Correlation analyses were also applied and supported the findings obtained using stochastic analyses. The results of this study may help local authorities to reduce the number of accidents and help save people lives. 相似文献
998.
In this research, the bioremediation of dispersed crude oil, based on the amount of nitrogen and phosphorus supplementation in the closed system, was optimized by the application of response surface methodology and central composite design. Correlation analysis of the mathematical‐regression model demonstrated that a quadratic polynomial model could be used to optimize the hydrocarbon bioremediation (R2 = 0.9256). Statistical significance was checked by analysis of variance and residual analysis. Natural attenuation was removed by 22.1% of crude oil in 28 days. The highest removal on un‐optimized condition of 68.1% were observed by using nitrogen of 20.00 mg/L and phosphorus of 2.00 mg/L in 28 days while optimization process exhibited a crude oil removal of 69.5% via nitrogen of 16.05 mg/L and phosphorus 1.34 mg/L in 27 days therefore optimization can improve biodegradation in shorter time with less nutrient consumption. 相似文献
999.
Mohamed O.Soliman Waleed B.Suleiman Mohamed M.Roushdy Eman N.Elbatrawy Ahmed M.Gad 《海洋学报(英文版)》2022,41(3):86-93
Marine microorganisms were considered to be important sources of marine bioactive compounds. The major objective of the study was to isolate and characterize bacteria with antimicrobial activities from the various marine environment of Egypt. In this respect, thirty-five bacterial isolates were recovered from sediment samples collected from different spots along the Egyptian Red Sea coastline and Alexandria coastline during the summer season of 2017 and 2018. According to the morphological, phys... 相似文献
1000.
Acta Geotechnica - Soil bio-cementation via microbially induced carbonate precipitation (MICP) has been extensively studied as a promising alternative technique to traditional chemical cementing... 相似文献