全文获取类型
收费全文 | 628篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 22篇 |
废物处理 | 18篇 |
环保管理 | 85篇 |
综合类 | 93篇 |
基础理论 | 138篇 |
环境理论 | 2篇 |
污染及防治 | 190篇 |
评价与监测 | 39篇 |
社会与环境 | 45篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 13篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 21篇 |
2017年 | 17篇 |
2016年 | 18篇 |
2015年 | 27篇 |
2014年 | 28篇 |
2013年 | 47篇 |
2012年 | 26篇 |
2011年 | 36篇 |
2010年 | 43篇 |
2009年 | 38篇 |
2008年 | 30篇 |
2007年 | 37篇 |
2006年 | 31篇 |
2005年 | 20篇 |
2004年 | 28篇 |
2003年 | 21篇 |
2002年 | 26篇 |
2001年 | 10篇 |
2000年 | 17篇 |
1999年 | 16篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1984年 | 2篇 |
1980年 | 3篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1958年 | 1篇 |
1955年 | 1篇 |
1949年 | 1篇 |
1948年 | 1篇 |
1937年 | 1篇 |
1920年 | 1篇 |
排序方式: 共有638条查询结果,搜索用时 421 毫秒
311.
Contamination of industrial sites by wood preservatives such as chromated copper arsenate (CCA) may pose a serious threat to groundwater quality. The objective of this study was to characterise the spatial variability of As and Cr concentrations in the solid phase and in the soil water at a former wood impregnation plant and to reveal the fundamental transport processes. The soil was sampled down to a depth of 2m. The soil water was extracted in situ from the vadose zone over a period of 10 months at depths of 1 and 1.5m, using large horizontally installed suction tubes. Groundwater was sampled from a depth of 4.5m. Results showed that arsenic and chromium had accumulated in the upper region of the profile and exhibited a high spatial variability (As: 21-621 mg kg(-1); Cr: 74-2872 mg kg(-1)). Concentrations in the soil water were high (mean As 167 microg L(-1); Cr: 62 microg L(-1)) and also showed a distinct spatial variability, covering concentration ranges up to three orders of magnitude. The variability was caused by the severe water-repellency of the surface soil, induced by the concurrent application of creosote wood preservatives, which leads to strong preferential flow as evident from a dye experiment. In contrast to soil water concentrations, only low As concentrations (<12 microg L(-1)) were detected in the groundwater. High Cr concentrations in the groundwater (approx. 300 microg L(-1)), however, illustrated the pronounced mobility of chromium. Our study shows that at sites with a heterogeneous flow system in the vadose zone a disparity between flux-averaged and volume-averaged concentrations may occur, and sampling of soil water might not be adequate for assessing groundwater concentrations. In these cases long-term monitoring of the groundwater appears to be the best strategy for a groundwater risk assessment. 相似文献
312.
Mann S 《Journal of environmental management》2007,85(1):198-203
Major benefit uncertainties prevent monetary quantification of some environmental amenities. Replacing mineral lubricants with biodegradable substitutes is shown to be a case in point. However, it is possible to rank the social benefits of substituting mineral lubricants with regard to different applications and environments. As the private costs and benefits of substitution are mainly constant, only a policy that prioritizes full substitution in the applications with the greatest benefits can be efficient. It is shown that regulations requiring substitution in certain fields are likely to fulfil this criterion, while subsidies for production, processing, market introduction and research usually fail to meet the efficiency criterion. 相似文献
313.
314.
Stefan Greiving Mark Fleischhauer Johannes Lückenkötter 《Journal of Environmental Planning and Management》2006,49(1):1-19
Natural and technological disasters of the past have shown that such incidences significantly affect local and regional development. Faced with the task of ensuring economic, human and environmental development as well as insuring physical structures, planning authorities, insurance companies and emergency managers are looking for methodologies to identify highly sensitive areas in terms of their overall risk. Existing methodologies like the Natural Hazard Index for Megacities or the Total Place Vulnerability Index have limitations due to their sectoral approach, which makes them less useful for integrated spatial planning. This paper presents the Integrated Risk Assessment of Multi-Hazards as a new approach to serve as a basis for a spatial risk management process. The approach integrates various hazards into an integrated hazard map, combines this with the region's vulnerability and thus produces an integrated risk map. Moreover, the methodology offers a tool to derive weighting factors for hazards as well as for vulnerability components. 相似文献
315.
316.
Ohne Zusammenfassung
Dipl.-Chem. Dr. Stefan Nowicki ist Physiko-Chemiker mit Spezialgebiet in der Phasen- und Grenzfl?chenchemie. Als Prokurist
und Leiter Forschung und Entwicklung der S?ll GmbH in Hof/Oberfranken geh?rt zu seinem Aufgabengebiet die chemikalienrechtliche
überwachung und Ausstattung der Produkte und die Einhaltung der o.a. Richtlinien beim Tochterunternehmen Lavaris-Lake GmbH. 相似文献
317.
318.
319.
320.
Schnitzer SA Klironomos JN Hillerislambers J Kinkel LL Reich PB Xiao K Rillig MC Sikes BA Callaway RM Mangan SA van Nes EH Scheffer M 《Ecology》2011,92(2):296-303
Ecosystem productivity commonly increases asymptotically with plant species diversity, and determining the mechanisms responsible for this well-known pattern is essential to predict potential changes in ecosystem productivity with ongoing species loss. Previous studies attributed the asymptotic diversity-productivity pattern to plant competition and differential resource use (e.g., niche complementarity). Using an analytical model and a series of experiments, we demonstrate theoretically and empirically that host-specific soil microbes can be major determinants of the diversity-productivity relationship in grasslands. In the presence of soil microbes, plant disease decreased with increasing diversity, and productivity increased nearly 500%, primarily because of the strong effect of density-dependent disease on productivity at low diversity. Correspondingly, disease was higher in plants grown in conspecific-trained soils than heterospecific-trained soils (demonstrating host-specificity), and productivity increased and host-specific disease decreased with increasing community diversity, suggesting that disease was the primary cause of reduced productivity in species-poor treatments. In sterilized, microbe-free soils, the increase in productivity with increasing plant species number was markedly lower than the increase measured in the presence of soil microbes, suggesting that niche complementarity was a weaker determinant of the diversity-productivity relationship. Our results demonstrate that soil microbes play an integral role as determinants of the diversity-productivity relationship. 相似文献