全文获取类型
收费全文 | 3402篇 |
免费 | 39篇 |
国内免费 | 96篇 |
专业分类
安全科学 | 70篇 |
废物处理 | 141篇 |
环保管理 | 418篇 |
综合类 | 649篇 |
基础理论 | 1248篇 |
污染及防治 | 626篇 |
评价与监测 | 195篇 |
社会与环境 | 178篇 |
灾害及防治 | 12篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 112篇 |
2017年 | 117篇 |
2016年 | 182篇 |
2015年 | 53篇 |
2014年 | 13篇 |
2013年 | 21篇 |
2012年 | 425篇 |
2011年 | 272篇 |
2010年 | 44篇 |
2009年 | 36篇 |
2008年 | 49篇 |
2007年 | 73篇 |
2006年 | 70篇 |
2005年 | 404篇 |
2004年 | 608篇 |
2003年 | 555篇 |
2002年 | 66篇 |
2001年 | 77篇 |
2000年 | 66篇 |
1999年 | 94篇 |
1998年 | 13篇 |
1997年 | 50篇 |
1996年 | 8篇 |
1995年 | 11篇 |
1994年 | 5篇 |
1993年 | 35篇 |
1992年 | 22篇 |
1991年 | 18篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1961年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有3537条查询结果,搜索用时 15 毫秒
991.
Başak S Cokgör EU Insel G Orhon D 《Environmental science and pollution research international》2012,19(8):3412-3420
Background
This study investigated the acute effect of benzo[a]anthracene, a significant compound among polycyclic aromatic hydrocarbons, on the biodegradation of a synthetic organic substrate??a peptone/meat extract mixture??under aerobic conditions.Methods
A laboratory-scale sequencing batch reactor was sustained at steady state at a sludge age of 10?days with substrate feeding. Inhibition tests involved running a series of batch reactors initially seeded with the biomass obtained from the parent reactor. After the biomass seeding, the reactors were started with the peptone mixture and a range of initial benzo[a]anthracene concentrations between 0.5 and 88?mg/L. Experimental profiles of oxygen uptake rates and polyhydroxyalkanoates were evaluated by calibration of a selected model.Results
Lower doses of benzo[a]anthracene had no effect on process kinetics. The noticeable acute impact was only observed with the addition of 88?mg/L of benzo[a]anthracene, but it was limited with the storage mechanism: the amount of organic substrate diverted to polyhydroxyalkanoates was significantly reduced with a corresponding decrease in the maximum storage rate, k STO, from 2.7 down to 0.6?day?1. Similarly, the maximum growth rate from internally stored polyhydroxyalkanoates was lowered from 2.3 to 1.0?day?1.Conclusion
Among the mechanisms for direct substrate utilization, only the hydrolysis rate was slightly reduced, but otherwise, the overall COD removal efficiency was not affected. 相似文献992.
Duarte CM Agustí S Wassmann P Arrieta JM Alcaraz M Coello A Marbà N Hendriks IE Holding J García-Zarandona I Kritzberg E Vaqué D 《Ambio》2012,41(1):44-55
The Arctic marine ecosystem contains multiple elements that present alternative states. The most obvious of which is an Arctic Ocean largely covered by an ice sheet in summer versus one largely devoid of such cover. Ecosystems under pressure typically shift between such alternative states in an abrupt, rather than smooth manner, with the level of forcing required for shifting this status termed threshold or tipping point. Loss of Arctic ice due to anthropogenic climate change is accelerating, with the extent of Arctic sea ice displaying increased variance at present, a leading indicator of the proximity of a possible tipping point. Reduced ice extent is expected, in turn, to trigger a number of additional tipping elements, physical, chemical, and biological, in motion, with potentially large impacts on the Arctic marine ecosystem. 相似文献
993.
994.
Konstanze Sch?nthaler 《Umweltwissenschaften und Schadstoff-Forschung》2001,13(2):107-116
Am Beispiel des l?nderübergreifenden Biosph?renreservates Rh?n wurde das Konzept einer ?kosystemaren Umweltbeobachtung konkretisiert. Die Arbeiten dienten der Operationalisierung der hohen fachlichen Anforderungen des Rats von Sachverst?ndigen für Umweltfragen an eine ‘Allgemeine ?kologische Umweltbeobachtung’, die medienund sektorübergreifende sowie m?glichst weitgehend harmonisierte Datenerhebungen und eine integrierte Datenauswertung vorsieht. Es werden die Bausteine einer stufenweisen Harmonisierung der Datenerhebung und Auswertung vorgestellt. Vertiefend behandelt werden Fragen nach methodischen Ans?tzen für eine nachvollziehbare Auswahl von Beobachtungsr?umen und Messtandorten sowie für die r?umliche Verallgemeinerung von Beobachtungsergebnissen. Das Konzept der ?kosystemaren Umweltbeobachtung nutzt hierfür das Instrument der bundesweiten standort?kologischen Raumgliederung sowie geostatistische Verfahren zur r?umlichen Zusammenführung bestehender Beobachtungsprogramme und Messnetze. Ferner werden M?glichkeiten aufgezeigt, wie mit der Durchführung hydrologischer Gebietsanalysen und mit einem ?kosystemarem Wasserhaushaltsmodell auf der Grundlage verfügbarer Daten integrierende Aussagen zur Entwicklung von Wassereinzugsgebieten getroffen werden k?nnen. 相似文献
995.
荣誉 《中国环境管理干部学院学报》2000,(2)
针对以往空气环境质量的模糊综合评价方法存在的不足提出了采用综合指数和模糊综合评价方法相结合的方法评价空气环境质量的新方法。 相似文献
996.
Tomáš Cajthaml Zdena K?esinová Kate?ina Svobodová Karel Sigler Tomáš ?ezanka 《Environmental pollution (Barking, Essex : 1987)》2009,157(12):3325-3335
Natural estrogens such as estrone, 17β-estradiol, estriol, and the particularly recalcitrant synthetic estrogen 17α-ethinylestradiol used as oral contraceptive, accumulate in the environment and may give rise to health problems. The processes participating in their removal from soil, wastewater, water-sediments, groundwater-aquifer material, and wastewater or sewage treatment plant effluents may involve the action of bacterial and microbial consortia, and in some cases fungi and algae. This review discusses the different efficiencies of bacterial degradation of 17α-ethinylestradiol under aerobic and anaerobic conditions, the role of sulfate-, nitrate-, and iron-reducing conditions in anaerobic degradation, and the role of sorption. The participation of autotrophic ammonia oxidizing bacteria and heterotrophic bacteria in cometabolic degradation of estrogens, the estrogen-degrading action of ligninolytic fungi and their extracellular enzymes (lignin peroxidase, manganese-dependent peroxidase, versatile peroxidase, laccase), and of algae are discussed in detail. 相似文献
997.
Jana Klánová Pavel ?upr Daniela Baráková Zdeněk Šeda Petr Anděl Ivan Holoubek 《Environmental pollution (Barking, Essex : 1987)》2009,157(12):3248-3254
Data from ten years of integrated monitoring were used here to evaluate whether pine needles are a feasible tool for an assessment of long-term trends of the atmospheric contamination. Pine needles collected once a year were compared to high volume air samples collected for 24 h, every 7 days, and passive air samples integrated over 28-day periods. Results showed the same concentration patterns of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) captured in needles and high volume samples. Passive air samplers were less efficient in sampling the particle-bound compounds. Theoretical air volume equivalent to each needle sample (VEQ) was calculated as a ratio of the needle concentration over the mean air concentration. Results indicated different equivalent volumes for PAHs and organochlorines, possibly due to the faster degradation rates of PAHs in needles. The most important finding is that in the long term a needle monitoring gives very similar information on temporal trends of the atmospheric pollution as does a high volume air monitoring. 相似文献
998.
Vesna Mici? 《Environmental pollution (Barking, Essex : 1987)》2009,157(10):2759-2768
Six hydrophobic alkylphenolic compounds were investigated for the first time simultaneously in four different matrices in the Danube River. Maximum sediment concentrations were 2.83, 2.10, 0.28, and 0.035 mg kg−1 for nonylphenol, nonylphenol monoethoxylate, nonylphenol diethoxylate and octylphenol. Maximum levels in suspended particulate matter (SPM) were 0.18, 0.12, 0.10, and 0.003 mg kg−1. No correlation between concentrations in SPM and sediments was found. Octylphenol monoethoxylate and octylphenol diethoxylate were recorded only in sediment at one location. In mussels and water only nonylphenol and octylphenol were found. Nonylphenol concentrations in mussels (up to 0.34 mg kg−1) correlate with concentrations found in SPM and indicate a slight bioaccumulation. Concentrations in water were close to the limit of quantification. We assume in situ formation of nonylphenol monoethoxylate and nonylphenol in sediments at some locations. In some cases nonylphenol in sediments exceeded the provisional EU environmental quality standards. 相似文献
999.
1000.
Jeremy?Andy?DominicEmail author Ahmad?Zaharin?ArisEmail author Wan?Nor?Azmin?Sulaiman Wan?Zakaria?Wan?Md?Tahir 《Environmental monitoring and assessment》2016,188(3):191
The approach of this paper is to predict the sand mass distribution in an urban stormwater holding pond at the Stormwater Management And Road Tunnel (SMART) Control Centre, Malaysia, using simulated depth average floodwater velocity diverted into the holding during storm events. Discriminant analysis (DA) was applied to derive the classification function to spatially distinguish areas of relatively high and low sand mass compositions based on the simulated water velocity variations at corresponding locations of gravimetrically measured sand mass composition of surface sediment samples. Three inflow parameter values, 16, 40 and 80 m3 s?1, representing diverted floodwater discharge for three storm event conditions were fixed as input parameters of the hydrodynamic model. The sand (grain size?>?0.063 mm) mass composition of the surface sediment measured at 29 sampling locations ranges from 3.7 to 45.5 %. The sampling locations of the surface sediment were spatially clustered into two groups based on the sand mass composition. The sand mass composition of group 1 is relatively lower (3.69 to 12.20 %) compared to group 2 (16.90 to 45.55 %). Two Fisher’s linear discriminant functions, F 1 and F 2, were generated to predict areas; both consist of relatively higher and lower sand mass compositions based on the relationship between the simulated flow velocity and the measured surface sand composition at corresponding sampling locations. F 1?=??9.405?+?4232.119?×?A???1795.805?×?B?+?281.224?×?C, and F 2?=??2.842?+?2725.137?×?A???1307.688?×?B?+?231.353?×?C. A, B and C represent the simulated flow velocity generated by inflow parameter values of 16, 40 and 80 m3 s?1, respectively. The model correctly predicts 88.9 and 100.0 % of sampling locations consisting of relatively high and low sand mass percentages, respectively, with the cross-validated classification showing that, overall, 82.8 % are correctly classified. The model predicts that 31.4 % of the model domain areas consist of high-sand mass composition areas and the remaining 68.6 % comprise low-sand mass composition areas. 相似文献