全文获取类型
收费全文 | 20541篇 |
免费 | 181篇 |
国内免费 | 136篇 |
专业分类
安全科学 | 436篇 |
废物处理 | 865篇 |
环保管理 | 2205篇 |
综合类 | 4361篇 |
基础理论 | 4779篇 |
环境理论 | 11篇 |
污染及防治 | 5481篇 |
评价与监测 | 1384篇 |
社会与环境 | 1273篇 |
灾害及防治 | 63篇 |
出版年
2022年 | 227篇 |
2021年 | 257篇 |
2020年 | 129篇 |
2019年 | 176篇 |
2018年 | 374篇 |
2017年 | 385篇 |
2016年 | 544篇 |
2015年 | 400篇 |
2014年 | 602篇 |
2013年 | 1452篇 |
2012年 | 679篇 |
2011年 | 916篇 |
2010年 | 679篇 |
2009年 | 716篇 |
2008年 | 918篇 |
2007年 | 920篇 |
2006年 | 821篇 |
2005年 | 671篇 |
2004年 | 679篇 |
2003年 | 644篇 |
2002年 | 589篇 |
2001年 | 683篇 |
2000年 | 425篇 |
1999年 | 335篇 |
1998年 | 203篇 |
1997年 | 222篇 |
1996年 | 240篇 |
1995年 | 255篇 |
1994年 | 256篇 |
1993年 | 226篇 |
1992年 | 211篇 |
1991年 | 221篇 |
1990年 | 214篇 |
1989年 | 183篇 |
1988年 | 182篇 |
1987年 | 164篇 |
1986年 | 171篇 |
1985年 | 159篇 |
1984年 | 178篇 |
1983年 | 180篇 |
1982年 | 191篇 |
1981年 | 152篇 |
1980年 | 145篇 |
1979年 | 131篇 |
1978年 | 142篇 |
1977年 | 122篇 |
1976年 | 109篇 |
1975年 | 115篇 |
1974年 | 121篇 |
1967年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
981.
A Carbon Cycle Science Update Since IPCC AR-4 总被引:1,自引:0,他引:1
Dolman AJ van der Werf GR van der Molen MK Ganssen G Erisman JW Strengers B 《Ambio》2010,39(5-6):402-412
982.
G. Shi Z. Chen C. Bi J. Teng S. Xu 《Environmental pollution (Barking, Essex : 1987)》2010,158(3):694-703
A set of toxic metals, i.e. As, Hg, Pb, Cd, Cu, Zn, Ni and Cr, in urban and suburban SDSs were investigated comparatively in the biggest metropolitan area of China, Shanghai. Results showed that all of the metals except As were accumulated greatly, much higher than background values. Geo-accumulation index indicated that metal contamination in urban SDSs was generally heavier than that in suburban SDSs. Potential ecological risk index demonstrated that overall risks caused by metals were considerable. Cd contributed 52% to the overall risk. Multivariate statistical analysis revealed that in urban SDSs, Zn, Ni, Cd, Pb, Cu and Cr were related to traffic and industry; coal combustion led to elevated levels of Hg; soil parent materials controlled As contents. In suburban SDSs, Pb, Cu, As and Cd largely originated from traffic pollution; Zn, Ni and Cr were associated with industrial contaminants; Hg was mainly from domestic solid waste. 相似文献
983.
Pérez-Parada A González J Pareja L Geis-Asteggiante L Colazzo M Niell S Besil N González G Cesio V Heinzen H 《Journal of environmental science and health. Part. B》2010,45(8):796-803
In order to evaluate the extraction of pesticide residues that are transferred to the brew during mate drinking process of P.U.1 yerba mate leaves (Ilex paraguariensis), a special device to simulate the way in which mate is drunk in Uruguay was developed. The transfer to the brew of 12 organophosphates, 5 synthethic pyrethroids and one organochlorine pesticide from spiked samples was studied. The relationship between the transfer data thus obtained and physicochemical properties like water solubility (Ws), octanol-water coefficient (Kow) and Henry's constant (H) was evaluated. The extractability of the pesticide residues from yerba mate can be correlated with log Ws and log Kow. These transfer values allowed the calculation of ARLs (acceptable residue level) for the pesticides following Food and Agriculture Organization (FAO), World Health Organizaion (WHO) guidelines. These results can help the future establishment of maximum residue levels (MRLs). 相似文献
984.
C. Munschy K. Héas-Moisan G. Pacepavicius 《Environmental pollution (Barking, Essex : 1987)》2010,158(12):3527-3533
The uptake, elimination and transformation of six PBDE congeners (BDE-28, -47, -99, -100, -153, -209) were studied in juvenile common sole (Solea solea L.) exposed to spiked contaminated food over a three-month period, and then depurated over a five-month period. Methoxylated (MeO-) and hydroxylated (OH-) PBDEs were determined in fish plasma exposed to PBDEs and compared to those obtained in control fish. While all MeO- and some OH- congeners identified in fish plasma were found to originate from non-metabolic sources, several OH- congeners, i.e., OH-tetraBDEs and OH-pentaBDEs, were found to originate from fish metabolism. Among these, 4′-OH-BDE-49 was identified as a BDE-47 metabolite. Congener 4′-OH-BDE-101, identified here for the first time, may be the result of BDE-99 metabolic transformation. Our results unequivocally showed that PBDEs are metabolised in juvenile sole via the formation of OH- metabolites. However, this was not a major biotransformation route compared to biotransformation through debromination. 相似文献
985.
The critical load (CL) of acidic atmospheric deposition represents the load of acidity deposited from the atmosphere to the earth’s surface at which harmful acidification effects on sensitive biological receptors are thought to occur. In this study, the CL for forest soils was estimated for 27 watersheds throughout the United States using a steady-state mass balance approach based on both national and site-specific data and using different approaches for estimating base cation weathering. Results suggested that the scale and source of input data can have large effects on the calculated CL and that the most important parameter in the steady-state model used to estimate CL is base cation weathering. These results suggest that the data and approach used to estimate weathering must be robust if the calculated CL is to be useful for its intended purpose. 相似文献
986.
Roberto Rosal Ismael Rodea-Palomares Karina Boltes Francisca Fernández-Piñas Francisco Leganés Soledad Gonzalo Alice Petre 《Environmental science and pollution research international》2010,17(1):135-144
Background, aim, and scope
The high consumption of blood lipid regulators is leading to frequent reports of the occurrence of fibrates in natural streams and wastewater effluents. This paper describes a study undertaken to evaluate the acute toxicity of bezafibrate, clofibric acid, gemfibrozil, and fenofibric acid, a metabolite of fenofibrate whose ecotoxicity has not been previously reported. 相似文献987.
The Efficacy of a Programme of Landslide Risk Reduction in Areas of Unplanned Housing in the Eastern Caribbean 总被引:1,自引:0,他引:1
Malcolm G. Anderson Elizabeth Holcombe Maricarmen Esquivel Joaquin Toro Francis Ghesquiere 《Environmental management》2010,45(4):807-821
Poor countries are disproportionately affected by the cost of disasters. Yet there is evidence of the benefits of seeking
to mitigate the impact of a disaster, compared with the costs incurred in ‘making good’ after a major event has occurred.
This article reviews a programme of landslide risk reduction in unplanned communities in the Eastern Caribbean. The construction
of appropriate surface water management measures, based on the application of scientific and engineering principles, has been
demonstrated to reduce the hazard from rainfall-triggered landslides. Adopting a community-based approach additionally delivers
social and environmental benefits relating to employment generation, improvements in the environmental conditions within the
community, and improvements slope management practices. The sustained implementation of the community-based projects has provided
the necessary evidence-base for these practices to influence Government policy and practice, and gain recognition from regional
development agencies. The strategic and incremental uptake of the community-based methodology is demonstrated to be an effective
means for delivering physical landslide risk reduction measures in the most ‘at risk’ areas of unplanned housing. 相似文献
988.
In this second part of the work, two other long-term technologies for power generation from coal are investigated. The Zecomag plant has the same syngas production system of the Zecomix plant, described in the first part of this paper, but hydrogen-rich syngas is here burned with air in an open-cycle gas turbine. The aim is a simplification of the power island, more similar to a combined cycle; however, CO2 capture falls from 100% to about 90% and NOx emissions are present.An advanced oxy-fuel IGCC is the second plant investigated in this paper, presenting the same zero-emission potential of Zecomix. Syngas is produced in a high pressure, dry feed, oxygen blown gasifier and cleaned in a hot-gas-clean-up system. Clean syngas is then burned with oxygen and expanded in a turbine, using compressed recirculated CO2 to moderate firing temperature and to cool turbine blades.The loss of net efficiency, with respect to Zecomix, is very limited (1–2 points) with both configurations. In order to better evaluate the performances obtained, a comparison with reference state-of-the art IGCCs and a long-term IGCC without CO2 capture is also presented. 相似文献
989.
P. Noorunnisa Khanam H. P. S. Abdul Khalil M. Jawaid G. Ramachandra Reddy C. Surya Narayana S. Venkata Naidu 《Journal of Polymers and the Environment》2010,18(4):727-733
The variation of mechanical properties such as tensile and flexural properties of randomly oriented unsaturated polyester
based sisal/carbon fibre reinforced hybrid composites with different fibre weight ratios have been studied. The chemical resistance
test of these hybrid composites to various solvents, acids and alkalies were studied. The effect of NaOH treatment of sisal
fibres on the tensile, flexural and chemical resistance properties of these sisal/carbon hybrid composites has also been studied.
The hybrid composites showed an increase in tensile and flexural properties with increase in the carbon fibre loading. The
tensile properties and flexural properties of these hybrid composites have been found to be higher than that of the matrix.
Significant improvement in tensile properties and flexural properties of the sisal/carbon hybrid composites has been observed
by alkali treatment. The chemical resistance test results showed that these untreated and alkali treated hybrid composites
are résistance to all chemicals except carbon tetra chloride. Hand lay-up technique was used for making the composites and
tests are carried out by using ASTM methods. 相似文献
990.
Jianjun Niu Pat E. Rasmussen Amanda Wheeler Ron Williams Marc Chénier 《Atmospheric environment (Oxford, England : 1994)》2010,44(2):235-245
Factors and sources affecting measurement uncertainty associated with monitoring metals in airborne particulate matter (PM) were investigated as part of the Windsor, Ontario Exposure Assessment Study (WOEAS). The assessment was made using co-located duplicate samples and a comparison of two analytical approaches: ED-XRF and ICP-MS. Sampling variability was estimated using relative percent difference (RPD) of co-located duplicate samples. The comparison of ICP-MS and ED-XRF results yields very good correlations (R2 ≥ 0.7) for elements present at concentrations that pass both ICP-MS and ED-XRF detection limits (e.g. Fe, Mn, Zn, Pb and Cu). PM concentration ranges (median, sample number) of 24-h indoor PM10 and personal PM10 filters, and outdoor PM2.5 filters were determined to be 2.2–40.7 (11.0, n = 48) μg m?3, 8.0–48.3 (11.9, n = 48) μg m?3, and 17.1–42.3 (21.6, n = 18) μg m?3, respectively. The gravimetric analytical results reveal that the variations in PM mass measurements for same-day sampling are insignificant compared to temporal or spatial variations: 92%, 100% and 96% of indoor, outdoor and personal duplicate samples, respectively, pass the quality criteria (RPD ≤ 20%). Uncertainties associated with ED-XRF elemental measurements of S, Ca, Mn, Fe and Zn for 24-h filter samples are low: 78%–100% of the duplicate samples passed the quality criteria. In the case of 24-h filter samples using ICP-MS, more elements passed the quality criteria due to the lower detection limits. These were: Li, Na, K, Ca, Si, Al, V, Fe, Mn, Co, Cu, Mo, Ag, Zn, Pb, As, Mg, Sb, Sn, Sr, Th, Ti, Tl, and U. Low air concentrations of metals (near or below instrumental detection limits) and/or inadvertent introduction of metal contamination are the main causes for excluding elements based on the pass/fail criteria. Uncertainty associated with elemental measurements must be assessed on an element-by-element basis. 相似文献