全文获取类型
收费全文 | 5567篇 |
免费 | 28篇 |
国内免费 | 26篇 |
专业分类
安全科学 | 136篇 |
废物处理 | 310篇 |
环保管理 | 442篇 |
综合类 | 834篇 |
基础理论 | 1367篇 |
环境理论 | 1篇 |
污染及防治 | 1389篇 |
评价与监测 | 405篇 |
社会与环境 | 710篇 |
灾害及防治 | 27篇 |
出版年
2023年 | 44篇 |
2022年 | 88篇 |
2021年 | 69篇 |
2020年 | 35篇 |
2019年 | 44篇 |
2018年 | 79篇 |
2017年 | 96篇 |
2016年 | 116篇 |
2015年 | 72篇 |
2014年 | 147篇 |
2013年 | 426篇 |
2012年 | 174篇 |
2011年 | 242篇 |
2010年 | 217篇 |
2009年 | 221篇 |
2008年 | 255篇 |
2007年 | 251篇 |
2006年 | 241篇 |
2005年 | 208篇 |
2004年 | 189篇 |
2003年 | 215篇 |
2002年 | 176篇 |
2001年 | 255篇 |
2000年 | 161篇 |
1999年 | 101篇 |
1998年 | 41篇 |
1997年 | 58篇 |
1996年 | 53篇 |
1995年 | 61篇 |
1994年 | 64篇 |
1993年 | 59篇 |
1992年 | 58篇 |
1991年 | 61篇 |
1990年 | 66篇 |
1989年 | 52篇 |
1988年 | 56篇 |
1987年 | 54篇 |
1986年 | 55篇 |
1985年 | 41篇 |
1984年 | 50篇 |
1983年 | 48篇 |
1982年 | 49篇 |
1980年 | 32篇 |
1979年 | 32篇 |
1978年 | 29篇 |
1977年 | 28篇 |
1976年 | 28篇 |
1974年 | 31篇 |
1973年 | 30篇 |
1972年 | 27篇 |
排序方式: 共有5621条查询结果,搜索用时 140 毫秒
261.
Distribution of 238U and 226Ra in soils and plants of an industrially polluted area are considered. The dependence between the biological uptake coefficients
(BUCs) for the plant species studied and the radionuclide concentrations in soil can be approximated by a decreasing power
function. Species differences in radionuclide uptake are demonstrated. 相似文献
262.
263.
264.
S. O. Asagba G. E. Eriyamremu J. O. T. Emudainohwo I. Okoro 《The Environmentalist》2010,30(3):260-266
The activities of some oxidative enzymes (aldehyde oxidase, AO, EC 1.2.3.1; xanthine oxidase, XO, EC 1.17.3.2; sulphite oxidase,
SO, EC 1.8.3.1; and monoamine oxidase, MO, EC 1.4.3.4) were investigated in the liver, gill, kidney, brain and muscle of a
variety of African catfish (Clarias gariepinus) after 7 and 21 days of exposure to 0.1, 0.2 and 0.4 ppm cadmium (Cd) in ambient water. MO, SO and AO activities were significantly
(p < 0.05) decreased in a dose-dependent manner in the liver, kidney and gill in the 7-day Cd-exposed fish when compared to
control. Conversely, brain MO, AO and SO activities were significantly (p < 0.05) elevated in a dose-dependent manner in the same fishes relative to control. As in the 7-day Cd-exposed fish, the
activities of MO, AO and SO were significantly (p < 0.05) decreased in a dose-dependent manner in the gill, kidney and liver of catfish exposed for 21 days. Same is true for
XO in these organs after both duration of exposure, except in the liver where no significant change was observed relative
to control. The inhibition of these oxidative enzymes in the liver, gill and kidney of catfish may interfere with their biotransformation
function, and ultimately the survival of the fish may be compromised. 相似文献
265.
Ecotoxicity of nanoparticles of CuO and ZnO in natural water 总被引:1,自引:0,他引:1
I. Blinova A. Ivask M. Mortimer A. Kahru 《Environmental pollution (Barking, Essex : 1987)》2010,158(1):41-47
The acute toxicity of CuO and ZnO nanoparticles in artificial freshwater (AFW) and in natural waters to crustaceans Daphnia magna and Thamnocephalus platyurus and protozoan Tetrahymena thermophila was compared. The L(E)C50 values of nanoCuO for both crustaceans in natural water ranged from 90 to 224 mg Cu/l and were about 10-fold lower than L(E)C50 values of bulk CuO. In all test media, the L(E)C50 values for both bulk and nanoZnO (1.1-16 mg Zn/l) were considerably lower than those of nanoCuO. The natural waters remarkably (up to 140-fold) decreased the toxicity of nanoCuO (but not that of nanoZnO) to crustaceans depending mainly on the concentration of dissolved organic carbon (DOC). The toxicity of both nanoCuO and nanoZnO was mostly due to the solubilised ions as determined by specific metal-sensing bacteria. 相似文献
266.
S. Guilherme M. A. Santos I. Gaivão M. Pacheco 《Environmental science and pollution research international》2014,21(14):8730-8739
The assessment of the direct impact of breakdown products of pesticide components on aquatic wildlife is ecotoxicologically relevant, but frequently disregarded. In this context, the evaluation of the genotoxic hazard posed by aminomethylphosphonic acid (AMPA—the major natural degradation product of glyphosate) to fish emerges as a critical but unexplored issue. Hence, the main goal of the present research was to assess the AMPA genotoxic potential to fish following short-term exposures (1 and 3 days) to environmentally realistic concentrations (11.8 and 23.6 μg L?1), using the comet and erythrocytic nuclear abnormalities (ENA) assays, as reflecting different levels of damage, i.e. DNA and chromosomal damage, respectively. Overall, the present findings pointed out the genotoxic hazard of AMPA to fish and, subsequently, the importance of including it in future studies concerning the risk assessment of glyphosate-based herbicides in the water systems. 相似文献
267.
Aarif H. El-Mubarak Ahmed I. Rushdi Khalid F. Al-Mutlaq Abdulqader Y. Bazeyad Staci L. M. Simonich Bernd R. T. Simoneit 《Environmental science and pollution research international》2014,21(1):558-567
In an effort to assess the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of Riyadh, Saudi Arabia, PM10 samples were collected during December 2010. Diagnostic PAH concentration ratios were used as a tool to identify and characterize the PAH sources. The results reflect high PM10 and PAH concentrations (particulate matter (PM)?=?270–1,270 μg/m3). The corresponding average PAH concentrations were in the range of 18?±?8 to 1,003?±?597 ng/m3 and the total concentrations (total PAHs (TPAHs) of 17 compounds) varied from 1,383 to 13,470 ng/m3 with an average of 5,871?±?2,830 ng/m3. The detection and quantification limits were 1–3 and 1–10 ng/ml, respectively, with a recovery range of 42–80 %. The ratio of the sum of the concentrations of the nine major non-alkylated compounds to the total (CPAHs/TPAHs) was 0.87?±?0.10, and other ratios were determined to apportion the PM sources. The PAHs found are characteristic for emissions from traffic with diesel being a predominant source. 相似文献
268.
G. I. Chandrasena A. Deletic D. T. McCarthy 《Environmental science and pollution research international》2014,21(8):5391-5401
Biofilters are widely adopted in Australia for stormwater treatment, but the reported removal of common faecal indicators (such as Escherichia coli (E. coli)) varies from net removal to net leaching. Currently, the underlying mechanisms that govern the faecal microbial removal in the biofilters are poorly understood. Therefore, it is important to study retention and subsequent survival of faecal microorganisms in the biofilters under different biofilter designs and operational characteristics. The current study investigates how E. coli survival is influenced by temperature, moisture content, sunlight exposure and presence of other microorganisms in filter media and top surface sediment. Soil samples were taken from two different biofilters to investigate E. coli survival under controlled laboratory conditions. Results revealed that the presence of other microorganisms and temperature are vital stressors which govern the survival of E. coli captured either in the top surface sediment or filter media, while sunlight exposure and moisture content are important for the survival of E. coli captured in the top surface sediment compared to that of the filter media. Moreover, increased survival was found in the filter media compared to the top sediment, and sand filter media was found be more hostile than loamy sand filter media towards E. coli survival. Results also suggest that the contribution from the tested environmental stressors on E. coli survival in biofilters will be greatly affected by the seasonality and may vary from one site to another. 相似文献
269.
S. J. Metcalf E. I. van Putten S. D. Frusher M. Tull N. Marshall 《Sustainability Science》2014,9(3):247-261
Identifying effective adaptation strategies for coastal communities dependent on marine resources and impacted by climate change can be difficult due to the dynamic nature of marine ecosystems. The task is more difficult if current and predicted shifts in social and economic trends are considered. Information about social and economic change is often limited to qualitative data. A combination of qualitative and quantitative models provide the flexibility to allow the assessment of current and future ecological and socio-economic risks and can provide information on alternative adaptations. Here, we demonstrate how stakeholder input, qualitative models and Bayesian belief networks (BBNs) can provide semi-quantitative predictions, including uncertainty levels, for the assessment of climate and non-climate-driven change in a case study community. Issues are identified, including the need to increase the capacity of the community to cope with change. Adaptation strategies are identified that alter positive feedback cycles contributing to a continued decline in population, local employment and retail spending. For instance, the diversification of employment opportunities and the attraction of new residents of different ages would be beneficial in preventing further population decline. Some impacts of climate change can be combated through recreational bag or size limits and monitoring of popular range-shifted species that are currently unmanaged, to reduce the potential for excessive removal. Our results also demonstrate that combining BBNs and qualitative models can assist with the effective communication of information between stakeholders and researchers. Furthermore, the combination of techniques provides a dynamic, learning-based, semi-quantitative approach for the assessment of climate and socio-economic impacts and the identification of potential adaptation strategies. 相似文献
270.
Vanina A. Angelini Elizabeth Agostini María I. Medina Paola S. González 《Environmental science and pollution research international》2014,21(4):2531-2539
2,4-Dichlorophenol (2,4-DCP) is widely distributed in wastewaters discharged from several industries, and it is considered as a priority pollutant due to its high toxicity. In this study, the use of different peroxidase extracts for 2,4-DCP removal from aqueous solutions was investigated. Tobacco hairy roots (HRs), wild-type (WT), and double-transgenic (DT) for tomato basic peroxidases (TPX1 and TPX2) were used to obtain different peroxidase extracts: total peroxidases (TPx), soluble peroxidases (SPx), and peroxidases ionically bound to the cell wall (IBPx). All extracts derived from DT HRs exhibited higher peroxidase activity than those obtained from WT HRs. TPx and IBPx DT extracts showed the highest catalytic efficiency values. The optimal conditions for 2,4-DCP oxidation were pH 6.5, H2O2 0.5 mM, and 200 U mL?1 of enzyme, for all extracts analyzed. Although both TPx extracts were able to oxidize different 2,4-DCP concentrations, the removal efficiency was higher for TPx DT. Polyethylene glycol addition slightly improved 2,4-DCP removal efficiency, and it showed some protective effect on TPx WT after 2,4-DCP oxidation. In addition, using Lactuca sativa test, a reduction of the toxicity of post removal solutions was observed, for both TPx extracts. The results demonstrate that TPx extracts from both tobacco HRs appear to be promising candidate for future applications in removing 2,4-DCP from wastewaters. This is particularly true considering that these peroxidase sources are associated with low costs and are readily available. However, TPx DT has increased peroxidase activity, catalytic efficiency, and higher removal efficiency than TPx WT, probably due to the expression of TPX1 and TPX2 isoenzymes. 相似文献