全文获取类型
收费全文 | 14078篇 |
免费 | 96篇 |
国内免费 | 73篇 |
专业分类
安全科学 | 213篇 |
废物处理 | 995篇 |
环保管理 | 2418篇 |
综合类 | 1315篇 |
基础理论 | 4078篇 |
环境理论 | 5篇 |
污染及防治 | 2812篇 |
评价与监测 | 1318篇 |
社会与环境 | 1045篇 |
灾害及防治 | 48篇 |
出版年
2023年 | 21篇 |
2022年 | 20篇 |
2021年 | 47篇 |
2020年 | 29篇 |
2019年 | 60篇 |
2018年 | 1525篇 |
2017年 | 1441篇 |
2016年 | 1281篇 |
2015年 | 229篇 |
2014年 | 118篇 |
2013年 | 542篇 |
2012年 | 621篇 |
2011年 | 1542篇 |
2010年 | 858篇 |
2009年 | 758篇 |
2008年 | 1103篇 |
2007年 | 1447篇 |
2006年 | 231篇 |
2005年 | 178篇 |
2004年 | 212篇 |
2003年 | 244篇 |
2002年 | 261篇 |
2001年 | 92篇 |
2000年 | 113篇 |
1999年 | 98篇 |
1998年 | 81篇 |
1997年 | 64篇 |
1996年 | 72篇 |
1995年 | 71篇 |
1994年 | 61篇 |
1993年 | 65篇 |
1992年 | 72篇 |
1991年 | 43篇 |
1990年 | 51篇 |
1989年 | 42篇 |
1988年 | 32篇 |
1987年 | 38篇 |
1986年 | 44篇 |
1985年 | 40篇 |
1984年 | 55篇 |
1983年 | 56篇 |
1982年 | 38篇 |
1981年 | 54篇 |
1980年 | 44篇 |
1979年 | 22篇 |
1978年 | 24篇 |
1977年 | 17篇 |
1976年 | 12篇 |
1975年 | 14篇 |
1971年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
861.
This study was conducted in the Swedish sub-Arctic, near Abisko, in order to assess the direction and scale of possible vegetation
changes in the alpine–birch forest ecotone. We have re-surveyed shrub, tree and vegetation data at 549 plots grouped into
61 clusters. The plots were originally surveyed in 1997 and re-surveyed in 2010. Our study is unique for the area as we have
quantitatively estimated a 19% increase in tree biomass mainly within the existing birch forest. We also found significant
increases in the cover of two vegetation types—“birch forest-heath with mosses” and “meadow with low herbs”, while the cover
of snowbed vegetation decreased significantly. The vegetation changes might be caused by climate, herbivory and past human
impact but irrespective of the causes, the observed transition of the vegetation will have substantial effects on the mountain
ecosystems. 相似文献
862.
863.
Floodplain soils containing elevated levels of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) were collected from several locations along the Tittabawassee River (Michigan, USA). The PCDD/F profiles of these soils exhibited distinct congener patterns consistent with byproducts from either chloralkali manufacturing or chlorophenols productions. Black carbon (BC) particles were isolated for the first time from floodplain soil impacted by PCDD/Fs. Petrographic analysis showed that BC particles, including coal, oxidized coal, metallurgical coke, depositional carbon, coal tar/pitch, cenosphere, and charcoal, comprised approximately 30% by volume of the organic fraction with size range of 250 μm-2000 μm from a typical floodplain soil. The BC particles with anthropogenic origin such as pitch and coke associated with the chloralkali production process served as both the source and subsequent transporter for the highly hydrophobic PCDD/Fs. These anthropogenic BC particles were enriched with high levels of PCDFs, containing approximately 1000-fold the concentration found in the bulk soil. The strong association of PCDD/Fs with anthropogenic BC directly impacts the physicochemical and biological availability thus the risk associated with these hydrophobic organochlorines in soils and sediments. 相似文献
864.
Concerns regarding the impacts of pesticides on aquatic species and drinking water sources have increased demands on water quality monitoring programs; however the costs of sample analysis can be prohibitive. In this study we investigated enzyme-linked immunosorbent assay (ELISA) as a cost-effective, high through-put method for measuring pesticide concentrations in surface waters. Seven hundred and thirty-nine samples from 158 locations throughout Ontario were analysed for atrazine and metolachlor from April to October 2007. Concentrations ranged from <0.1 to 3.91 μg L−1 (median = 0.12 μg L−1) for atrazine and from <0.1 to 1.83 μg L−1 (median = 0.09 μg L−1) for metolachlor. Peak concentrations occurred in late spring/early summer, in rural agricultural locations, and decreased over the remainder of the growing season for both herbicides. About 3% of the samples that had ELISA results occurring above the limit of quantification (0.10 μg L−1) were evaluated against gas chromatography-mass spectrometry (GC-MS). Linear regression analysis revealed a R2 value of 0.88 and 0.39, for atrazine and metolachlor, respectively. ELISA tended to overestimate concentrations for atrazine and metolachlor, most likely because the ELISA kits also detect their metabolites. Atrazine data suggest that ELISA may be used complementary with GC-MS analysis to enhance the spatial and temporal resolution of a water quality monitoring study. The commercially available metolachlor ELISA kit requires further investigation. ELISA may be used to detect atrazine and metolachlor in surface water samples, but it is not recommended as a quantitative replacement for traditional analytical methods. 相似文献
865.
Onandia G Olsson AK Barth S King JS Uddling J 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2350-2354
With rising concentrations of both atmospheric carbon dioxide (CO2) and tropospheric ozone (O3), it is important to better understand the interacting effects of these two trace gases on plant physiology affecting land-atmosphere gas exchange. We investigated the effect of growth under elevated CO2 and O3, singly and in combination, on the primary short-term stomatal response to CO2 concentration in paper birch at the Aspen FACE experiment. Leaves from trees grown in elevated CO2 and/or O3 exhibited weaker short-term responses of stomatal conductance to both an increase and a decrease in CO2 concentration from current ambient level. The impairement of the stomatal CO2 response by O3 most likely developed progressively over the growing season as assessed by sap flux measurements. Our results suggest that expectations of plant water-savings and reduced stomatal air pollution uptake under rising atmospheric CO2 may not hold for northern hardwood forests under concurrently rising tropospheric O3. 相似文献
866.
Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods 总被引:7,自引:0,他引:7
Zhang C Qiao Q Piper JD Huang B 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):3057-3070
Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. 相似文献
867.
Giloteaux L Solé A Esteve I Duran R 《Environmental science and pollution research international》2011,18(7):1147-1159
Introduction
A Microcoleus sp. consortium, obtained from the Ebro delta microbial mat, was maintained under different conditions including uncontaminated, lead-contaminated, and acidic conditions. 相似文献868.
Kabra AN Khandare RV Kurade MB Govindwar SP 《Environmental science and pollution research international》2011,18(8):1360-1373
Purpose
The dyes and dye stuffs present in effluents released from textile dyeing industries are potentially mutagenic and carcinogenic. Phytoremediation technology can be used for remediating sites contaminated with such textile dyeing effluents. The purpose of the work was to explore the potential of Glandularia pulchella (Sweet) Tronc. to decolorize different textile dyes, textile dyeing effluent, and synthetic mixture of dyes. 相似文献869.
Mladenova EK Dakova IG Karadjova IB 《Environmental science and pollution research international》2011,18(9):1633-1643
Purpose
Chitosan membranes (non-crosslinked, crosslinked, and modified with l-cysteine) were evaluated as sorbents prior to electrothermal atomic absorption spectrometry (ETAAS) determination of total dissolved metal content in surface water samples. 相似文献870.
Trier X Nielsen NJ Christensen JH 《Environmental science and pollution research international》2011,18(8):1422-1432