全文获取类型
收费全文 | 737篇 |
免费 | 57篇 |
国内免费 | 243篇 |
专业分类
安全科学 | 44篇 |
废物处理 | 11篇 |
环保管理 | 51篇 |
综合类 | 453篇 |
基础理论 | 191篇 |
污染及防治 | 134篇 |
评价与监测 | 116篇 |
社会与环境 | 34篇 |
灾害及防治 | 3篇 |
出版年
2024年 | 1篇 |
2023年 | 24篇 |
2022年 | 31篇 |
2021年 | 32篇 |
2020年 | 34篇 |
2019年 | 33篇 |
2018年 | 28篇 |
2017年 | 31篇 |
2016年 | 46篇 |
2015年 | 30篇 |
2014年 | 34篇 |
2013年 | 78篇 |
2012年 | 45篇 |
2011年 | 63篇 |
2010年 | 44篇 |
2009年 | 37篇 |
2008年 | 54篇 |
2007年 | 42篇 |
2006年 | 36篇 |
2005年 | 32篇 |
2004年 | 32篇 |
2003年 | 24篇 |
2002年 | 30篇 |
2001年 | 22篇 |
2000年 | 25篇 |
1999年 | 21篇 |
1998年 | 26篇 |
1997年 | 10篇 |
1996年 | 16篇 |
1995年 | 16篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 11篇 |
1991年 | 2篇 |
1990年 | 10篇 |
1989年 | 4篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1976年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有1037条查询结果,搜索用时 156 毫秒
521.
The accumulation and trophic transfer of the platinum group elements (PGE): Rh, Pd and Pt; have been studied in short-term (5 day) exposures conducted in aquaria containing the marine macroalga, Ulva lactuca, and/or the grazing mollusc, Littorina littorea. Metals added to sea water (to concentrations of 20 μg L−1) were taken up by U. lactuca in the order Rh, Pt > Pd and by L. littorea in the order Pd ≥ Pt ≥ Rh, with greatest metal accumulation in the latter generally occurring in the visceral complex and kidney. When fed contaminated alga, accumulation of Rh and Pd by L. littorea, relative to total available metal, increased by an order of magnitude, while accumulation of Pt was not readily detected. We conclude that the diet is the most important vector for accumulation of Rh and Pd, while accumulation of Pt appears to proceed mainly from the aqueous phase. 相似文献
522.
523.
Teofilo Vamerali Marianna Bandiera Federica Zanetti Giuliano Mosca 《Environmental pollution (Barking, Essex : 1987)》2009,157(3):887-894
At a site in Udine, Italy, a 0.7 m layer of As, Co, Cu, Pb and Zn contaminated wastes derived from mineral roasting for sulphur extraction had been covered with an unpolluted 0.15 m layer of gravelly soil. This study investigates whether woody biomass phytoremediation is a realistic management option. Comparing ploughing and subsoiling (0.35 m depth), the growth of Populus and Salix and trace element uptake were investigated in both pot and field trials. Species differences were marginal and species selection was not critical. Impaired above-ground productivity and low translocation of trace elements showed that bioavailable contaminant stripping was not feasible. The most significant finding was of coarse and fine roots proliferation in surface layers that provided a significant sink for trace elements. We conclude that phytostabilisation and effective immobilisation of metals and As could be achieved at the site by soil amelioration combined with woody species establishment. Confidence to achieve a long-term and sustainable remediation requires a more complete quantification of root dynamics and a better understanding of rhizosphere processes. 相似文献
524.
Chemical characteristics of precipitation at metropolitan Newark in the US East Coast 总被引:5,自引:0,他引:5
To investigate the chemical characteristics of precipitation in the polluted coastal atmosphere, a total of 46 event-based precipitation samples were collected using a wet-only automatic precipitation collector from September 2006 to October 2007 at metropolitan Newark, New Jersey in the US East Coast. Samples were analyzed by ion chromatography for the concentrations of major inorganic ions (Cl−, NO3−, SO42−, F−, NH4+, Ca2+, Mg2+, Na+, K+) and organic acid species (CH3COO−, HCOO−, CH2(COO)22−, C2O42−). Selected trace metals (Sb, Pb, Al, V, Fe, Cr, Co, Ni, Cu, Zn, Cd) in samples were determined by ICPMS. Mass concentration results show that SO42− was the most dominant anion accounting for 51% of the total anions, controlling the acidity of the precipitation. NH4+ accounted for 48.6% of the total cations, dominating the precipitation neutralization. CH3COO− and HCOO− were the two dominant water-soluble organic acid species, accounting for 42% and 40% of the total organic acids analyzed, respectively. Al, Zn and Fe were the three major trace metals in precipitation, accounting for 34%, 27%, and 25% of the total mass of metals analyzed. The pH values in precipitation ranged from 4.4 to 4.9, indicating an acidic nature. Enrichment Factor (EF) Analysis showed that Na+, Cl−, Mg2+ and K+ in the precipitation were primarily of marine origin, while most of the Fe, Co and Al were from crust sources. Pb, V, Cr, Ni were moderately enriched with EFs ranging 43–410, while Zn, Sb, Cu, Cd and F− were highly enriched with EFs > 700, indicating significant anthropogenic influences. Factor analysis suggests 6 major sources contributing to the observed composition of precipitation at this location: (1) nitrogen-enriched soil, (2) secondary pollution processes, (3) marine sources, (4) incinerations, (5) oil combustions, and (6) malonate–vanadium enriched sources. To further explore the source–precipitation event relationships and seasonality, cluster analysis was performed for all precipitation events. Results show that about half of the precipitation events were characterized by mixed sources. Significant influences of nitrogen-enriched soil and marine sources were associated with precipitation events in spring and autumn, while secondary pollution processes, incineration and oil combustion contributed greatly in summer. 相似文献
525.
Relationships between hepatic trace element concentrations, reproductive status, and body condition of female greater scaup 总被引:1,自引:0,他引:1
Shannon S. Badzinski Paul L. Flint 《Environmental pollution (Barking, Essex : 1987)》2009,157(6):1886-1893
We collected female greater scaup (Aythya marila) on the Yukon-Kuskokwim Delta, Alaska during two breeding seasons to determine if concentrations of 18 trace elements in livers and eggs were elevated and if hepatic concentrations correlated with body condition or affected reproductive status. Fifty-six percent, 5%, and 42% of females, respectively, had elevated hepatic cadmium (Cd: >3 μg g−1 dry weight [dw]), mercury (Hg: >3 μg g−1 dw), and selenium (Se: >10 μg g−1 dw). Somatic protein and lipid reserves were not correlated with hepatic Cd or Hg, but there was a weak negative correlation between protein and Se. Hepatic Cd, Hg, and Se were similar in females that had and had not initiated egg production. In a sample of six eggs, 33% and 100%, respectively, contained Se and Hg, but concentrations were below embryotoxicity thresholds. We conclude that trace element concentrations documented likely were not adversely impacting this study population. 相似文献
526.
Food chain models are essential tools to assess risks of soil contamination in view of product quality including fodder crops and animal products. Here we link soil to plant transfer (SPT) models for potentially toxic elements (PTEs) including As, Ba, Cd, Co, Cu, Hg, Ni, Pb, Sb, U and Zn with models describing accumulation in animal organs. Current EU standards for food products and acceptable daily intake levels (ADI) for humans were used as critical limits. The combined model is used to assess the impact of soil contamination on animal health, product quality and human health using data from 100 arable fields. Results indicate that 42 existing arable fields near industrial and mining sites are unsuitable for animal grazing in view of food safety due to elevated intake of Cd, Cu, Hg and Pb by cows and sheep. At 10 sites daily intake levels of As by cows exceeded threshold concentrations regarding the quality of animal products.The food chain model also was used inversely to derive soil threshold concentrations in view of EU fodder standards. Calculated threshold levels in soil for As, Cd, Cu, Pb, Hg and Zn appear to be in line with those proposed or used in other EU countries. As such the approach applied here can form a conceptual basis for a more harmonized risk assessment strategy regarding the protection of animal and human health. 相似文献
527.
Nicholas A. Warner Gary Kozerski Jeremy Durham Martin Koerner Reinhard Gerhards Roy Campbell Debra A. McNett 《Chemosphere》2013
Contamination and analytical variation can significantly hinder trace analysis of cyclic methyl volatile siloxanes (cVMS); potentially resulting in the report of false positives at concentrations approaching detection limits. To assess detection and variation associated with trace cVMS analysis in environmental matrices, a co-operative laboratory comparison for the analysis of octametylcyclotetrasiloxane (D4), decamethylcylcopentasiloxane (D5), and dodecametylcyclohexasiloxane (D6) in sediment and biota from the Svalbard Archipelago was conducted. Two definitions of detection limits were evaluated in this study; method detection limits (MDL, matrix defined) and limits of detection (LOD, solvent defined). D5 was the only cVMS detected above both LOD (0.08–0.81 ng g−1 ww) and MDL (0.47–2.36 ng g−1 ww) within sediment by all laboratories where concentrations ranged from 0.55 to 3.91 ng g−1 ww. The percentage of positive detects for D5 decreased by 80% when MDL was defined as the detection limit. D5 was also detected at the highest frequency among all laboratories in fish liver with concentrations ranging from 0.72 to 345 ng g−1 ww. Similar to sediment, percentage of positive detects for D5 decreased by 60% across all laboratories for fish livers when using MDL (0.68–3.49 ng g−1 ww). Similar observations were seen with both D4 and D6, indicating that sample matrix significantly contributes to analytical response variation. Despite differences in analytical methods used between laboratories, good agreement was obtained when using MDL to define detection limits. This study shows the importance of incorporating variation introduced by sample matrices into detection limit calculations to insure data accuracy of cVMS at low concentrations. 相似文献
528.
Wind erosion selectively winnows the fine, most chemically concentrated portions of surface soils and results in the inter-regional
transport of fugitive dust containing plant nutrients, trace elements and other soil-borne contaminants. We sampled and analyzed
surface soils, sediments in transport over eroding fields, and attic dust from a small area of the Southern High Plains of
Texas to characterize the physical nature and chemical constituents of these materials and to investigate techniques that
would allow relatively rapid, low cost techniques for estimating the chemical constituents of fugitive dust from an eroding
field. From chemical analyses of actively eroding sediments, it would appear that Ca is the only chemical species that is
enriched more than others during the process of fugitive dust production. We found surface soil sieved to produce a sub-sample
with particle diameters in the range of 53–74 μm to be a reasonably good surrogate for fugitive dust very near the source
field, that sieved sub-samples with particle diameters <10 μm have a crustal enrichment factor of approximately 6, and that
this factor, multiplied by the chemical contents of source soils, may be a reasonable estimator of fugitive PM10 chemistry from the soils of interest. We also found that dust from tractor air cleaners provided a good surrogate for dust
entrained by tillage and harvesting operations if the chemical species resulting from engine wear and exhaust were removed
from the data set or scaled back to the average of enrichment factors noted for chemical species with no known anthropogenic
sources. Chemical analyses of dust samples collected from attics approximately 4 km from the nearest source fields indicated
that anthropogenic sources of several environmentally important nutrient and trace element species are much larger contributors,
by up to nearly two orders of magnitude, to atmospheric loading and subsequent deposition than fugitive dust from eroding
soils. 相似文献
529.
Singh G Gupta SK Kumar R Sunderarajan M 《Environmental monitoring and assessment》2007,130(1-3):173-185
The present study describes the development of empirical models for the prediction of various trace metals i.e., Mn, Cu, Fe,
Zn and Pb found in the leachates generated from the ash ponds of various thermal power plants. The dispersion phenomenon of
these trace metals followed first order reaction rate kinetics. The empirical models for individual trace metals derived from
the lab scale models data correlate well with the real field data with regression coefficients varying from 0.93 to 0.98.
The predicted concentrations of the trace metals varied within ±3% of the observed values in the leachates generated from
the ash ponds of four thermal power plants with standard deviation varying from 0.001 to 0.032. The empirical models derived
from the study can be applied for prediction of trace metals in leachates generated from similar thermal power plants. 相似文献
530.
Godinho RM Wolterbeek HT Verburg T Freitas MC 《Environmental pollution (Barking, Essex : 1987)》2008,151(2):318-325
This experiment compares the short and long time element accumulation behaviour of transplants of Flavoparmelia caperata lichen thalli and total deposition in an atmospheric polluted area. It was found that lichens exposed for a short time behaved differently from lichens in cumulative exposition suggesting the presence of acclimatization behaviour. The lichen transplant elemental content does not unequivocally represent the average or cumulative environmental availability of the exposure period. Reflection characteristics depend on the element and the lichen physiological conditions. Good correlations between lichen elemental contents and total deposition were obtained when a physiological lichen parameter was introduced in a mathematical model, suggesting that metabolically mediated accumulation is important. 相似文献