全文获取类型
收费全文 | 2113篇 |
免费 | 1249篇 |
国内免费 | 176篇 |
专业分类
安全科学 | 33篇 |
废物处理 | 39篇 |
环保管理 | 372篇 |
综合类 | 1889篇 |
基础理论 | 648篇 |
污染及防治 | 272篇 |
评价与监测 | 166篇 |
社会与环境 | 91篇 |
灾害及防治 | 28篇 |
出版年
2025年 | 4篇 |
2024年 | 48篇 |
2023年 | 89篇 |
2022年 | 87篇 |
2021年 | 102篇 |
2020年 | 108篇 |
2019年 | 117篇 |
2018年 | 90篇 |
2017年 | 132篇 |
2016年 | 155篇 |
2015年 | 171篇 |
2014年 | 146篇 |
2013年 | 278篇 |
2012年 | 201篇 |
2011年 | 216篇 |
2010年 | 160篇 |
2009年 | 173篇 |
2008年 | 142篇 |
2007年 | 154篇 |
2006年 | 166篇 |
2005年 | 112篇 |
2004年 | 103篇 |
2003年 | 80篇 |
2002年 | 68篇 |
2001年 | 55篇 |
2000年 | 51篇 |
1999年 | 43篇 |
1998年 | 45篇 |
1997年 | 44篇 |
1996年 | 28篇 |
1995年 | 17篇 |
1994年 | 21篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 13篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 15篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有3538条查询结果,搜索用时 22 毫秒
1.
《Chemistry and Ecology》2006,22(6):479-488
Tin concentrations were determined in surface and core sediments from three hot spots along the Alexandria coast, namely: Abu-Qir Bay, Eastern Harbour, and Western Harbour. The mean concentrations in surface sediment were 2.434, 3.212, and 5.572 μg/g dry weight for Abu-Qir Bay, Eastern Harbour, and Western Harbour, respectively. A sharp decrease in tin level in core sediments with depth was observed in almost all locations except for core 4 in Abu-Qir Bay and core 17 in the Eastern Harbour, where the sub-sample at the 5 cm level recorded the highest tin concentrations. 相似文献
2.
本文主要介绍了用~(210)Pb─~(210)Bi法测定海洋现代沉积速率和数据处理方法的研究。该方法测定的结果与~(210)Pb─~(210)Po法和阴离子交换-EDTA纯化-硫酸钡镭沉淀-α计数法(简称~(226)Ra法)以及厦门大学海洋系经研究改进的分离、纯化~(210)Pb的离子交换法的测定结果相当吻合。 相似文献
3.
4.
Willie Peijnenburg Lennart Eriksson Arthur de Groot Michael Sjöström Hans Verboom 《Environmental science and pollution research international》1998,5(1):12-16
Disappearance rate constants are reported for the reductive transformation of 17 halogenated aliphatic hydrocarbons in anaerobic
sediment-water samples. Statistical experimental design in combination with multivariate chemical characterization of their
chemical properties was used to select the compounds. Degradation followed pseudo first-order kinetics through at least two
half-lives for 15 of the 17 compounds. Of all the compounds investigated, 1,2,3-trichloropropane and dichloromethane were
unique in that they were dehalogenated according to zero-order kinetics. Reductive dehalogenation was the sole transformation
reaction taking place. 相似文献
5.
6.
Anaerobic degradation of diethyl phthalate, di-n-butyl phthalate, and di-(2-ethylhexyl) phthalate from river sediment in Taiwan 总被引:5,自引:0,他引:5
We investigated anaerobic degradation rates for three phthalate esters (PAEs), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and di-(2-ethylhexyl) phthalate (DEHP), from river sediment in Taiwan. The respective anaerobic degradation rate constants for DEP, DBP, and DEHP were observed as 0.045, 0.074, and 0.027 1/day, with respective half-lives of 15.4, 9.4, and 25.7 days under optimal conditions of 30 °C and pH 7.0. Anaerobic degradation rates were enhanced by the addition of the surfactants brij 35 and triton N101 at a concentration of 1 critical micelle concentration (CMC), and by the addition of yeast extract. Degradation rates were inhibited by the addition of acetate, pyruvate, lactate, FeCl3, MnO2, NaCl, heavy metals, and nonylphenol. Our results indicate that methanogen, sulfate-reducing bacteria, and eubacteria are involved in the degradation of PAEs. 相似文献
7.
Bioassays are widely used to estimate ecological risks of contaminated sediments. We compared the results of three whole sediment bioassays, using the midge larva Chironomus riparius, the water louse Asellus aquaticus, and the mayfly nymph Ephoron virgo. We used sediments from sixteen locations in the Dutch Rhine-Meuse Delta that differed in level of contamination. Previously developed protocols for each bioassay were followed, which differed in sediment pretreatment, replication, and food availability. The Chironomus bioassay was conducted in situ, whereas the other two were conducted in the laboratory. The measured endpoints, survival and growth, were related to contaminant levels in the sediment and to food quantity in water and sediment.
Only the response of A. aquaticus in the bioassay was correlated with sediment contamination. Food availability in overlying water was much more important for C. riparius and E. virgo, thereby masking potential sediment contaminant effects. We conclude that growth of A. aquaticus was depressed by sediment contamination, whereas growth of E. virgo and C. riparius was stimulated by seston food quantity. We discuss that the trophic state of the ecosystem largely affects the ecological risks of contaminated sediments. 相似文献
8.
Screening 31 endocrine-disrupting pesticides in water and surface sediment samples from Beijing Guanting reservoir 总被引:13,自引:0,他引:13
For screening 31 potential or suspected endocrine-disrupting pesticides in water and surface sediments, a multiresidue analysis method based on gas chromatography with electron capture detection (GC/ECD) was developed. Solid phase extraction (SPE) technology with Oasis® HLB cartridge was also applied in sample extraction. The relevant mean recoveries were 70–103% and 71–103% for water and sediment, respectively. Relative standard deviations (RSD) are 2.0–7.0%, 4.0–8.0% for water and sediment, respectively. Thirty one pesticides (-HCH, β-HCH, γ-HCH, δ-HCH, hexachlorobenzene (HCB), aldrin, heptachlor, endosulfan I & II, p,p′-DDD, o,p′-DDT, p,p′-DDT, p,p′-DDE, endrin aldehyde, endosulfan sulphate, methoxychlor, hepachlor epoxide, -chlordane, γ-chlordane, dieldrin, endrin, dicofol, acetochlor, alachlor, metolachlor, chlorpyriphos, nitrofen, trifluralin, cypermethrin, fenvalerate, deltamethrin) in water and surface sediment samples from Beijing Guanting reservoir were analyzed. Concentrations of pesticides ranged from 7.59 to 36.0 ng g−1 on a dry wt. basis for sediment samples, from 279.3 to 2740 ng l−1 for pore waters and from 48.8 to 890 ng l−1 for water samples, respectively, with a mean concentration of 10.7 ng g−1 in sediment, 735 ng l−1 in pore water and 295 ng l−1 in water, respectively. The data obtained provides information on the levels and sources of endocrine-disrupting pesticides in Guanting reservoir. These results underscore the need to improved environmental protection measures in order to reduce the exposure of the population and aquatic biota to these endocrine-disrupting compounds. 相似文献
9.
Feiler U Ahlf W Hoess S Hollert H Neumann-Hensel H Meller M Weber J Heininger P 《Environmental science and pollution research international》2005,12(5):257-258
- In current biotest approaches, intact organisms or in vitro systems are exposed to sediments using different exposure scenarios.
The most important issue in sediment toxicity testing protocols is the question which test phase (solid or liquid) should
be used. Whole-sediment exposure protocols represent the most realistic scenario to simulate in situ exposure conditions in
the laboratory. However, until now there is no agreement in how to acquire and to evaluate the data of the various available
sediment contact assays. The SeKT joint research project was initiated with the aim to compare recently developed sediment
contact assays by addressing reference conditions, control sediments and toxicity thresholds for limnic sediment contact tests. 相似文献
10.
Hollert H Dürr M Holtey-Weber R Islinger M Brack W Färber H Erdinger L Braunbeck T 《Environmental science and pollution research international》2005,12(6):347-360
Goal, Scope and Background In order to evaluate the estrogenic activity of sediments and XAD water extracts of selected sites of the catchment area
of the River Neckar, a river system in Southern Germany, an integrative assessment approach was used to assess the ecological
hazard potential of endocrine-disrupting compounds in sediment and water.
Methods The approach is based on estrogen receptor-mediated vitellogenin synthesis induced in isolated hepatocytes of rainbow trout
and quantified in a non-radioactive dot blot/RNAse protection-assay in parallel to comprehensive chemical analyses of estrogenic
substances.
Results and Discussion Numerous investigated extracts revealed an estrogen activity comparable to that of the positive control (1 nM 17?-estradiol
corresponding to 270 ng/L in the test medium). Based on a concentration factor of 30 in the extracts and a recovery of XAD
resins of approximately 80 %, 17?-estradiol equivalent concentrations between 20 and 26.7 ng/L could be calculated downstream
of a sewage treatment plant (< 0.1 ng/L for a reference site). A comparison of the bioassay-derived Bio-TEQs (toxicity equivalents)
and the Chem-TEQs revealed a high correlation with a Pearson coefficient of 0.85, indicating that the same ranking of the
samples could be obtained with respect to the endocrine disrupting potential with both chemical and bioanalytical analysis.
However, the TEQ concentrations computed from chemical analyses were significantly lower than the bioassay-derived TEQ concentrations.
In fact, in none of the samples, more than 14 % of the vitellogenin-inducing potency could be attributed to the substances
(steroids, alkylphenols, bisphenol A, diethylstilbestrol) analyzed.
A comparison of the endocrine disrupting potential of sediments extracted by the solvents acetone and methanol revealed lower
biological effects for acetone-extracted samples. Possible reasons may be a masking of endocrine effects in acetone extracts
by cytotoxicity, a low extraction efficiency of the solvent acetone, or anti-estrogen potencies of some extracted sediment
compounds.
Using a mass balance approach, the contribution of the compounds analyzed chemically (Chem-TEQs) to the total endocrine activity
(Bio-TEQs) was calculated. Based on the very low detection limits, particularly of the steroids with their high TEF factors,
results revealed that a calculation of the Chem-TEQs is associated with considerable scale inaccuracy: Whereas only 7-15 %
of the biological effectiveness (Bio-TEQs) could be explained by endocrine substances identified above the detection limits,
the assumption of concentrations slightly below the given detection limits would result in a significant over estimation (137-197
%) of the Bio-TEQs. Even the interassay variation of the dot blot assay with different fish donors for primary hepatocyte
(factor 2 - 2.5) is relatively low, when compared to the large range of the Chem-TEQ concentrations (factor 20) obtained when
applying different modes of calculation.
Conclusions and Outlook Overall, only a minor portion of the endocrine activity detected by bioassays could be linked to compounds identified by
chemical analysis. In vitro assays for assessment of endocrine activities are useful as sensitive integrating methods that
provide quantitative estimates of the total activity of particular receptor-mediated responses. Although discrepancies may
also result from different bioanalytical approaches, it is overall likely that bioanalytical and not chemical analytical approaches
give the correct estimate of endocrine disrupting potencies in environmental samples. As a conclusion, assessment of endocrine
disruption based on chemical analysis alone does not appear sufficient and further research into the spectrum of substances
with potential endocrine activity as well as into additive or even synergistic effects in complex environmental samples is
urgently needed. 相似文献