全文获取类型
收费全文 | 600篇 |
免费 | 32篇 |
国内免费 | 289篇 |
专业分类
安全科学 | 40篇 |
废物处理 | 27篇 |
环保管理 | 50篇 |
综合类 | 378篇 |
基础理论 | 129篇 |
污染及防治 | 230篇 |
评价与监测 | 33篇 |
社会与环境 | 10篇 |
灾害及防治 | 24篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 27篇 |
2021年 | 27篇 |
2020年 | 25篇 |
2019年 | 21篇 |
2018年 | 24篇 |
2017年 | 25篇 |
2016年 | 31篇 |
2015年 | 42篇 |
2014年 | 40篇 |
2013年 | 72篇 |
2012年 | 55篇 |
2011年 | 65篇 |
2010年 | 49篇 |
2009年 | 37篇 |
2008年 | 45篇 |
2007年 | 40篇 |
2006年 | 42篇 |
2005年 | 26篇 |
2004年 | 19篇 |
2003年 | 20篇 |
2002年 | 26篇 |
2001年 | 15篇 |
2000年 | 21篇 |
1999年 | 15篇 |
1998年 | 19篇 |
1997年 | 26篇 |
1996年 | 20篇 |
1995年 | 11篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1984年 | 2篇 |
排序方式: 共有921条查询结果,搜索用时 609 毫秒
51.
Oxidation of Cr(III) by manganese oxides may pose a potential threat to environments due to the formation of toxic Cr(VI) species. At present, it was still unclear whether the extent of Cr(III) oxidation and fate of Cr(VI) would be changed when manganese oxides co-exist with other minerals, the case commonly occurring in soils. This study investigated the influence of goethite and kaolinite on Cr(III) oxidation by birnessite under acidic pH condition (pH 3.5) and background electrolyte of 0.01 mol/L NaCl. Goethite was found not to affect Cr(III) oxidation, which was interpreted as the result of overwhelming adsorption of cationic Cr(III) onto the negatively-charged birnessite (point of zero charge (PZC) < 3.0) rather than the positively-charged goethite (PZC = 8.8). However, more Cr(VI) would be retained by the surface with the increase in addition of goethite because of its strong ability on adsorption of Cr(VI) at low pH. Moreover, either Cr(III) oxidation or distribution of the generated Cr(VI) between the solid and solution phases was not affected by kaolinite (PZC < 3.0), indicating its low affinity for Cr species. Reactions occurring in the present mixed systems were suggested, which could be partly representative of those in the soils and further indicates that the mobility and risk of Cr(VI) would be decreased if goethite was present. 相似文献
52.
Xiaobin Dong Fei Wang Weidong Kong Mukan Ji Kang Zhao Hao Chen Linyan Yue 《环境科学学报(英文版)》2022,34(11):48-57
Excessive livestock grazing degrades grasslands ecosystem stability and sustainability by reducing soil organic matter and plant productivity. However, the effects of grazing on soil cellulolytic fungi, an important indicator of the degradation process for soil organic matter, remain less well understood. Using T-RFLP and sequencing methods, we investigated the effects of grazing on the temporal changes of cellulolytic fungal abundance and community structure in dry steppe soils during the growing months from May to September, on the Tibetan Plateau using T-RFLP and sequencing methods. The results demonstrated that the abundance of soil cellulolytic fungi under grazing treatment changed significantly from month to month, and was positively correlated with dissolved organic carbon (DOC) and soil temperature, but negatively correlated with soil pH. Contrastingly, cellulolytic fungal abundance did not change within the fencing treatment (ungrazed conditions). Cellulolytic fungal community structure changed significantly in the growing months in grazed soils, but did not change in fenced soils. Grazing played a key role in determining the community structure of soil cellulolytic fungi by explaining 8.1% of the variation, while pH and DOC explained 4.1% and 4.0%, respectively. Phylogenetically, the cellulolytic fungi were primarily affiliated with Ascomycota (69.65% in relative abundance) and Basidiomycota (30.35%). Therefore, grazing substantially reduced the stability of soil cellulolytic fungal abundance and community structure, as compared with the fencing treatment. Our finding provides a new insight into the responses of organic matter-decomposing microbes for grassland managements. 相似文献
53.
Recycling strongly acidic wastewater as diluted H2SO4 after contaminants contained being removed was previously proposed, however, Cl(-I), a kind of contaminant contained in strongly acidic wastewater, is difficult to remove, which severely degrades the quality of recycled H2SO4. In this study, the removal of Cl(-I) using PbO2 was investigated and the involved mechanisms were explored. The removal efficiency of Cl(-I) reached 93.38% at 50℃ when PbO2/Cl(-I) mole ratio reached 2:1. The identification of reaction products shows that Cl(-I) was oxidized to Cl2, and PbO2 was reduced to PbSO4. Cl2 was absorbed by NaOH to form NaClO, which was used for the regeneration of PbO2 from the generated PbSO4. Cl(-I) was removed through two pathways, i.e., surface oxidation and •OH radical oxidation. •OH generated by the reaction of PbO2 and OH− plays an important role in Cl(-I) removal. The regenerated PbO2 had excellent performance to remove Cl(-I) after six-time regeneration. This study provided an in-depth understanding on the effective removal of Cl(-I) by the oxidation method. 相似文献
54.
55.
Ammonium-dependent regulation of aerobic methane-consuming bacteria in landfill cover soil by leachate irrigation 总被引:1,自引:0,他引:1
The impacts of landfill leachate irrigation on methane oxidation activities and methane-consuming bacteria populations were studied by incubation of landfill cover soils with leachate and (NH4)2SO4 solution at different ammonium concentrations. The community structures and abundances of methane-oxidizing bacteria (MOB) and ammonia-oxidizing bacteria (AOB) were examined by PCRDGGE and real-time PCR. Compared with the pure (NH4)2SO4 solution, leachate addition was found to have a positive effect on methane oxidation activity. In terms of the irrigation amount, ammonium in leachate was responsible for the actual inhibition of leachate. The extent of inhibitory effect mainly depended on its ammonium concentration. The suppression of the predominant methaneconsuming bacteria, type I MOB, was responsible for the decreased methane oxidation activity by ammonium inhibition. Methaneconsuming bacteria responded diversely in abundance to ammonium. The abundance of type I MOB decreased by fivefold; type II MOB showed stimulation response of fivefold magnification upon the first addition but lessened to be lower than the original level after the second addition; the amount of AOB was stimulated to increase for 20-30 times gradually. Accumulated nitrate from nitrification strengthened the ammonium inhibition on type I and type II MOB, as a result, repetitive irrigation was unfavorable for methane oxidation. 相似文献
56.
Shanxian Wang Xiaojun Li Wan Liu Peijun Li Lingxue Kong Wenjie Ren Haiyan Wu Ying Tu 《环境科学学报(英文版)》2012,24(9):1662-1669
Biodegradation of polycyclic aromatic hydrocarbons (PAHs) is very difficult in saline-alkaline soil due to the inhibition of microbial growth under saline-alkaline stress. The microorganisms that can most effectively degrade PAHs were screened by introducing microorganisms immobilized on farm byproducts and assessing the validity of the immobilizing technique for PAHs degradation in pyrene-contaminated saline-alkaline soil. Among the microorganisms examined, it was found that Mycobacterium sp. B2 is the best, and can degrade 82.2% and 83.2% of pyrene for free and immobilized cells after 30 days of incubation. The immobilization technique could increase the degradation of pyrene significantly, especially for fungi. The degradation of pyrene by the immobilized microorganisms Mucor sp. F2, fungal consortium MF and co-cultures of MB+MF was increased by 161.7% (P < 0.05), 60.1% (P < 0.05) and 59.6% (P < 0.05) after 30 days, respectively, when compared with free F2, MF and MB+MF. Scanning electron micrographs of the immobilized microstructure proved the positive effects of the immobilized microbial technique on pyrene remediation in saline-alkaline soil, as the interspace of the carrier material structure was relatively large, providing enough space for cell growth. Co-cultures of different bacterial and fungal species showed different abilities to degrade PAHs. The present study suggests that Mycobacterium sp. B2 can be employed for in situ bioremediation of PAHs in saline-alkaline soil, and immobilization of fungi on farm byproducts and nutrients as carriers will enhance fungus PAH-degradation ability in saline-alkaline soil. 相似文献
57.
58.
We studied the influence of hydroxypropylcyclodextrins (HPCDs) on the toxicity of some mixtures. Using the Photobacterium phosphoreum toxicity test, the joint toxicological effect for Mixture I (containing p-nitrobenzaldehyde and 1-nitronaphthalene) and Mixture II (containing p-nitrobenzaldehyde and malononitrile) were determined in water and in aqueous solutions of HPCDs. The results indicate that, although the toxicological joint effect for Mixture I (simple addition) differs from that of Mixture II (synergism), alpha- and beta-HPCD can significantly reduce the toxicity of the test compounds, whereas gamma-HPCD has only a slight effect. Explanations for these observations are given that invoke the molecular structure of the individual chemicals as well as the structures of HPCDs. This provides information to assist the application of HPCDs in remediation of environmental pollution. 相似文献
60.