全文获取类型
收费全文 | 2958篇 |
免费 | 212篇 |
国内免费 | 1417篇 |
专业分类
安全科学 | 71篇 |
废物处理 | 74篇 |
环保管理 | 305篇 |
综合类 | 2056篇 |
基础理论 | 853篇 |
污染及防治 | 723篇 |
评价与监测 | 363篇 |
社会与环境 | 135篇 |
灾害及防治 | 7篇 |
出版年
2024年 | 34篇 |
2023年 | 132篇 |
2022年 | 144篇 |
2021年 | 143篇 |
2020年 | 126篇 |
2019年 | 140篇 |
2018年 | 148篇 |
2017年 | 162篇 |
2016年 | 174篇 |
2015年 | 199篇 |
2014年 | 212篇 |
2013年 | 439篇 |
2012年 | 217篇 |
2011年 | 255篇 |
2010年 | 198篇 |
2009年 | 205篇 |
2008年 | 235篇 |
2007年 | 244篇 |
2006年 | 221篇 |
2005年 | 145篇 |
2004年 | 122篇 |
2003年 | 124篇 |
2002年 | 95篇 |
2001年 | 89篇 |
2000年 | 58篇 |
1999年 | 49篇 |
1998年 | 44篇 |
1997年 | 41篇 |
1996年 | 38篇 |
1995年 | 33篇 |
1994年 | 21篇 |
1993年 | 17篇 |
1992年 | 17篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有4587条查询结果,搜索用时 0 毫秒
991.
A review of biochars' potential role in the remediation, revegetation and restoration of contaminated soils 总被引:30,自引:0,他引:30
Beesley L Moreno-Jiménez E Gomez-Eyles JL Harris E Robinson B Sizmur T 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3269-3282
Biochars are biological residues combusted under low oxygen conditions, resulting in a porous, low density carbon rich material. Their large surface areas and cation exchange capacities, determined to a large extent by source materials and pyrolysis temperatures, enables enhanced sorption of both organic and inorganic contaminants to their surfaces, reducing pollutant mobility when amending contaminated soils. Liming effects or release of carbon into soil solution may increase arsenic mobility, whilst low capital but enhanced retention of plant nutrients can restrict revegetation on degraded soils amended only with biochars; the combination of composts, manures and other amendments with biochars could be their most effective deployment to soils requiring stabilisation by revegetation. Specific mechanisms of contaminant-biochar retention and release over time and the environmental impact of biochar amendments on soil organisms remain somewhat unclear but must be investigated to ensure that the management of environmental pollution coincides with ecological sustainability. 相似文献
992.
Pitkänen T Karinen P Miettinen IT Lettojärvi H Heikkilä A Maunula R Aula V Kuronen H Vepsäläinen A Nousiainen LL Pelkonen S Heinonen-Tanski H 《Ambio》2011,40(4):377-390
The raw water quality and associations between the factors considered as threats to water safety were studied in 20 groundwater supplies in central Finland in 2002-2004. Faecal contaminations indicated by the appearance of Escherichia coli or intestinal enterococci were present in five small community water supplies, all these managed by local water cooperatives. Elevated concentrations of nutrients in raw water were linked with the presence of faecal bacteria. The presence of on-site technical hazards to water safety, such as inadequate well construction and maintenance enabling surface water to enter into the well and the insufficient depth of protective soil layers above the groundwater table, showed the vulnerability of the quality of groundwater used for drinking purposes. To minimize the risk of waterborne illnesses, the vulnerable water supplies need to be identified and appropriate prevention measures such as disinfection should be applied. 相似文献
993.
Berglund ÅM Koivula MJ Eeva T 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2368-2374
We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. 相似文献
994.
The microbial community in soil samples from two long-term contaminated sites was characterized by using culture-dependent and culture-independent methods. The two sites investigated contained high amounts of heavy metals and were located in the upper Silesia Industrial Region in southern Poland. The evaluation of the aerobic soil microbial population clearly demonstrated the presence of considerable numbers of viable, culturable bacteria at both sites. A high fraction of the bacterial population was able to grow in the presence of high amounts of metals, i.e. up to 10 mM Zn2+, 3 mM Pb2+ or 1 mM Cu2+. Site 1 contained significantly (P < 0.05) lower bacterial numbers growing in the presence of 10 mM Zn2+ than site 2, while the opposite was observed for bacteria tolerating 1 mM Cu2+. This coincided with the contents of these two metals at the two sites. Ecophysiological (EP) indices for copiotrophs (r-strategists) and oligotrophs (K-strategists) pointed to high bacterial diversity at both sites. Fluorescence in situ hybridization (FISH) analysis indicated that Actinobacteria and Proteobacteria represent the physiologically active fraction of bacteria at the two sites. Shannon diversity (H′) indices for FISH-detected bacterial phylogenetic groups were not significantly different at the two sites. 相似文献
995.
996.
乌梁素海表层沉积物重金属与营养元素含量的统计分析 总被引:7,自引:0,他引:7
对乌梁素海表层沉积物营养盐与重金属的分布情况进行研究,应用SPSS统计分析软件对乌梁素海表层沉积物重金属与营养元素进行相关分析和因子分析,并对重金属元素进行聚类分析。营养元素与重金属间的相关分析表明:重金属元素Cu、Cr、Pb和Cd相互间具有极显著的正相关性;有机质与As和Hg呈极显著的正相关;总氮与Hg呈极显著相关,与As呈显著相关,而与Pb呈极显著负相关,与Cd呈显著负相关;总磷与As呈显著负相关。重金属元素间的R-型聚类分析结果将本论文研究的9种金属元素分为3类。采用主成分分析法对乌梁素海表层沉积物重金属与营养元素进行因子分析,得到4个因子,并进一步分析讨论了各主成分的科学内涵。 相似文献
997.
998.
999.
1000.
钢铁工业遗留场地土壤重金属洗脱剂筛选研究 总被引:1,自引:0,他引:1
土壤重金属污染限制了工业遗留场地再利用,通过振荡试验考察了HCl、HNO3和EDTA对工业遗留场地土壤中超标重金属Pb、Zn、Cd和As的洗脱效果。结果表明:土壤Pb、Zn、Cd、As的脱除效果均随洗脱剂浓度增加而增加;HCl、HNO3和EDTA等3种洗脱剂浓度分别为0.5、0.5和0.1 mol.L-1时,土壤Pb、Cd质量分数可降低至场地安全再利用的控制标准以内(分别为140 mg.kg-1、1mg.kg-1);洗脱剂浓度分别增至2、2和0.2 mol.L-1时,土壤Pb、Cd质量分数继续降低,Zn、As质量分数有大幅降低但没有达到其相应的场地安全控制标准(分别为200、20 mg.kg-1);与EDTA相比,HCl在低浓度时的重金属脱除效果较差,但HCl浓度增加对重金属脱除率的提高效果更为明显;洗脱液pH值(7.88~0.15)与重金属脱除率均呈显著负相关且与As的负相关系数最小,说明洗脱液pH值变化对As去除的影响相对较小;与HCl和HNO3相比,EDTA洗脱液pH值与Pb脱除率之间的负相关系数较大,与Zn、Cd、As脱除率之间的负相关系数较较小,说明EDTA洗脱液pH值变化更易对Pb的去除产生影响。 相似文献