全文获取类型
收费全文 | 747篇 |
免费 | 90篇 |
国内免费 | 438篇 |
专业分类
安全科学 | 25篇 |
废物处理 | 33篇 |
环保管理 | 57篇 |
综合类 | 640篇 |
基础理论 | 253篇 |
污染及防治 | 169篇 |
评价与监测 | 54篇 |
社会与环境 | 31篇 |
灾害及防治 | 13篇 |
出版年
2024年 | 2篇 |
2023年 | 15篇 |
2022年 | 31篇 |
2021年 | 36篇 |
2020年 | 26篇 |
2019年 | 33篇 |
2018年 | 39篇 |
2017年 | 46篇 |
2016年 | 39篇 |
2015年 | 60篇 |
2014年 | 61篇 |
2013年 | 102篇 |
2012年 | 84篇 |
2011年 | 89篇 |
2010年 | 64篇 |
2009年 | 56篇 |
2008年 | 59篇 |
2007年 | 79篇 |
2006年 | 52篇 |
2005年 | 52篇 |
2004年 | 30篇 |
2003年 | 36篇 |
2002年 | 32篇 |
2001年 | 29篇 |
2000年 | 29篇 |
1999年 | 13篇 |
1998年 | 16篇 |
1997年 | 16篇 |
1996年 | 14篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有1275条查询结果,搜索用时 31 毫秒
991.
河道疏浚废弃淤泥改良土的强度变化规律探讨 总被引:3,自引:0,他引:3
通过系列室内试验,研究了添加生石灰改良高含水量疏浚淤泥的处理土的无侧限抗压强度的主要影响因素;探讨了高含水量疏浚淤泥生石灰处理土的无侧限抗压强度与原泥初始含水量、生石灰掺入比、处理土含水量的关系,得出了生石灰处理土的无侧限抗压强度随着含水量降低率的增加而线性增加的变化规律;建立了生石灰处理土无侧限抗压强度与原泥初始含水量及处理土含水量的定量表达式,给出了生石灰改良高含水量疏浚淤泥的处理土不排水强度的预测方法,可为高含水量疏浚淤泥的有效利用和相关工程设计、施工提供理论基础和指导。 相似文献
992.
Organochlorine pesticides and polybrominated diphenyl ethers in irrigated soils of Beijing, China: Levels, inventory and fate 总被引:2,自引:0,他引:2
Limited information on the levels, inventory and fate of Organochlorine pesticides (OCPs) and Polybrominated diphenyl ethers (PBDEs) in the soils irrigated by sewage or wastewater is available. In this study, variation in concentrations, profiles and fate of OCPs and PBDEs were investigated using soil samples collected from a region irrigated by sewage, mixed water and clean water in the east of Beijing, China. No significant variation was observed among groups, except for penta-BDEs. The measured ΣOCPs and ΣPBDEs residues ranged from 6.4 to 171.2 ng g−1 (dw) and 501.9 to 3310.7 pg g−1 (dw), respectively. ΣDDTs and BDE-209 were the most abundant congeners accounting for about 76% of ΣOCPs and 93% of ΣPBDEs. Concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDTs) and its major degradation products, and hexachlorobenzene (HCB) ranged from 1.2 to 11.4 ng g−1 (dw), 4.0 to 155.6 ng g−1 (dw) and 0.3 to 3.4 ng g−1 (dw), respectively. The major DDT degradation products were p,p′-DDT and p,p′-DDE. The major hexachlorocyclohexane (HCH) isomer in irrigated soils is β-HCH, reflecting its higher affinity to solids and resistance to degradation than other isomers. Both α-HCH/β-HCH and p,p′-DDT/p,p′-DDE ratios were log-normally distributed and negatively correlated to log(ΣHCHs) and log(ΣDDTs), respectively, suggesting no significant recent application of OCPs. Individual BDE congeners, ΣPBDEs and ΣOCPs were significantly correlated with total organic carbon (TOC). Moreover, a good correlationship between ΣPBDEs and black carbon (BC) was obtained but not between ΣOCPs and BC. Sewage irrigation did not have obvious effect on their contaminant levels and inventory of OCPs and PBDEs. 相似文献
993.
Hsu-Wen Hung G. Daniel Sheng Tsair-Fuh Lin Yuhong Su Cary T. Chiou 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):2928-2932
Concentrations of organic contaminants in common productive soils based on the total soil mass give a misleading account of actual contamination effects. This is attributed to the fact that productive soils are essentially water-saturated, with the result that the soil uptake of organic compounds occurs principally by partition into the soil organic matter (SOM). This report illustrates that the soil contamination intensity of a compound is governed by the concentration in the SOM (Com) rather than by the concentration in whole soil (Cs). Supporting data consist of the measured levels and toxicities of many pesticides in soils of widely differing SOM contents and the related levels in in-situ crops that defy explanation by the Cs values. This SOM-based index is timely needed for evaluating the contamination effects of food crops grown in different soils and for establishing a dependable priority ranking for intended remediation of numerous contamination sites. 相似文献
994.
Ion activity and distribution of heavy metals in acid mine drainage polluted subtropical soils 总被引:3,自引:0,他引:3
Yong-Tao Li Thierry Becquer Cécile Quantin 《Environmental pollution (Barking, Essex : 1987)》2009,157(4):1249-1257
The oxidative dissolution of mine wastes gives rise to acidic, metal-enriched mine drainage (AMD) and has typically posed an additional risk to the environment. The poly-metallic mine Dabaoshan in South China is an excellent test site to understand the processes affecting the surrounding polluted agricultural fields. Our objectives were firstly to investigate metal ion activity in soil solution, distribution in solid constituents, and spatial distribution in samples, secondly to determine dominant environment factors controlling metal activity in the long-term AMD-polluted subtropical soils. Soil Column Donnan Membrane Technology (SC-DMT) combined with sequential extraction shows that unusually large proportion of the metal ions are present as free ion in the soil solutions. The narrow range of low pH values prevents any pH effects during the binding onto oxides or organic matter. The differences in speciation of the soil solutions may explain the different soil degradation observed between paddy and non-paddy soils. 相似文献
995.
超声破解吸持稠油粘土颗粒的研究 总被引:2,自引:0,他引:2
在频率为28 kHz的超声辐照下,研究了超声作用功率和辐照时间对石油污染土壤淋洗液中吸持稠油粘土颗粒的破解作用,并采用GC/MS分析了超声辐照时间对淋洗液中特征有机物的影响。结果表明,随着超声作用功率和辐照时间的增加,粘土颗粒吸持的稠油显著下降,辐照时间为45 min,作用功率为100 W时,粘土颗粒吸持稠油的解吸率为7925%;作用功率为60 W,辐照时间为75 min时,粘土颗粒吸持稠油的解吸率为77.36%。超声波能够显著增加解吸稠油在水中的溶解率,辐照时间为45 min,作用功率为80 W时,水相含油率升高92%;当作用功率为60 W,辐照时间为75 min时,水相含油率升高近1倍。随着超声辐照时间的增加,极性相对较强的环烷酮类有机物的相对丰度随之增加,极性相对较弱的环烷二酮类有机物相对丰度则显著减小。超声波有利于异位化学淋洗在高含粘土颗粒石油污染土壤修复中的应用。 相似文献
996.
铬渣污染场地污染状况研究与修复技术分析 总被引:8,自引:1,他引:7
选取某一化工厂铬渣堆放场地作为典型铬渣污染场地,对其钻孔并采集不同深度土壤和地下水样品进行分析。研究发现,该铬渣污染场地存在很严重的土壤和地下水污染。污染物地表扩散较小,剖面扩散很严重,污染深度达6 m,不同特性土壤对六价铬的截留作用不同。在此基础上,归纳总结了国外常用铬渣污染场地修复治理技术的优缺点,并提出具体污染场地修复技术的选取应该根据勘探情况选择合适的某些技术组合。 相似文献
997.
V. N. Pozolotina P. I. Sobakin I. V. Molchanova E. N. Karavaeva L. N. Mikhailovskaya 《Russian Journal of Ecology》2000,31(1):14-19
A complex radioecological study of technogenic landscapes of southern Yakutia showed that the main factor responsible for
their contamination with uranium and radium is radionuclide dispersal by air with products of rock weathering. Coefficients
of biological absorption by plants decrease with an increase in the contamination level, which is explained by the fact that
strongly fixed forms of uranium and radium prevail in the contaminated areas. In addition, the root barrier plays an important
role. Radiation load is mainly determined by background gamma-radiation. The contribution of internal irradiation accounted
for by incorporated radionuclides does not exceed 16% and decreases with an increase in the level of soil contamination. Manchurian
alder seeds produced under conditions of enhanced background radiation are more viable than those from the control area. It
is shown that seed generations of plants growing under conditions of chronic irradiation are highly resistant to the radiation
factor. 相似文献
998.
999.
湖南省稻田土壤硫素状况研究 总被引:2,自引:0,他引:2
采集湖南省主要母质类型的稻田土壤,进行土壤全硫、有效硫及其相关性质的分析研究。结果表明,(1)供试耕层土壤全硫含量在0.266~0.885 g/kg 之间,平均0.539 g/kg。土壤有效硫变动范围为17.7~135.1 mg/kg,平均56.7 mg/kg。土壤全硫和有效硫之间有极显著的相关性,相关系数为0.423**(n =40)。(2)随着土壤剖面层次的加深,土壤有效硫和全硫含量逐渐减少。(3)耕层土壤C∶N,C∶S,N∶S比率分别为9.3~14.5,34.5~62.8和3.1~6.3;土壤C∶N∶P∶S比率平均为48.7∶4.67∶1.4∶1。(4)相关分析表明,土壤全硫与土壤全N、 全P、有机C之间均呈极显著正相关,且以N、S之间的相关性最为密切。 相似文献
1000.
酸性硫酸盐土是一种分布于热带、亚热带湿润气候区海岸带的劣质土壤,在港湾生态系统中实际扮演着潜在污染源的角色.本文系统综述了酸性硫酸盐土的环境影响及其防治技术,提出了我国酸性硫酸盐土环境影响防治的对策。 相似文献