全文获取类型
收费全文 | 727篇 |
免费 | 9篇 |
国内免费 | 23篇 |
专业分类
安全科学 | 34篇 |
废物处理 | 76篇 |
环保管理 | 68篇 |
综合类 | 51篇 |
基础理论 | 129篇 |
环境理论 | 1篇 |
污染及防治 | 242篇 |
评价与监测 | 117篇 |
社会与环境 | 36篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 11篇 |
2022年 | 89篇 |
2021年 | 71篇 |
2020年 | 16篇 |
2019年 | 30篇 |
2018年 | 36篇 |
2017年 | 44篇 |
2016年 | 48篇 |
2015年 | 33篇 |
2014年 | 40篇 |
2013年 | 96篇 |
2012年 | 39篇 |
2011年 | 49篇 |
2010年 | 22篇 |
2009年 | 33篇 |
2008年 | 17篇 |
2007年 | 17篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有759条查询结果,搜索用时 46 毫秒
601.
602.
603.
604.
Groundwater-level trends and implications for sustainable water use in the Kabul Basin, Afghanistan 总被引:1,自引:0,他引:1
The Kabul Basin, which includes the city of Kabul, Afghanistan, with a population of approximately 4 million, has several Afghan, United States, and international military installations that depend on groundwater resources for a potable water supply. This study examined groundwater levels in the Kabul Basin from 2004 to 2012. Groundwater levels have increased slightly in rural areas of the Kabul Basin as a result of normal precipitation after the drought of the early 2000s. However, groundwater levels have decreased in the city of Kabul due to increasing water use in an area with limited recharge. The rate of groundwater-level decrease in the city is greater for the 2008–2012 period (1.5 meters per year (m/yr) on average) than for the 2004–2008 period (0–0.7 m/yr on average). The analysis, which is corroborated by groundwater-flow modeling and a non-governmental organization decision-support model, identified groundwater-level decreases and associated implications for groundwater sustainability in the city of Kabul. Military installations in the city of Kabul (the Central Kabul subbasin) are likely to face water management challenges resulting from long-term groundwater sustainability concerns, such as the potential drying of shallow water-supply wells. Installations in the northern part of the Kabul Basin may have fewer issues with long-term water sustainability. Groundwater-level monitoring and groundwater-flow simulation can be valuable tools for assessing groundwater management options to improve the sustainability of water resources in the Kabul Basin. 相似文献
605.
Mohadeseh Madadizadeh Mohammad Ali Taher Hamid Ashkenani 《Environmental monitoring and assessment》2013,185(5):4097-4105
The present research reports on the application of modified multiwalled carbon nanotubes as a new, easily prepared, and stable solid sorbent for the column preconcentration of ultra-trace amounts of cadmium in aqueous solution. Multiwalled carbon nanotubes were oxidized with concentrated HNO3 and modified with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and then were used as a solid phase for the column preconcentration of Cd(II). Elution was carried out with 0.5 mol?L?1 HNO3. The amount of eluted Cd(II) was measured using electrothermal atomic absorption spectrometry. Various parameters such as pH, sample and eluent flow rate, eluent concentration, breakthrough volume, and interference of a great number of anions and cations on the retention of analyte on sorbent were studied. Under the optimized conditions, the calibration graph was linear in the range of 0.67 ng?L?1 to 5.0 μg?L?1 and the detection limit (3Sb, n?=?7) was 0.14 ng?L?1 in initial solution. A preconcentration factor of 300 and relative standard deviations of ±3.6 % for seven successive determinations of 3 ng of Cd(II) were achieved. The column preconcentration was successfully applied to the analysis of river water, waste water, and Persian Gulf water sample. 相似文献
606.
Mohammad Abbas Mahmood Sunandan Baruah Anil Kumar Anal Joydeep Dutta 《Environmental Chemistry Letters》2012,10(2):145-151
Increasing water pollution by microbes has become a source of serious health concern across the globe. Production of potentially
carcinogenic disinfection by-products has marred credibility of traditional water purification techniques like chlorination.
Photocatalysis has emerged as a promising alternative technique for the disinfection of water with minimal risk of harmful
by-products. The process involves a wide band gap semiconductor material which, upon irradiation of light, produces electrons
and holes with high redox potential to degrade organic contaminants and microbes. In this review, we analyze the research
trends in photocatalytic inactivation of water borne microorganisms. This report analyzes the major factors that affect the
disinfection efficiency using this process. The discussion also includes plausible mechanisms of microbial degradation as
well as a kinetic model of the inactivation process. Different approaches, like doping of semiconductors or energy band engineering
or plasmon coupling, have been reported for the enhancement and utilization of ambient solar light. Photocatalysis could be
a cost-effective and environmentally friendly water purification technique though further research is required to enhance
its efficiency with the use of solar light. 相似文献
607.
Yusuf M Fariduddin Q Varshney P Ahmad A 《Environmental science and pollution research international》2012,19(1):8-18
Introduction
This study was hypothesized that salicylic acid elevates the level of antioxidant system that will protect plants from the stress generated by nickel and/or salinity. 相似文献608.
Mohammad T. Dastorani Alireza Moghadamnia Jamshid Piri Miguel Rico-Ramirez 《Environmental monitoring and assessment》2010,166(1-4):421-434
Hydrological yearbooks, especially in developing countries, are full of gaps in flow data series. Filling missing records is needed to make feasibility studies, potential assessment, and real-time decision making. In this research project, it was tried to predict the missing data of gauging stations using data from neighboring sites and a relevant architecture of artificial neural networks (ANN) as well as adaptive neuro-fuzzy inference system (ANFIS). To be able to evaluate the results produced by these new techniques, two traditionally used methods including the normal ratio method and the correlation method were also employed. According to the results, although in some cases all four methods presented acceptable predictions, the ANFIS technique presented a superior ability to predict missing flow data especially in arid land stations with variable and heterogeneous data. Comparing the results, ANN was also found as an efficient method to predict the missing data in comparison to the traditional approaches. 相似文献
609.
Use of Geosynthetic Clay Liners (GCLs) in landfill barrier design has been the focus of recent studies investigating their ability to prevent contaminant transport to groundwater. In this paper, the hydration of two GCL products placed in contact with clay subsoils at different initial moisture contents is described under both isothermal conditions at room temperature, and daily thermal cycles. The rate of hydration of the GCL and its final equilibrium moisture content were significantly influenced by the amount of moisture made available to it through the subsoil. The two types of GCLs were also found to exhibit different hydration behaviors under similar experimental conditions. The study revealed that GCLs undergoing daily thermal cycles absorbed much less moisture over time than the GCLs kept at constant room temperature (ratio 1:4). In comparison with other types of subsoils, the final equilibrium moisture content attained by the GCL from clay subsoil was significantly less than that for sand subsoil. 相似文献
610.
Ali Behnamfard Mohammad Mehdi Salarirad Francesco Veglio 《Waste management (New York, N.Y.)》2013,33(11):2354-2363
A novel hydrometallurgical process was proposed for selective recovery of Cu, Ag, Au and Pd from waste printed circuit boards (PCBs). More than 99% of copper content was dissolved by using two consecutive sulfuric acid leaching steps in the presence of H2O2 as oxidizing agents. The solid residue of 2nd leaching step was treated by acidic thiourea in the presence of ferric iron as oxidizing agent and 85.76% Au and 71.36% Ag dissolution was achieved. The precipitation of Au and Ag from acidic thiourea leachate was investigated by using different amounts of sodium borohydride (SBH) as a reducing agent. The leaching of Pd and remained gold from the solid reside of 3rd leaching step was performed in NaClO-HCl-H2O2 leaching system and the effect of different parameters was investigated. The leaching of Pd and specially Au increased by increasing the NaClO concentration up to 10 V% and any further increasing the NaClO concentration has a negligible effect. The leaching of Pd and Au increased by increasing the HCl concentration from 2.5 to 5 M. The leaching of Pd and Au were endothermic and raising the temperature had a positive effect on leaching efficiency. The kinetics of Pd leaching was quite fast and after 30 min complete leaching of Pd was achieved, while the leaching of Au need a longer contact time. The best conditions for leaching of Pd and Au in NaClO-HCl-H2O2 leaching system were determined to be 5 M HCl, 1 V% H2O2, 10 V% NaClO at 336 K for 3 h with a solid/liquid ratio of 1/10. 100% of Pd and Au of what was in the chloride leachate were precipitated by using 2 g/L SBH. Finally, a process flow sheet for the recovery of Cu, Ag, Au and Pd from PCB was proposed. 相似文献