全文获取类型
收费全文 | 882篇 |
免费 | 81篇 |
国内免费 | 404篇 |
专业分类
安全科学 | 95篇 |
废物处理 | 72篇 |
环保管理 | 72篇 |
综合类 | 611篇 |
基础理论 | 127篇 |
污染及防治 | 251篇 |
评价与监测 | 38篇 |
社会与环境 | 44篇 |
灾害及防治 | 57篇 |
出版年
2024年 | 7篇 |
2023年 | 17篇 |
2022年 | 72篇 |
2021年 | 71篇 |
2020年 | 63篇 |
2019年 | 48篇 |
2018年 | 43篇 |
2017年 | 60篇 |
2016年 | 54篇 |
2015年 | 60篇 |
2014年 | 58篇 |
2013年 | 69篇 |
2012年 | 64篇 |
2011年 | 77篇 |
2010年 | 69篇 |
2009年 | 68篇 |
2008年 | 67篇 |
2007年 | 42篇 |
2006年 | 48篇 |
2005年 | 49篇 |
2004年 | 46篇 |
2003年 | 16篇 |
2002年 | 17篇 |
2001年 | 17篇 |
2000年 | 30篇 |
1999年 | 23篇 |
1998年 | 19篇 |
1997年 | 25篇 |
1996年 | 17篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 7篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 5篇 |
1985年 | 1篇 |
排序方式: 共有1367条查询结果,搜索用时 312 毫秒
371.
Luo W Lu Y Wang B Tong X Wang G Shi Y Wang T Giesy JP 《Environmental monitoring and assessment》2009,158(1-4):507-517
Fifty-seven typical surface soils and 108 deeper soils were collected from five former industrial sites in Beijing and concentrations of total Hg (SigmaHg) as well as pH, total carbon (TC), total nitrogen (TN), total sulfur, and dissolved organic carbon concentrations determined. The mean concentration of SigmaHg in surface soils was significantly greater than background concentrations in the vicinity of Beijing. Forty-eight percent of the samples exceeded the "critical" concentration of 1.0 mg Hg/kg, dry weight in soils, which has been established by the Chinese government. At depths of 0-80 cm in the soil, profile concentrations of SigmaHg also exceeded the background value. There were significant correlations between concentrations of SigmaHg, TC, and TN in the industrial soils. The greater concentration of SigmaHg in most soils could have been due in part to combustion of coal and leakage from industrial processes. 相似文献
372.
373.
在往复流现象明显的蕰藻浜中下游河道选择16个采样点,分析研究沉积物性状以及Cr、Cu、Zn、Cd、Ni、Pb、Mn的含量以及分布情况。结果表明:蕰藻浜总体污染程度为中等,其中陈行桥、江杨北路桥以及淞港码头污染较严重。Cr、Cd、Pb、Ni、Cu、Zn和Mn的含量分别为24.0~357.0、0.06~0.69、20.0~85.4、18.2~132、14.2~136、84.6~685、472~1 086 mg/kg。通过分析发现,Pb、Ni、Cu、Zn和Cr总量都具有显著的相关性,很有可能来自同一外源污染,而中游河段的Mn主要来自于沉积物母质。河道两岸以往的工业与生活排污以及往复水流使得重金属污染物在沉积物中聚集是造成重金属污染的潜在原因。运用地累积指数法、潜在生态危害指数法、污染负荷指数3种风险评价法对沉积物重金属进行风险评估,总体来说,3种评价方法都表明Cu的污染程度较严重,Mn的污染较轻。其中地累积指数法结果显示,各重金属的污染顺序为CuZn≥CdPb≥CrNiMn,然而由于Cd本身生物毒性较高,对沉积物生态环境危害贡献率可达到60%;污染负荷指数评价结果发现蕰藻浜下游河段部分断面沉积物达到了极强污染程度,应当受到重视。 相似文献
374.
垃圾的TOC含量是评价垃圾矿质腐殖化机理研究的重要指标,以本课题组模拟垃圾填埋系统中的垃圾样品为研究对象,以土壤TOC测定方法为基础,通过单因素实验和正交实验(L25(56))对垃圾样品的TOC的测定方法进行优化。结果表明,TOC测定优化条件为:风干样品(0.1±0.0005)g,Ag2SO40.075 g,0.4 mol/L(1/6K2Cr2O7)-H2SO4溶液(含1/2H2SO412.6 mol/L)10 mL,180℃的砂浴加热45 min。此条件下,RSD小于3.23%,表明该方法精密度高,可行性强。 相似文献
375.
Wing-Tat Hung Hing-Yan Tong Chun-Shun Cheung 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1431-1440
Abstract This study reports on the analysis of emissions and fuel consumption from motor vehicles using a modal approach. The four standard driving modes are idling, accelerating, cruising, and decelerating. On‐road data were collected using instrumented test vehicles traveling many times through the urban areas of Hong Kong. A model was developed for estimating vehicular fuel consumption and emissions as a function of instantaneous speed and driving mode. Piecewise interpolation functions were proposed for each nonidling driving mode. Idling emission and fuel consumption rates were estimated as negative exponential functions of idling time. Preliminary modeling results showed good agreements for the test vehicles and indicated that the on‐road measurements are feasible for the development of modal emission and fuel consumption models. 相似文献
376.
Ma Lefan Tong Zhiquan Zhang Junfeng 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1543-1549
Abstract A novel process for removal of nitrogen oxides (NOx) from flue gases with iron filings reduction following complex absorption in iron-ethylenediaminetetraacetic acid aqueous solution is proposed. The reaction mechanism involved in the process is discussed briefly. The parameters influencing the process, including the concentration of ferrous chelates, initial pH, amount of iron filings, temperature, flow rate of the flue gas, and inlet nitric oxide concentration and oxygen content of the flue gas, are researched in detail. The optimal NOx removal conditions are established. The regeneration and circular utilization of the absorption solution also is studied. 相似文献
377.
Rui Lu Guo-Ping Sheng Yi Liang Wei-Hua Li Zhong-Hua Tong Wei Chen Han-Qing Yu 《Environmental science and pollution research international》2013,20(4):2220-2225
Polycyclic aromatic hydrocarbons (PAHs) are persistent, bioaccumulative, and toxic chemicals and are listed as priority pollutants by the US EPA. Although they are sparsely soluble in water, their solubility can be increased by binding to dissolved organic matter in natural waters, which will further increase their environmental risk as toxic pollutants. In this study, the interaction between PAHs, exemplified by fluorene and anthracene, and fulvic acid (FA) was studied using fluorescence quenching titration method with fluorescence emission spectra, respectively. The association of FA with the mixture of fluorene and anthracene was also evaluated by excitation–emission matrix (EEM) fluorescence spectrometry combined with parallel factor (PARAFAC) analysis. Results demonstrate that EEM fluorescence spectrometry with PARAFAC analysis was sensitive and reliable to determine the binding properties of PAHs with FA in a mixed aqueous solution. The conditional stability constants and binding capacities show that both PAHs bind to FA tightly. 相似文献
378.
天然锰砂去除水中的砷 总被引:2,自引:0,他引:2
天然锰砂是一种廉价、高效的水处理用材料,但尚未用于水中砷的去除。实验研究了反应时间、砷形态、初始砷浓度、温度、溶液初始pH对吸附过程的影响。结果表明,天然锰砂对As(Ⅲ)的吸附能力大于As(Ⅴ)。25℃时,固液比为10 g/L的条件下,天然锰砂对初始浓度为5.0 mg/L的砷溶液吸附过程经72 h基本达到平衡,平衡时对As(Ⅲ)和As(Ⅴ)的去除率分别达到94.5%和85.9%。吸附过程符合Lagergren准一级反应动力学模型和假二级反应动力学模型。相比之下,假二级动力学模型拟合程度更高。对As(Ⅲ)和As(Ⅴ),45℃时的吸附量均大于25℃时。不同温度下,天然锰砂对As(Ⅲ)和As(Ⅴ)的吸附过程更符合Freundlich等温吸附模型。在溶液初始pH为3~10范围内,锰砂对砷的吸附能力受pH的影响较小。实验结果表明,天然锰砂是一种具有实际应用潜力的除砷材料。 相似文献
379.
380.