全文获取类型
收费全文 | 872篇 |
免费 | 52篇 |
国内免费 | 263篇 |
专业分类
安全科学 | 61篇 |
废物处理 | 54篇 |
环保管理 | 65篇 |
综合类 | 464篇 |
基础理论 | 188篇 |
污染及防治 | 251篇 |
评价与监测 | 34篇 |
社会与环境 | 35篇 |
灾害及防治 | 35篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 46篇 |
2021年 | 33篇 |
2020年 | 29篇 |
2019年 | 32篇 |
2018年 | 33篇 |
2017年 | 39篇 |
2016年 | 39篇 |
2015年 | 40篇 |
2014年 | 62篇 |
2013年 | 72篇 |
2012年 | 70篇 |
2011年 | 63篇 |
2010年 | 52篇 |
2009年 | 58篇 |
2008年 | 40篇 |
2007年 | 47篇 |
2006年 | 31篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 33篇 |
2002年 | 37篇 |
2001年 | 24篇 |
2000年 | 30篇 |
1999年 | 32篇 |
1998年 | 41篇 |
1997年 | 23篇 |
1996年 | 17篇 |
1995年 | 21篇 |
1994年 | 13篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1977年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有1187条查询结果,搜索用时 296 毫秒
921.
欧美于20世纪90年代开始系统研究环境内分泌干扰物(EDs),为此成立了专门的工作机构负责EDs研究的规划与协调工作。研究框架包括确认EDs对人类和生态效应的方法,剂量一效应关系模型以及检测环境暴露水平等。研究对环境威胁最大受试物的主要毒理学终点有致癌性,生殖发育毒性,神经毒性和免疫毒性,目前危险评价的新进展是应用定量结构活性关系(QSAR)模型预测化学物的安全性。 相似文献
922.
Dina Tan Honghu Zeng Jie Liu Xiaozhang Yu Yanpeng Liang Lanjing Lu 《环境科学学报(英文版)》2013,25(7):1492-1499
The kinetics of the degradation of trace nitrobenzene (NB) by a granular activated carbon (GAC) enhanced microwave (MW)/hydrogen peroxide (H2O2) system was studied. Effects of pH, NB initial concentration and tert-butyl alcohol on the removal efficiency were examined. It was found that the reaction rate fits well to first-order reaction kinetics in the MW/GAC/H2O2 process. Moreover, GAC greatly enhanced the degradation rate of NB in water. Under a given condition (MW power 300 W, H2O2 dosage 10 mg/L, pH 6.85 and temperature (60±5)℃), the degradation rate of NB was 0.05214 min-1 when 4 g/L GAC was added. In general, alkaline pH was better for NB degradation; however, the optimum pH was 8.0 in the tested pH value range of 4.0-12.0. At H2O2 dosage of 10 mg/L and GAC dosage of 4 g/L, the removal of NB was decreased with increasing initial concentrations of NB, indicating that a low initial concentration was beneficial for the degradation of NB. These results indicated that the MW/GAC/H2O2 process was effective for trace NB degradation in water. Gas chromatography-mass spectrometry analysis indicated that a hydroxyl radical addition reaction and dehydrogenation reaction enhanced NB degradation. 相似文献
923.
污泥电子传递体系(ETS)活性测定中萃取剂的选择 总被引:5,自引:1,他引:5
比较了丙酮、乙醇、正丁醇、磷酸三丁酯、乙酸乙酯、甲苯和三氯甲烷等7种萃取剂检测活性污泥电子传递体系(ETS)活性的特性.结果表明,这7种萃取剂制作标准曲线的性能相近;在实际污泥样品检测中,37℃下丙酮的萃取时间仅需10min,待测样品量相同时,其萃取速度约是其它萃取剂的4~22倍,37℃下丙酮萃取污泥样品中三苯基甲脂(TF)的能力大于其它萃取剂在37℃或90℃下的萃取能力,同时以丙酮作萃取剂测定的污泥电子传递体系活性也最大,说明丙酮是污泥电子传递体系活性测定中萃取剂的最佳选择. 相似文献
924.
925.
926.
927.
Deng H Ge L Xu T Zhang M Wang X Zhang Y Peng H 《Journal of environmental quality》2011,40(6):1730-1736
Microorganisms are an integral part of the biogeochemical processes in wetlands. To improve the performance of constructed wetlands, it is very important to know the metabolic properties and functional diversity of the microbial communities. The purpose of this study is to analyze the metabolic properties and functional diversity of the microbial community in a horizontal subsurface-flow constructed wetland (CW) in a laboratory study through the sole-carbon-source utilization profiles using Biolog-ECO microplates. The technique has advantages over traditional cell culture techniques, such as molecular-level techniques-RNA amplification, which are time-consuming, expensive, and only applicable to the small number of species that may be cultured. This CW was designed to treat rural eutrophic water in China, using the plant L. This study showed that the metabolic activities of upper front substrate microorganisms (UF) were greater than those of the lower back substrate microorganisms (LB) in the CW. Integrated areas under average well color development (AWCD) curves of substrate microorganisms in the UF were 131.9, 4.8, and 99.3% higher than in the lower front part (LF), the upper back part (UB), and the LB part of the CW, respectively. Principal components analysis showed significant differences in both community structure and metabolic utilization of carbon sources between substrate microorganisms from different sampling sites. Carbon source utilization of polymers, carbohydrates, carboxylic acids, and amino acids was higher in UF than in LF, but that of amines and phenolic compounds was very similar in UF and LF. The richness, evenness, and diversity of upper substrate microbial communities were significantly higher than those of lower substrate. The LF substrate microbial communities had lower evenness than the other sampling plots, and the lowest richness of substrate microbial community was found in the LB part of the CW. 相似文献
928.
Jinxue Luo Jinsong Zhang Xiaohui Tan Diane McDougal Guoqiang Zhuang Anthony G. Fane Staffan Kjelleberg Yehuda Cohen Scott A. Rice 《环境科学学报(英文版)》2015
Biofilmformation, one of the primary causes of biofouling, results in reducedmembrane flux or increased transmembrane pressure and thus represents a major impediment to the wider implementation of membrane bioreactor (MBR) technologies for water purification. Most studies have focused on the role of bacteria in membrane fouling as they are the most dominant and best studied organisms present in the MBR. In contrast, there is limited information on the role of the archaeal community in biofilm formation in MBRs. This study investigated the composition of the archaeal community during the process of biofouling in an MBR. The archaeal community was observed to have lower richness and diversity in the biofilmthan the sludge during the establishment of biofilms at low transmembrane pressure (TMP). Clustering of the communities based on the Bray-Curtis similarity matrix indicated that a subset of the sludge archaeal community formed the initial biofilms. The archaeal community in the biofilm was mainly composed of Thermoprotei, Thermoplasmata, Thermococci, Methanopyri, Methanomicrobia and Halobacteria. Among them, the Thermoprotei and Thermoplasmata were present at higher relative proportions in the biofilms than they were in the sludge. Additionally, the Thermoprotei, Thermoplasmata and Thermococci were the dominant organisms detected in the initial biofilms at low TMP, while as the TMP increased, the Methanopyri, Methanomicrobia, Aciduliprofundum and Halobacteria were present at higher abundances in the biofilms at high TMP. 相似文献
929.
放电等离子体降解三氯乙烯 总被引:10,自引:0,他引:10
采用2种放电方式和2种反应器对三氯乙烯进行降解,脉冲放电和交流放电均对三氯乙烯有较好的降解效果,且电压越高降解率越大.对脉冲放电,当气体停留时间为15s、三氯乙烯初始浓度1350mg/m3、电压42kV时空腔式反应器对三氯乙烯的降解率接近100%;对交流放电,使用32kV的电压可使降解率达98%,且频率越高降解效果越好.与脉冲放电相比,交流放电的功率消耗量大、能量利用率低,且填充式反应器的能量利用率也低于空腔式反应器.对于空腔式反应器,三氯乙烯降解率达80%时所需的脉冲和交流放电能量消耗分别为4.9W·h/m3和116W·h/m3. 相似文献
930.