全文获取类型
收费全文 | 2570篇 |
免费 | 186篇 |
国内免费 | 675篇 |
专业分类
安全科学 | 220篇 |
废物处理 | 128篇 |
环保管理 | 239篇 |
综合类 | 1440篇 |
基础理论 | 373篇 |
污染及防治 | 638篇 |
评价与监测 | 145篇 |
社会与环境 | 145篇 |
灾害及防治 | 103篇 |
出版年
2024年 | 5篇 |
2023年 | 46篇 |
2022年 | 145篇 |
2021年 | 133篇 |
2020年 | 107篇 |
2019年 | 106篇 |
2018年 | 124篇 |
2017年 | 130篇 |
2016年 | 116篇 |
2015年 | 151篇 |
2014年 | 211篇 |
2013年 | 264篇 |
2012年 | 213篇 |
2011年 | 221篇 |
2010年 | 174篇 |
2009年 | 175篇 |
2008年 | 143篇 |
2007年 | 148篇 |
2006年 | 118篇 |
2005年 | 98篇 |
2004年 | 70篇 |
2003年 | 82篇 |
2002年 | 74篇 |
2001年 | 76篇 |
2000年 | 56篇 |
1999年 | 43篇 |
1998年 | 25篇 |
1997年 | 32篇 |
1996年 | 23篇 |
1995年 | 20篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 20篇 |
1991年 | 15篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有3431条查询结果,搜索用时 78 毫秒
881.
本文对从高硫原油很容易制取的一种新的廉价萃取剂——石油亚砜(PSO)所合成的树脂,即PSO萃淋树脂处理低浓度甲基汞废水的可能性进行了研究。研究结果表明:在中性范围内(pH5—8)树脂对甲基汞的吸附能力很强,吸附率≥99%(废水浓度为10—20ppb);随着流速的增加,吸附率下降幅度很小;树脂易再生, 十倍树脂体积的再生剂(4mol HCl),洗脱率可达97.9%,再生五个周期后,净化率未见明显变化;Mg~(2+)、Fe~(2+)(Fe~(3+)、Ag+、cu~(2+)、Hg~(2+)、PA(黄腐酸)及Cl~-的干扰实验表咀除Hg~(2+)、Ag+外,其他离子基本没有影响。 相似文献
882.
通过采用GDX-502富集,GC-MS分析,对城市河流、湖库中的痕量有机污染物进行分析,共检出58种有机污染物,其中含有多种美国EPA公布的重点污染物,从而为痕量有机污染物的研究建立了灵敏度高,分辨率好的测试方法。 相似文献
883.
884.
针对压缩空气输送白灰进入矿槽的空气动力学特点 ,用压力损失的预定值和脉冲间隔时间计算方法选择配带通风机的仓顶式布袋除尘器 ,既除尘又达到了卸压目的 相似文献
885.
McCready S Birch GF Long ER Spyrakis G Greely CR 《Environmental monitoring and assessment》2006,120(1-3):187-220
Correlation analyses between measures of toxicity and concentrations of chemical contaminants were conducted for 103 surficial sediments from Sydney Harbour, Australia, and vicinity. Toxicity tests consisted of amphipod survival and reburial tests of whole sediments (Corophium colo), sea urchin fertilisation and larval development tests of pore waters (Heliocidaris tuberculata) and microbial bioluminescence (Microtox) tests of solvent extracts and pore waters. Toxicity in most tests correlated with concentrations of metallic contaminants, in particular, zinc, lead and copper. Organic contaminants did not correlate as significantly with toxicity. However, Heliocidaris tuberculata showed relationships with organochlorine compounds in samples with low to moderate metals contamination. Toxicity in the Microtox solvent extract test appeared to be primarily influenced by the presence of sulfur. This study has no precedent in Australia and the results support the validity of using local indigenous species in toxicity tests of field-collected sediments. This toxicity/chemistry dataset may be used in evaluations of sediment quality guidelines recently introduced to Australia. 相似文献
886.
Adsorbent sampling with analysis by thermal desorption, gas chromatography and mass spectrometry (TD/GC/MS) offers many advantages for volatile organic compounds (VOCs) and thus is increasingly used in many applications. For environmental samples and other complex mixtures, the MS detector typically is operated in the scan mode to aid identification of co-eluting compounds. However, scan mode does not achieve the optimal sensitivity, thus compounds occurring at low concentrations may not be detected. This paper develops and evaluates the application of a more sensitive TD/GC/MS method using selective ion monitoring (SIM) that is applicable to VOC mixtures found in ambient and indoor air. Based on toxicity and prevalence, 94 VOCs (including terpenes, aromatic, halogenated and aliphatic compounds) were selected as target compounds. Two analytical methods were developed: a conventional full scan method for ions from 29 to 270 m/z; and a SIM method using 16 time windows and different ions selected for the compounds in each window. Both methods used the same Tenax GR adsorbent sampling tubes, TD and GC parameters, and target and qualifier ions. Laboratory tests determined calibrations, method detection limits (MDLs), precisions, recoveries and storage stability. Field tests compared scan and SIM mode analyses for duplicate samples of indoor air in 51 houses and outdoor air at 41 sites. Statistical analyses included the development of error/precision models. The laboratory tests showed that most compounds demonstrated excellent precision (<10% for concentrations exceeding approximately 0.5 microg m(-3)), good linearity, near identical calibrations for scan and SIM modes, a wide dynamic range (up to 1500 microg m(-3)), and negligible storage losses after 1 month (7 compounds showed moderate losses). SIM mode MDLs ranged from 0.004 to 0.27 microg m(-3), representing a modest (1.1 to 22-fold) improvement compared to scan mode. However, in field tests the SIM method detected significantly more compounds (e.g., styrene and chloroform). Error models fit most compounds and allow quantification of errors at selected percentiles. Overall, while the new SIM method is somewhat time-consuming to develop, it offers greater sensitivity and maintains the high selectivity of traditional scan methods. 相似文献
887.
888.
花生壳提取物的体外抗氧化活性研究 总被引:4,自引:1,他引:3
为研究花生壳提取物的体外抗氧化活性,测定了花生壳提取物的还原能力、抗脂质过氧化作用、抑制油脂过氧化作用以及清除超氧阴离子自由基、羟基自由基、DPPH自由基的能力,并与抗坏血酸进行了比较.结果表明,花生壳提取物具有较好的总抗氧化活性和总还原性,能抑制脂质过氧化和油脂过氧化作用以及清除自由基.它对DPPH自由基、羟基自由基、超氧阴离子自由基的IC50分别为27.82μg/ml、183μg/ml、89μg/ml.研究表明,花生壳提取物具有较强的综合抗氧化能力,是一种很有开发价值的天然抗氧化剂. 相似文献
889.
890.