全文获取类型
收费全文 | 1778篇 |
免费 | 116篇 |
国内免费 | 597篇 |
专业分类
安全科学 | 117篇 |
废物处理 | 55篇 |
环保管理 | 152篇 |
综合类 | 1020篇 |
基础理论 | 409篇 |
污染及防治 | 499篇 |
评价与监测 | 87篇 |
社会与环境 | 70篇 |
灾害及防治 | 82篇 |
出版年
2024年 | 1篇 |
2023年 | 20篇 |
2022年 | 43篇 |
2021年 | 40篇 |
2020年 | 34篇 |
2019年 | 35篇 |
2018年 | 48篇 |
2017年 | 63篇 |
2016年 | 75篇 |
2015年 | 100篇 |
2014年 | 111篇 |
2013年 | 126篇 |
2012年 | 109篇 |
2011年 | 193篇 |
2010年 | 135篇 |
2009年 | 76篇 |
2008年 | 80篇 |
2007年 | 89篇 |
2006年 | 80篇 |
2005年 | 52篇 |
2004年 | 151篇 |
2003年 | 134篇 |
2002年 | 89篇 |
2001年 | 70篇 |
2000年 | 60篇 |
1999年 | 66篇 |
1998年 | 60篇 |
1997年 | 97篇 |
1996年 | 36篇 |
1995年 | 28篇 |
1994年 | 32篇 |
1993年 | 51篇 |
1992年 | 39篇 |
1991年 | 30篇 |
1990年 | 6篇 |
1989年 | 15篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有2491条查询结果,搜索用时 0 毫秒
31.
John W. Wang Henrique C. G. Do Nascimento Teh Fu Yen 《Resources, Conservation and Recycling》1989,2(4)
Biodegradation of nitrogen-enriched lignite by soil bacteria previously acclimated in hydrogen peroxide-acetic acid lignitic substrate was carried out to assess the effects of nitrogen functional groups on the biodegradation of lignite. Chlorination, oxidation plus nitration, and ammoniation were applied in an attempt to modify the chemical structure of lignite so as to obtain a lignitic substrate that is more compatible to the enzymatical system of ordinary soil bacteria than that of unmodified lignite. Incorporation of nitrogen containing functional groups into lignite structure achieved 4.71 wt%, a value five times higher than that usually found in unmodified (raw) lignite. Data collected through a 16 day incubation time, monitoring production as well as depletion of both nitrate and organic acids, concluded that biodegradation was expedited by the incorporation of nitrogen into the structure of lignite. Twenty-eight compounds were identified based on the results from GC/MS analysis of the products. 相似文献
32.
33.
34.
35.
Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China 总被引:53,自引:0,他引:53
Mai BX Fu JM Sheng GY Kang YH Lin Z Zhang G Min YS Zeng EY 《Environmental pollution (Barking, Essex : 1987)》2002,117(3):457-474
Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng/g, dry weight, while those of PCBs range from 11 to 486 ng/g. The CPs concentrations of the estuarine sediment samples are in the range 6-1658 ng/g, while concentrations of PCBs are in the range 10-339 ng/g. Total PAH concentration ranges from 1168 to 21,329 ng/g in the riverine sediment samples, whereas the PAH concentration ranges from 323 to 14,812 ng/g in the sediment samples of the Estuary. Sediment samples of the Zhujiang River and Macao harbor around the Estuary show the highest concentrations of CPs, PCBs, and PAHs. Possible factors affecting the distribution patterns are also discussed based on the usage history of the chemicals, hydrologic condition, and land erosion due to urbanization processes. The composition of PAHs is investigated and used to assess petrogenic, combustion and naturally derived PAHs of the sediment samples of the Pearl River Delta. In addition, the concentrations of a number of organic compounds of the Pearl River Delta samples indicate that sediments of the Zhujiang river and Macao harbor are most likely to pose biological impairment. 相似文献
36.
The photocatalytic oxidation of phenanthrene was investigated in aqueous TiO2 suspensions under UV light irradiation. Chemical oxygen demand (COD) measurements, UV-Vis spectrophotometer, IR spectrometer and gas chromatography-mass spectrometry (GC-MS) analytical techniques were used to monitor the reaction process. Some factors affecting the photodegradation rate were studied and some aromatic intermediates were detected during the reaction process. Fast and complete mineralization of phenanthrene was achieved in this reaction system. 相似文献
37.
沉积物中多环芳烃和有机氯农药定量分析的质量保证和质量控制 总被引:118,自引:8,他引:118
以美国EPA为方法为基础,进行了沉积物中多环芳烃和有机氯农药分析的质量保证和质量控制实验,采用回收率指示物控制回收率,用内标法定量。结果表明多环芳烃的指示物回收率为50.67-97.33%,目标化合物的回收率为58.67-96.33%,方法检测限为3.30-9.26μg.kg^-1。 相似文献
38.
39.
40.
The present study was carried out to evaluate the question of whether or not royal jelly affects N-acetylation and metabolism of 2-aminofluorene (2-AF) in the human liver tumor cell line (J 5). N-acetylation and metabolism of 2-AF in intact J5 cells was determined by using high performance liquid chromatography for the amounts of acetylated and nonacetylated 2-AF and profile of 2-AF metabolism. The results indicated that royal jelly displayed a dose-dependent inhibition of N-acetylation of 2-AF in J5 cells. Royal jelly also decreased the profile of 2-AF metabolites in J5 cells. This report is the first demonstration which showed that royal jelly affects N-acetylation of 2-AF in human liver tumor cells (J5). 相似文献