全文获取类型
收费全文 | 22096篇 |
免费 | 283篇 |
国内免费 | 768篇 |
专业分类
安全科学 | 664篇 |
废物处理 | 1096篇 |
环保管理 | 2552篇 |
综合类 | 3706篇 |
基础理论 | 5575篇 |
环境理论 | 4篇 |
污染及防治 | 6113篇 |
评价与监测 | 1736篇 |
社会与环境 | 1516篇 |
灾害及防治 | 185篇 |
出版年
2023年 | 136篇 |
2022年 | 344篇 |
2021年 | 317篇 |
2020年 | 213篇 |
2019年 | 256篇 |
2018年 | 400篇 |
2017年 | 401篇 |
2016年 | 623篇 |
2015年 | 464篇 |
2014年 | 693篇 |
2013年 | 1919篇 |
2012年 | 813篇 |
2011年 | 1010篇 |
2010年 | 915篇 |
2009年 | 886篇 |
2008年 | 982篇 |
2007年 | 1084篇 |
2006年 | 942篇 |
2005年 | 771篇 |
2004年 | 757篇 |
2003年 | 758篇 |
2002年 | 728篇 |
2001年 | 950篇 |
2000年 | 677篇 |
1999年 | 438篇 |
1998年 | 313篇 |
1997年 | 281篇 |
1996年 | 331篇 |
1995年 | 295篇 |
1994年 | 262篇 |
1993年 | 257篇 |
1992年 | 254篇 |
1991年 | 217篇 |
1990年 | 224篇 |
1989年 | 222篇 |
1988年 | 207篇 |
1987年 | 161篇 |
1986年 | 129篇 |
1985年 | 138篇 |
1984年 | 172篇 |
1983年 | 153篇 |
1982年 | 195篇 |
1981年 | 136篇 |
1980年 | 119篇 |
1979年 | 152篇 |
1978年 | 118篇 |
1977年 | 107篇 |
1976年 | 100篇 |
1975年 | 83篇 |
1974年 | 88篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
101.
The toxic effects of the composites of Fe~0 and Cu~0 with different percentages of CNTs were examined based on the activity of bacterial bioluminescence and seed germination. In terms of the EC_50 values, the toxic effects of Cu~0 on bacterial bioluminescence and seed germination were approximately 2 and 180 times greater than that of Fe~0, respectively. The toxicity increased with increasing CNT content in the Cu-CNT mixtures for both organisms,whereas opposite results were observed with Fe-CNT mixtures. The mean toxic effects of Cu-CNT(6%) were approximately 1.3–1.4 times greater than that of Cu-CNT(0%), whereas the toxic effects of Fe-CNT(6%) were approximately 2.1–2.5 times lower than that of Fe-CNT(0%) for both the bioluminescence activity and seed germination. The causes of this phenomenon are unclear at this point. More research will be needed to elucidate the mechanism of the toxicity of nano-mixture materials and the causes of the different patterns of toxicity with Cu-and Fe-CNT mixtures. 相似文献
102.
103.
104.
为了降低天津市滨海新区中PM_(2.5)的污染,需要对天津市滨海新区PM_(2.5)污染的时空分布和影响因素进行研究。研究天津市滨海新区近年来PM_(2.5)的时空分布特征,并选取PM_(2.5)的相关指标,对天津市滨海新区PM_(2.5)污染影响因素进行分析。结果表明,在天津市滨海新区的冬季时,PM_(2.5)的质量浓度值最高,在滨海新区的夏季时,PM_(2.5)的质量浓度值最低。PM_(2.5)在天津市滨海新区昼间大气中的质量浓度低于夜间大气中的质量浓度。 相似文献
105.
随着经济的快速发展,科技水平不断地提高,中国石油行业发展迅速,石油储运的技术也在不断提高。对考虑环境污染物减排的石油储运策略进行研究,对石油储运的过程中出现污染源以及产生的危害进行论述,在此基础上对石油储运污染物减排存在的障碍性因素进行说明,最后针对上述问题,提出石油储运策略对污染物减排相应的解决措施,由变频调速污染物的减排技术、可燃气体的排放与回收技术等措施对石油储运策略的污染物减排进行优化,减少污染物的排放,对生态环境进行保护。 相似文献
106.
107.
108.
Studies on the effects of some organic pollutants on the heavy metal transport in an Indian soil 总被引:1,自引:0,他引:1
The translocation of some heavy metals, such as Hg, Cd, Cu, Co, Ni and Zn, as affected by organic pollutants, i.e. methanol, ethanol, propanol, formaldehyde, acetaldehyde, benzaldehyde, acetone, ethyl methyl ketone and cyclo-hexanone, was studied in an Indian red soil using soil thin layer chromatography. It was observed that an increase in the concentration of organic compounds in developer enhances the heavy metal mobility, except in the case of Cu and Hg which show a decreasing trend. The results are discussed in relation to the physico-chemical characteristics of the soil and adsorption/desorption phenomena. 相似文献
109.
Ronald Fuge Ian M. S. Laidlaw William T. Perkins Kerry P. Rogers 《Environmental geochemistry and health》1991,13(2):70-75
The many abandoned base metal mines of the mid-Wales ore field are sources of extensive pollution. Some of the mineralised veins contain large amounts of pyrite and marcasite and oxidative weathering of these produces sulphuric acid resulting in very acidic mine drainage waters. In addition, the spoil tips associated with these mines can contain abundant iron sulphides. Drainage waters from these sources have pH values as low as 2.6 and are heavily contaminated with metals such as Al, Zn, Cd and Ni.Two of the main rivers of the area, the Rheidol and Ystwyth, intercept heavily contaminated acidic drainage which has a marked effect on water quality. The Rheidol contains over 100 g L–1 Zn for 16 km downstream of the acid water influx. This level is over three times the recommended EEC limit for Zn in salmonoid waters of low hardness. 相似文献
110.
Lead and zinc effects on Bufo arenarum larval survival were studied in single and combined treatments. On a weight basis, lead is about twice as toxic as zinc. The antagonism or synergism between these heavy metals is dose-dependent. 相似文献