全文获取类型
收费全文 | 4404篇 |
免费 | 503篇 |
国内免费 | 1798篇 |
专业分类
安全科学 | 393篇 |
废物处理 | 176篇 |
环保管理 | 748篇 |
综合类 | 3202篇 |
基础理论 | 637篇 |
污染及防治 | 894篇 |
评价与监测 | 357篇 |
社会与环境 | 228篇 |
灾害及防治 | 70篇 |
出版年
2024年 | 9篇 |
2023年 | 67篇 |
2022年 | 159篇 |
2021年 | 177篇 |
2020年 | 173篇 |
2019年 | 197篇 |
2018年 | 201篇 |
2017年 | 231篇 |
2016年 | 305篇 |
2015年 | 285篇 |
2014年 | 331篇 |
2013年 | 425篇 |
2012年 | 432篇 |
2011年 | 423篇 |
2010年 | 339篇 |
2009年 | 434篇 |
2008年 | 261篇 |
2007年 | 337篇 |
2006年 | 293篇 |
2005年 | 269篇 |
2004年 | 188篇 |
2003年 | 180篇 |
2002年 | 164篇 |
2001年 | 131篇 |
2000年 | 120篇 |
1999年 | 103篇 |
1998年 | 81篇 |
1997年 | 67篇 |
1996年 | 64篇 |
1995年 | 73篇 |
1994年 | 39篇 |
1993年 | 30篇 |
1992年 | 32篇 |
1991年 | 16篇 |
1990年 | 13篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 5篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有6705条查询结果,搜索用时 15 毫秒
41.
Virendra Misra Shri Dhar Pandey P. N. Viswanathan 《Environmental monitoring and assessment》2000,61(2):231-237
Effect of various concentrations of humic acid (0.2 to 1%) on thebioavailability of -HCH in vegetative clones of theaquatic fern Marsilea minuta was studied in a staticexperimental bioassay system on different photoperiods. Additionof humic acid showed the reduction in the bioavailability of-HCH in all the photoperiods (72 hr light to 144 hrlight) at the interval of 16 hr light (L) and 8 hr dark (D) inboth aerial and submerged portion as compared to controlindicating its protective role in toxicity. 相似文献
42.
43.
The purpose of this work was to study the distribution of airborne particles in the surroundings of an iron and steel factory in southern Finland. Several sources of particulate emissions are lying side by side, causing heavy dust loading to the environment. This complicated multi-pollutant situation was studied mainly by SEM/EDX methodology.Particles accumulated on Scots pine bark were identified andquantitatively measured according to their element content,size and shape. As a result, distribution maps of particulateelements were drawn and the amount of different particle typesalong the study lines was plotted. Particulate emissions fromthe industrial or energy production processes were not themain dust source. Most emissions were produced from theclinker crusher. Numerous stockpiles of the industrial wastesand raw materials also gave rise to particulate emissions as aresult of wind erosion. It was concluded that SEM/EDXmethodology is a useful tool for studying the distribution ofparticulate pollutants. 相似文献
44.
45.
46.
大气颗粒物中元素碳的直接测定 总被引:4,自引:1,他引:4
对原来用元素分析仪测定大气颗粒物样品中有机碳、元素碳的方法[1 ] 进行改进 ,将差减法间接测定元素碳改为一步直接测定元素碳。有机碳、元素碳的测量标准偏差的平均值分别为 0 35 %、0 34% ,提高了元素碳的测量精度 ,同时避免了误差传递 ,解决了差减法测定元素碳时出现负值的情况。 相似文献
47.
详细介绍了“城市空气质量日报自动发布系统”的开发背景和开发过程 ,并对系统整体的架构和所用到的技术作了针对性的说明 ,阐明了作者对此类系统的前景和发展方向的看法。 相似文献
48.
49.
Wong MY Sauser KR Chung KT Wong TY Liu JK 《Environmental monitoring and assessment》2001,67(3):361-378
The green alga Selenastrum capricornutum expresses a uniqueascorbate peroxidase, that responds to copper and lead. Attemptswere made to test if this peroxidase could be used to monitor thelevels of copper and lead in natural waters. When S.capricornutum was exposed to a stormwater sample, the specificactivity of the peroxidase in the cell extract was commensuratewith the combined copper and lead contents in the sample. Theperoxidase responses were also correlated with the 96 hr biomasstoxicity assay of S. capricornutum. However, unlike thebiomass toxicity assay, the peroxidase activity was not affectedby the anions in the samples. The use of this peroxidase can beused as a marker for testing heavy metal toxicity in the water. 相似文献
50.
A positive correlation has been established between increased levels of airborne particulate pollution and adverse health effects, the toxicological mechanisms of which are poorly understood. For toxicologists to unambiguously determine thesemechanisms, truly representative samples of ambient PM10 are required. This presents problems, as PM10 collecting equipment commonly employed, such as the Tapered Element Oscillating Microbalance (TEOM®), heat the inflow toexclude moisture or use fibrous filters, resulting in a PM10sample that may have undergone significant chemical change on thefilter surface or is contaminated by filter fibres. Other systems(i.e. Negretti and Partisol) can successfully collect PM10 without chemical alteration or filter contamination. Comparativecollections from Port Talbot, S. Wales suggest that TEOMs and Negretti/Partisol systems collect different PM10's; the principle difference arising from the TEOM's heating chamber, which precipitates water-soluble ions and volatilises some organic components. This results in both the mass and compositionof the PM10's being altered. Particle size distributionsfor Negretti and Partisol collections highlighted differences mainly attributed to different flow rates. The results of thiswork demonstrate that simple correlations between PM10 massand adverse health effects are problematic. Furthermore, elucidation of the complex fractionation and chemical changes indifferent collectors is necessary. 相似文献