全文获取类型
收费全文 | 37275篇 |
免费 | 690篇 |
国内免费 | 3233篇 |
专业分类
安全科学 | 1390篇 |
废物处理 | 1559篇 |
环保管理 | 4736篇 |
综合类 | 9913篇 |
基础理论 | 8777篇 |
环境理论 | 10篇 |
污染及防治 | 10860篇 |
评价与监测 | 1961篇 |
社会与环境 | 1458篇 |
灾害及防治 | 534篇 |
出版年
2023年 | 264篇 |
2022年 | 606篇 |
2021年 | 584篇 |
2020年 | 420篇 |
2019年 | 492篇 |
2018年 | 635篇 |
2017年 | 714篇 |
2016年 | 948篇 |
2015年 | 879篇 |
2014年 | 1300篇 |
2013年 | 3177篇 |
2012年 | 1550篇 |
2011年 | 1865篇 |
2010年 | 1417篇 |
2009年 | 1532篇 |
2008年 | 1772篇 |
2007年 | 1701篇 |
2006年 | 1565篇 |
2005年 | 1236篇 |
2004年 | 1168篇 |
2003年 | 1204篇 |
2002年 | 1156篇 |
2001年 | 1296篇 |
2000年 | 1047篇 |
1999年 | 774篇 |
1998年 | 582篇 |
1997年 | 559篇 |
1996年 | 597篇 |
1995年 | 567篇 |
1994年 | 525篇 |
1993年 | 488篇 |
1992年 | 454篇 |
1991年 | 422篇 |
1990年 | 415篇 |
1989年 | 383篇 |
1988年 | 350篇 |
1987年 | 324篇 |
1986年 | 289篇 |
1985年 | 303篇 |
1984年 | 301篇 |
1983年 | 308篇 |
1982年 | 310篇 |
1981年 | 309篇 |
1980年 | 265篇 |
1979年 | 284篇 |
1978年 | 234篇 |
1977年 | 203篇 |
1976年 | 205篇 |
1973年 | 203篇 |
1972年 | 202篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
251.
Bouhamra WS 《Environmental pollution (Barking, Essex : 1987)》1995,90(1):121-125
Interest in indoor air quality is steadily increasing. Exposure to volatile organic compounds (VOCs) is associated with health effects as diverse as childhood respiratory disease, lung cancer and cardiovascular disease. In an effort to assess the environmental impact indoors from possible sources of VOCs, such as (i) open oil lakes, (ii) chemical and petrochemical industries and (iii) indoor pollution from household items, concentrations of aliphatic and aromatic VOCs, comprising n-hexane to n-hexadecane, benzene, toluene, xylene, ethyl benzene, methanol and o-dichlorobenzene, were measured in indoor air samples from seven different cities in Kuwait using a gas chromatograph. The data for the period March to May 1993 are presented. The VOCs, as measured, were surprisingly low and they are below the concentrations set by the American Hygienists Association. However, although the concentration of the estimated VOCs being low, were cumulative effects of them entering the human body and water sources cannot be ruled out. 相似文献
252.
Mahaney WC Wilson E Boyer MG Hancock RG 《Environmental pollution (Barking, Essex : 1987)》1995,87(1):71-75
Recent lichen surveys in the foreland of The Syterb?cken glacier reveal that the crustose lichens, principally species of Rhizocarpon section Rhizocarpon, exhibit marginal bleaching, readily distinguishable from normal pigmented forms. The largest elliptical thallus of Rhizocarpon measured 290 mm maximum diameter on a bedrock outcrop beyond the margin of Little Ice Age moraines in the upper Syterb?cken Valley. Many small and large thalli of Rhizocarpon suffered damage to the periphery of individual thalli. We examine here some of the possible hypotheses explaining these occurrences. Among others, these are bedrock lithology, ice crystal blasting, long-term snowbank cover, ultraviolet exposure and acid rain. While at this time none of the possibilities can be ruled out entirely, acid rain would appear to be at least one of the factors involved. Acid rain, which is known to produce a soil pH as low as 3.3 in the field area, appears to provide a high input of H(+) ions that the lichen algal component cannot withstand. However, the lack of similar effects on associated foliose or fruticose forms raises the possibility that perhaps two or more factors specific to the environment of Rhizocarpon are operating. 相似文献
253.
Aston C.Chipanshi 《Ambio-人类环境杂志》2002,31(1):30-34
本文分析了在博茨瓦纳有效执行<蒙特利尔议定书>中遇到的困难;并就在发展中国家执行国际协定问题时如何向决策者提出建议提供了一个总的认识.对臭氧耗损物质(ODSs)的正式和非正式用户进行的问卷调查表明:所散发的有关ODSs的信息,对于用户们选择制冷气体几乎没有什么影响,而且这个信息偏向有利于ODSs的正式用户.因此,ODS使用数量的年统计资料可能估计偏低.困难在于,要在短期内从老技术转向新技术,成本较高.回收废气和处理废旧硬件设备的基础设施缺乏或不足.这些问题的解决需要一个全面的政策,它能满足所有ODSs用户的要求;还需要把经济发展与环境保护结合起来进行考虑. 相似文献
254.
255.
256.
IntroductionHeavymetalsinwaterbodiesaresignificantlydifferentfromorganicpollutantsthatcanbemicrobiologicallydegradedordecomposed .Generally ,theyarepurifiedthroughtheiradsorptionontosuspendedsubstratesinrivers.Adsorptionofheavymetalsonriversuspendedsub… 相似文献
257.
CHEN Wen-ying 《环境科学学报(英文版)》2003,15(4):541-547
Emission projection and marginal abatement cost curves (MACs) are the central components of any assessment of future carbonmarket, such as CDM (clean development mechanism) potentials, carbon quota price etc. However, they are products of very complex,dynamic systems driven by forces like population growth, economic development, resource endowments, technology progress and so on. The modeling approaches for emission projection and MACs evaluation were summarized, and some major models and their results were compared.Accordingly, reduction and cost requirements to achieve the Kyoto target were estimated. It is concluded that Annex I Parties‘ total reduction requirements range from 503--1304 MtC with USA participation and decrease significantly to 140--612 MtC after USA‘ s withdrawal. Total costs vary from 21--77 BUSD with USA and from 5--36 BUSD without USA if only domestic reduction actions are taken. The costs would sharply reduce while considering the three flexible mechanisms defined in the Kyoto Protocol with domestic actions‘ share in the all mitigation strategies drons to only 0--16%. 相似文献
258.
1IntroductionNovelbiologicalactivatedcarbonandactivatedsludgesystemhasshownitsefectiveabilitytoreduceCODintoxicorganicwastewa... 相似文献
259.
Becker E. W. Bier W. Ehrfeld W. Schubert K. Schütte R. Seidel D. 《Die Naturwissenschaften》1976,63(9):407-411
The Science of Nature - The development of reliable manufacturing methods for commercial separation elements, the successful operation of separative stages, and extensive tests performed on plant... 相似文献
260.