全文获取类型
收费全文 | 706篇 |
免费 | 3篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 12篇 |
环保管理 | 29篇 |
综合类 | 388篇 |
基础理论 | 120篇 |
环境理论 | 2篇 |
污染及防治 | 109篇 |
评价与监测 | 25篇 |
社会与环境 | 22篇 |
灾害及防治 | 3篇 |
出版年
2019年 | 10篇 |
2018年 | 17篇 |
2017年 | 11篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 12篇 |
2013年 | 25篇 |
2012年 | 22篇 |
2011年 | 18篇 |
2010年 | 22篇 |
2009年 | 23篇 |
2008年 | 21篇 |
2007年 | 26篇 |
2006年 | 15篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 19篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1992年 | 7篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1968年 | 6篇 |
1967年 | 6篇 |
1966年 | 8篇 |
1965年 | 7篇 |
1964年 | 8篇 |
1961年 | 9篇 |
1960年 | 6篇 |
1955年 | 7篇 |
1952年 | 6篇 |
1942年 | 6篇 |
1941年 | 8篇 |
1940年 | 9篇 |
1938年 | 6篇 |
1937年 | 12篇 |
1936年 | 10篇 |
1935年 | 9篇 |
1934年 | 12篇 |
1933年 | 7篇 |
1931年 | 7篇 |
1929年 | 8篇 |
1922年 | 6篇 |
1921年 | 7篇 |
排序方式: 共有716条查询结果,搜索用时 15 毫秒
601.
Nordqvist Y Nilsson U Colmsjo A Dahl A Gudmundsson A 《Journal of environmental monitoring : JEM》2005,7(5):469-474
A denuder/filter system constructed for solvent-free personal exposure measurements was evaluated for separation of vapour and particulate 4,4'-methylenediphenyl diisocyanate (4,4'-MDI) generated from heated PUR-foam. The two different phases were collected in the denuder and on the filter, respectively, by chemosorption on a polydimethylsiloxane (SE-30)-dibutylamine (DBA) stationary phase. Both repeatability and the total mass concentration of 4,4'-MDI were similar to that obtained from the reference method, in this case an impinger/filter system. The penetration of particles through the denuder at 300 ml min(-1) was nearly 100% in the particle size range 25 to 700 nm, which fits well with the Gormley-Kennedy equation. Denuder/filter sampling of the 4,4'-MDI aerosol at 500 ml min(-1) yielded a phase distribution that was in accordance with the results from the reference method. The method limit of detection was 6 ng m(-3) and 4 ng m(-3) for the denuder and filter, respectively, when using an air sampling flow rate of 300 ml min(-1) and a sampling period of 15 min. This is well below the Swedish occupational exposure limit (OEL) of 50 and 100 microg m(-3) for an 8-hour working day and a 5-min period, respectively. 相似文献
602.
von Tiedemann A Weigel HJ Jäger HJ 《Environmental pollution (Barking, Essex : 1987)》1991,72(3):205-224
Spring wheat (Triticum aestivum L. cv. Turbo) was exposed in open-top chambers to six different ozone levels (8-h daily means from 12.4 to 122 microg m(-3)), to non-filtered air and to chamberless field conditions for 31 days from seedling stage through ear emergence. Powdery mildew (Erysiphe graminis DC. f.sp. tritici Marchal) which developed during the exposure period was significantly enhanced from 0.3/0.6% (two chamber replicates), 1.2/2.1%, 0.9/2.2% in charcoal-filtered air (CF) to 1.5/1.6%, 3.7/4.3%, 4.4/4.6% at the highest level of ozone, on the flag leaf, second and third leaf position, respectively. Post-exposure inoculation with Septoria nodorum Berk. led to increases of disease severity on the flag leaf from 40.9/43.6% in CF to 66.3/70.6% at the highest ozone concentration and on the ears from 15.7/16.5% to 26.3/26.6%. In the same comparison, severity of spot blotch following inoculation with Bipolaris sorokiniana (Sacc.) Shoem. (syn. Helminthosporium sativum Pamm., King et Bakke) was increased on the flag leaf from 3.6/8.9% to 12.3/23.4%. The three diseases examined correlated significantly with the ozone treatments in fumigated chambers. Disease severity was enhanced even on undamaged plant tissue (flag leaves). Infections of the two facultative pathogens on lower leaf positions started only in part from visible ozone lesions, mildew did not start from such lesions. No significant effects of ozone in the chambers on the saprobial colonization of the phyllosphere were detected, whereas there were marked differences in this respect between plants from the field and the chambers. At the highest ozone treatment, contents of chlorophyll a and carotenoids on the second leaf position declined significantly, which was associated with symptoms of premature senescence. Senescing effects of ozone are therefore assumed to be one major factor in predisposing wheat for necrotrophic leaf pathogens. Surprisingly, injurious and predisposing effects of ozone were completely absent in chambers supplied with non-filtered air containing ambient ozone at doses equivalent to those in CF + ozone chambers. Evidently, biological effects of ozone in pure air and in ambient air may differ markedly. 相似文献
603.
604.
605.
606.
607.
608.
Zusammengestellt von G. H. Altenmüller 《Die Naturwissenschaften》1999,86(3):152-154
Ohne Zusammenfassung 相似文献
609.
Klaus von Berlepsch 《Die Naturwissenschaften》1980,67(7):338-342
A modern approach to the search for biologically active substances of potential therapeutic use isolated from marine organisms is illustrated by a presentation of the multidisciplinary project pursued by the Roche Research Institute of Marine Pharmacology near Sydney, Australia. This specialized insitute is part of the world-wide research endeavour of our company and has now been in operation for five years. Following a brief outline of the technical functions the main scientific achievements published by the scientists of the institute are reviewed. This institute is, to our knowledge, the only one of its kind in private industry and we have attempted to demonstrate how its activities should be viewed in the overall context of today's drug or product development. 相似文献
610.