全文获取类型
收费全文 | 1299篇 |
免费 | 14篇 |
国内免费 | 15篇 |
专业分类
安全科学 | 48篇 |
废物处理 | 59篇 |
环保管理 | 190篇 |
综合类 | 239篇 |
基础理论 | 263篇 |
环境理论 | 2篇 |
污染及防治 | 330篇 |
评价与监测 | 112篇 |
社会与环境 | 80篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 16篇 |
2022年 | 27篇 |
2021年 | 31篇 |
2020年 | 19篇 |
2019年 | 21篇 |
2018年 | 39篇 |
2017年 | 32篇 |
2016年 | 40篇 |
2015年 | 30篇 |
2014年 | 45篇 |
2013年 | 67篇 |
2012年 | 68篇 |
2011年 | 78篇 |
2010年 | 51篇 |
2009年 | 71篇 |
2008年 | 64篇 |
2007年 | 82篇 |
2006年 | 53篇 |
2005年 | 53篇 |
2004年 | 54篇 |
2003年 | 42篇 |
2002年 | 43篇 |
2001年 | 32篇 |
2000年 | 20篇 |
1999年 | 16篇 |
1998年 | 23篇 |
1997年 | 13篇 |
1996年 | 17篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 15篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 4篇 |
1969年 | 2篇 |
1968年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有1328条查询结果,搜索用时 15 毫秒
111.
Various developmental stages (early larvae to adults) of Euphausia superba have been collected in different seasons in the Weddell Sea, the Lazarev Sea and off the Antarctic Peninsula to investigate
the role of lipids and fatty acids in the life cycle of the Antarctic krill. The total-lipid data for E. superba exhibited seasonal variations, with low lipid levels in late winter/early spring and the highest levels in autumn. Seasonal
changes were most pronounced in the immature and adult specimens, increasing from about 10% lipid of dry mass to more than
40%. The fatty-acid compositions of the younger stages were dominated by 20:5(n-3), 22:6(n-3) and 16:0. These are typical
phospholipid fatty acids, which are major biomembrane constituents. The phospholipid composition was similar in the older
stages. With increasing storage of triacylglycerols in the lipid-rich immature and adult stages, the fatty acids 14:0, 16:0
and 18:1(n-9) prevailed, comprising about 70% of total triacylglycerol fatty acids. The trophic-marker fatty acids 16:1(n-7)
and 18:4(n-3), indicating phytoplankton ingestion, were less abundant. They reflected, however, the dependence of the larvae
on phytoplankton as well as the seasonal changes in algal composition. The generally close linear relationships between fatty
acids and lipid suggest that the fatty-acid compositions of the collected specimens were largely independent of the respective
developmental stage, season and region. The linear fit indicates that triacylglycerol accumulation started at a level of about
5% of total lipid. Considering the various overwintering scenarios under discussion, the life cycle and reproductive strategies
of krill are discussed in the context of the lipid metabolism and fatty-acid composition of E. superba. Lipid production is effective enough to accumulate large energy reserves for the dark season, but E. superba does not exhibit the sophisticated biosynthetic pathways known from other Antarctic euphausiids and copepods. Although important,
lipid utilisation appears to be just one of several strategies of E. superba to thrive under the extreme Antarctic conditions, and this pronounced versatility may explain the success of this species
in the Southern Ocean.
Received: 16 June 2000 / Accepted: 18 December 2000 相似文献
112.
Louis P. Lue C.C. Lewis Veronica E. Melchor 《Journal of environmental science and health. Part. B》2013,48(3):343-354
Abstract Aldicarb, Temik® 15 G, was incorporated in furrows at 3.37 and 6.73 kg ai (active ingredent)/ha and carrots (Caucus carota L.) were directly seeded on the same day. The numbers of nematode larvae were significantly suppressed in the treated plots; averages were 249, 74, and 51/ 50 cc soil samples for control (0), 3.37 and 6.73 kg ai/ha, respectively. Aldicarb treatment resulted in a 28% yield increase as compared to the untreated. Aldicarb residue in carrots was 28 ppb for the low treatment and 46 ppb for the high. Residual levels in soil of high treatment declined from 6l to 31 ppb during two weeks prior to harvest, meanwhile, those in the low decreased slightly from 13 to 12 ppb. Carrots placed in hydroponic solution containing aldicarb 14.5 ppm for 6 days, had an aldicarb residue of 10.26 ppb and the hydroponic solution, 2.7 ppb. Persistence of aldicarb residue was in carrot > in soil > in hydroponic solution. 相似文献
113.
114.
115.
Joke Muys Yves Jacquemyn Bettina Blaumeiser Laura Bourlard Nathalie Brison Saskia Bulk Patrizia Chiarappa Anne De Leener Marjan De Rademaeker Julie Désir Anne Destrée Koenraad Devriendt Annelies Dheedene Armelle Duquenne Annelies Fieuw Erik Fransen Jean-Stéphane Gatot Mauricette Jamar Sandra Janssens Jorien Kerstjens Kathelijn Keymolen Damien Lederer Björn Menten Bruno Pichon Sonia Rombout Yves Sznajer Ann Van Den Bogaert Kris Van Den Bogaert Joris Vermeesch Katrien Janssens 《黑龙江环境通报》2020,40(10):1272-1283
116.
117.
118.
119.
120.
Joke Muys Bettina Blaumeiser Yves Jacquemyn Claude Bandelier Nathalie Brison Saskia Bulk Patrizia Chiarappa Winnie Courtens Anne De Leener Marjan De Rademaeker Julie Désir Anne Destrée Koenraad Devriendt Annelies Dheedene Annelies Fieuw Erik Fransen Jean-Stéphane Gatot Philip Holmgren Mauricette Jamar Sandra Janssens Kathelijn Keymolen Damien Lederer Björn Menten Marije Meuwissen Benoit Parmentier Bruno Pichon Sonia Rombout Yves Sznajer Ann Van Den Bogaert Kris Van Den Bogaert Olivier Vanakker Joris Vermeesch Katrien Janssens 《黑龙江环境通报》2018,38(13):1120-1128