全文获取类型
收费全文 | 479篇 |
免费 | 2篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 5篇 |
环保管理 | 29篇 |
综合类 | 173篇 |
基础理论 | 144篇 |
污染及防治 | 113篇 |
评价与监测 | 13篇 |
社会与环境 | 14篇 |
出版年
2017年 | 5篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 5篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 22篇 |
2010年 | 13篇 |
2009年 | 15篇 |
2008年 | 20篇 |
2007年 | 24篇 |
2006年 | 33篇 |
2005年 | 21篇 |
2004年 | 9篇 |
2003年 | 16篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 19篇 |
1998年 | 10篇 |
1997年 | 10篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1991年 | 4篇 |
1989年 | 5篇 |
1987年 | 3篇 |
1985年 | 3篇 |
1983年 | 6篇 |
1969年 | 3篇 |
1966年 | 8篇 |
1965年 | 4篇 |
1964年 | 8篇 |
1963年 | 8篇 |
1962年 | 2篇 |
1961年 | 5篇 |
1960年 | 6篇 |
1959年 | 4篇 |
1958年 | 3篇 |
1957年 | 7篇 |
1956年 | 3篇 |
1955年 | 5篇 |
1954年 | 4篇 |
1953年 | 7篇 |
1951年 | 3篇 |
1950年 | 2篇 |
1939年 | 3篇 |
1938年 | 2篇 |
1934年 | 2篇 |
排序方式: 共有499条查询结果,搜索用时 9 毫秒
491.
The Science of Nature - 相似文献
492.
493.
494.
495.
Karl-Werner Schramm Petra Marth Alexander Wolf Klaus Hahn Konstantin Oxynos Johannes Schmitzer und Antonius Kettrup 《Umweltwissenschaften und Schadstoff-Forschung》1999,11(5):277-280
Zusammenfassung Lipidbezogene Verteilungskoeffizienten (KLM/L) zwischen Muskelkonzentrationen-(CML) und Leberkonzentrationen (CLL) zweier Friedfischarten Brassen (Abramis brama) und Aalmutter (Zoarces viviparus) ergeben theoriekonform (KLM/L=CML/CLL=1) nominale Werte um 1 für persistente (hochchlorierte PCB) und Werte über 1 für metabolisierbare lipophile Umweltchemikalien
wie chlorierte Cyclohexane oder DDT.
相似文献
496.
Sutter K Jung K Krauss GJ 《Environmental science and pollution research international》2002,9(6):417-421
The assessment of pollution in aquatic systems necessitates an accurate indication of toxicity of heavy metals for organisms and ecosystems. We used the stable nitrogen isotope 15N to estimate the influence of the heavy metals Cd, Pb and Zn on the synthesis of nitrogen-containing fractions in the aquatic moss Fontinalis antipyretica. This method permits conclusions concerning inhibitory effects of these heavy metals on the assimilation of nitrogen and the biosynthesis of amino acids and proteins. The moss was exposed to metal concentrations of 25-500 microM over a period of 5-10 days. 15N abundance of exposed plants was compared with that of control plants. Similar to a loss of vitality determined using a fluorometric assay, a decrease of the 15N abundance in the N fractions of Fontinalis antipyretica was measured in dependence on the metal concentration. Nevertheless, the individual inhibition by the distinct metals was different, so that the following order of toxicity was derived: Cd > Pb > Zn. 相似文献
497.
Katie E. Slocombe Tanja Kaller Laurel Turman Simon W. Townsend Sarah Papworth Paul Squibbs Klaus Zuberbühler 《Behavioral ecology and sociobiology》2010,64(12):1959-1966
Chimpanzees produce acoustically distinct calls when encountering food. Previous research on a number of species has indicated
that food-associated calls are relatively widespread in animal communication, and the production of these calls can be influenced
by both ecological and social factors. Here, we investigate the factors influencing the production of food-associated calls
in wild chimpanzees and examine whether male chimpanzees produce food-associated calls selectively in the presence of important
social partners. Male chimpanzees form stable long-term social relationships with each other, and these social bonds are vital
in enabling a range of cooperative activities, such as group hunting and territory defence. Our data show that males were
significantly more likely to produce food-associated calls if an important social partner was nearby, regardless of the size
of the audience or the presence of oestrus females. Call production was also mediated by the size of the food patch and by
whether or not the food could be monopolised. The presence of important social partners explained most of the variation in
male calling behaviour, indicating that food-associated calls are socially directed and serve a bonding function. 相似文献
498.
Infrared spectrometry is a versatile basis to analyse greenhouse gases in the atmosphere. A multicomponent air pollution software (MAPS) was developed for retrieval of gas concentrations from radiation emission as well as absorption measurements. Concentrations of CO, CH4, N2O, and H2O as well as CO2, NO, NO2, NH3, SO2, HCl, HCHO, and the temperature of warm gases are determined on-line. The analyses of greenhouse gases in gaseous emission sources and in ambient air are performed by a mobile remote sensing system using the double-pendulum interferometer K300 of the Munich company Kayser-Threde. Passive radiation measurements are performed to retrieve CO, N2O, and H2O as well as CO2, NO, SO2, and HCl concentrations in smoke stack effluents of thermal power plants and municipal incinerators and CO and H2O as well as CO2 and NO in exhausts of aircraft engines. Open-path radiation measurements are used to determine greenhouse gas concentrations at different ambient air conditions and greenhouse gas emission rates of diffusive sources as garbage deposits, open coal mining, stock farming together with additional compounds (e.g. NH3), and from road traffic together with HCHO. Some results of measurements are shown. A future task is the verification of emission cadastres by these inspection measurements. 相似文献
499.
碳底物含量对厌氧条件下水稻土N2、N2O、NO、CO2和CH4排放的影响 总被引:1,自引:3,他引:1
理解底物碳氮对厌氧条件下水稻土排放氮素气体——氮气(N2)、氧化亚氮(N2O)和一氧化氮(NO)以及二氧化碳(CO2)和甲烷(CH4)的影响,有助于制定合理的温室气体减排措施,定量了解反硝化产物组成对碳底物水平的依赖性,也有助于氮转化过程模型研发中制定正确的关键过程参数选取方法或参数化方案.本研究采用粉砂壤质水稻土为研究对象,设置对照(CK)和加碳(C+)两个处理,前者的初始硝态氮和可溶性有机碳(DOC)含量分别为~50 mg·kg-1和~28 mg·kg-1,后者的分别为~50 mg·kg-1和~300 mg·kg-1.采用氦环境培养-气体及碳氮底物直接同步测定系统,研究了完全厌氧条件下碳底物水平对上述气体排放的影响.结果表明,CK处理无CH4排放,而C+处理可观测到CH4排放;C+处理的综合增温潜势显著高于CK处理(P<0.01);NO、N2O和N2排放量占这3种氮素气体排放总量的比重,在CK处理分别约为9%、35%和56%,在C+处理分别约为31%、50%和19%,处理间差异显著(P<0.01).由此表明,碳底物水平可显著改变所排放氮素气体的组成;对于旱地阶段硝态氮比较丰富的水稻土,避免在淹水前或淹水期间施用有机肥,有利于削减温室气体排放. 相似文献