全文获取类型
收费全文 | 224篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 8篇 |
环保管理 | 5篇 |
综合类 | 87篇 |
基础理论 | 59篇 |
环境理论 | 1篇 |
污染及防治 | 50篇 |
评价与监测 | 6篇 |
社会与环境 | 4篇 |
出版年
2021年 | 3篇 |
2016年 | 2篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 5篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 13篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 13篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 5篇 |
1965年 | 4篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1962年 | 4篇 |
1961年 | 2篇 |
1960年 | 7篇 |
1959年 | 4篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1955年 | 5篇 |
1954年 | 1篇 |
排序方式: 共有227条查询结果,搜索用时 31 毫秒
171.
172.
Jürgen Maguhn Andrea Wimschneider Raimund Brotsack Peter Spitzauer Dieter Freitag und Antonius Kettrup 《Umweltwissenschaften und Schadstoff-Forschung》2000,12(5):259-268
Zusammenfassung Die Immissionsbelastung im ?stlichen Umland des neuen Münchner Flughafens wurde im Zeitraum von 1992 bis 1995 mit Hilfe einer
Reihe unterschiedlicher Messmethoden untersucht. Für die wirkungsbezogene Erfassung von Umwelteinflüssen wurden Bioindikatoren
zur Bestimmung der PAK-Belastung und zur Quantifizierung der Photooxidantienbelastung eingesetzt. Darüber hinaus wurde der
PAK-Gehalt des Oberbodens bestimmt. Die aktuelle Luftbelastungssituation wurde w?hrend photochemisch aktiver Wetterlagen im
Sommer im Rahmen von 7 Intensivmesskampagnen untersucht. Die Bodenbelastung mit PAK liegt im Bereich der für l?ndliche Regionen
typischen Hintergrundwerte mit den h?chsten Konzentrationen in der N?he stark befahrener Stra?en und weist keinen zeitlichen
Trend auf. Auch der aktuelle PAK-Eintrag liegt an allen Standorten in einem für l?ndliche Regionen in Bayern typischen Bereich.
Als Hauptemittent wird im Sommer der Kfz-Verkehr identifiziert, w?hrend die deutlich erh?hte Belastung im Winter auf den Hausbrand
zurückgeführt werden kann. Die Photooxidantien-belastung zeigt im Flughafenumland keine ausgepr?gten Unterschiede, sie ist
an den durch Stra?enverkehr beeinflussten Standorten jedoch am geringsten. Die Konzentrationen leicht flüchtiger Kohlenwasserstoffe
sind an einer verkehrsreichen Stra?enkreuzung in Erding deutlich h?her als im l?ndlichen Flughafenumland. Sie zeigen ausgepr?gte
Tagesg?nge, die u.a. auf den luftchemischen Abbau zurückzuführen sind. Die Hydroperoxide als sekund?re Luftschadstoffe weisen
einen gegens?tzlichen Verlauf auf, der dem des Ozons mit nachmitt?glichem Maximum ?hnelt.
Online-First: 23. August 2000 相似文献
173.
Zusammenfassung Mit einem Bioaktivit?tssensor kann die Aktivit?t der Mikroorganismen im Belebtschlamm gemessen werden. Das Signal des Sensors
reagiert empfindlich auf eine Ver?nderung des Substratangebots und das Auftreten von toxischen Stoffen. Mit dem Bioaktivit?tssensor
ist es damit einerseits m?glich,online die Belebungsstufe hinsichtlich ihrer mikrobiellen Aktivit?t zu kontrollieren und andererseits die zuflie?enden Abw?sser
bezüglich ihres toxischen Potentials zu überwachen.
相似文献
174.
Maren Olbrich Marion Wenig Karl-Heinz Häberle Rainer Matyssek Michael Leuchner Katja Schlink Gerhard Welzl Dieter Ernst Günther Bahnweg 《Environmental pollution (Barking, Essex : 1987)》2010,158(4):1043-1050
In 2006, a controlled infection study was performed in the ‘Kranzberger Forst’ to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2× ozone) and three control trees (ambient = 1× ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. 相似文献
175.
Dieter Helm 《Environmental Sciences Europe》2007,19(4):240-242
Goal and Scope
An extension for trend analysis with Mann Kendall test and Theil estimator is presented which enables the weighting of data by weight factors.Methods
It is shown in which way the weighting can effect the outcome of a trend analysis. Weighting is done in relation to the different sample sizes of the data points. A value or an observation derived from many specimens will be considered more reliable than a value derived from only a few specimens and will thus get a higher weighting factor.Results
When weighting is applied, this will effect the Theil estimator rather than the Mann Kendall test. As a result the regression line is tilted towards those points with higher weights.Outlook
Future must show whether the extensions presented here and in part 1 prove to be practical for the trend analysis in environmental monitoring or not. 相似文献176.
Dieter Helm 《Environmental Sciences Europe》2007,19(2):91-95
Goal and Scope
The influence of the measurement uncertainty on the outcomes of statistical evaluations is shown.Methods
Examplarily using data from the Environmental Specimen Bank the influence of measurement uncertainties on results of trned analyses (Mann Kendall test and Theil estimator) was tested. Both, the simple and the double measurement uncertainty were tested, as well as the standard deviation of repeated measurements.Results
Considering measurement uncertainty means that not points but intervals are used. A value yj is then considered larger [smaller] than yi if applies: yj-u(yj>yi+u(yi) [yj+u(yj)<yi-u(yj)], where u(yj) and u(yi) are measurement uncertainties of yj and yi. Mann Kendall test of trend will react more conservatively (in sense of the maintenance of null hypothesis: no trend), when measurement uncertainties are considered. Thus, the resulting trend statements will be safer.Outlook
For future application a decision is neccessary about the kind of the measurement uncertainty to be used (none, simple, double, standard deviation). Part 2 will deal with weighting of the data. 相似文献177.
Igor W. K. Ouédraogo Erol Pehlivan Hien T. Tran Samuel Paré Yvonne L. Bonzi-Coulibaly Dieter Zachmann 《毒物与环境化学》2016,98(7):736-747
Arsenic (V) adsorption on manganese oxide coated rice wastes was investigated in this study. The modified adsorbents were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and pH measurements to determine the point of zero charge. Batch adsorption equilibrium experiments were conducted to study the effects of pH, contact time, and initial concentration on arsenic removal efficiency. The adsorption capacity of rice waste was significantly improved after modification with permanganate. The Langmuir isotherm model fitted the equilibrium data better than the Freundlich model which confirms surface homogeneity of the adsorbent. Maxima adsorption capacities are determined as 10 and 12 mg/g at pH 3 for manganese oxide coated rice husk and straw, respectively. The adsorption energy indicates that the adsorption process may be dominated by chemisorption. Pseudo-second-order rate equation described the kinetics sorption of arsenic with good correlation coefficients, better than a pseudo-first-order equation. Manganese oxide coated rice husk and straw appear to be promising low cost adsorbents for removing arsenic from water. 相似文献
178.
Populations in small, ephemeral habitat patches may drive dynamics in a Daphnia magna metapopulation
Migration is the key process to understand the dynamics and persistence of a metapopulation. Many metapopulation models assume a positive correlation between habitat patch size or stability and the number of emigrants. However, few empirical data exist, and habitat patch size and habitat stability may affect dispersal differently than they affect local persistence. Here, we studied the production of the migration stage (i.e., resting eggs called ephippia) of the cladoceran Daphnia magna in a metapopulation consisting of 530 rock pool habitat patches over 25 years. Earlier, the functioning of this metapopulation was explained with a Levins-type metapopulation model or with a mainland-island metapopulation model, based on local extinction and colonization data or time series data, respectively. We used pool volume, hydroperiod length, and number of desiccation events to calculate per-pool production of ephippia (i.e., migration stages). We estimated that populations in small and ephemeral habitat patches produced more than half of the 250 000 to 1 million ephippia that were produced in the metapopulation as a whole per year between 1982 and 2006. Furthermore, these small populations contributed approximately 90% of the ephippia exposed during desiccation events, while the contribution of the long-lived populations in large pools was minimal. We term this an "inverse mainland-island" type metapopulation and propose that populations in small, ephemeral habitat patches may also be the driving force for metapopulation dynamics in other systems. 相似文献
179.
Bill S. Hansson Markus Knaden Silke Sachse Marcus C. Stensmyr Dieter Wicher 《Chemoecology》2010,20(2):51-61
Drosophila melanogaster is today one of the three foremost models in olfactory research, paralleled only by the mouse and
the nematode. In the last years, immense progress has been achieved by combining neurogenetic tools with neurophysiology,
anatomy, chemistry, and behavioral assays. One of the most important tasks for a fruit fly is to find a substrate for eating
and laying eggs. To perform this task the fly is dependent on olfactory cues emitted by suitable substrates as e.g. decaying
fruit. In addition, in this area, considerable progress has been made during the last years, and more and more natural and
behaviorally active ligands have been identified. The future challenge is to tie the progress in different fields together
to give us a better understanding of how a fly really behaves. Not in a test tube, but in nature. Here, we review our present
state of knowledge regarding Drosophila plant-odor-related olfactory neuroethology to provide a basis for new progress. 相似文献
180.
von Bobrutzki K Ammon C Berg W Einert P Fiedler M Müller HJ Scherer D Strohbach B 《Environmental monitoring and assessment》2012,184(6):3775-3787
Agricultural NH3 emissions affect air quality and influence the nitrogen cycle. In the subject study, NH3 emissions from a broiler farm and the resulting atmospheric concentrations in the immediate vicinity during three growing
cycles have been quantified. Additionally, vegetation along a transect in an adjacent woodland was analysed. The emissions
were as high as 10 kg NH3 h−1 and the atmospheric concentrations ranged between 33 and 124 μg NH3 m−3 per week in the immediate vicinity. Measurements of the atmospheric concentrations over 7 weeks showed a substantial decline
of mean concentrations (based on a 3-week average) from ∼13 to <3 μg NH3 m−3, at 45- and 415-m distance from the farm. Vegetation surveys showed that nitrophilous species flourished when they grew closest
to the farm (their occurrence sank proportionately with distance). A clearly visible damage of pine trees was observed within
200 m of the farm; this illustrated the significant impact of NH3 emissions from agricultural sources on the sensitive ecosystem. 相似文献