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排序方式: 共有551条查询结果,搜索用时 546 毫秒
541.
542.
The objective of this study was to assess the effect of compost application on soil respiration and dissolved organic carbon (DOC) output of nutrient-depleted forest soils. An amount of 6.3 kg m(-2) mature compost was applied to the forest floor of European beech (Fagus sylvatica L.), Norway spruce (Picea abies Karst.), and Scots pine (Pinus sylvestris L.) stands at Soiling and Unterlüss, Germany. Cumulative soil respiration significantly increased by 499 g C m(-2) in the spruce stand at Unterlüss and by 274 g C m(-2) in the beech stand at Soiling following compost application whereas soil respiration of the other four stands was not affected. The increases in soil respiration of the two stands were explained by improved microbial decomposition of soil organic matter. The DOC concentrations and fluxes in throughfall and seepage water at 10- and 100-cm depths were determined from August 1997 to March 2000. In the control plots, cumulative DOC outputs at 10 cm ranged between 57 and 95 g C m(-2), with the highest rates in the pine stands. Compost treatment significantly increased cumulative DOC outputs by 31 to 69 g C m(-2) at 10 cm and by 0.3 to 6.6 g C m(-2) at 100 cm. The mineral soils between the 10- and 100-cm depths acted as significant sinks for DOC, as shown by much lower cumulative outputs at 100 cm of 3 to 11 g C m(-2) in the control and 6 to 16 g C m(-2) in the compost plots. Our results suggest that a single, moderate application of mature compost to nutrient-depleted forest soils has little effect on C losses to the atmosphere and ground water. 相似文献
543.
Al-Jundi J Werner E Roth P Höllriegl V Wendler I Schramel P 《Journal of environmental radioactivity》2004,71(1):61-70
Inductively coupled plasma mass spectrometry (ICP-MS) has been used for the determination of (232)Th and (238)U in urine of unexposed Jordanian subjects living in six cities. The range of (232)Th excretion in all subjects was found to be 1.4-640 microBq d(-1) with an average of 34.8 microBq d(-1) (geometric mean 15.8 microBq d(-1)). Results showed no statistically significant correlation with age and residential area. The average value obtained is in agreement with levels considered normal in some recent publications. The average value of (238)U in all samples was found to be 3955 microBq d(-1) (geometric mean 1107 microBq d(-1)), which is higher than reported figures from Germany and India, but in agreement with those figures given in ICRP publication, number 23. The mean values of the different groups were found to be proportional to age up to 60 years. A noticeable drop is observed for subjects greater than 60 years old. 相似文献
544.
Bagatti D Cantone MC Giussani A Veronese I Roth P Werner E Höllriegl V 《Journal of environmental radioactivity》2003,65(3):357-364
Knowledge of the level of natural uranium (U) in the human body is fundamental in order to estimate the potentially hazardous incorporation in accidentally exposed subjects. A constant monitoring of exposed workers needs reliable reference baseline values, which can be determined by measuring the U concentration in urine. ICPMS has proven to be a fast, reliable and highly sensitive technique for this purpose. Non-uniformity in the distribution of U levels in various regions and differences in dietary habits account for the significant regional variations of U concentration in urine in non-exposed subjects. In this paper, the determination of daily uranium urinary excretion levels in a group of 12 non-exposed subjects from Northern Italy is presented and compared to data present in the published literature and to values obtained in a larger group of German volunteers. The urinary U output values observed in the Italian subset are generally higher than the corresponding levels measured in other groups. This could be the result of a higher intake of U from liquids, as assessed by the determination of U concentration in drinking waters. 相似文献
545.
546.
Werner Reichardt 《Die Naturwissenschaften》1961,48(7):192-207
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Peter Viebahn Michael Matthies Werner Berens und Bodo Rieger 《Umweltwissenschaften und Schadstoff-Forschung》1999,11(5):303-307
Zusammenfassung Grundlage für die erste Stoff- und Energieflu?analyse der Universit?t Osnabrück und die Erstellung der ?kobilanz war eine
umfangreiche und damit zeitaufwendige Datensammlung, — aufbereitung und — weiterverarbeitung. Um die Bilanzierung für die
Folgejahre zu vereinfachen und die ermittelten Daten für ein ?ko-Controlling nutzen zu k?nnen, wurde ein Konzept für ein Umweltinformationssystem
(UIS) der Universit?t erarbeitet. Es setzt sich zusammen aus der operativen Ebene mit den dezentralen Daten(banken) der Verwaltung,
einer zentralen Datenbankebene, in der die ?kobilanz erstellt und Umweltkennzahlen berechnet werden, und einer Auswertungs-
und Pr?sentationsebene als Schnittstelle zwischen Daten und ihren Nutzern. Das UIS wird mittelfristig als Teil des Management-Informationssystem
implementiert, das die Universit?t als erste Hochschule Deutschlands zur Zeit entwickelt.
相似文献
550.
J. B. Legradi C. Di Paolo M. H. S. Kraak H. G. van der Geest E. L. Schymanski A. J. Williams M. M. L. Dingemans R. Massei W. Brack X. Cousin M.-L. Begout R. van der Oost A. Carion V. Suarez-Ulloa F. Silvestre B. I. Escher M. Engwall G. Nilén S. H. Keiter D. Pollet P. Waldmann C. Kienle I. Werner A.-C. Haigis D. Knapen L. Vergauwen M. Spehr W. Schulz W. Busch D. Leuthold S. Scholz C. M. vom Berg N. Basu C. A. Murphy A. Lampert J. Kuckelkorn T. Grummt H. Hollert 《Environmental Sciences Europe》2018,30(1):46
The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts invested in the last years in developing novel in vitro or in silico test systems, in vivo tests with rodents are still the only accepted test for neurotoxicity risk assessment in Europe. Despite an increasing number of reports of species showing altered behaviour, neurotoxicity assessment for species in the environment is not required and therefore mostly not performed. Considering the increasing numbers of environmental contaminants with potential neurotoxic potential, eco-neurotoxicity should be also considered in risk assessment. In order to do so novel test systems are needed that can cope with species differences within ecosystems. In the field, online-biomonitoring systems using behavioural information could be used to detect neurotoxic effects and effect-directed analyses could be applied to identify the neurotoxicants causing the effect. Additionally, toxic pressure calculations in combination with mixture modelling could use environmental chemical monitoring data to predict adverse effects and prioritize pollutants for laboratory testing. Cheminformatics based on computational toxicological data from in vitro and in vivo studies could help to identify potential neurotoxicants. An array of in vitro assays covering different modes of action could be applied to screen compounds for neurotoxicity. The selection of in vitro assays could be guided by AOPs relevant for eco-neurotoxicity. In order to be able to perform risk assessment for eco-neurotoxicity, methods need to focus on the most sensitive species in an ecosystem. A test battery using species from different trophic levels might be the best approach. To implement eco-neurotoxicity assessment into European risk assessment, cheminformatics and in vitro screening tests could be used as first approach to identify eco-neurotoxic pollutants. In a second step, a small species test battery could be applied to assess the risks of ecosystems. 相似文献