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191.
To estimate the accumulation and vertical migration of radiocesium and radioruthenium, the activity concentrations of Chernobyl-derived 134Cs, 137Cs and 106Ru as well as of 137Cs from the global fallout of weapons testing observed in the upper horizons of a forest soil (Hapludult, spruce stand) were evaluated with a compartment model. The resulting residence half-times were used to estimate the mean rates of transport of these radionuclides. For Chernobyl-derived 134Cs and 137Cs within the time period of 200–600 days after the beginning of the fallout the rates were between 4 cm/yr (Of1-horizon) and 2 cm/yr (Oh-horizon), and for 106Ru between 4 cm/yr (Of1-horizon) and 7 cm/yr (Oh-horizon). These rates, though considerably slower than observed in the same soil during the initial infiltration of these radionuclides with a rain shower, are (depending on the soil horizon) still higher by a factor of 3–6, when compared to the rates of transport of 137Cs from the global fallout of weapons testing in the same soil. Because global fallout 137Cs is in the soil since about 20 years, these results suggest that the fixation of radiocesium in the forest soil is a rather slow process. 相似文献
192.
Papagiannopoulos M Wollseifen HR Mellenthin A Haber B Galensa R 《Journal of agricultural and food chemistry》2004,52(12):3784-3791
The polyphenolic patterns of carob pods (Ceratonia siliqua L.) and derived products were identified and quantified using high-performance liquid chromatography-UV absorption-electrospray ion trap mass spectrometry after pressurized liquid extraction and solid-phase extraction. In carob fiber, 41 individual phenolic compounds could be identified. In addition, spectrophotometric quantification using the Folin-Ciocalteu and vanillin assays was performed, and the antioxidative activity was determined as the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Carob pods contain 448 mg/kg extractable polyphenols comprising gallic acid, hydrolyzable and condensed tannins, flavonol-glycosides, and traces of isoflavonoids. Among the products investigated, carob fiber, a carob pod preparation rich in insoluble dietary fiber (total polyphenol content = 4142 mg/kg), shows the highest concentrations in flavonol-glycosides and hydrolyzable tannins, whereas roasted carob products contain the highest levels of gallic acid. The production process seems to have an important influence on the polyphenolic patterns and quantities in carob products. 相似文献
193.
Kerstin?Hund-RinkeEmail author Rudolf?Achazi J?rg?R?mbke Dietmar?Warnecke 《Journal of Soils and Sediments》2003,3(1):7-12
Intention, Goal, Scope, Background. The habitat function of soils is often assessed using the reproduction test withEisenia fetida. As this test is rather labour-intensive, an alternative is needed which is less cost-intensive in terms of duration and workload, but gives reasonable results. The avoidance test withE. fetida is a suitable screening test meeting these criteria. However, before a novel test system can be generally recommended it has to be ensured that comparable results are acquired from different laboratories on the basis of the respective test guideline. 相似文献
Objective
The avoidance test withE. fetida was performed as laboratory comparison test. The results were compared with those of the earthworm acute and reproduction tests carried out with the same soils.Methods
The three tests were performed by three laboratories using eight contaminated soils and three control soils. The contaminated soils were mixed with the control soils to obtain different concentrations of the contamination.Results and Discussion
The results of the avoidance test show that despite the partially considerable standard deviations a 72% agreement in the assessment of soils was reached with a toxicity criterion of >80% avoidance response. The sensitivity is at least that for the reproduction test and considerably surmounts the sensitivity of the acute test.Recommendation and Outlook
The avoidance test is considered to be a suitable screening test for assessing the habitat function of soils. The whole test design could be improved by reducing the standard deviations among parallel test batches. With regard to standardization it is recommended to use control soils which have the same properties as the soils described in respective guidelines (e.g. ISO 11269-2, OECD 216, 217).194.
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Rudolf Geiger 《Forstwissenschaftliches Centralblatt》1928,50(19):633-644
Ohne Zusammenfassung 相似文献
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Rudolf Geiger 《Forstwissenschaftliches Centralblatt》1928,50(3):73-85
Ohne Zusammenfassung 相似文献