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排序方式: 共有479条查询结果,搜索用时 57 毫秒
91.
Increasing levels and biomagnification of persistent organic pollutants (POPs) in Antarctic biota 总被引:3,自引:0,他引:3
Representatives of the Antarctic food web (krill, cephalopod, fish, penguin, seal) of the area around Elephant Island and from the Weddell Sea were analysed for the most recalcitrant organochlorine compounds. Due to sorption of the compounds to sinking particles and accumulation in sediments, two benthic fish species (Gobionotothen gibberifrons, Chaenocephalus aceratus) feeding on benthos invertebrates and fish reflected significantly increasing concentrations within a decade (1987-1996), while a benthopelagic species (Champsocephalus gunnari) feeding on krill did not. In the pelagic food chain, lipid normalised concentrations of all compounds increased from Antarctic krill to fish proving that biomagnification of highly lipophilic pollutants (log octanol-water partition coefficient>5) occurs in water-breathing animals. As top predators Weddell and southern elephant seals (Leptonychotes weddellii, Mirounga leonina) biomagnified the persistent organic pollutants relative to krill 30-160 fold with the exception of hexachlorobenzene, the levels of which were lower than in fish indicating its intense specific elimination. 相似文献
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William LIU Michel BLANC Chi WANG Eric DONAVAN John FOSTER Mark LESTER Hermann OPGENOORTH Liwen REN 《中国科学:地球科学(英文版)》2021,(12):2090-2097
Earth's ecosystems and human activities are threatened by a broad spectrum of hazards of major importance for the safety of ground infrastructures,space systems... 相似文献
95.
Manfred F. Buchroithner Guido Ehlert Bernd Hetze Horst Kohlschmidt Nikolas Prechtel 《Pure and Applied Geophysics》2014,171(6):1077-1087
Mountain-rescue operations require rapid response whilst also ensuring the security of the rescue teams. Rescuing people in a big rock-face is even more difficult if night or fog prevent sight. The paper presents a technical solution to optimally support, under these aggravated conditions, the location of the casualties and the navigation of the rescue team(s) in a rock-face from a coordination station. In doing so, standard components like a smartphones with GPS functionality, a data communication on a client–server basis and VR visualisation software have been adapted to the specific requirements. Remote support of the navigation in steep rocky terrain requires a highly accurate wall model which permits the local experts of the coordination station to dependably estimate geometry and structure of the rock along the rescue route and to convey necessary directives to the retrieval team. Based on terrestrial laser-scans from different locations, such a model has been generated for the mighty Dachstein South Face (Austria) and texturised with digital photographs. Over a twelve-month period, a transdisciplinary team of the Dresden University of Technology (Informatics, Electrical Engineering, Cartography) developed and integrated the various technical modules of the mountain-rescue support-system (digital rock-face model, optimised GPS data transmission between mobile device, server and client, data filtering, and dynamic visualisation component). In summer 2011 the proper functioning of the prototype was demonstrated in a rescue exercise under foggy dusk conditions. 相似文献
96.
The OECD soil, which is standardised for use in the sediment toxicity with the midge Chironomus riparius revealed inhibition of the nematode Caenorhabditis elegans in body growth length and egg production of 41.0% and 84%, respectively. 18 formulated sediments were tested to optimise the sediment composition for growth and reproduction of C. elegans. Their components were chosen to simulate native sediments, whereby different quantities and different clay minerals were tested. The mixture that we found to be optimal in our experiments consisted of 5% sphagnum peat, 70% calcitic sand, 0.5% dolomite limestone, 4.5% iron(III) oxide, and a clay combination of 1.5% chlorite and 18.5% aluminium(III) oxide. When applying this mixture to C. riparius, the new formulated sediment improved also growth in comparison to the OECD sediment. 相似文献
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Horst Wiese 《Studia Geophysica et Geodaetica》1965,9(4):415-419
Резюме Значительные раэности электропроводности в горизонтальном направлении заставляют индуцируемые ионосферными временными вариациями
электрические токи в подстиляющих слоях протекать по преимущественным направлениям. В статье представляются вызванные этим
вариации вертикальной и горизонтальной составляющих для периодов 19–40 мун в 20 пунктах в ЧССР, где регистрировались магнитные
вариации при помощи полевых регистрирующих станций.
Mitteilung Nr. 194 des Geomagnetischen Instituts Potsdam. 相似文献
Mitteilung Nr. 194 des Geomagnetischen Instituts Potsdam. 相似文献
100.
Hermann L. F. Meyer 《International Journal of Earth Sciences》1916,7(5-6):193-248
Ohne Zusammenfassung 相似文献