نتایج جستجو برای: natural and anthropogenic sources

تعداد نتایج: 16910230  

Journal: :Geophysical Research Letters 2010

2007
Claude F. Boutron Clair C. Patterson

Concentrations of lead have been Patterson, 1986]. Soil dusts were shown to be the measured by ultraclean isotope dilution mass major source of natural lead. The volcanic spectrometry in large blocks of surface snow contribution was found to be significant during collected along a 433-km coast-interior axis in low-lead time periods only and the contribution East Antarctica and near the geograph...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند 1390

abstract this study attempted to investigate the strategies used to translate clichés of emotions in dubbed movies in iranian dubbing context for home video companies. the corpus of the current study was parallel and comparable in nature, consisting of five original american movies and their dubbed versions in persian, and five original persian movies which served as a touchstone for judging n...

2008
Peter Steier Max Bichler L. Keith Fifield Robin Golser Walter Kutschera Alfred Priller Francesca Quinto Stephan Richter Michaela Srncik Lukas Wacker Anton Wallner Gabriele Wallner Klaus M. Wilcken Eva Maria Wild

The interaction of thermal neutrons with U results in fission with a probability of 85% and in the formation of U (t1/2 = 2.3 10 yr) with a probability of 15%. While anthropogenic U is, therefore, present in spent nuclear fuel at levels of U/U up to 10 , the expected natural ratios in the pre-anthropogenic environment range from 10 14 to 10 . At VERA, systematic investigations suggest a detecti...

2011
A M R Petrescu J Van Huissteden M Jackowicz-Korczynski A Yurova T R Christensen P M Crill K Bäckstrand

Together with water vapour and carbon dioxide (CO2), methane (CH4) is an important contributor to the warming of the atmosphere. The atmospheric mixing ratios of so-called greenhouse gases, CO2, and nitrous oxide (N2O) have increased about 31%, and 17%, respectively, above pre-industrial values, whereas CH4 has increased 151 ± 25%, (Watson et al., 2001). The CH4 concentration in 2005 of about 1...

2013
Meredith D. A. Howard Martha Sutula David A. Caron Yi Chao John D. Farrara Hartmut Frenzel Burton Jones George Robertson Karen McLaughlin Ashmita Sengupta

Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity...

Journal: :Journal of Marine Science and Engineering 2018

Journal: :Proceedings. Biological sciences 2016
Maria S Vorontsova Guillaume Besnard Félix Forest Panagiota Malakasi Justin Moat W Derek Clayton Paweł Ficinski George M Savva Olinirina P Nanjarisoa Jacqueline Razanatsoa Fetra O Randriatsara John M Kimeu W R Quentin Luke Canisius Kayombo H Peter Linder

Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show ...

Journal: :Proceedings of the Royal Society B: Biological Sciences 2016

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