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Blood transfusions in cats: A precious resource requiring a considered approach 新闻
来源平台：EurekAlert. 发布日期：2021
作者:  admin
收藏  |  浏览/下载：11/0  |  提交时间：2021/04/29
Seeing no longer believing: the manipulation of online images 新闻
来源平台：EurekAlert. 发布日期：2020
作者:  admin
收藏  |  浏览/下载：0/0  |  提交时间：2020/10/26
DNA-barcoded microbial spores can trace origin of objects, agricultural products 新闻
来源平台：EurekAlert. 发布日期：2020
作者:  admin
收藏  |  浏览/下载：13/0  |  提交时间：2020/06/05
Blockchain: forget the criminal record, it might just save your life -- new study 新闻
来源平台：EurekAlert. 发布日期：2020
作者:  admin
收藏  |  浏览/下载：0/0  |  提交时间：2020/05/15
Hydrothermal (NN)-N-15-N-15 abundances constrain the origins of mantle nitrogen 期刊论文
NATURE, 2020, 580 (7803) : 367-+
作者:  Zhao, Steven;  Jang, Cholsoon;  Liu, Joyce;  Uehara, Kahealani;  Gilbert, Michael;  Izzo, Luke;  Zeng, Xianfeng;  Trefely, Sophie;  Fernandez, Sully;  Carrer, Alessandro;  Miller, Katelyn D.;  Schug, Zachary T.;  Snyder, Nathaniel W.;  Gade, Terence P.;  Titchenell, Paul M.;  Rabinowitz, Joshua D.;  Wellen, Kathryn E.
收藏  |  浏览/下载：14/0  |  提交时间：2020/05/13

Nitrogen is the main constituent of the Earth'  s atmosphere, but its provenance in the Earth'  s mantle remains uncertain. The relative contribution of primordial nitrogen inherited during the Earth'  s accretion versus that subducted from the Earth'  s surface is unclear(1-6). Here we show that the mantle may have retained remnants of such primordial nitrogen. We use the rare (NN)-N-15-N-15 isotopologue of N-2 as a new tracer of air contamination in volcanic gas effusions. By constraining air contamination in gases from Iceland, Eifel (Germany) and Yellowstone (USA), we derive estimates of mantle delta N-15 (the fractional difference in N-15/N-14 from air), N-2/Ar-36 and N-2/He-3. Our results show that negative delta N-15 values observed in gases, previously regarded as indicating a mantle origin for nitrogen(7-10), in fact represent dominantly air-derived N-2 that experienced N-15/N-14 fractionation in hydrothermal systems. Using two-component mixing models to correct for this effect, the (NN)-N-15-N-15 data allow extrapolations that characterize mantle endmember delta N-15, N-2/Ar-36 and N-2/He-3 values. We show that the Eifel region has slightly increased delta N-15 and N-2/Ar-36 values relative to estimates for the convective mantle provided by mid-ocean-ridge basalts(11), consistent with subducted nitrogen being added to the mantle source. In contrast, we find that whereas the Yellowstone plume has delta N-15 values substantially greater than that of the convective mantle, resembling surface components(12-15), its N-2/Ar-36 and N-2/He-3 ratios are indistinguishable from those of the convective mantle. This observation raises the possibility that the plume hosts a primordial component. We provide a test of the subduction hypothesis with a two-box model, describing the evolution of mantle and surface nitrogen through geological time. We show that the effect of subduction on the deep nitrogen cycle may be less important than has been suggested by previous investigations. We propose instead that high mid-ocean-ridge basalt and plume delta N-15 values may both be dominantly primordial features.


  
Markets for Data 科技报告
来源：Oxford Martin School, University of Oxford. 出版年： 2020
作者:  Pantelis Koutroumpis;  Aija Leiponen;  Llewellyn D W Thomas
收藏  |  浏览/下载：0/0  |  提交时间：2020/05/26
Highly bioavailable dust-borne iron delivered to the Southern Ocean during glacial periods 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2018, 115 (44) : 11180-11185
作者:  Shoenfelt, Elizabeth M.;  Winckler, Gisela;  Lamy, Frank;  Anderson, Robert F.;  Bostick, Benjamin C.
收藏  |  浏览/下载：6/0  |  提交时间：2019/11/27
iron speciation  Southern  Ocean iron bioavailability  dust  productivity  
Competing English, Spanish, and French alabaster trade in Europe over five centuries as evidenced by isotope fingerprinting 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2017, 114 (45) : 11856-11860
作者:  Kloppmann, W.;  Leroux, L.;  Bromblet, P.;  Le Pogam, P. -Y.;  Cooper, A. H.;  Worley, N.;  Guerrot, C.;  Montech, A. T.;  Gallas, A. M.;  Aillaud, R.
收藏  |  浏览/下载：6/0  |  提交时间：2019/11/27
alabaster  provenance  isotope fingerprinting  Middle Ages  Renaissance