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. 2004 Apr 1;109(2):185–217. doi: 10.6028/jres.109.013

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The Journal of Research of the National Institute of Standards and Technology is a publication of the U.S. Government. The papers are in the public domain and are not subject to copyright in the United States. Articles from J Res may contain photographs or illustrations copyrighted by other commercial organizations or individuals that may not be used without obtaining prior approval from the holder of the copyright.

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Fig. 11 — Short term ¹⁴C “decay” curve, representing geochemical relaxation of excess atmospheric ¹⁴C from nuclear testing [Levin et al., in (Ref. [19]; Ref. [20], Chap. 31). Information critical for the discussion in Sec. 7.2.1 is indicated by the arrow—namely, the sampling date and corresponding biomass ¹⁴C enrichment for SRM 1649a (urban dust).