KULP J L, SCHULERT A R, HODGES E J, ANDERSON E C, LANGHAM W H
Science. 1961 Jun 2;133(3466):1768-70. doi: 10.1126/science.133.3466.1768.
The strontium-90 and cesium-137 concentrations in powdered milk in North America vary roughly with the specific activity of rain. The Sr(90)/Cs(137). ratios in over 800 powdered milk samples taken from 60 stations in North America from 1957-60 have a standard deviation of only 44 percent.
北美奶粉中锶 - 90和铯 - 137的浓度大致随降雨的比活度而变化。1957年至1960年从北美60个站点采集的800多个奶粉样品中的Sr(90)/Cs(137) 比值,其标准差仅为44%。