@article{oai:repo.qst.go.jp:00047018,
 author = {ト, 文庭 and 鄭, 建 and Guo, Qiuju and 内田, 滋夫 and ト 文庭 and 鄭 建 and 内田 滋夫},
 journal = {Journal of Environmental Radioactivity},
 month = {Jun},
 note = {Soil samples collected in southwestern China were analyzed for Pu isotopes. The 240Pu/239Pu atom ratios were around 0.18, which indicated the dominant source of global fallout. Consistent sub-surface maximums followed by exponential decline of 239+240Pu activities in the soil cores were observed. Most of the Pu has still remained in the 0-10 cm layers since its deposition. Convection velocities and dispersion coefficients for Pu migration in the soils were estimated by the convection-dispersion equation (CDE) model. The convection velocities and dispersion coefficients ranged from 0.05 to 0.11 cm/y and from 0.06 to 0.29 cm2/y, respectively. Other factors that control the vertical migration of Pu in soil besides precipitation, soil particle size distribution and organic matter were suggested. Long-term migration behaviors of Pu in the soils were simulated. The results provide the Pu background baseline for further environmental monitoring and source identification of non-global fallout Pu inputs in the future.},
 pages = {174--180},
 title = {Vertical distribution and migration of global fallout Pu in forest soils in southwestern China},
 volume = {136},
 year = {2014}
}