中文摘要：

数的低级β --同时为 thorium-234 的β 放射和 thorium-228 的α 光谱的察觉使用的α 光谱仪器和为丰富的一个容易的操作过程，收音机化学药品分开，在海洋的 thorium-234 anduranium-238 的采样和测量基于经由 thorium-234 在水之最上层的地区分析出口生产率的要求被开发- uranium-238 放射性不平衡。检测效率两个都β和α放射比 20% 高。β放射的背景是不到 0。5 min~(-1), 和α察觉者的精力分辨率比 1% 好。全部再循环 thorium-234 的比率是大约 75% 。用上述仪器和过程，在 SouthChina 海，南部的海洋和北极海洋的海水的溶解 thorium-234 和 uranium-238，粒子 thorium-234 和 uranium-238 的放射性被分析。

英文摘要：

A low-level β counting-or spectrum apparatus used for the detection of the β radiation of thorium-234 and α spectrum of thorium- 228 simultaneously and an easy operating procedure for the enrichment, radiochemical separating, sampling and measurement of thorium-234 and uranium-238 in the ocean are developed based on the requirements of analyzing export productivity in the eupho- ric zone via thorium-234 - uranium-238 radioactivity disequilibrium. The detecting efficiency both of 13 and α radiation is higher than 20%. The background of βradiation is less than 0. 5 min ^-1 , and the energy resolution of ct detector is better than 1%. Total recycle ratio of thorium-234 is about 75%. Using the above apparatus and procedure, the radioactivities of dissolved thorium-234 and uranium-238, particle thorium-234 and uranium-238 in seawater of the South China Sea, the Southern Ocean and the Arctic Ocean were analyzed.