Re-Os法能够直接厘定内生金属矿床成矿时代,但是封闭Carius管法化学流程复杂,且有一定的危险性。本文建立了一种简便快速测定辉钼矿Re-Os年龄及其Re含量的方法。用3 m L浓硝酸在10 m L比色管中溶解5~15 mg辉钼矿样品,将溶液中的钼酸沉...Re-Os法能够直接厘定内生金属矿床成矿时代,但是封闭Carius管法化学流程复杂,且有一定的危险性。本文建立了一种简便快速测定辉钼矿Re-Os年龄及其Re含量的方法。用3 m L浓硝酸在10 m L比色管中溶解5~15 mg辉钼矿样品,将溶液中的钼酸沉淀分离后稀释定容,直接采用质谱测量187和185质量数比值（M187/M185）。利用辉钼矿Re-Os年龄标准物质JDC和HLP的M187/M185值与其年龄的正相关线性关系计算未知辉钼矿样品的Re-Os年龄,并通过185Re计数利用相对法计算Re含量。本方法应用于测量13.26~2130 Ma的辉钼矿,Re-Os年龄的测定值与推荐值的相对偏差多数在0.36%~7.42%之间,由于放射性积累较多,长年龄样品测量的准确度较高。与传统Carius管法相比,该方法不需要加入稀释剂,省去了封闭和打开Carius管环节以及Re-Os分离纯化流程,适合于辉钼矿Re-Os年龄的初步分析。展开更多
A new value for the emission probability of 137.144 keV γ-rays from 186gRe decay is recommended to be （9.47±0.03）/%. Using this value the measured cross sections for 187Re（n,2n）186mRe and 187Re（n,2n）186gRe...A new value for the emission probability of 137.144 keV γ-rays from 186gRe decay is recommended to be （9.47±0.03）/%. Using this value the measured cross sections for 187Re（n,2n）186mRe and 187Re（n,2n）186gRe reactions around 14 MeV are analyzed, and the cross section for187Ke（n,2n）186m＋gRe reaction at 14.g MeV is （2213=k116） mb. The UNF code was adopted to calculate the cross sections for the 187Re（n,2n）186m＋gRe reaction below 20 MeV, fitting to the value （2213±116） mb at 14.8 MeV using a set of optimum neutron optical potential parameters which were obtained based on the relevant experimental data of rhenium. The isomeric cross section ratio for the 187Re（n,2n）186m,gRe reaction was analyzed using the V-H method based on nuclear statistical theory. Combining these calculated results, the excitation functions for the 187Re（n,2n）lS6mRe and 187Re（n,2n）186gRe reactions were obtained. The obtained results are in good agreement with the available experimental data.展开更多
文摘Re-Os法能够直接厘定内生金属矿床成矿时代,但是封闭Carius管法化学流程复杂,且有一定的危险性。本文建立了一种简便快速测定辉钼矿Re-Os年龄及其Re含量的方法。用3 m L浓硝酸在10 m L比色管中溶解5~15 mg辉钼矿样品,将溶液中的钼酸沉淀分离后稀释定容,直接采用质谱测量187和185质量数比值（M187/M185）。利用辉钼矿Re-Os年龄标准物质JDC和HLP的M187/M185值与其年龄的正相关线性关系计算未知辉钼矿样品的Re-Os年龄,并通过185Re计数利用相对法计算Re含量。本方法应用于测量13.26~2130 Ma的辉钼矿,Re-Os年龄的测定值与推荐值的相对偏差多数在0.36%~7.42%之间,由于放射性积累较多,长年龄样品测量的准确度较高。与传统Carius管法相比,该方法不需要加入稀释剂,省去了封闭和打开Carius管环节以及Re-Os分离纯化流程,适合于辉钼矿Re-Os年龄的初步分析。
文摘A new value for the emission probability of 137.144 keV γ-rays from 186gRe decay is recommended to be （9.47±0.03）/%. Using this value the measured cross sections for 187Re（n,2n）186mRe and 187Re（n,2n）186gRe reactions around 14 MeV are analyzed, and the cross section for187Ke（n,2n）186m＋gRe reaction at 14.g MeV is （2213=k116） mb. The UNF code was adopted to calculate the cross sections for the 187Re（n,2n）186m＋gRe reaction below 20 MeV, fitting to the value （2213±116） mb at 14.8 MeV using a set of optimum neutron optical potential parameters which were obtained based on the relevant experimental data of rhenium. The isomeric cross section ratio for the 187Re（n,2n）186m,gRe reaction was analyzed using the V-H method based on nuclear statistical theory. Combining these calculated results, the excitation functions for the 187Re（n,2n）lS6mRe and 187Re（n,2n）186gRe reactions were obtained. The obtained results are in good agreement with the available experimental data.
