Based on years of practice and survey methods of grassland resources at home and abroad, the technical problems that may occur in the survey process are analyzed, the preparatory work before survey, specific content o...Based on years of practice and survey methods of grassland resources at home and abroad, the technical problems that may occur in the survey process are analyzed, the preparatory work before survey, specific content of field survey and sample processing and analysis and specimen preparation are elaborated. Moreover, the announcements of major technical methods are also described in details.展开更多
基于石墨靶的加速器质谱分析是目前获得高精度^(14)C年代的最佳手段,石墨的品质直接影响年代结果的可靠性。自动石墨合成系统能够高效且精确地合成石墨,对于开展地球科学、考古学、环境科学等相关领域的研究提供技术保障。该文采用自动...基于石墨靶的加速器质谱分析是目前获得高精度^(14)C年代的最佳手段,石墨的品质直接影响年代结果的可靠性。自动石墨合成系统能够高效且精确地合成石墨,对于开展地球科学、考古学、环境科学等相关领域的研究提供技术保障。该文采用自动石墨合成系统针对不同测年材料开展了石墨制备方法研究。确定了不同材料的样品量范围;厘清了样品制备的序列,在实验过程中应遵循从老到新的年代顺序和氧化程度难易的原则;获取了不同质量样品的石墨合成效率。结果表明:反应效率随初始碳量的增加而增大,当初始碳质量大于400μg时,反应效率优于90%,同位素分馏效应微弱。国际标准物质和本底测试结果表明:标准的测试值和参考值在误差范围内一致性很好;本底的^(14)C值为0.32 pMC,^(14)C年代大于46 ka BP,仪器性能良好。展开更多
基金Supported by Nature Fund Projects of Liaoning Province(2015020809)Special Investigation Pro-ject of Grassland Plant Resources in Liaoning Province
文摘Based on years of practice and survey methods of grassland resources at home and abroad, the technical problems that may occur in the survey process are analyzed, the preparatory work before survey, specific content of field survey and sample processing and analysis and specimen preparation are elaborated. Moreover, the announcements of major technical methods are also described in details.
文摘基于石墨靶的加速器质谱分析是目前获得高精度^(14)C年代的最佳手段,石墨的品质直接影响年代结果的可靠性。自动石墨合成系统能够高效且精确地合成石墨,对于开展地球科学、考古学、环境科学等相关领域的研究提供技术保障。该文采用自动石墨合成系统针对不同测年材料开展了石墨制备方法研究。确定了不同材料的样品量范围;厘清了样品制备的序列,在实验过程中应遵循从老到新的年代顺序和氧化程度难易的原则;获取了不同质量样品的石墨合成效率。结果表明:反应效率随初始碳量的增加而增大,当初始碳质量大于400μg时,反应效率优于90%,同位素分馏效应微弱。国际标准物质和本底测试结果表明:标准的测试值和参考值在误差范围内一致性很好;本底的^(14)C值为0.32 pMC,^(14)C年代大于46 ka BP,仪器性能良好。