共生方解石和白云石的碳氧同位素组成的在线自动分析技术

复杂的成岩过程和沉积环境往往造成大部分碳酸盐岩具有不同的碳酸盐矿物组合,如方解石和白云石以不同比例共生。这些矿物的碳氧同位素组成是研究其成岩过程、沉积环境的重要工具。例如,利用C同位素示踪碳来源,或者利用氧同位素推算沉积环境孔隙水的盐度和温度(Fritz and Smith,1970;Dowrkin et al.,2005)。具体而言,这些不同组合

直升机齿轮传动系统干运转研究进展

传动系统的稳定性直接关系到直升机的生存能力。战伤状态下润滑系统失效，干运转工况加速了齿轮表面损伤和破坏。齿轮干运转能力已成为衡量现代直升机的一项重要指标。回顾了齿轮传动系统干运转热分析的研究现状，从齿轮表面改性、涂层、表面结构处理、传动系统与润滑系统设计等现有提升齿轮干运转能力的方法以及试验研究等方面进行综述，总结了各种方法的应用现状，为该领域的研究和发展提供参考

Determination of Chlorofluorocarbons in Seawater by Purge-trap Gas Chromatography

建立了吹扫捕集气相色谱法测定海水中氟氯烃的方法.结果表明,本方法测得的氟氯烃的精密度和回收率高,CFC-11、CFC-113、CCl4的相对标准偏差为1.9%~4.1%,回收率为99.3%~101.0%,检测限分别为0.014 5 pmol/kg、0.033 2pmol/kg0、.019 8 pmol/kg.本方法操作简便快速,是一种海水氟氯烃测定的可靠分析方法,已成功应用于北冰洋海域海水样品的分析测定.An analytical technique has been established for rapid and accurate measurement of three anthropogenically produced chlorofluorocarbons(CFCs),CCl_3F(CFC-11),CCl_2FCClF_2(CFC-113) and CCl_4 in seawater.Seawater samples are transferred into glass ampoules for storage until analysis.CFCs in seawater are determined by purge-trap gas chromatography with a capillary column and electron capture detector(ECD).The experimental result shows that the precision and recovery of the analytical method are good,with the relative standard deviation of 1.9%~4.1% and the recovery of 99.3%~101.0%,and the detection limits are 0.014 5 pmol/kg,0.033 2 pmol/kg and 0.019 8 pmol/kg for CFC-11,CFC-113 and CCl_4 respectively.The procedure is simple and fast,it has been proved to be a reliable method for the determination of CFCs in seawater and has been successfully used in CFCs determination of seawater samples in the Arctic Ocean.国家自然科学基金(40276035)资