烟草挥发性有机物(Volatile organic compounds,VOCs)含量低、组成复杂、挥发性强,同时烟草及其产品基体极其复杂,发展烟草VOCs的高效采样分析技术具有重要意义.该文综述了近年来烟草VOCs分离富集介质(如石墨烯及其复合材料、硅基材料、磁性富集材料等)及相关采样技术(如QuEChERS技术、固相微萃取技术、液相微萃取技术等)的研究进展,总结了烟草VOCs分析技术在烟草产品质量控制等方面的实际应用情况,并展望了该领域的未来研究趋势.

JPEG images are widely used in Internet,owing to its high compression ratio and multi-quality.Analyses the JPEG compression algorithm in details of JPEG files from the view of decoding instead of encoding,dicusses some problems and solutions encountered in practice.