Research on the Legal System of Food Safety Market Access Supervision

目前我国法学界对食品安全市场准入监管的研究很少见，从而影响了我国食品安全市场准入监管机制的整体构建。因此，系统地研究其基本问题具有强烈的理论和现实意义。本文借鉴国内外已有的研究成果，在搜集分析大量资料的基础上，从界定食品安全、市场准入等概念入手，运用相关经济学、法理学原理，完成了重要的理论分析，并通过实证分析研究，阐述了我国食品安全现状和食品安全市场准入制度的发展、特点、作用以及不足，揭示了完善我国食品安全市场准入制度的必要性。最后，笔者提出了具体的监管法制完善建议。全文正文共分5章。 第一章对食品安全、市场准入等基本概念进行了界定，系统地概述了食品安全市场准入监管过程中涉及到的重要经济学、...There is rare legal research on the supervision over market access of food safety system in our country, this situation affect the construction of our country’s food safety supervision legal system, so strongly theoretical and realistic meanings should be emphasized to research these basic problems. This dissertation learns from existent research fruits, in the foundation of collecting much datum ...学位：法律硕士院系专业：法学院法律系_经济法学学号：20040820

Determination of Buprofezin, Methamidophos, Acephate, and Triazophos Residues in Chinese Tea Samples by Gas Chromatography

建立了同时测定茶叶中噻嗪酮、甲胺磷、乙酰甲胺磷和三唑磷4种农药残留量的测定方法。在45℃加温条件下,用乙酸乙酯 正己烷混合溶剂提取及活性炭色谱柱净化,用不同配比的乙酸乙酯 正己烷混合液梯度洗脱待测组分,以DB 210毛细管色谱柱分离、氮磷检测器测定。结果表明,上述4种农药在10min内能很好地分离;样品加标回收率(n=3)为73 4%～96 9%。方法的变异系数为2.49%～3.35%,茶叶(干重)中4种农药的定量检测下限为7 0～12 0μg/kg。A method has been developed for the simultaneous determination of buprofezin, methamidophos, acephate and triazophos residues in Chinese tea samples. The pesticide residues were extracted from tea samples with a mixture of ethyl acetate and n-hexane (50∶50, v/v) at 45 ℃. The extracts were subsequently treated with a column packed with 40 mg of active carbon by gradient elution with ethyl acetate and n-hexane. Buprofenzin and the three (organophosphorus) pesticides were analyzed by gas chromatography using a DB-210 capillary column and a nitrogen-phosphorus detector. The recoveries for spiked standards were 73.4%-96.9%. The relative standard deviations were all within 4.63%. The limits of quantitation (3σ) in the tea samples were about 7.0-12.0 μg/kg.福建省自然科学基金重点项目(B0220001)

Photoelectrochemical Studies on the TiO_2 Nanostructured Porous Film Sensitized by Cyanine Dye

研究了三甲川菁染料敏化ＴｉＯ２ 纳米结构电极的光电化学行为．结果表明，使用该染料敏化可显著提高ＴｉＯ２ 纳米结构电极的光电流，使电极的吸收波长红移至可见光区，光电转换效率得到明显改善，ＩＰＣＥ值最高可达１２－１ ％ ．The photoelectrochemical behaviors of the TiO 2 nanostructured porous film sensitized by cyanine dye were investigated in this paper.The results showed that the excitaed state level matched the conduction band edge of TiO 2 nanoparticle.Therefore the sensitization of the dye can increase the photocurrent intensity of the TiO 2 nanostructured electrode obviously and results in a red-shift of optical absorption from the ultra_violet region to the visible.As a result,the light_to _electricity conversion efficiency was improved evidently,the maximum value of IPCE has reached 12.1%.作者联系地址：北京大学化学与分子工程学院!北京100871,北京大学化学与分子工程学院!北京100871,北京大学化学与分子工程学院!北京100871,北京大学化学与分子工程学院!北京100871,北京大学化学与分子工程学院!北京100871,北京大学化学与分子工程学院!北京100871,华东理工大学精细化工研究所!Author's Address: College of Chenistry and Molecular Engineering,Peking University,Beijing 100871 Meng Fanshum Tian He Institute of Fine Chemicals,East China University of Scienc