纸吸管中非挥发性迁移物的非靶向筛查及风险评估

根据欧盟法规推荐的两种食物模拟物对纸吸管样品进行模拟迁移试验,并基于超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF MS)对样品中的迁移物进行非靶向筛查,得到包括润滑剂、施胶剂、抗氧剂降解产物、消泡剂在内的31种有意添加物和非有意添加物。利用该课题组前期建立的风险矩阵,即风险=危害(毒性水平+Cramer分级+4×致突变性)×暴露(4×水溶性+4×渗透性),对纸吸管中31种迁移物进行风险分级。结果表明,未发现Ⅰ级高风险物质,Ⅱ级风险物质中得分较高的来自润滑剂(十六酸酰胺等)、施胶剂(海松酸等)和消泡剂(聚乙二醇等)中的成分,对Ⅱ级风险物质进行半定量分析,通过对比暴露量和TTC阈值,发现酰胺类润滑剂(尤其是芥酸酰胺)存在健康风险,应在纸吸管生产加工过程中引起关注。     

基于离子迁移谱的假币用纸快速检测及溯源

该文采用离子迁移谱（IMS）对20种假币用纸进行分析,通过快速检测假币用纸中的可挥发性组分,构建假币用纸的指纹谱图库。基于主成分分析（PCA）和层次聚类分析（HCA）对迁移时间8～17.5 ms范围的迁移谱信息进行处理,从而对假币用纸进行分类。PCA可将同种假币用纸聚类,HCA则可进一步将20种假币用纸准确分类,其对6个未知来源的半成品假币的分类正确率达83.33%。结果表明,IMS快速检测分析是比较和分类假币用纸的有效方法。     

纳米氧化亚铜固载亚甲兰复合膜修饰玻碳电极的电化学性质及其对多巴胺的电催化

用十六烷基三甲基溴化铵为软模板制备了纳米氧化亚铜晶须,利用XRD和TEM进行表征。研究了纳米Cu2O-Nafion膜修饰玻碳电极的电化学性质,结果表明,纳米氧化亚铜在电极上表现出一对较为可逆的氧化还原峰,对应于Cu(Ⅱ)/Cu(Ⅰ)的氧化还原,峰电流与扫速成正比,表明纳米氧化亚铜在电极表面的电化学受表面控制。研究发现在亚甲基兰为媒介的情况下电极对多巴胺的催化能力进一步提高。在此电极上多巴胺呈现一对响应良好的准可逆氧化还原峰,峰电位差106 mV,峰电流大大提高,氧化峰电位大大降低,表现出良好的电催化作用。该电极可以在抗坏血酸存在下测定多巴胺。     

碳酸乙烯酯合成碳酸二苯酯的GC-MS分析

以钛酸四丁酯催化碳酸乙烯酯与乙酸苯酯酯交换合成碳酸二苯酯(DPC)。GC-MS定性分析表明,反应液中含主产物DPC,中间体2-乙酰氧乙基苯基碳酸酯(1),副产物乙二醇二乙酸酯、乙二醇苯醚乙酸酯和苯酚。1的结构经1H NMR,13C NMR,FT-IR和EI-MS确证。     

苯酚羟化反应中焦油的分离与分析

利用高速离心、减压蒸馏和萃取等方法分离和定量分析苯酚催化羟化反应中所产生的副产物焦油,讨论各种方法的特点.使用萃取方法系统地考察了各种条件下,以Cu2(OH)PO4为催化剂时苯酚羟化反应体系中焦油的生成量.     

纳米ZnO的阳极消耗法制备和表征

采用阳极消耗法制备了纳米ZnO粉体,并利用XRD,TEM,XPS,UV-V is和PL测试技术对样品进行了表征.结果表明,所制样品为纤锌矿结构的纳米ZnO,颗粒呈类球形,平均粒径15 nm,具有很强的紫外吸收能力.位于531.44 eV的O1 s峰和PL谱上的绿带共同证明了氧空位存在,纳米ZnO的绿光发射带来自氧空位电子与价带空穴的辐射复合.     

Rheological Behavior of the Melts for Polyethylene-based Montmorillonite Nanocomposites

IntroductionOwing to their special structures or morphologies,polymer-based montmorillonite nanocomposites exhibitsome particular characteristics,such as,physical,thermal,and mechanical properties,induced by theaddition of very small amounts of inorganic …     

磷酰化氨基酸反应性质的理论研究

采用量子化学计算研究了磷酰化氨基酸的反应性质,包括N-磷酰氨基酸成肽反应、成酯反应、磷上酯交换反应和磷上的N→O迁移反应的机理以及计算模型和计算方法的选择,并从理论上解释了自然界选择α-氨基酸而不是β,γ-氨基酸的实验事实.     

Properties of TiO2-SiO2 Mixed Oxides and Photocatalytic Oxidation of Heptane and Sulfur Dioxide

A series of TiO2-XSiO2[X denotes the molar fraction(%) of silica in the mixed oxides] with different n(Ti)/n(Si) ratios was prepared with ammonia water as a hydrolysis catalyst. The photocatalysts prepared were characterized by XRD, thermal analysis, FTIR, UV-Vis and SPS. The characterization results of FTIR and UV-Vis spectra show that Ti atoms were gradually changed from octahedral coordination to tetrahedral coordination with the addition of silica, which is not beneficial for obtaining strong Bronsted acidity and higher photocatalytic activity. The photocatalytic activity experiments, which were conducted by using heptane (or SO2) as the model reactant, showed that TiO2-SiO2 containing a suitable amount of silica can exhibit much higher photocataiytic activity than pure TiO2. The enhanced photocatalytic activity can be attributed tothree following factors.. (1) smaller crystalline size;(2) higher thermal stability; (3) the new strong Broensted acidity.     

Synthesis and Characterization of {2-Formyl-6-[1-(2,4,6-trimethylphenyl)]-4- chlorophenoxy}_2Ni and Its Ethylene Oligomerization

1 INTRODUCTION Late-transition metal complexes as catalysts for ethylene oligomerization and polymerization have become an intense research subject[1]. Nickel com- plexes are in hot point due to the significant achieve- ments of academic research[2, 3] and industrial appli- cations[4, 5]. The nickel complexes with bidentate [P,O] ligands were industrialized as the SHOP pro- cess for α-olefins[4]. It is supposed that late transition metal complexes have a strong propensity of under- goi…