一种甲醇直接气相羰基化新催化剂

本世纪７０年代Ｍｏｎｓａｎｔｏ公司成功开发了甲醇液相羰化ＲｈＩ催化体系，使甲醇羰化生产醋酸成为重要的工业过程．然而，由于此工艺产物与催化剂分离复杂、铑资源紧缺以及体系中还必须加大量的碘甲烷（或氢碘酸）作促进剂，设备腐蚀严重．８０年代以来，甲醇气相羰...     

铁基超细粒子催化剂结构与还原行为的Mssbauer谱研究

铁基超细粒子催化剂具有优良的F-T反应性能。本工作利用原位Mssbauer谱辅以XRD技术研究了含有钾助剂的F-T合成铁基超细粒子催化剂的结构与还原行为,考察了催化剂组成和第二金属组分(Mn,Zn,Mg)的影响。“纯”铁超细粒子催化剂在氢气中很容易经Fe_3O_4还原为零价铁。第二金属组分的引入,一方面阻碍了催化剂的还原,另一方面稳定了Fe~(2+)的存在而使其成为还原的主要中间相,这有利于反应条件下形成类尖晶石结构的活性相。对于Fe-Mn催化剂,上述效应随锰含量的增加而更趋显著。铁基超细粒子催化剂在氢气中的还原能力依“纯”Fe>Fe-Zn>Fe-Mn>Fe-Mg的顺序递减,这在一定程度上反映了铁与第二金属组分之间相互作用的强弱。     

Study of the Complexation Behavior of Calixarene with Transition Metal Cations by UV—vis and Fluorescent Spectra

A new fluorescent compound based on calix[4] arene skeleton was synthesized.Its complexation ability with transition metal ions,such as Fe^3 ,Co^2 ,Ni^2 ,Cu^2 ,Zn^2 and Ag^ ,Was investigated by UV-vis and fluorescent spectra.     

Strong influences of cocatalyst on ethylene/propylene copolymerization with a MgCl2/SiO2/TiCl4/diester type Ziegler-Natta catalyst

Using triethylaluminum (TEA), triisobutylaluminum (TIBA) or TEA/TIBA mixtures of molar ratio 75/25, 50/50 and 25/75 as the cocatalyst, five different ethylene-propylene copolymer samples were synthesized by a MgCl₂/SiO₂/TiCl₄/diester type Ziegler-Natta catalyst in a slurry polymerization process. The synthesized copolymers are strongly heterogeneous in chain structure and were fractionated into part of nearly random copolymer and part of segmented copolymer. Both polymerization activity and copolymer structure were found to be markedly changed when the cocatalyst was changed from TEA to TEA/TIBA mixtures or pure TIBA. As the content of TEA in cocatalyst increases, yield of the random part of product increases and the yield of the crystalline segmented copolymer part decreases. There is also a decrease in ethylene content of the whole product with increasing TEA amount. Copolymerization behaviors of the TEA/TIBA mixture activated catalysis systems are not simple superposition of those activated by pure TEA and TIBA. When a 50/50 TEA/TIBA mixture was used as cocatalyst, the copolymerization activity became the highest, and yields of both the random copolymer part and the segmented copolymer part are close to the highest level. On the other hand, both parts of the copolymer produced with a 50/50 TEA/TIBA mixture are relatively more blocky than the products of TEA or TIBA systems, and difference in ethylene content between the random part and the segmented part was the smallest. The segmented copolymer part of three typical samples was further fractionated by temperature-gradient extraction fractionation into fractions of different ethylene content and sequence distribution. Changing TEA content in the cocatalyst exerted strong influences also on the fraction distribution of the segmented part of copolymer.     

Determination of inosine 5′-monophosphate and guanosine 5′-monophosphate in pig feed by capillary zone electrophoresis

A capillary zone clectrophoresis method was developed for the determination of IMP and GIMP, commonly used as flavor enhancers in poultry feed, in a real sample of complex composition. A baseline separation of inosine 5′-monophosphate and guanosine 5′-monophosphate was achieved within 10 min and the other components in the sample did not interfere with the separation. Quantitative results obtained from pig feed samples are presented. The separation conditions and experimental reproducibility are also discussed.     

铬（Ⅲ）邻菲咯啉,8—羟基喹啉配合物／Y型分子筛的制备及苯酚催化羟化

制备了铬（Ⅲ）邻菲咯啉，８－羟基喹啉配合物／Ｙ型分子筛，利用元素分析，ＳＥＭ，ＵＶ－ＶｉｓＢＥＴ及ＸＲＤ等方法确定了分子筛选笼中金属配合物的生在及其晶体结构，考察了实验参数对苯酚转化率及产物选择性的影响。     

Facile synthesis of 9-（N-amino-4-fluoromethyl-3-pyrrolidinyl）-2- fluoro-6-aminopurine from trans-4-hydroxy-L-proline

A novel and simple procedure for synthesis of azanucleoside by Mitsunobu reaction between N-(p-nitrobenzyloxycarbonyl)- trans-4-hydroxy-D-proline methyl ester obtained from trans-4-hydroxy-L-proline after six-step reaction and 2-fluoro-6-azidopurine is described,and azanucleoside is fluorinated by new fluridizer 2,2-difluoro-1,3-dimethylimidazolidine (DFI).All reactions could be carded out under mild condition.     

喷雾热解法合成球形(Y,Gd)BO3:Eu荧光粉的研究

采用喷雾热解法合成了无团聚的球形(Y,Gd)BO3∶Eu荧光粉。研究了各因素对(Y,Gd)BO3∶Eu荧光粉体的结晶性能、外观形貌及发光强度的影响。结果表明,按120%硼酸的化学计量比于900℃喷雾热解,再经过1200℃后处理2 h,可以合成结晶良好的(Y,Gd)BO3∶Eu荧光粉体;喷雾热解溶液的浓度和载气流量对荧光粉的外观形貌影响较大;铕含量为10%时可以获得最佳的发光强度。在优化喷雾热解实验条件下成功合成出良好发光强度的PDP用(Y0.6Gd0.3)BO3∶Eu0.1荧光粉。