STUDIES OF MULTICOMPONENT COMPLEX OXIDE CATALYSTS FOR OXIDATIVE COUPLING OF METHANE VI.SURFACE BASICITY AND SURFACE ACTIVE OXYGEN SPECIES OF LiTi_xLa_(1-x)O_2 λ MULTICOMPONENT OXIDE CATALYSTS

The surface basicity of Ti-La-Li multicoinponent oxides has been investigated by means of CO2-TPD. The experiment results show that C2 (C2H6 C2H4) selectivity is related to surface basic strength. The surface active oxygen species have also been characterized by means of XPS, O2-TPD and so on. It has been indicated that C2 selectivity and CH4 conversion are correlated with lattice oxygen and the adsorbed oxygen on the surface of the catalyst respectively In the O2-TPD experiments, it has also been found that there are three kinds of oxygen species on the surface of the series catalvsts, which are a (100℃ 750℃) Among them α-oxvgen causes deep oxidation whileβand γ oxygen species are related to oxidalive coupling of methane (OCM).     

SYNTHESIS OF DBN AND ITS CATALYTIC PERFORMANCE FOR METHANOL CARBONYLATION TO METHYL FORMATE

1 , 5-diazabicyclo['1, 3, 0]non-5-ene(DBN) has been synthesized in our laboratory, and its catalytic activity and selectivity for methanol carbonylation to methyl formate (MF) have been studied. The experimental results have demonstrated that the synthetic processes of DBN used for the present work are reasonable and feasible. The total yield of three steps of DBN synthsis is approximate to 80%. The activity evaluation has shown that DBN can effectively catalyze the carbonylation reaction of methanol in the presence of propylene oxide (PO) promoter. PO-promoted DBN is a novel catalytic system superior to sodium methoxide.     

杯[6]芳烃-双金属卟啉仿P-450酶模型的研究Ⅳ.对异丙苯氧化的催化行为

研究了杯[6]芳烃-双金属卟啉在氧化异丙苯中的催化行为，结果表明杯[6]芳烃-双金属卟啉比之相应的金属卟啉具有更高的催化活性，并表现同样的选择性，生成苯乙酮和醇组份。此一结果同通常酞菁或其它如西弗碱大分子金属络合物催化下生成丙酮和酚不同。还考察了温度、轴向配体、催化剂用量及金属离子种类等对反应的影响，仔细地通过测定反应速度比较了反应的活性。     

Synthesis and characterization of insulin-5-Fu conjugate,enabling insulin as multi-drug carrier via dendritic approach

To enable insulin as multi-drug carrier, we designed and synthesized dendritic linker molecule bearing three 5-Fluorouracil residues at the branch ends. The new conjugate showed excellent water solubility. The stabilities under different conditions were investigated. The results showed that the conjugate was a potential prodrug to release free 5-Fu.     

几种树脂对西红花糖苷的吸附性能的研究

本文系统研究了硅胶和几种国产吸附树脂对西红花提取物溶液的吸附与洗脱性能，包括树脂的筛选，洗脱剂的选择，并研究了pH，温度和西红花提取物的浓度对西红花提取在SZ－1吸附树脂上的吸附影响，结果表明，SZ－1吸附树脂对西红花提取物的吸附能力较强，洗脱能力为最好，其吸附性能和洗脱性能均优于常用色谱固定相硅胶，SZ－1吸附树脂的静态吸附容量为1．04g/g，动态吸附容量为0．5－0．6g/g，洗脱率可达98％以上，且吸附速度快，易于洗脱和再生。     

高效液相色谱分析对-羟基苯甲酸

对-羟基苯甲酸是常用的化学试剂和化工原料,其质量的优劣主要取决于邻、间位杂质含量。对-羟基苯甲酸分析主要是采用高效液相色谱法。分析对-羟基苯甲酸的主要困难在于对位和间位异构体的分离,大量的对-羟基苯甲酸易于掩盖间-羟基苯甲酸出峰。本工作采用吸附色谱,以含乙酸的二氯甲烷-乙醇为流动相,使邻、间、对-羟基苯甲酸获得了较好的分离。柱后通过双紫外检测器串联进行测定。     

等离子体减阻技术的研究进展

利用等离子体的特性减小飞行器的气动阻力是一种新概念的减阻思路.目前国外的一些风洞实验和计算结果已证明了等离子体减阻效果的显著性.本文介绍了国外等离子体减阻技术的研究进展,包括:逆向等离子体喷流减阻、基于等离子体边界层控制减阻和局部施加能量点源减阻.分析了等离子体减阻的基本原理及所涉及的一些关键技术点.最后针对我国的减阻研究情况,提出了等离子体减阻技术的研究方向.      

Dirichlet空间上的超循环复合算子

设Bn是复平面C中的单位圆盘(n=1)或复空间Cn中的单位球.众所周知,在Hardy空间上存在丰富的符号在Aut(Bn)中的超循环复合算子.然而,在复平面中单位圆盘上的Dirichlet空间中, 任何复合算子都不能是超循环的.本文则证明,当n>1时,Bn上的Dirichlet空间中确有超循环复合算子.     

Synthesis and properties of two novel copolymers based on squaraine and fluorene units for solar cell materials

Two novel copolymers based on squaraine and fluorine units have been synthesized through palladium catalyzed Suzuki coupling reaction and Sonogashira coupling reaction,respectively.The structures and properties of the two copolymers were characterized by FT-IR.NMR,UV-vis absorbance（Abs）,gel permeation chromatography（GPC）,thermal gravimetric analysis （TGA）,differential scanning calorimetry（DSC） and cyclic voltammetry（CV）.The solution absorption spectrums of P₁ and P₂ show two distinct absorption bands,one locates at 300-500 nm and the other at 600-800 nm.The absorption spectrums of P₁ and P₂ in films are broadened obviously and the spectral responses are extended up to 900 nm.Thermal gravimetric analysis demonstrates that the polymers are stable.Cyclic voltammetry experiment shows that the band gaps of the copolymers are 1.65 eV and 1.67 eV. respectively,suggesting their potential for applications as solar cells materials.     

A facile and efficient synthetic method for 4-phenylethynylphthalic anhydride

A novel approach to the synthesis of 4-phenylethynylphthalic anhydride has been described.The target compound was synthesized by Pd/Cu catalyzed Sonogashira coupling reaction between phenylacetylene and 4-bromophthalic acid which was for the first time employed as start material,followed by dehydration of 4-phenylethynylphthalic acid.Compared with traditional synthetic routes,this method provides several advantages such as readily available raw materials,convenient manipulation and high yield.The product...