多核羰基钴配合物的合成及其催化活性的研究

多核羰基钴配合物对很多有机化学反应有良好的催化作用,从而引起人们很大关注.但这类配合物由高压反应得到,因此给实用带来不便. 我们通过各种含膦配体的氯化钴,在锌粉存在下,与一氧化碳在常温常压下反应,得到了一系列通式为:(PR_3)_mCo_n(CO)_x的多核羰基钴配合物,讨论了它们的结构,并对这些配合物在由十四碳烯羰基合成作为表面活性剂原料的十五碳伯醇反应中的催化性能进行了研究.     

光度法测定松脂中的铝

研究了用铝试剂,乙酸－乙酸铵缓冲溶液组织的体系以及光度法测定松脂微量铝的条件,提出了一种灵敏度、选择性与稳定性较好的测定松脂中铝的方法,在０－５０μｇ／５０ｍＬ范围内服从比耳定律。     

微波消解-FAAS法测定三种蒙成药中铜、铁、锰、钙和镁

微波消解 -火焰原子吸收分光光度法测定蒙成药中 5种金属元素。实验结果表明 ,微波消解方法简便 ,消化时间短 ;测试方法具有较好的精密度和准确度     

一类求解抛物型方程侧边值问题的最优滤波方法

该文考虑一类特殊的抛物型方程侧边值问题,即一类含有对流项的非标准逆热传导问题. 给定在x=1处的温度测量值来确定区间(0,1)上的未知解u(x, t). 这是一类不适定问题,即问题的解(如果解存在)不连续依赖于数据.为了求解这一问题, 必须采用某些正则化技巧. 该文给出了一种最优滤波方法, 使得问题的真实解和近似解之间的误差估计达到了Hölder型最优. 同时还证明了问题的解在x=0处的收敛性.     

氩氧流量比对CeOx-SnOx膜微观结构及光学性能的影响

采用磁控反应共溅射的方法,以金属Ce和Sn为金属源,成功地制备出CeOx-SnOx薄膜.利用扫描电子显微镜(SEM)、X射线衍射(XRD)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等测试手段对薄膜的结构、表面形貌及成分进行了分析和表征.结果表明薄膜以岛状模式生长,随氩氧比降低,结晶性增强,出现CeO2和SnO相.此外,利用紫外-可见分光光度计对薄膜的光学性能进行了研究,测试结果表明薄膜对紫外光有极强的吸收作用.当氩氧流量比为3∶1时,紫外光平均透过率仅为5.80;,而可见光平均透过率为81.48;.     

Effect of Sulfonation Degree on Performance of Proton Exchange Membranes for Direct Methanol Fuel Cells

A series of proton exchange membranes based on sulfonated polyarylene ether ketones(SPAEKs) was used to study the effect of sulfonation degree on proton conductivity, methanol permeation and performance of direct methanol fuel cells(DMFCs). Dependences of physical characteristics of the membranes, i. e., proton conductivity, water uptake, swelling ratio, methanol permeability and ion exchange capacity(IEC) were systematically studied. Both methanol permeability and proton conductivity of the SPAEK membrane grow rapidly as the increase in sulfonation degree since methanol molecules and protons share the same transfer channel. However,the methanol permeability plays more important role comparing to proton conductivity. As a result, the SPAEK membrane with a medium sulfonation degree(60%) was found to yield the best performance in a DMFC due to the acquirement of balanced conductivity and methanol permeability.     

Hybird Membrane with High Proton Conductivity and Selectivity Based on SPEEK for Direct Methanol Fuel Cells

Composite membranes based on sulfonated silica/sulfonated poly(ether ether ketone)(SPEEK) were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfonated silica is generated in situ via the hydrolysis of sulfonated 3-anminopropyl triethoxysilane(KH550) synthesized newly from 3-aminopropyl triethoxysilane and 1,4-butane sultone.The membrane with a silica mass fraction of 5% exhibits a conductivity of 0.187 S/cm at 80 °C and a methanol coefficient with 9.72×10-7 cm2/s.The composite membranes show improved condutive ability and better selectivity that can be promisingly used in direct methanol fuel cell.     

KF/Al2O3催化合成2-甲基-3-(3,4-亚甲二氧基苯基)丙烯醛

缩合;催化剂;洋茉莉醛;KF/Al2O3催化合成2-甲基-3-(3;4-亚甲二氧基苯基)丙烯醛     

用广角X光衍射测定不同晶型间规聚苯乙烯结晶度

多晶型;用广角X光衍射测定不同晶型间规聚苯乙烯结晶度     

Effects of Heat Treatment on the Crystallization Behavior of Poly(3-alkylthiophenes)

IntroductionPoly( 3- alkylthiophenes) ( P3ATs) ,as a newkind of soluble,fusible and processable conductivepolymers,have attracted a great interest and muchattention ofchemistsand physicists[1,2 ] . Ithas beenwidely accepted that P3ATs can form similarlayered structures with alkyl side chains beingoriented in the lateral a- axis direction[3— 6] .Moreover,when the number of the carbon atoms inthe alkyl side chains is more than1 0 ,some orderlyarrangements of the side chains will occur between…