聚氯乙烯复合热稳定剂中铅镉钡的同时测定

聚氯乙烯（PVC）材料广泛应用于建筑、电讯、交通、电子、化工、包装等行业。然而，PVC加工时存在着一个致命的弱点，就是其流动温度为136℃，分解温度为140℃，两者相差仅4℃，给加工带来很大难度，为了能顺利加工就必须加入热稳定剂，热稳定剂是PVC加工不可缺少的主要助剂之一。热稳定剂种类繁多，我国目前大量使用的稳定剂为铅盐及金属皂等稳定剂，产量高达4．5万吨。由于铅、镉、钡等金属元素具有一定的毒性，使用中易造成环境污染，有害于人体健康，因此必须严格加以控制。     

固相氯化法合成氯化聚乙烯的红外光谱研究

本文研究在不同条件固相氯化聚乙烯(CPE)的红外光谱,探讨了一步和两步氯化合成的CPE的结构差别,着重讨论了两步氯化的CPE结构特点。从观察表征结晶结构和—(CH_2)_n—链段氯分布的特征频率变化表明,低温固相氯化主要发生在无定形区,并且在CPE中形成高氯化和低氯化链段(或未氯化)的嵌段结构。在两步固相氯化时,晶区受到较大程度的破坏,氯化作用已不局限在无定形区,其结晶结构的破坏主要同第二步氯化程度有关,即使CPE氯含量相同,若前后两步氯化程度不同,结构有很大差异。     

不同碳酸铵试剂对共沉淀法制备的GDC粉性状的影响

近年来工作温度在500￣700℃的中温固体氧化物燃料电池(IT-SOFC)受到广泛关注。稀土掺杂氧化铈尤其是钐、钆掺杂氧化铈在中温下的离子电导率远高于钇掺杂氧化锆(YSZ),是较为理想的IT-SOFC电解质材料。由于掺杂氧化铈难于烧结,不便于制备致密的电解质膜,通过提高掺杂氧化铈粉体细度来降低其烧结温度,是近年来该材料应用领域的一个研究热点。已有各种合成掺杂氧化铈纳米粉的报道,如采用共沉淀法、固态反应法、水热处理法、燃烧法、溶胶-凝胶法等等。其中碳酸盐共沉淀法由于具有成本低、设备简单以及合成粉体细度高等优点而倍受青睐。通…     

铁轴草中Teucvidin的衍生物研究

从唇形科植物铁轴草中分离得去甲克罗烷二萜化合物Ｔｅｕｃｖｉｄｉｎ，通过催化氢化、酯交换、水解等反应合成了８个衍生物，用＾１ＨＮＭＲ、ＭＳ和ＩＲ确定了其结构，初步生物活性测定结果表明，化合物Ⅱ和Ⅳａ的拒食作用显著。     

手性螺环单磷配体在不对称氢甲酰化反应中的应用

为了进一步拓展具有螺二氢茚骨架的亚磷酸酰胺酯、亚磷酸酯、亚膦酸酯等手性螺环单磷配体在不对称反应中的应用范围, 研究了手性螺环单磷配体在铑催化苯乙烯衍生物的氢甲酰化反应中的选择性.     

三环己基锡芳氧乙酸盐的合成及其结构表征

三环己基锡衍生物(Cy_3SnX,Cy=环己基,X=配体或取代基)是一类具有较强生物活性的有机锡化合物,它们广泛用作杀螨剂,杀菌剂和海洋防污剂。有关三环己基锡芳氧乙酸盐的合成至今报道很少。Bubblitz 合成了两个三环已基锡芳氧乙酸盐,此后,Matsuda 等人制备了三环已基锡-2,4-二氯苯氧乙酸盐,它们都具有良好的杀螨、杀菌活性,后者还可应用于海洋     

Ce0.8Y0.2O1.9-Ca3(PO4)2-K3PO4复合电解质在中温区的质子导电性及在常压合成氨中的应用

A precursor of Ce_0.8Y_0.2O_1.9(YDC) solid electrolyte was synthesized by the gol-gel method. YDC and phosphates powders were prepared by mixing the YDC and phosphates according to different weight ratios. The mixtures of the YDC and binary phosphates were ground and sintered at 1 400 ℃. The proton conductivity in solid electrolyte of the sintered samples was examined using electrochemical methods at 400～800 ℃. Ammonia was synthesized from nitrogen and hydrogen at atmospheric pressure in the solid state proton conducting cell reactor. The optimal condition for the ammonia production was determined. The result indicated that composite electrolyte of 80wt% YDC: 20wt% binary phosphates as proton conductor could obtain the highest ionic conductivity and ammonia production rate among the four samples, the rate of evolution of ammonia was up to 9.5 × 10^-9 mol·s^-1·cm^-2.     

REE AND Sr, Nd, Pb ISOTOPIC GEOCHEMISTRY OF HUANGYISHAN BASALT, KUANDIAN, LIAONING, NORTHEAST CHINA

In the light of major element geochemistry, mineral chemistry and REE and isotopic data, the small but apparent isotopic differences between the Cenozoic volcanic rocks east and west of the Tancheng-Lujiang fault are believed to be caused by the mixing and metasomatism of crustal and mantle material in tho mantle source region in response to Pacific plate subduction. The presence of phlogopite and pargasite in mantle xenoliths lends strong support to mantle metasomatism.     

8-羟基喹啉单体及二聚体质子转移反应的理论研究

Density functional theory （DFT） of quantum chemistry method was employed to investigate proton transfer reactions of 8-hydroxyquinoline （8-HQ） monomers and dimers. By studying the potential energy curves of the isomerization, the most possible reaction pathway was found. The total energy of 8-hydroxyquinoline was lower than that of quinolin-8（1H）-one, whereas the order was reversed in dimers. The findings explained the contrary experimental phenomena. The minimum reaction barrier of intramolecular proton transfer was 47.3 kJ/mol while that in dimer was only 25.7 kJ/mol. Hence it is obvious that proton transfer reactions of 8-HQ monomer have a considerable rate but it is easier to proceed for 8-HQ dimer than monomers. It implied that the hydrogen bond played an important role in depressing the activation energy of reaction. The mechanism of the tautomerization was discussed on the basis of theoretical results.     

芴取代的有机膦化合物的合成及发光性能

合成了以芴为取代基，P原子为核的一类新型有机膦化合物．此类化合物的HOMO值在-5．35～-5．24eV之间．在二氯甲烷中的最大紫外吸收光谱峰值在313～351nm之间，荧光光谱峰值在334～397nm之间．利用此类小分子与纯聚芴进行掺杂，制作了有机电致发光器件．低HOMO值有机膦化合物的引入有效地降低了聚芴发光器件的开启电压，提高了器件的发光效率．