Physico-chemical properties and catalytic behavior of LnSrNiO(4) mixed oxides for NO decomposition

A series of LnSrNiO(4)(A(2)BO(4), Ln = La, Pr, Nd, Sm, Gd) mixed oxides with K2NiF4 structure, in which A-site(Sr) was partly substituted by individual light rare earth element, was prepared. The solid state physico-chemical properties including crystal structure, defect structure, IR spectrum, valence state of H-site ion, nonstoichiometric oxygen, oxygenous species, the properties of oxidation and reduction etc. as well as the catalytic behavior for NO decomposition on these mixed oxides were investigated. The results show that all of these mixed oxide catalysts have high activity for the direct decomposition of NO(at 900 degrees C the conversion of NO is more than 90%). The effect of the substitution of light rare earth elements at A-site on catalytic behavior for NO decomposition was elucidated.

异丙基膦酸单(1-已基-4-乙基)辛酯的某些基本常数的测定

用两相滴定法测定异丙基膦酸单(1-己基-4-乙基)辛酯(PT-2,HL)在水中的溶解度S，在水中的解离常数K在水-正庚烷中的分配常数Kd及二聚常数K2，利用SOLWR计算程序，简单快速地处理两相滴定数据，得到结果为：S=3.68×10-5mol/L，pKa=5.49，logK2=4.67，logKd=2.67(25±0.5℃)

Synthesis and characterization of soluble polyimides from 1,1-bis(4-aminophenyl)cyclohexane derivatives

A series of novel aromatic diamines (1-3) containing kinked cyclohexylidene moieties was synthesized by a reaction of excess aniline and corresponding methyl-substituted cyclohexanone derivatives. The structures of (1-3) were identifield by H-1 NMR, C-13 NMR, and FT-IR. The polymers were synthesized from the obtained diamines and various aromatic dianhydrides by the conventional polycondensation reaction followed by chemical imidization as well as high-temperature one-step polymerization. The inherent viscosities and weight-average molecular weights of the resulting polyimides were in the ranges of 0.55-1.58 dL/g and (7.4-15.2) x 10(4) g/mol, respectively. The prepared polyimides showed excellent thermal stabilities and good solubility. All polymers were readily soluble in common organic solvents such as tetrahydrofuran, chloroform, tetrachloroethane, etc., and the glass transition temperatures were observed at 290-372 degrees C.

Gas permeability in polyimides from oxydianiline and isomeric thiaphthalic dianhydride or 1,4-bis(dicarboxyphenoxy) benzene dianhydride

The gas permeability and permselectivity properties were investigated of polyimides, prepared from 3,3',4,4'- and 2,2',3,3'-thiaphthalic dianhydride (p-TDPA and m-TDPA, respectively), or 1,4-bis(3,4-dicarboxyphenoxy)- and 1,4-bis(2,3-dicarboxyphenoxy) benzene dianhydride (p-HQDPA and m-HQDPA, respectively), and 4,4-oxydianiline. The polyimides prepared from meta-dianhydrides, which have lower chain-segment packing density, possess higher permeability and lower permselectivity than those prepared from para-dianhydrides. Copyright (C) 1996 Elsevier Science Ltd.

Comparative study on polyimides from 3,3'- and 4,4'-linked diphthalic anhydride

1,4-Bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy)benzene dianhydride, bis(2,3-dicarboxyphenoxy) sulfide dianhydride, bis (3,4-dicarboxyphenoxy)sulfide dianhydride, and 2,3,3',4'-tetracarboxy diphenyl sulfide dianhydride were synthesized from 3-chlorophthalic anhydride and 4-chlorophthalic anhydride. Bis(2,3-dicarboxyphenyl)sulfone and bis(3,4-dicarboxyphenyl) sulfone were obtained by the oxidation of the corresponding bis(dicarboxyphenyl)sulfide by hydrogen peroxide. The polyimides from the dianhydrides mentioned above and 4,4'-oxydianiline were prepared. The properties, such as dynamic mechanical behavior, thermooxidative stability, stress-strain behavior, chemical resistance, and permeability to some gases have been in investigated for the isomeric polyimides. (C) 1996 John Wiley & Sons, Inc.

含二羟基二苯酮系列热致液晶共聚酯的合成与表征──Ⅱ．含4，4＇－二羟基二苯酮，对苯二甲酸，对羟基苯甲酸，间苯二酚的共聚酯

采用直接熔融缩聚及固相聚合方法由４，４’－二羟基二苯酮（ＢＨＰ），对苯二甲酸（ＴＰ），对羟基苯甲酸（ＰＨＢＡ），间苯二酚（ＲＥＳ）成功地合成了四元共聚酯高分子，该聚酯的组成结构及性质由偏光显微镜、广角Ｘ－射线衍射、ＤＳＣ等手段进行表征，结果表明共聚酯具有向列型液晶特征．

Ni顺1.4一聚丁二烯的形态结构

本文选用不同微观结构、不同分子量、支化度及不同交联度的Ni-PB,用电子显微镜研究了其室温的聚集状态及低温下的结晶行为。讨论了其结构与性能的关系。

冲绳海槽黑潮流域近4万年以来的古海洋环境演化

本文采用取自冲绳海槽的91个站位的表层样品和2个柱状岩芯，通过微体古生物有孔虫分析、氧碳同位素测试、AMS~(14)C测年、沉积物粒度和地球化学分析，探讨了现代生物群落、表层沉积物氧同位素与现代海洋环境之间的关系，进而对冲绳海槽区域近4万年来的古海洋环境和古黑潮演化进行了详细的研究。表层沉积物中的浮游有孔虫氧同位素与现代海洋环境之间的关系密切，浮游有孔虫从G.ruber到G.sacculifer到N.dutertrei其δ~(18)O值由轻变重，表明三种有孔虫其生活水层依次由浅到深。在横穿海槽的剖面上浮游有孔虫δ~(18)O在近陆端因受冲淡小影响较强而变轻，而在东侧站位，受黑潮暖流或其支流的影响氧同位素同样有变轻的趋势。N. dutertrei和G.ruber的氧同位素差值表明了冲绳海槽北部区域黑潮支流对表层水体的影响要大于次表层水体，而在冲绳海槽南部区域，黑潮暖流对次表层水体有相对较强的影响。冲绳海槽南部表层沉积物中的浮游有孔虫整体上属于赤道区组合，溶解作用对该区的浮游有孔虫群落有显的影响，冲绳海槽北部区浮游有孔虫组合对具有温带群落的特征。浮游有孔虫分布与海洋环境密切相关，南北区的浮游有孔虫分布都明显受暖流的影响，在暖流的主流轴处浮游有孔虫丰度通常较高。冲绳海槽具有相对较浅的碳酸盐溶跃面，浮游有孔虫丰度和底栖有孔虫深水胶结壳的含量都进一步表明了该区碳酸钙溶跃面大约在1700 m水深左右，比开放大洋明显要浅得多。表层沉积物中的底栖有孔虫主要受水深和水团等因素的制约。水深制约着有孔虫属种的分带，也影响底栖有孔虫的组合。根据Q型因子分析，冲绳海槽南部表层沉积物中的底栖有孔虫从陆架连缘到海槽底部可以划分为5个特定的组合，分别对应黑潮表层水和次层水影响环境、黑潮中层水影响环境、溶跃面以上的黑潮深层水影响环境、黑潮底层水团影响环境和溶解作用较强的槽底环境；北部区的底栖有孔虫群落反映了四个组合，分别代表了陆架混合水团影响环境、黑潮暖流中层水影响环境、冷涡沉积和上升流区影响环境以及对马暖流水团影响下的环境。以氧同位素曲线为基础，结合AMS~(14)C测年和生物地层学对柱状岩芯进行了地层划分和对比，E107孔记录了冰消期以来大约15,000 a来的古环境演化记录，具有较高的沉积速率，DOC－42孔保存在主要是末冰期中40－10ka BP期间的古环境沉积记录，沉积物记录的分辨率相对较低。浮游有孔虫有碎壳比和底栖有孔虫深海胶结壳含量表明了现代冲绳海槽的浅溶跃面是大约最近2000 a BP才开始突然变浅形成的，碳酸盐的溶解作用从冰消期到现在逐增强。冲绳海槽南部E107孔的底栖有孔虫组合把映了15,000 a来的底层水团具有两种完全不同的营养状况，约6500 a BP以前有机质通量较高，6500 a BP以后有机质通量则明显降低。DOC－42孔的底栖有孔虫组合反映该区约4万年以来的底部水团演化主要受有机质通量和氧含量的共同制约，氧同位素3期主要为高有机质通量的沉积环境，伴随有氧含量水平的较大波动；氧同位素2期有机质通量有所降低，氧含量整体为中等水平；氧同位素1期早期义部水体则较高氧含量为主。浮游有孔虫温跃层转换函数反映了冲绳海槽中部的温跃层在约13100 a BP有一个明显的变化，在这之前产温跃层深度较浅，平均89 m，而在该时间以后，温跃层平均深度变为166 m。此外在160 cm处和100 cm的温跃层深度的两次明显的降低，分别对应于新仙女木事件和黑潮暖流的重新入侵，表明这两个事件导致了海洋上层水体结构的突然变化。冲绳海槽北部浮游有孔虫转换函数古温度和浮游有孔虫的低温、低盐特征种反映了在氧同位素3期早期约40000a BP和氧同位素2期间存在两个明显的低温、低盐阶段，可能与沿岸水在该期间加强有关。其中氧同位素3期早期的表层海水古水温比末次冰期还要低，反映了区域海洋环境的重大变化。冲绳海槽南部E107孔的沉积物粒度、地球化学特征、黑潮特征指示种、表层古水温以及底层水团的性质在6500 a BP左右发生了重大的改变，与冲绳海槽南部的其他岩芯反映的古环境化基本一致，表明了南部海槽在6500 a BP前后古黑潮流径发生了重大变化。而冲绳海槽北部区域2万年以来的古环境则与南部有明显差异，总结前人对冲绳海槽古黑潮流径的研究，笔者对未次冰盛期古黑潮流径提出了新的推测。