Electroluminescence based on a beta-diketonate ternary samarium complex

The triplet energy state of the HTH [HTH: 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl) hexane-1,3-dione] ligand was measured to be 20 400 cm(-1), which indicated that Sm(HTH)(3) phen (phen: 1,10-phenanthroline) is a good complex to produce strong PL intensity and high fluorescence yield. Electroluminescent (EL) devices using the Sm( HTH) 3 phen complex as the emissive center were fabricated by vapor deposition and spin-coating methods. The relative intensity of the EL spectra changed compared to the photoluminescence (PL) spectrum, which suggested that the luminescence mechanisms of PL and EL have differences. A luminance of 9 cd m(-2) and a higher brightness of 21 cd m(-2) were obtained from the devices ITO/TPD (40 nm)/ Sm( HTH)(3) phen (50 nm)/ PBD (30 nm)/ Al (200 nm) and ITO/PVK (40 nm)/ PVK : Sm( HTH)(3) phen (2.5 wt%, 50 nm)/ PBD (30 nm)/ Al (200 nm), respectively.

Mass transfer of Er(III) between HBTMPTP dissolved in n-heptane and HAc-NaAc

The rate of extraction of Er(III) from aqueous acetate solutions at 0. 2 mol/L ionic strength by HBTMPTP in n-heptane was studied by using a constant interfacial area cell with laminar flow at (30+/- 0. 5)degrees C. The interfacial activity of HBTMPTP was investigated at n-heptane/0. 2 mol/L (H, Na)Ac (pH=5. 00) interface, The rate of Er(III) extraction was measured at different chemical compositions by varying hydrogen ion, HBTMPTP, Cyanex 302 and chlorine ion concentrations, The effect of stirring speed, temperature and special interfacial area on the rate of extraction was also studied. The results showed that, under the conditions of the experiments, the overall rate is diffusion controlled, that the impurities of Cyanex 302 have the effect of synergistic extraction.

铒在HBTMPTP-正庚烷/水溶液间的传质动力学

在 ( 3 0± 0 .5)℃下 ,用层流恒界面池研究了铒在 HBTMPTP-正庚烷 -0 .2 mol/ L( H,Na) Ac萃取体系中的传质动力学 .测定了该体系的界面张力 ,考察了水相酸度、萃取剂浓度、氯离子浓度、温度和比界面对萃取速率的影响 .实验表明 ,在本实验条件下 ,萃取过程属于扩散控制过程 .Cyanex3 0 2中的杂质具有动力学的协萃作用

高效离心分配色谱仪对稀土萃取体系的研究

木文首次用高效离心分配色谱仪(HPCPC)研究Cyanex272-P_(507)体系分离重稀土元素,评估HPCPC的性能及萃取剂的萃取性能,考察了流动相的流速、pH及HPCPC的转速等对分离效率的影响,并对此体系萃取分离重稀土(Ⅲ)的行为进行了探讨。

Separation of zinc(II) from europium(III) by using hollow fiber membrane

Extraction and separation of Eu3+ and Zn2+ in sulfuric acid solution was investigated by hollow fiber membrane with cyanex 302 (bis (2,4,4-trimethylpentyl) monothiophosphinic acid) in counter-currently circulating operation. Reaction mechanism of membrane extraction and effect of extractant concentration and H+ concentration in aqueous phase on the mass transfer coefficient were discussed. It can be concluded that Zn2+ can be extracted completely from Eu3+ sulfate solution according to the kinetics competing difference. In one extractor process, extraction percentage of Zn2+ was not completely and Eu3+ was not extracted. Extraction percentage of Zn2+ reached 94.92%, but Eu3+ only reached 8.59% after 100 minutes extraction in two series connectors and that of Zn2+ and Eu3+ reached 99.9% and 6.53% respectively after 40 minutes extraction in three series connectors.

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.

有机膦类化合物在金属溶剂萃取中的研究和应用

评述近十年有机膦类化合物-Cyanex 商品化萃取剂在金属溶剂萃取中的应用与发展.

SOLVENT-EXTRACTION OF SC(III), ZR(IV), TH(IV), FE(III), AND LU(III) WITH THIOSUBSTITUTED ORGANOPHOSPHINIC ACID EXTRACTANTS

The solvent extraction of Sc(III), Zr(IV), Th(IV), Fe(III) and Lu(III) with Cyanex 302 (bis(2,4,4-trimethylpentyl)monothiophosphinic acid) and Cyanex 301 ( bis(2,4,4-trimethylpentyl) dithiophosphinic acid) in n-hexane from acidic aqueous solutions has been investigated systematically. The effect of equilibrium aqueous acidity on the extraction with these reagents was studied. The separation of Th(IV), Fe(III) and Lu(III) from Sc(III), or the separation of other metals from Lu(III) with Cyanex 302, can be achieved by controlling the aqueous acidity. However, Cyanex 301 exhibited a poor selectivity for the above metals, except for Lu(III). The extraction of these metals with Cyanex 272, Cyanex 302 and Cyanex 301 has been compared. The stripping percentages of Sc(III) for Cyanex 302 and Cyanex 301 in a single stage are near 78% and 75% with 3.5 mol/L and 5.8 mol/L sulphuric acid solutions, respectively. The effects of extractant concentration and temperature on the extraction of Sc(III) were investigated. The stoichiometry of the extraction of Sc(III) with Cyanex 302 was determined. The role of different components of Cyanex 302 in the extraction of Sc(III) was discussed.

二(2,4,4-三甲基戊基)膦酸萃取分离稀土元素(Ⅲ)的研究

本文研究了二(2,4,4-三甲基戊基)磷酸(Cyanex 272)的煤油溶液在不同介质(HCI,HNO_3)中对三价混合稀土的萃取分离性能.观测了平衡水相酸度对萃取平衡的影响,由酸度曲线求出相邻元素的平均分离系数,并考察了酸度对反萃取平衡的影响.比较了HCI和HNO_3介质中,Cyanex 272对混合稀土(Ⅲ)的萃取性能.

Geochemical character and material source of sediments in the eastern Philippine Sea

Based upon analyses of grain-size, rare earth element (REE) compositions, elemental occurrence phases of REE, and U-series isotopic dating, the sediment characteristics and material sources of the study area were examined for the recently formed deep-sea clays in the eastern Philippine Sea. The analytical results are summarized as follows. (1) Low accumulation rate, poor sorting and roundness, and high contents of grains coarser than fine silt indicate relatively low sediment input, with localized material source without long distance transport. (2) The REE Contents are relatively high. Shale-normalized patterns of REE indicate weak enrichment in heavy REE (HREE), Ce-passive anomaly, and Eu-positive anomaly. (3) Elemental occurrence phases of REE between the sediments with and without crust are similar. REE mainly concentrate in residual phase and then in ferromanganese oxide phase. The light REE (LREE) enrichment, Ce-positive anomaly, and Eu-positive anomaly occur in residual phase. Ferromanganese oxide phase shows the characteristics of relatively high HREE content and Ce-passive anomaly. (4) There are differences in each above mentioned aspect between the sediments with and without ferromanganese crust. (5) Synthesizing the above characteristics and source discriminant analysis, the study sediments are deduced to mainly result from the alteration of local and nearby volcanic materials. Continental materials transported by wind and/or river (ocean) flows also have minor contributions.

Distribution of the nonlinear random ocean wave period

Because of the intrinsic difficulty in determining distributions for wave periods, previous studies on wave period distribution models have not taken nonlinearity into account and have not performed well in terms of describing and statistically analyzing the probability density distribution of ocean waves. In this study, a statistical model of random waves is developed using Stokes wave theory of water wave dynamics. In addition, a new nonlinear probability distribution function for the wave period is presented with the parameters of spectral density width and nonlinear wave steepness, which is more reasonable as a physical mechanism. The magnitude of wave steepness determines the intensity of the nonlinear effect, while the spectral width only changes the energy distribution. The wave steepness is found to be an important parameter in terms of not only dynamics but also statistics. The value of wave steepness reflects the degree that the wave period distribution skews from the Cauchy distribution, and it also describes the variation in the distribution function, which resembles that of the wave surface elevation distribution and wave height distribution. We found that the distribution curves skew leftward and upward as the wave steepness increases. The wave period observations for the SZFII-1 buoy, made off the coast of Weihai (37A degrees 27.6' N, 122A degrees 15.1' E), China, are used to verify the new distribution. The coefficient of the correlation between the new distribution and the buoy data at different spectral widths (nu=0.3-0.5) is within the range of 0.968 6 to 0.991 7. In addition, the Longuet-Higgins (1975) and Sun (1988) distributions and the new distribution presented in this work are compared. The validations and comparisons indicate that the new nonlinear probability density distribution fits the buoy measurements better than the Longuet-Higgins and Sun distributions do. We believe that adoption of the new wave period distribution would improve traditional statistical wave theory.

单环刺螠线粒体全基因组及其系统发生研究

在分子系统发生学研究中，因为线粒体基因组相对于其他分子标记具有明显的优越性，所以线粒体基因组已经逐渐成为一个研究后生动物系统发生的基本工具。螠虫动物大约有150多种，因为它体节不分节，具有真体腔的和两边对称的特性，所以在传统分类学上，人们把螠虫动物归类为一个独立的门。然而，螠虫动物和环节动物门的关系一直以来存在着很多的争议。越来越多的形态学和分子数据证明，我们应该重新考虑螠虫动物门的独立地位的合理性，因为大量包括形态和分子方面的证据都表明螠虫动物门很有可能起源于类似环节动物的祖先。本研究利用线粒体基因组作为系统发生研究的工具，对这个问题进行了进一步的探索研究。我们对一种螠虫动物代表种---单环刺螠（Urechis unicinctus）的线粒体全基因组序列进行测定，单环刺螠线粒体基因组DNA的总长度为15,761 bp，A+T含量为61.9%，包含13个蛋白质编码基因，22个tRNA基因，2个核糖体RNA基因，1个长度为923 bp的非编码区，37个基因都编码在同一条链上。基因顺序排列和基于氨基酸序列构建的系统发生树两方面的证据都支持：螠虫动物可能起源于环节动物。

甘肃黄芪对多柔比星心肌病大鼠心肌组织部分基因表达的影响

目的 比较正常大鼠和多柔比星心肌病大鼠心肌组织部分基因表达谱的差异,探讨甘肃黄芪对上述基因表达谱的影响.方法 30只Wistar大鼠随机分3组:对照组即生理盐水组(n=10),多柔比星组(n=10)和黄芪+多柔比星组(n=10).分别从3组心肌组织中抽提总RNA,用Cy3,Cy5荧光标记,经逆转录合成动物来源的eDNA探针;eDNA探针与4000点基因表达谱芯片杂交,结果由软件分析表达信号.结果 共有923条基因出现差异表达,其中586条基因表达下调,337条基因表达上调.凋亡相关基因表达在多柔比星心肌病时上调;氧化和能量代谢相关基因的表达在多柔比星心肌病时下调.6个在多柔比星组上调的基因在黄芪+多柔比星组下调,8个在多柔比星组下调的基因在黄芪+多柔比星组上调,3个在多柔比星组上调的基因在黄芪+多柔比星组表达进一步增强.结论 凋亡和能量代谢障碍及免疫因素在多柔比星心肌病的发病机制中参与作用,甘肃黄芪对多柔比星诱导的心肌病大鼠的心脏保护作用是通过多基因多途径调节相关基因表达而实现的.

鹅观草属的地理分布

鹅观草属是禾本科小麦族中的最大的属，现知全世界有4组、20系、126种，分布于北半球的温带和寒带；中国有4组、18系、79种，主要分布于西北、西南、华北和东北，是鹅观草属植物种类最为集中的区域；尤其青藏高原东北部的唐古特地区双是我国鹅观草属分布相对密集之地，有3组、12系、30种，而且其间不同等组、不同演化水平的类群均有分布，该地可能就是该属的现代分布中心。同时，唐古特地区多汇聚有鹅观草属不同等级的原始类群和与原始类群很近缘的短柄草属植物，其中最原始的大柄鹅观草特产于该区，而该区缺乏的是高级的大颖组类群，故推测唐古特地区可能又是该属的起源地，起源时间大约在青藏高原明显增高、气候转凉的晚第三纪初的中新世。鹅观草属起源后，在中国境内地质活动比较剧烈的地区得到了进一步的发展和分化，但只有少数适应性较强的类群大概以3条路径扩展到国外，并向东到达北美的巴芬岛，向西延伸到大西洋滨岸，向北进入寒冻的北极地区。