Multifunctional metallophosphors with anti-triplet–triplet annihilation properties for solution-processable electroluminescent devices

With the goal to provide organometallic triplet emitters with good hole-injection/hole-transporting properties, highly amorphous character for simple solution-processed organic light-emitting diodes, and negligible triplet-triplet (T-T) annihilation, a series of new phosphorescent cyclometalated Ir-III and Pt-II complexes with triphenylamine-anchored fluorenylpyridine dendritic ligands were synthesized and characterized. The photophysical, thermal, electrochemical and electroluminescent properties of these molecules are reported.

Polyimides derived from 3,3 '-bis(N-aminophthalimide)

A novel diamine, 3,3'-bis(N-aminophthalimide) (BAPI), was prepared from 3,3'-bis(N-phenylphthalimide). Its structure was determined via IR, H-1 NMR, N-15 NMR, elemental analysis, and single-crystal X-ray diffraction analysis. A series of homo- and copolyimides were synthesized by a conventional one-step method in p-chlorophenol. The characteristic IR absorption bands of hydrazine-based imide groups were near 1780, 1750, 1350, 1100, and 730 cm(-1). The polymers showed good solubility in polar aprotic solvents and phenols at room temperature. The temperatures of 5% weight loss (T-5%) of the polyimides ranged from 495 to 530 degrees C in air. DMTA analyses indicated that the glass-transition temperatures (Tgs) of the polyimides were in the range 371-432 degrees C. These polymers had cutoff wavelengths between 350 and 400 nm. The polyimide films of 6FDA/BAPI and 4,4'-HQPDA/BAPI were colorless; other films were pale yellow or yellow.

Chlorohydrin water swellable rubber compatibilized by an amphiphilic craft copolymer. I. Synthesis and characterization of compatibilizer PVA-g-PBA

The graft copolymerization of butyl acrylate onto poly(vinyl alcohol) with eerie ammonium nitrate as redox initiator in a aqueous medium has been investigated. The formation of graft copolymer was confirmed by means of IR, scanning electron microscopy (SEM), and wide-angle X-ray diffraction (WAXD). The percentage of mononer conversion and percentage of grafting varied with concentrations of initiator, nitric acid, monomer, macromolecular backbone (X-n = 1750, M = 80 000), reaction temperature and reaction time. Some inorganic salts and organic solvents have a great influence upon grafting. The reaction mechanism has been explored, and rate equations for the reaction are established. (C) 2000 John Wiley & Sons, Inc.

Cure processing modeling and cure cycle simulation of epoxy-terminated poly(phenylene ether ketone) .3. Determination of the time of pressure application

The curing temperature, pressure, and curing time have significant influence on finished thermosetting composite products. The time of pressure application is one of the most important processing parameters in the manufacture of a thermosetting composite. The determination of the time of pressure application relies on analysis of the viscosity variation of the polymer, associated with curing temperature and curing time. To determine it, the influence of the time of pressure application on the physical properties of epoxy-terminated poly(phenylene ether ketone) (E-PEK)-based continuous carbon fiber composite was studied. It was found that a stepwise temperature cure cycle is more suitable for manufacture of this composite. There are two viscosity valleys, in the case of the E-PEK system, associated with temperature during a stepwise cure cycle. The analysis on the effects of reinforcement fraction and defect content on the composite sheet quality indicates that the width-adjustable second viscosity valley provides a suitable pressing window. The viscosity, ranging from 400 to 1200 Pa . s at the second viscosity valley, is the optimal viscosity range for applying pressure to ensure appropriate resin flow during curing process, which enables one to get a finished composite with optimal fiber volume fraction and low void content. (C) 1997 John Wiley & Sons, Inc.

Crystalline behavior and critical crystalline sequence length of propylene/alpha-olefin copolymer

The melting points(T-m), crystalline temperature(T-c) and crystallinity(chi(c)) of propylene/alpha-olefin (pentene-l, octene-1 and decene-1) copolymers have been investigated, The results show that the T-m, T-c and chi(c) of the copolymers are lower than those of propylene homopolymer, indicating that lower alpha-olefin incorporation in copolymer has strongly hampered the crystallization of propylene, From critical crystalline sequence length of several propylene/alpha-olefin copolymers, it can be seen that a long chain alpha-olefin has much stronger effect on crystallization of PP than a short alpha-olefin does.

Study of ion solvation and ion association in polymer gel electrolyte with polyethylene oxide-co-polypropylene oxide as a plasticizer

Using a molal conductance method, ion solvation and ion association in polytriethylene glycol dimethacrylate (PTREGD)-LiClO4 gel electrolytes with amorphous ethylene oxide-co-propylene oxide (EO-co-PO, <(M)over bar (n)>, = 1750) as the plasticizer were investigated. It was found that the fraction of solute existing as single ions (alpha(i)) and ion pairs (alpha(p)) decreases, while that of triple ions (alpha(t)) increases linearly with increasing salt concentration. The dependence of these fractions on molecular weight of plasticizer was also examined. It was shown that alpha(i) and alpha(t) increase and alpha(p) decreases with increasing molecular weight. The result of temperature dependence of these fractions was very interesting: when the temperature is lower than 55 degrees C, alpha(i) increases while alpha(p) and alpha(t) decrease with increasing temperature; however, when the temperature is higher than 55 degrees C, the reverse is true.

丙烯／α－烯烃共聚物的结晶行为及临界结晶序列长度研究

丙烯／α－烯烃共聚物的结晶行为及临界结晶序列长度研究陈辉，王建国，张学全，庞德仁，黄葆同（中国科学院长春应用化学研究所，长春，１３００２２）关键词丙烯／α－烯烃共聚物，结晶行为，临界结晶序列长度聚丙烯（ＰＰ）是最重要的通用塑料之一，但其低温抗冲性能差...

Li_8SiN_4-Li_3N-BN体系中立方BN转化行为的研究

研究了高温高压下x·Li_8SiN_4-0.1(1-x)·Li_3N-0.9(1-x)·BN体系中立方氮化硼(cBN)的转化行为。Li_8SiN_4的存在可显著改善cBN晶体的发育,提高晶体质量。在4.2～5.5GPa,1340～1750℃范围内确定了x=4.8％时体系的cBN转化区,并对转化区内cBN转化率、平均生长速度、成核速度及破碎强度与转化温度和压力的关系进行了研究。

Crystallization of Clinopyroxene NaAlSi2O6 from Glass

Clinopyroxene NaAlSi2O6 was synthesized under varying pressures of 3.0-5.0GPa and at the temperature range of 1150.1750 degrees C, for periods of 1.480min. The glass material was completely transformed into homogeneous penetrating fibrous texture of clino

稀土（Nd，Pr）（Ⅲ）双酞菁衍生物的合成、表征和气敏特性

合成了八－４－（四氢糠氧基）酞菁钕（Ⅲ）（Ａ）、八－４－（β－萘氧基）酞菁钕（Ⅲ）（Ｂ）、八－４－（２，４－二叔戊基苯氧基）酞菁钕（Ⅲ）（Ｃ）和八－４－（２，４－二叔戊基苯氧基）酞菁镨（Ⅲ）（Ｄ）４种新的稀土（Ｎｄ、Ｐｒ）（Ⅲ）双酞菁衍生物，经元素分析、红外光谱、核磁共振谱表征．紫外可见光谱表明，它们在氯仿（１０￣（－６）ｍｏｌ／Ｌ）溶液中以单分子形式存在．热重分析证明配合物的热稳定性：Ｂ＞Ｃ～Ｄ＞Ａ．４种配合物成膜性好，Ｚ型沉积形成的单层ＬＢ膜材料对氨气有响应，特别是八－４－（四氢糠氧基）酞菁钕（Ⅲ）的膜材料对氨气很敏感，可与铜酞菁ＬＢ膜气敏性相比．

钠铝辉石由非晶态到晶态的转化研究

在3．0－5．0GPa，1150－1750℃，1－480min条件范围内，合成了钠铝辉石，通过XRD、SEM及IR分析对比研究了人工翡翠和天然翡翠的微观精细结构；通过DAT分析测定了人工翡翠与天然翡翠的熔点，淬火实验检验了人工翡翠的熔点，通过退火及老化实验研究了翡翠的热稳定性。同时还就人工翡翠和天然翡翠的硬度、密度及折射率等其它物化性质进行了比较研究。根据上述研究总结了合成优质钠铝辉石翡翠的最佳实验条件为压力＞4．0GPa，温度＞1450℃，晶化时间＞45min。

固熔体60%NaAlSi_2O_6-40%CaMgSi_2O_6在高温高压下的相图的研究

在1.0～5.0GPa、700～1750℃条件范围内,对固熔体0.6NaAlSi_2O_6-0.4CaMgSi_2O_6进行了研究,探讨了该固熔体在高温高压下的存在行为,研究了由非晶态玻璃向翡翠转化过程中γT作用的相图,得到的透辉石翡翠的晶胞参数为α=0.9439nm,b=0.8573nm,c=0.5233nm,β=107.28°和V=0.41702nm~3。本实验中合成的宝石级翡翠为色泽温润,具有玻璃光泽,半透明的极富观赏性的透辉石翡翠。

Genome-wide analysis of restriction-modification system in unicellular and filamentous cyanobacteria

Cyanobacteria are an ancient group of gram-negative bacteria with strong genome size variation ranging from 1.6 to 9.1 Mb. Here, we first retrieved all the putative restriction-modification (RM) genes in the draft genome of Spirulina and then performed a range of comparative and bioinformatic analyses on RM genes from unicellular and filamentous cyanobacterial genomes. We have identified 6 gene clusters containing putative Type I RMs and 11 putative Type II RMs or the solitary methyltransferases (MTases). RT-PCR analysis reveals that 6 of 18 MTases are not expressed in Spirulina, whereas one hsdM gene, with a mutated cognate hsdS, was detected to be expressed. Our results indicate that the number of RM genes in filamentous cyanobacteria is significantly higher than in unicellular species, and this expansion of RM systems in filamentous cyanobacteria may be related to their wide range of ecological tolerance. Furthermore, a coevolutionary pattern is found between hsdM and hsdR, with a large number of site pairs positively or negatively correlated, indicating the functional importance of these pairing interactions between their tertiary structures. No evidence for positive selection is found for the majority of RMs, e. g., hsdM, hsdS, hsdR, and Type II restriction endonuclease gene families, while a group of MTases exhibit a remarkable signature of adaptive evolution. Sites and genes identified here to have been under positive selection would provide targets for further research on their structural and functional evaluations.

胶州湾浮游动物的物种组成与优势种时空分布特征

浮游动物作为海洋食物链中承上启下的一环，其群落结构和动态变化直接影响着海洋生态系统能流、物流的方向和效率。胶州湾作为一个受自然环境和人类活动双重影响的海湾，是研究人为活动对自然生态系统影响的模式港湾。因此，深入研究胶州湾浮游动物的群落特征及时空分布特点对了解该海湾生态系统的现状与历史变化趋势以及生态系统对自然条件变化和人类干扰的响应具有重要意义，也可为其他海区的研究提供参考资料。 本文根据2004年1月－12月用浅水I型和浅水II型浮游生物网在胶州湾每月一次的垂直拖网采集的浮游动物样品，分析了胶州湾浮游动物的物种组成和优势种的时空分布特征。2004年胶州湾浮游动物共74个种，分属于暖温带近岸种和暖温带近海种。浮游动物丰度周年波动范围1006－15571 ind./m3，全年平均5187 ind./m3。在胶州湾体长<1mm的浮游动物丰度和生物量最大。浮游动物的丰度和物种多样性季节变化明显，春夏大（高），秋冬小（低）。多数月份浮游动物丰度在湾内大于湾外。物种多样性在湾北和湾南较低，在湾中心和湾外较高。 胶州湾浮游动物优势种为双刺纺锤水蚤、小拟哲水蚤、太平洋纺锤水蚤、中华哲水蚤、拟长腹剑水蚤、近缘大眼剑水蚤、长尾住囊虫、强壮箭虫、短角长腹剑水蚤、八斑芮氏水母和小介穗水母等。双刺纺锤水蚤全年都是优势种，小拟哲水蚤除了4月其余月份都是优势种。其他优势种季节更替明显，冬、春季（12月、1－5月）优势种为中华哲水蚤、拟长腹剑水蚤、近缘大眼剑水蚤、长尾住囊虫等；夏季（6－8月）太平洋纺锤水蚤代替中华哲水蚤、拟长腹剑水蚤成为优势种；秋季（9－11月）优势种更替频繁，9月为短角长腹剑水蚤和太平洋纺锤水蚤，10月为太平洋纺锤水蚤、拟长腹剑水蚤和长尾住囊虫，11月为拟长腹剑水蚤、长尾住囊虫、近缘大眼剑水蚤和强壮箭虫。 双刺纺锤水蚤与中华哲水蚤在4月达到数量高峰，丰度分别为5604ind./m3和493 ind./m3。长尾住囊虫6月丰度1809 ind./m3为全年最大。小拟哲水蚤、太平洋纺锤水蚤和近缘大眼剑水蚤在7月达到数量高峰，丰度分别为1667 ind./m3、4000 ind./m3、775 ind./m3。短角长腹剑水蚤和强壮箭虫在8月丰度最大，分别为389ind./m3和192 ind./m3。八斑芮氏水母和小介穗水母分别在3、8月大量出现，丰度分别为194 ind./m3、358 ind./m3。拟长腹剑水蚤全年有7、10月两个高峰。双刺纺锤水蚤、小拟哲水蚤、太平洋纺锤水蚤、短角长腹剑水蚤、八斑芮氏水母和小介穗水母主要在湾北密集；中华哲水蚤密集区趋向于湾中心和湾外；近缘大眼剑水蚤、拟长腹剑水蚤、异体住囊虫和强壮箭虫等分布广泛，不同月份密集区不同。 从目前我们所掌握的资料来看，近30年来，胶州湾浮游动物的种类组成和优势种群没有发生大的变化。与70年代相比，2004年的物种数基本不变，但物种组成稍有不同；优势种丰度大大降低。与90年代相比，2004年物种数有所增加，其中水母类增加了15种，八斑芮氏水母成为冬季优势种；浮游动物的丰度和优势种的水平分布格局基本不变。胶州湾浮游动物的生态类型与渤海相似，但与黄海有所差异；胶州湾优势种的丰度大于渤海，且高峰期比渤海提前一个月。