Stability study of saturated red polymer light-emitting diodes

Saturated red polymer light-emitting diodes have been fabricated with a single emitting polymer blend layer of poly[2-(2-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene] (MEH-PPV) and poly[9,9-dioc- tylfluorene-co-4,7-di-2-thienyl-2,1,3-benzothiadiazole] (PFO-DBT15). Saturated red emission with the Commission Internationale de l’Eclairage (CIE) coordinates of (0.67, 0.33) was obtained. The device stability was investigated. The results showed that energy transfer occurred from MEH-PPV to PFO-DBT15, and MEH-PPV improved the hole injection and transportation.     

High-efficiency conjugated-polymer-hosted blue phosphorescent light-emitting diodes

Highly-efficient blue phosphorescent light-emitting diodes were fabricated based on a conjugated-polymer host by doping bis(2-(4,6-difluorophenyl)-pyridinato-N,C2’) picolinate(FIrpic) into poly(9,9-dioctylfluorene)(PFO).Previously,conjugated polymers were not considered as potential hosts for blue phosphorescent dyes because of their low-lying triplet energy levels.Energy back transfer would occur and lead to poor luminescent efficiency in both photoluminescence(PL) and electroluminescence(EL) processes.However,by inserting a hole-transporting layer of poly(N-vinylcarbazole)(PVK),the energy back transfer was suppressed.At low FIrpic-doping concentrations,PFO emissions were completely quenched;with 8 wt% FIrpic,a maximum luminous efficiency of 11.5 cd/A was achieved.     

Spectral variation of light-emitting diodes based on organic molecules doped polymer

Organic light-emitting diodes based on naphthylimine-gallium complexes doped into a PPV derivative have been fabricated by a spin coating method. Color variation from green to blue with increase of the applied voltage has been observed. And the electroluminescent intensity of the blend samples is much stronger than that of the samples containing the complexes only. The results have been attributed to the variation of the recombination zone and the charge transfer between the materials. The process of the charge transport has been analyzed in detail.     

Pure and stable white organic light-emitting device with an ultra-thin layer

Due to high brightness, low viewing angle, low driving voltage and short response time, organic light-emitting display is appraised as one of the most promising flat displays in the near future. Full-color technology is the bottle neck for industrializati…     

含有喹啉和香豆素的蓝色发光材料的合成及性能

合成了一种含有喹啉和香豆素基团且发射蓝光的发光材料(QCC),通过紫外-可见吸收光谱和荧光发射光谱对QCC的光物理性质进行了测试.结果 表明QCC的最大吸收峰为330 nm,且在360～540 nm内具有强的荧光发射带.随着溶剂极性的增加,QCC的荧光发射峰出现明显的红移.通过荧光猝灭技术分别观察了QCC与电子给体(D...     

Preparation, characterization and photodegradation of methylene blue based on TiO2 microparticles modified with thiophene substituents

The new microparticles,2-formylthiophene(FT)/TiO2 and(E)-1,2-bis(5-formyl-2-thienyl) ethylene(EBFTE)/TiO2 were synthesized with a silane coupling agent.The prepared TiO2 composites were characterized using Ultraviolet-Vis absorption(UV-Vis),X-ray diffraction(XRD),scanning electron microscope(SEM) and thermogravimetric analyzer(TGA).Methylene blue was used as a model material to examine the photocatalytic activities of the prepared catalysts under both Ultraviolet-Vis(UV) and visible(Vis) light.The enhanced photocatalytic activities were observed in the presence of(FT)/TiO2 and EBFTE/TiO2 under Vis light.It suggests that FT or EBFTE plays a block or active role in the photodegradation mechanisms under UV and Vis light irradiation,respectively.     

鱼群算法与神经网络结合的节能减排效果评价

从污染物减排率、单位工业增加值减排量、治理工业污染投资总额、GDP相关指标、能耗下降率5个方面建立节能减排效果评价指标体系,分析BP神经网络与鱼群算法结合的可行性,探讨鱼群算法优化神经网络的步骤。最后对7个地区2006~2009年节能减排效果评价指标,在专家打分测评的基础上,运用神经网络及鱼群算法优化神经网络方法进行节能减排效果评价。研究结果表明:在收敛过程中,运用神经网络所得实际输出值与专家评分的误差长时间停留在0.7左右,而运用鱼群算法优化神经网络方法能够以较大的斜率快速收敛到期望误差;在误差为0.001时,前者经过202次训练后能够达到目标,而后者只需要75次训练就能达到目标,这表明鱼群算法优化神经网络具有准确、快捷、简易等优点,此方法用于节能减排效果评价行之有效。     

基于能量法的C2连续过渡曲面的求解及应用

针对基于能量法的C^2连续过渡曲面优化模型进行处理,将其转化为线性约束二次数学规划问题,并采用拉格朗日乘子法进行求解,结合工程实际,给出了运用该方法构造的C^2连续过渡曲面实例．研究表明,能量曲面造型方法能较好地满足工程实际需要．     

Study on mimetic peroxidase and molecular recognition of phenols with inclusion complex of ironporphyrin immobilized by β-CD polymer

β-Cyclodextrin (β-CD) and its cross-linked polymer (β-CDP) were known as the mimetic models. Metalloporphyrin had been widely used in the enzymatic method of analysis and molecular recognition. In present work, it was investigation that supramolecular recognition for halogenated phenols, three crosols, three nitrophenols and three aminophenols, served respectively as the substrate of the mimetic receptor, iron-5, 10, 15, 20-tetrakis (sulforphenyl)-21H, 23H-porphine (FeTPPS) or FeTPPS-β-CDP. Supramolecular complex, FeTPPS-β-CDP with function of mult i-recognition and induced-fit, was a advanced kind of mimetic peroxidase; Methyl phenol or polyphenol was the substitute of chlorophenic acid, while aminophenols and other phenols were suggested not to be utilized to enzymatic assay of H₂O₂. Being a mimetic enzyme mimicking the space structure of overall proteinase, beaimed by immobilized mimetic enzyme with a large number of β-CD interior cavities, chlorophenol was identified optimal substrate in the system tested. Foundation item: Supported by the National Natural Science Foundation of China Biography: MAO Lu-yuan(1959-), male, Associate Professor, Postdoctor.