Design and synthesis of pyromellitic diimide‐based donor–acceptor conjugated polymers for photovoltaic application

Three of conjugated polymers based on pyromellitic diimide (PMDI) as the acceptor unit and thienothiophene (TT) as the donor unit were successfully synthesized by Stille coupling. The effect of the side chain length and thiophene π‐bridge on the polymers' optical and electrochemical properties was investigated. Electrochemical characterization indicated that these polymers have deep highest occupied molecular orbital energy levels between ?5.7 and ?5.8 eV. Polymer solar cells were fabricated by using these PMDI‐based polymers as the donor and [6,6]‐phenyl‐C61‐butyric acid methyl ester as the acceptor. The polymer P1 whose PMDI unit was functionalized with 2‐ethylhexyl side chain shows the higher short‐circuit current (J_sc) and fill factor (FF) compared with that of P2 with a 2‐octyldodecyl side chain on the PMDI unit. The results also illustrate that the insertion of a thiophene π‐bridge between PMDI and TT (the polymer P3) leads to the broader absorption and better photovoltaic performance. The best performance was obtained from the cell based on the polymer P3 with a power conversion efficiency of 0.43% under the illumination of AM 1.5 G, 100 mW/cm². Copyright © 2014 John Wiley & Sons, Ltd.     

Dendronized Polymers with High FTC-chromophore Loading Density:Large Second-order Nonlinear Optical Effects,Good Temporal and Thermal Stability

In this study,two new dendronized nonlinear optical(NLO)polymers were synthesized with high FTC chromophore loading density by introduction of high generation chromophore dendrons on the side chains.Due to their suitable molecular weights,both of them possessed good solubility in common solvents.They also inherited the advantages of dendrimers(large NLO coefficient),especially for PG2 whose NLO coefficient d33 value was as high as 282 pm·V^–1.Also,PG2 had a good temporal stability with 80%of its maximum value being retained at the temperature as high as 129℃.     

校准蒸发光散射检测器选用标准物质的比较与分析

通过对葡萄糖和三氯蔗糖的物理、化学性质的比较,采用高效液相色谱仪和蒸发光散射检测器进行标准溶液色谱峰面积的检测,并用G rubbs检验法对其数据进行异常值检验。结果表明,三氯蔗糖相对于葡萄糖较为稳定,选用三氯蔗糖作为蒸发光检测器校准用标准物质比较合适。     

Fe掺杂ZnO空心微球的制备与光催化性能

ZnO是一种重要的Ⅱ-Ⅵ族半导体材料,其能带宽度约为3.37eV,在光电子学、传感、光催化、发电等诸多领域都具有巨大的应用潜力。本文采用简单的离子交换和热蒸发法成功制备了Fe掺杂ZnO空心微球,并利用扫描电镜、透射电镜、X射线粉末衍射仪对其形貌、结构以及成分等进行了详细的表征。光吸收测试证明Fe元素掺杂能够扩展ZnO的光吸收波段,实现波长375~600nm的光波吸收。另外,光催化实验证明Fe掺杂ZnO空心微球能够有效地促进罗丹明B的降解,表明合成的Fe掺杂ZnO空心微球是一种优异的光催化剂。     

水力机械内鲤鱼草鱼的压力损伤模拟试验

通过试验人工模拟水力机械内压力变化过程,测量压力时间变化,观察并解剖分析不同压力变化过程对鲤鱼和草鱼造成损伤的情况。试验发现,负压状态下的压力变化过程会对鱼的生存构成直接威胁,并得到了新型环保水力机械设计中应采用的压力时变导数极限值。     

Effect of the thickness of InGaN interlayer on a-plane GaN epilayer

In this paper,we use the a-plane InGaN interlayer to improve the property of a-plane GaN.Based on the a-InGaN interlayer,a template exhibits that a regular,porous structure,which acts as a compliant effect,can be obtained to release the strain caused by the lattice and thermal mismatch between a-GaN and r-sapphire.We find that the thickness of InGaN has a great influence on the growth of a-GaN.The surface morphology and crystalline quality both are first improved and then deteriorated with increasing the thickness of the InGaN interlayer.When the InGaN thickness exceeds a critical point,the a-GaN epilayer peels off in the process of cooling down to room temperature.This is an attractive way of lifting off a-GaN films from the sapphire substrate.     

纳米SiO_2及其改性物的透射和漫反射傅里叶变换红外光谱研究

对两种纳米SiO2材料及两种SiO2改性物的透射及漫反射红外光谱进行了研究。漫反射红外光谱法更能表征出纳米SiO2材料及其改性物结构的表面状态特征,当样品取样量受限的条件下,表征结果更优于透射法。     

Determination and quantification of active phenolic compounds in pigeon pea leaves and its medicinal product using liquid chromatography–tandem mass spectrometry

A novel method using liquid chromatography coupled to electrospray ionization mass spectrometry (LC-ESI-MS) has been optimized and established for the qualitative and quantitative analysis of ten active phenolic compounds originating from the pigeon pea leaves and a medicinal product thereof (Tongluo Shenggu capsules). In the present study, the chromatographic separation was achieved by means of a HiQ Sil C18V reversed-phase column with a mobile phase consisting of methanol and 0.1% formic acid aqueous solution. Low-energy collision-induced dissociation tandem mass spectrometry (CID-MS/MS) using the selected reaction monitoring (SRM) analysis was employed for the detection of ten analytes which included six flavonoids, two isoflavonoids and two stilbenes. All calibration curves showed excellent coefficients of determination (r(2) ≥ 0.9937) within the range of tested concentrations. The intra- and inter-day variations were below 5.36% in terms of relative standard deviation (RSD). The recoveries were 95.08-104.98% with RSDs of 2.06-4.26% for spiked samples of pigeon pea leaves. The method developed was a rapid, efficient and accurate LC-MS/MS method for the detection of phenolic compounds, which can be applied for quality control of pigeon pea leaves and related medicinal products.     

Two-dimensional porphyrin- and phthalocyanine-based covalent organic frameworks

Covalent organic frameworks (COFs) represent an emerging class of porous crystalline materials and have recently shown interesting applications from catalysis to optoelectronic devices. In this review, by covering most of the reported work, we summarized the research progress of two-dimensional (2D) porphyrin- and phthalocyanine-based COFs, with highlighting the synthesis of these 2D COFs via various dynamic covalent reactions and emphasizing their potential applications in different areas.