Aggregation-induced Emission Materials for High-efficiency Perovskite Solar Cells

The perovskite solar cells (PSCs) with high efficiency and stability are in great demand for commercial applications. Although the remarkable photovoltaic feature of perovskite layer plays a great role in improving the PCE of PSCs, the inevitable defects and poor stability of perovskite, etc. are the bottleneck and restrict the commercialization of PSCs. Herein, a review provides a strategy of applying aggregation-induced emission (AIE) molecules, containing passivation functional groups and distinct AIE character, which serves as the alternative materials for fabricating high-efficiency and high-stability PSCs. The methods of introducing AIE molecules to PSCs are also summarized, including additive engineering, interfacial engineering, hole transport materials and so on. In addition, the functions of AIE molecule are discussed, such as defects passivation, morphology modulation, well-matched energy level, enhanced stability, hole transport ability, carrier recombination suppression. Finally, the detailed functions of AIE molecules are offered and further research trend for high performance PSCs based on AIE materials is proposed.     

Elution–extrusion counter-current chromatographic separation and theoretical mechanism of antioxidant from Robinia pseudoacacia flower

Robinia pseudoacacia flowers have attracted much attention because of numerous bioactivities. In this study, its extract showed the potential scavenging ability for 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) and 1,1-diphenyl-2-picrylhydrazyl free radicals. Under the guidance of antioxidant activity, the antioxidant extract was enriched by liquid-liquid extraction. The partition coefficients of the two main components in antioxidant extracts differed greatly, so in this study, elution-extrusion counter-current chromatography with the solvent system of n-hexane-ethyl acetate-methanol-water (2.5:5:2.5:5, v/v) was used to enhance the separation efficiency, and the two main components were successfully obtained. Among them, kaempferol showed strong antioxidant activity, which can be responsible for the activity of the extract. In order to deeply understand the antioxidant mechanism of kaempferol, the thermodynamics, frontier molecular orbital, and kinetics of scavenging free radicals were investigated by density functional theory. The results showed that 4′-OH in kaempferol was the most active group, which can scavenge free radicals by hydrogen atom transfer in non-polar solvents and activate 3-OH to generate double hydrogen atom transfer in the gas phase. But in polar solvents, it was more inclined to clear radicals through single electron transfer and proton transfer. The kinetic result showed that kaempferol needed 9.17 kcal/mol of activation energy to scavenge free radicals.     

基于比率的三种群混合扩散模型的动力学行为

讨论了一类基于比率的非自治三种群混合扩散模型,三种群间既有捕食关系又有竞争关系.我们研究了该模型的动力学行为:包括一致持久性,全局渐近稳定性,周期解,概周期解的存在唯一性.表明即使食饵种群在某些孤立的斑块中可能绝灭,也可以通过适当选取扩散率来保证系统持续生存.     

液相色谱串联质谱法测定水果中复硝酚钠残留量

以甲醇提取样品,采用超高效液相色谱串联质谱法(UPLC–MS/MS)测定水果中复硝酚钠的残留量。以甲醇–10 mmol/L乙酸铵水溶液(体积比为60∶40)为流动相,质谱采用电喷雾负离子MRM检测模式。对硝基苯酚钠和5-硝基愈创木酚钠的线性范围为0.05~2.00 mg/L,检出限为0.01 mg/kg,邻硝基苯酚钠的线性范围为2.5~100.0 mg/L,检出限为0.5 mg/kg,线性相关系数均大于0.995。实际样品中对硝基苯酚钠、邻硝基苯酚钠和5-硝基愈创木酚钠的加标回收率分别为83.0%~93.4%,81.0%~87.4%,83.0%~91.8%,测定结果的相对标准偏差小于7%(n=6)。该法操作简单、快捷,精密度、准确度高,适用于水果中复硝酚钠的残留分析。     

自然光照下PEG/PAA凝胶在Fe~(3+)/CA溶液中的凝胶-溶胶转化行为

将PEG/PAA凝胶浸入铁/柠檬酸(Fe3+/CA)溶液中,自然光照一定时间可实现凝胶-溶胶的相互转化,而且转化行为受溶液的组成及其p H影响。只有当溶液中[Fe3+]0∶[CA]0≤1∶2,且溶液的p H在1~6之间,该转化才会发生,通过改变溶液中[Fe3+]0∶[CA]0的值或溶液的p H可以有效地控制其转化速率。此外,结果还表明,当凝胶转化为溶胶后,向其中加入高价金属阳离子,例如Fe3+、Al3+、Ce4+、Cu2+等,溶胶又会再次转化为凝胶。由于这种新颖的特性,该凝胶有望应用于药物释放、细胞培养等领域。     

Nickel N‐Heterocyclic Carbene Catalyzed CC Bond Formation: A New Route to Aryl Ketones

A novel nickel N‐heterocyclic carbene catalyzed cross‐coupling reaction of aryl aldehydes with boronic esters for the synthesis of aryl ketones was developed. This reaction provides a mild, practical method toward aryl ketones, which are versatile intermediates and building blocks in organic synthesis.     

Cobalt‐Catalyzed Cross‐Coupling of 3‐ and 4‐Iodopiperidines with Grignard Reagents

A cobalt‐catalyzed cross‐coupling between 3‐ and 4‐iodopiperidines and Grignard reagents is disclosed. The reaction is an efficient, cheap, chemoselective, and flexible way to functionalize piperidines. This coupling was used as the key step to realize a short synthesis of (±)‐preclamol. Some mechanistic investigations were conducted that highlight the formation of radical intermediates.     

Remote Construction of Chiral Vicinal Tertiary and Quaternary Centers by Catalytic Asymmetric 1,6‐Conjugate Addition of Prochiral Carbon Nucleophiles to Cyclic Dienones

An unprecedented remote construction of chiral vicinal tertiary and quaternary centers by a catalytic asymmetric 1,6‐conjugate addition of prochiral carbon nucleophiles to cyclic dienones has been developed. Both 5H‐oxazol‐4‐ones and 2‐oxindoles were found to be very efficient carbon nucleophiles in this reaction at a remote position, giving products with excellent enantio‐ and diastereoselectivities (up to 99 % ee and >19:1 d.r. for 5H‐oxazol‐4‐ones and up to 97 % ee and >19:1 d.r. for 2‐oxindoles).     

Simultaneous determination of naphazoline and pyridoxine in eye drops using excitation–emission matrix fluorescence coupled with second-order calibration method based on alternating trilinear decomposition algorithm

A novel method is developed for the direct determination of naphazoline hydrochloride(NAP) and pyridoxine hydrochloride(VB6) in commercial eye drops. By using excitation–emission matrix(EEM)fluorescence coupled with second-order calibration method based on the alternating trilinear decomposition(ATLD) algorithm, the proposed approach can achieve quantitative analysis successfully even in the presence of unknown and uncalibrated interferences. The method shows good linearity for NAP and VB6 with correlation coefficients greater than 0.99. The results were in good agreement with the labeled contents. To further confirm the feasibility and reliability of the proposed method, the same batch samples were analyzed by multiple reaction monitoring(MRM) based on LC–MS/MS method.T-test demonstrated that there are no significant differences between the prediction results of the two methods. The satisfactory results obtained in this work indicate that the use of the second-order calibration method coupled with the EEM is a promising tool for industrial quality control and pharmaceutical analysis due to its advantages of high sensitivity, low-cost and simple implementation.     

触控屏制程防护材料技术进展

结合手机触控屏结构概述了触控屏盖板玻璃的加工工艺,说明触控屏盖板玻璃防护材料需要防护性和可剥落的特点,介绍了聚对苯二甲酸乙二酯(PET)薄膜、可剥胶和UV保护油墨三种防护材料的优点和需要克服的缺陷。说明触控屏玻璃防护材料的发展及应用状况,对其今后的发展做出了展望,指出了水退型UV保护油墨是将来的发展方向。