A Porous Tricyclooxacalixarene Cage Based on Tetraphenylethylene

A quadrangular prismatic tricyclooxacalixarene cage 1 based on tetraphenylethylene (TPE) was efficiently synthesized by a one‐pot S_NAr condensation reaction. As a result of the porous internal structure in the solid state, cage 1 exhibited a good CO₂ uptake capacity of 12.5 wt % and a high selectivity for CO₂ over N₂ adsorption of 80 (273 K, 1 bar) with a BET surface area of 432 m² g^?1. Formation of cage 1 led to the fluorescence of TPE being switched on in solution. The system was employed as a single‐molecule platform to study the mechanism of aggregation‐induced emission (AIE) by examining the restriction of intramolecular rotation (RIR).     

Application of magnetic graphitic carbon nitride nanocomposites for the solid‐phase extraction of phthalate esters in water samples

Magnetic graphitic carbon nitride nanocomposites were successfully prepared in situ and used to develop a highly sensitive magnetic solid‐phase extraction method for the preconcentration of phthalate esters such as di‐n‐butyl phthalate, butyl phthalate, dihexyl phthalate, and di‐(2‐ethyl hexyl) phthalate from water. The adsorption and desorption of the phthalate esters on magnetic graphitic carbon nitride nanocomposites were investigated and the parameters affecting the partition of the phthalate esters, such as adsorption, desorption, recovery, were assessed. Under the optimized conditions, the proposed method showed excellent sensitivity with limits of detection (S/N = 3) in the range of 0.05–0.1 μg/L and precision in the range of 1.1–2.6% (n = 5). This method was successfully applied to the analysis of real water samples, and good spiked recoveries over the range of 79.4–99.4% were obtained. This research provides a possibility to apply this nanocomposite for adsorption, preconcentration, or even removal of various carbon‐based ring or hydrophobic pollutants.     

质子交换膜燃料电池铂基催化剂研究进展北大核心CSCD

燃料电池是一种将化学能直接转化为电能的能量转换装置,具有能量密度高、利用率高、清洁安静等优点。在不同类型的燃料电池中,质子交换膜燃料电池(PEMFC)不仅能量密度高,而且具有在近常温条件下工作的特点,因此受到广泛关注。目前,商业化PEMFC仍采用铂基纳米材料作为催化剂,其中缺乏低成本、高效的阴极催化剂是限制PEMFC性能提升和成本降低的关键因素之一。本文综述PEMFC催化剂的结构可控制备及其对阴极氧还原反应和膜电极性能的影响,阐述调控催化剂结构提高PEMFC性能的方法,特别是提高贵金属催化剂的利用率,降低膜电极中贵金属用量的研究进展。     

SCN掺杂提高CsPbI3胶体量子点的稳定性和光探测性能

无机卤化物钙钛矿CsPbI₃胶体量子点因其优越的光电性能在光伏和发光器件领域中表现出极大的发展前景。然而,CsPbI₃较差的稳定性阻碍了实际应用。为此,我们采用SCN?离子掺杂CsPbI₃(SCN-CsPbI₃)量子点用于提高量子点的光学性能和稳定性。研究表明,SCN?离子掺杂不仅减少了量子点缺陷、改善了光学性能,还提高了Pb-X键能、量子点结晶质量以及钙钛矿结构稳定性。结果表明,SCN-CsPbI₃量子点的荧光量子产率(PLQY)超过90%,远高于未掺杂原始样品(PLQY为68%)。高的荧光量子产率表明量子点具有较低的缺陷态密度,这归咎于缺陷的减少。空间限制电荷和时间分辨荧光光谱等研究也证实SCN?离子掺杂减少了量子点的缺陷。此外,SCN-CsPbI₃量子点展现出很好的抗水性能,其荧光强度在水中浸泡4 h后依然保持85%的初始值。而未掺杂原始样品的荧光性能很快消失,这是因为水诱导其相变。基于SCN-CsPbI₃量子点的光电探测器表现出宽波域响应(400–700 nm),高的响应率(90 mA·W^?1)和超过1011 Jones的探测度,远高于未掺杂原始量子点探测器的性能(响应率为60 mA·W^?1和探测度为1010 Jones)。     

One-pot synthesis of CoO–ZnO/rGO supported on Ni foam for high-performance hybrid supercapacitor with greatly enhanced cycling stability

The high specific capacitance along with good cycling stability are crucial for practical applications of supercapacitors,which always demands high-performance and stable electrode materials.In this work,we report a series of ternary composites of CoO-ZnO with different fractions of reduced graphene oxide(rGO) synthesized by in-situ growth on nickel foam,named as CZG-1,2 and 3,respectively.This sort of binder-free electrodes presents excellent electrochemical properties as well as large capacitance due to their low electrical resistance and high oxygen vacancies.Particularly,the sample of CZG-2(CoO-ZnO/rGO 20 mg) in a nanoreticular structure shows the best electrochemical performance with a maximum specific capacitance of 1951.8 F/g(216.9 mAh/g) at a current intensity of 1 A/g.The CZG-2-based hybrid supercapacitor delivers a high energy density up to 45.9 Wh/kg at a high power density of 800 W/kg,and kept the capacitance retention of 90.1% over 5000 charge-discharge cycles.     

基于蛋白模板金纳米簇及羟基氧化钴纳米片的激活型荧光纳米探针用于免标记和灵敏检测生物硫醇

该文基于牛血清白蛋白模板金纳米簇（BSA@AuNCs）与羟基氧化钴（CoOOH）纳米片构建了一种激活型荧光纳米探针用于生物硫醇的检测。带负电的BSA@AuNCs能通过静电吸附作用组装到带正电的CoOOH纳米片表面,与此同时,BSA@AuNCs的荧光由于内滤效应（IFE）有效地被CoOOH纳米片猝灭,形成BSA@AuNCs－CoOOH纳米探针。当向纳米探针溶液加入生物硫醇（0.05～150 μmol/L）时,生物硫醇与纳米探针中的CoOOH纳米片发生氧化还原反应,CoOOH纳米片被降解生成Co2+,同时释放出BSA@AuNCs,BSA@AuNCs荧光信号恢复。结果表明,该纳米探针可以检测低浓度的生物硫醇,对生物硫醇（半胱氨酸、谷胱甘肽和高半胱氨酸）的检出限为30 nmol/L。相对于其他的氨基酸、金属离子及糖类化合物,该纳米探针对生物硫醇具有较高的选择性并成功应用于人血清样品中生物硫醇的检测。     

临床免疫检验分析前的质量控制及对策分析

目的评价临床免疫检验分析前进行质量控制的效果,分析临床影响免疫检验分析结果的相关因素,并探讨解决对策。方法选取深圳市盐田区妇幼保健院2016年2月至9月期间收治的116例患者作为研究对象,并将116例患者随机分为试验组和对照组,对试验组患者实施临床免疫检验分析前进行质量控制,对照组进行常规临床免疫检验分析,对比两组患者临床免疫检验分析结果与病理结果的符合率,分析影响临床免疫检验分析结果的相关因素。结果试验组患者各项免疫指标检验分析结果与病理结果的符合率均较对照组患者高,两组比较存在的差异具有统计学意义(P0.05);经分析发现清洗液更换、检验环境、检验人员的专业技能等因素均会对临床免疫检验结果产生影响,医院检验科应加强临床免疫检验前的分析、准备工作以及各个检验环节的质量控制和工作人员的专业技能培训。结论多种因素会对临床免疫检验结果产生影响,检验分析前的质量控制能够提高临床免疫检验结果的准确性。     

Development of Microtiter Plate Culture Method for Rapid Screening of ε-Poly-L-Lysine-Producing Strains

ε-Poly-l-lysine (ε-PL) produced by Streptomyces albulus possesses a broad spectrum of antimicrobial activity and is widely used as a food preservative. To extensively screen ε-PL-overproducing strain, we developed an integrated high-throughput screening assay using ribosome engineering technology. The production protocol was scaled down to 24- and 48-deep-well microtiter plates (MTPs). The microplate reader assay was used to monitor ε-PL production. A good correlation was observed between the fermentation results obtained in both 24-(48)-deep-well MTPs and conventional Erlenmeyer flasks. Using this protocol, the production of ε-PL in an entire MTP was determined in <5 min without compromising on accuracy. The high-yielding strain selected through this protocol was also tested in Erlenmeyer flasks. The result showed that the ε-PL production of the high-yielding mutants was nearly 45% higher than that of the parent stain. Thus, development of this protocol is expected to accelerate the selection of ε-PL-overproducing strains.     

Enzymatic epoxidation of soybean oil in the presence of perbutyric acid

Enzymatic epoxidation of vegetable oils using a long chain fatty acid as an active oxygen carrier could produce a desirable epoxy oxygen group content (EOC); however, the acid value (AV) of final epoxidized oil is too high. The present study was to investigate the effect of different fatty acids with varying length of carbon chain on EOC and AV of the final epoxidized soybean oil (ESO); finding butyric acid was the choice of active oxygen carrier when hydrogen peroxide was used as an oxygen donor in the presence of lipase Novozyme 435. And in situ IR was used to monitor the epoxidation process, which revealed that the formation of perbutyric acid was the key step in the whole reaction. The epoxidation process was optimized as follows: molar ratio of butyric acid/C=C bonds of 0.19:1, 8% of immobilized lipase Novozyme 435 load (relative to the weight of soybean oil) and molar ratio of H₂O₂/C=C bonds of 3.5:1, reaction time of 4 h and reaction temperature of 45 °C. Under these conditions, ESO with a high EOC (7.62 ± 0.20%) and a lower AV value (8.53 ± 0.18 mgKOH/g) was obtained. The oxriane conversion degree was up to 97.94%.