High-Performance Solution-Processed Nondoped Circularly Polarized OLEDs with Chiral Triptycene Scaffold-Based TADF Emitters Realizing Over 20% External Quantum Efficiency

Recently, circularly polarized organic light-emitting diodes (CP-OLEDs) fabricated with thermally activated delayed fluorescence (TADF) emitters are developed rapidly. However, most devices are fabricated by vacuum deposition technology, and developing efficient solution-processed CP-OLEDs, especially nondoped devices, is still a challenge. Herein, a pair of triptycene-based enantiomers, (S,S)-/(R,R)-TpAc-TRZ, are synthesized. The novel chiral triptycene scaffold of enantiomers avoids their intermolecular π–π stacking, which is conducive to their aggregation-induced emission characteristics and high photoluminescence quantum yield of 85% in the solid state. Moreover, the triptycene-based enantiomers exhibit efficient TADF activities with a small singlet-triplet energy gap (ΔE_ST) of 0.03 eV and delayed fluorescence lifetime of 1.1 µs, as well as intense circularly polarized luminescence with dissymmetry factors (|g_PL|) of about 1.9 × 10⁻³. The solution-processed nondoped CP-OLEDs based on (S,S)-/(R,R)-TpAc-TRZ not only display obvious circularly polarized electroluminescence signals with g_EL values of +1.5 × 10⁻³ and −2.0 × 10⁻³, respectively, but also achieve high efficiencies with external quantum, current, and power efficiency up to 25.5%, 88.6 cd A⁻¹, and 95.9 lm W⁻¹, respectively.     

Maskless Preparation of Spatially-Resolved Plasmonic Nanoparticles on Polydimethylsiloxane via In Situ Fluoride-Assisted Synthesis

Here, a fluoride-assisted route for the controlled in-situ synthesis of metal nanoparticles (NPs) (i.e., AgNPs, AuNPs) on polydimethylsiloxane (PDMS) is reported. The size and coverage of the NPs on the PDMS surface are modulated with time and over space during the synthetic process, leveraging the improved yield (10×) and faster kinetics (100×) of NP formation in the presence of F⁻ ions, compared to fluoride-free approaches. This enables the maskless preparation of both linear and step gradients and patterns of NPs in 1D and 2D on the PDMS surface. As an application in flexible plasmonics/photonics, continuous and step-wise spatial modulations of the plasmonic features of PDMS slabs with 1D and 2D AgNP gradients on the surface are demonstrated. An excellent spatially resolved tuning of key optical parameters, namely, optical density from zero to 5 and extinction ratio up to 100 dB, is achieved with AgNP gradients prepared in AgF solution for 12 minutes; the performance are comparable to those of commercial dielectric/interference filters. When used as a rejection filter in optical fluorescence microscopy, the AgNP-PDMS slabs are able to reject the excitation laser at 405 nm and retain the green fluorescence of microbeads (100 µm) used as test cases.     

Hierarchical Ni-BDC coated FeOOH nanosheets: A coordination tuning synergistic electrocatalyst with enhanced activity for water oxidation

Hierarchical composites represent a class of efficient electrocatalysts for renewable energy storage and conversion technologies owing to the porous structure and additional exposure of metal sites. Herein, a Ni-based metal organic frameworks (MOFs) (marked as Ni-BDC, BDC stands for 1,4-benzenedicarboxylic acid) nanosheet is successfully fabricated on hydroxyl iron oxide (FeOOH) array with carbon fiber cloth (CFC) as substrate. Benefit from the coordination tuning synergistic effect of the distinct chemical composition and the hierarchical structure for fast mass transportation, the as-obtained FeOOH@Ni-BDC illustrates excellent catalytic ability for electrochemical water oxidation with low overpotential of 270 mV to reach 10 mA/cm² current and good durability in alkaline electrolyte. The novelty of this work lies in the modulation of electronic structure of the FeOOH with Ni-BDC through coordination effect to enhance the activity of the hierarchical composite electrocatalyst. This work is expected to guide the preparation of efficient electrocatalyst for new type alternative energy sources exploitation in near future.     

Preparation of molecularly imprinted fluorescence sensor based on carbon quantum dots via precipitation polymerization for fluorescence detection of tetracycline

A facile and effective method was proposed to prepare the molecularly imprinted fluorescence sensor with carbon quantum dots, which were modified vinyl groups by acrylic acid on the surface. The obtained fluorescence composite material was investigated by transmission electron microscope and Fourier transform infrared spectra. After the experimental conditions were optimized, a linear range of 1.0–60 μmol L⁻¹ was obtained and the detection limit was 0.17 μmol L⁻¹. The novel fluorescence sensor can be successfully used to detect tetracycline in real samples. This study provides a convenient strategy for selective recognition and rapid detection of tetracycline in the complex environment.     

氢化物原子荧光光谱法测定酱油中微量铅的方法研究

建立了一种快速、高效的QuEChERS-高效液相色谱-质谱联用法（QuEChERS-HPLC-MS/MS）测定谷类杂粮制品中脱氧雪腐镰刀菌烯醇（DON）、3-乙酰脱氧雪腐镰刀菌烯醇（3-ADON）、15-乙酰脱氧雪腐镰刀菌烯醇（15-ADON）和玉米赤霉烯酮（ZON）共4种真菌毒素。样品前处理采用乙腈-水溶剂提取，经Florisil+C18+无水硫酸镁净化后检测。以0.10%甲酸-乙腈作为流动相，在质谱检测器的多反应监测模式下进行分析。结果表明，4种真菌毒素在各自的线性范围内线性关系良好，相关系数R2均大于0.999，回收率在85.1%～102.0%，相对标准偏差（RSD）为2.11%～6.22%。该方法具有前处理简单、净化效果好、灵敏度高和检测速度快的优点，适用于谷类杂粮制品中DON、3-ADON、15-ADON 和ZON的分析和定量检测。     

汽油烃类族组成测试方法对比

介绍了使用荧光指示剂吸附色谱法、多维气相色谱法的测定影响因素和近红外光谱快速法的分析特点以及三种方法在汽油族组成测定中的应用，并就三种方法对同一试样的测定结果进行了对比，找出各种测定方法容易产生误差的原因及分析对策。     

基于调谐频率与分频处理的高分辨率反演技术

讨论了基于调谐频率与分频处理的高分辨率反演技术，给出了方法的基本原理，即利用地震数据的调谐频率和分频处理分析，半定量地确定储层厚度，并将其作为地震反演的约束条件。方法的实现过程是：通过层状地质模型的地震正演模拟，建立不同主频子波时地层厚度与调谐频率的关系；利用地震资料时-频分析技术，实现地震资料分频处理；利用合成地震记录标定地震子波主频；利用分频处理结果，借助于调谐频率分析与调谐振幅分析，给出地震反演约束条件；利用反演算法消除地震子波影响，提高和拓展地震资料的频带范围，实现储层的高分辨率成像。普光地区的应用实例表明，调谐频率与分频处理的高分辨率反演方法无需对储层空间变化规律进行假设，适用于强非均质碳酸盐岩储层的高分辨率成像。