将星际化学知识引入大学基础化学教学的意义与模式

20世纪中期兴起的星际化学推进了人类对宇宙产生与演化、生命起源和地球环境的认识。天文学与天体物理学、光谱学、基础化学等多学科的互相结合,为星际化学尤其是对星际空间中新型化合物和化学反应的认知突破起到了重要作用。创造性地提出将星际化学的探索和发现引入大学基础化学教学的方案。在分析星际化学所涉及的典型化学知识和应用实例的基础上,初步探讨了本方案的可行性。将化学与星际化学知识相结合的教学方式在拓宽学生的眼界的同时,可以有效增加课堂的趣味性。     

Reductive Amination of Carbonyl Compounds with Ammonia and Hydrogenation of Nitriles to Primary Amines with Heterogeneous Cobalt Catalysts

Reductive amination of aldehydes/ketones with aqueous NH3 and hydrogenation of nitriles to primary amines with Co catalysts were reported. Co@NC-700 exhibited remarkable activity and high selectivity for the reductive amination of aldehydes/ketones with aqueous NH3 and the hydrogenation of nitriles to primary amines. Several primary amines can be obtained with good to excellent yields via the reductive amination of aldehydes/ketones and the hydrogenation of nitriles. The nitrogen-doped carbon(C)-supported Co@NC-700 metal catalyst was prepared via the pyrolysis of bioMOF Co/adenine in activated C. Co@NC-700 can be reused five times without evident loss of activity.     

New red Y0.85Bi0.1Eu0.05V1−yMyO4 (M=Nb, P) phosphors for light-emitting diodes

The Y_0.85Bi_0.1Eu_0.05V_1−yM_yO₄ (M=Nb, P) as new near-ultraviolet excited phosphors were synthesized and their luminescence properties under 365 nm excitation were investigated in detail. It indicated that by doping small amount of P⁵⁺ into V⁵⁺ sites, the excitation intensity of charge transfer (CT) band of Bi–O (330–400 nm) was greatly improved. By substituting Nb⁵⁺ for V⁵⁺, both the CT bands of Bi–O and Eu–O (240–320 nm) were significantly enhanced. As a result, the emission intensity of Y_0.85Bi_0.1Eu_0.05V_1−yM_yO₄ (M=Nb, P) could be improved about 90% by doping 5 mol% P⁵⁺ and 110% by doping 5 mol% Nb⁵⁺. Comparing with the commercial Y₂O₂S:Eu³⁺ phosphors, the Y_0.85Bi_0.1Eu_0.05V_0.95M_0.05O₄ (M=Nb, P) phosphors exhibited excellent color purity and much higher brightness. The results showed that these Y_0.85Bi_0.1Eu_0.05V_1−yM_yO₄ (M=Nb, P) phosphors could be considered as promising red phosphors for application in LED.     

磁约束等离子体推进器磁体系统的电磁力和机械应力分析

根据磁约束等离子体推进器磁体系统的设计参数,通过ANSYS有限元分析软件在电磁-结构耦合场方面的计算,得到磁体系统的轴向电磁力和机械应力的分布。计算超导磁体在通电情况下,磁体中平面上所有节点所受的轴向电磁压缩力以及磁体间的相互作用力;计算出磁体外层用不锈钢钢丝加固前后机械应力分布情况的变化。     

基于高分辨质谱技术的婴幼儿食品中过敏原蛋白质的高灵敏检测

基于高效液相色谱-串联质谱(LC-MS/MS)技术,选择稳定性好、灵敏度高的特征肽段,利用平行反应监测(PRM)技术,实现了多类过敏原蛋白质的高灵敏度同时检测,并成功应用于婴幼儿食品中过敏原成分的分析。对于婴幼儿食品中蛋白质的提取,与传统的丙酮沉淀法比,采用膜上原位样品预处理方法(i-FASP)可实现更高的蛋白质提取效率和抗干扰能力。所检测的过敏原蛋白质的定量限(LOQ)最小可达到0.028 mg/L,其线性范围最宽可跨越4个数量级,且线性关系良好(相关系数R~2≥0.99)。该方法为食品中过敏原蛋白质组学快速分析提供了一种可靠的分析方法。     

Suppressing Strong Exciton–Phonon Coupling in Blue Perovskite Nanoplatelet Solids by Binary Systems

Quasi-two-dimensional (2D) perovskites are promising candidates for light generation owing to their high radiative rates. However, strong exciton–phonon interactions caused by mechanical softening of the surface act as a bottleneck in improving their suitability for a wide range of lighting and display applications. Moreover, it is not easily available to tune the phonon interactions in bulk films. Here, we adopt bottom-up fabricated blue emissive perovskite nanoplatelets (NPLs) as model systems to elucidate and as well as tune the phonon interactions via engineering of binary NPL solids. By optimizing component domains, the phonon coupling strength can be reduced by a factor of 2 driven by the delocalization of 2D excitons in out-of-plane orientations. It shows the picosecond energy transfer originated from the Förster resonance energy transfer (FRET) efficiently competes with the exciton–phonon interactions in the binary system.     

Simultaneous Ultrasound and Heat Enhance Functional Properties of Glycosylated Lactoferrin

Protein-polysaccharide covalent complexes exhibit better physicochemical and functional properties than single protein or polysaccharide. To promote the formation of the covalent complex from lactoferrin (LF) and beet pectin (BP), we enhanced the Maillard reaction between LF and BP by using an ultrasound-assisted treatment and studied the structure and functional properties of the resulting product. The reaction conditions were optimized by an orthogonal experimental design, and the highest grafting degree of 55.36% was obtained by ultrasonic treatment at 300 W for 20 min and at LF concentration of 20 g/L and BP concentration of 9 g/L. The formation of LF-BP conjugates was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared (FTIR) spectroscopy. Ultrasound-assisted treatment can increase the surface hydrophobicity, browning index, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radicals scavenging activity of LF due to the changes in the spatial configuration and formation of Maillard reaction products. The thermal stability, antioxidant activity and emulsifying property of LF were significantly improved after combining with BP. These findings reveal the potential application of modified proteins by ultrasonic and heat treatment.     

A novel combining strategy of cellulose aerogel and hierarchically porous metal organic frameworks (HP-MOFs) to improve the CO2 absorption performance

Cellulose - High CO2 concentration in atmosphere causes serious environmental issues, and carbon capture and storage technologies have attracted attention as a means to reduce the atmospheric CO2...     

Aggregation of Electrochemically Active Conjugated Organic Molecules and Its Impact on Aqueous Organic Redox Flow Batteries

Molecule aggregation in solution is acknowledged to be universal and can regulate the molecule's physiochemical properties, which however has been rarely investigated in electrochemistry. Herein, an electrochemical method is developed to quantitatively study the aggregation behavior of the target molecule methyl viologen dichloride. It is found that the oxidation state dicationic ions stay discrete, while the singly-reduced state monoradicals yield a concentration-dependent aggregation behavior. As a result, the molecule's energy level and its redox potential can be effectively regulated. This work does not only provide a method to investigate the molecular aggregation, but also demonstrates the feasibility to tune redox flow battery's performance by regulating the aggregation behavior.     

Manipulating OH−-Mediated Anode-Cathode Cross-Communication Toward Long-Life Aqueous Zinc-Vanadium Batteries

The anode-cathode interplay is an important but rarely considered factor that initiates the degradation of aqueous zinc ion batteries (AZIBs). Herein, to address the limited cyclability issue of V-based AZIBs, Al₂(SO₄)₃ is proposed as decent electrolyte additive to manipulate OH⁻-mediated cross-communication between Zn anode and NaV₃O₈ ⋅ 1.5H₂O (NVO) cathode. The hydrolysis of Al³⁺ creates a pH≈0.9 strong acidic environment, which unexpectedly prolongs the anode lifespan from 200 to 1000 h. Such impressive improvement is assigned to the alleviation of interfacial OH⁻ accumulation by Al³⁺ adsorption and solid electrolyte interphase formation. Accordingly, the strongly acidified electrolyte, associated with the sedated crossover of anodic OH⁻ toward NVO, remarkably mitigate its undesired dissolution and phase transition. The interrupted OH⁻-mediated communication between the two electrodes endows Zn||NVO batteries with superb cycling stability, at both low and high scan rates.