An Abnormal 3.7 Volt O3‐Type Sodium‐Ion Battery Cathode

Layered O3‐type sodium oxides (NaMO₂, M=transition metal) commonly exhibit an O3–P3 phase transition, which occurs at a low redox voltage of about 3 V (vs. Na⁺/Na) during sodium extraction and insertion, with the result that almost 50 % of their total capacity lies at this low voltage region, and they possess insufficient energy density as cathode materials for sodium‐ion batteries (NIBs). Therefore, development of high‐voltage O3‐type cathodes remains challenging because it is difficult to raise the phase‐transition voltage by reasonable structure modulation. A new example of O3‐type sodium insertion materials is presented for use in NIBs. The designed O3‐type Na_0.7Ni_0.35Sn_0.65O₂ material displays a highest redox potential of 3.7 V (vs. Na⁺/Na) among the reported O3‐type materials based on the Ni²⁺/Ni³⁺ couple, by virtue of its increased Ni?O bond ionicity through reduced orbital overlap between transition metals and oxygen within the MO₂ slabs. This study provides an orbital‐level understanding of the operating potentials of the nominal redox couples for O3‐NaMO₂ cathodes. The strategy described could be used to tailor electrodes for improved performance.     

Organic nanosynthesis of diarylfluorene-based ladder-type gridarene isomers via intramolecular A1-B1 type Friedel-Crafts gridization

Fluorene-based ladder-type nanogrids have been synthesized via the stepwise and iterative Friedel-Crafts/Suzuki cross-coupling reactions, and efficient intramolecular gridization reaction could enhance yield up to ～95%. Multiple configurational isomers were successfully separated with the yield of 10%, 20% and 65% for Grid-DFCz-1, Grid-DFCz-2 and Grid-DFCz-3 respectively. The molecular configurations of Grid-arene isomers were characterized and confirmed by the NMR spectra. We found that molecular configuration has little influence on photophysical and electrochemical properties.     

Energy equalities for the 2D reduced-gravity two-and-a-half layer system

In this work, we study the energy balance for the weak solutions of a reduced-gravity two-and-a-half model in oceanic fluid dynamics. Inspired by the work of Nguyen et al. (2020), based on some delicate commutator estimates, we prove the energy conservation in 2D bounded domains under certain regularity conditions.     

双联光声传感器和差分池在液体光声检测中的应用

利用双联传感器得到光声信号的叠加作用,可提高光声检测灵敏度或扣除溶液背景吸收。以亚硝基R盐测定钴为例,得到最低检测浓度为0.3ng/mL,相当于4.25×10~(-5)的吸收。     

Use of liquid crystal to study the interactions of alkyl polyglycosides with gelatin and bovine serum albumin

In this study, liquid crystal (LC) was used to study the interactions of alkyl polyglycosides (APG) with gelatin and bovine serum albumin (BSA) at the LC-aqueous interface. The LC easily undergo an orientational transition from a homeotropic to a planar state after proteins were in contact to the LCaqueous interface decorated with APG, thus inducing an optical change from dark to bright. The optical image analysis reveals that the rearrangement rate of APG monolayer is tightly dependent on the concentration and chemical structure of the protein of interest. For example, the rearrangement rate of APG monolayer increases with an increasing gelatin concentration. We also find that the chemical structure of the proteins has a significant impact on the difference in the growth behavior of bright domains in LC.