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Four new alkaloids, arecatines A–D (1–4), were isolated from the peels of Areca catechu. Compound 1 is an unusual piperidine-pyridine hybrid alkaloid, whereas compounds 2–4 feature bis-piperidine alkaloids. Their structures were elucidated by UV, IR, HRESIMS, and NMR spectra analysis. The molecular docking analysis indicated that compound 3 exhibited the best binding affinity with the GABAA receptor, indicating its potential anti-epilepsy activity. [ABSTRACT FROM AUTHOR]

Anisotropic volume changes in primary particles of layered Ni‐rich transition metal oxides generate mechanical stresses during electrochemical cycling. This results in structural degradation and side reactions that deteriorate battery performance. To address this issue, a cross‐linked epoxy natural rubber (CENR) is employed as the protective elastomeric interphase. The viscoelastic properties of CENR facilitated a strong adhesion to the surface of Ni‐rich cathodes, thereby helping alleviate mechanical stresses during cycling. This approach maintained the structural integrity of the Ni‐rich cathodes and suppressed detrimental interfacial reactions. Consequently, the fortified Ni‐rich cathode retained 95.9% of its capacity after 300 cycles at 0.5 C and 82.8% after 500 cycles at 1 C. This study highlights the essential role of elastomeric materials in stabilizing Ni‐rich cathodes and offers insights that can enable the development of additional protective elastomeric layers for battery electrode materials. [ABSTRACT FROM AUTHOR]

Lithium–oxygen batteries (LOBs) have been regarded as a promising energy storage system for applications in electric vehicles and aviation. However, the development of high-performance LOBs has been hindered by the challenges associated with insulating discharge products, such as low energy efficiency and poor rate performance. Here, we report that insulating lithium peroxide (Li2O2) can deposit with a carbon nanotube (CNT) additive during the discharge process and eventually be woven into a conductive network. The constructed network enhances the conductivity of Li2O2 and accelerates the kinetics of electrode reactions. As a result, the battery containing 1.0 mg mL−1 CNTs in the electrolyte exhibits a high areal capacity of 5.7 mA h cm−2 and superior rate performance at 1.41 A gCNT−1. Furthermore, the introduction of ruthenium nanoparticles to the CNTs results in stable cycling for 550 hours. This research opens up a new avenue for addressing the issues caused by insulating discharge products in LOBs. [ABSTRACT FROM AUTHOR]

Marine sedimentary phosphorites usually contain high rare earth elements (REEs) content, especially the heavy REEs (HREEs), which account for over 30% of the total REEs. The phosphorites may became another important source for HREEs in the future. Phosphorite deposits are widely distributed in China and most of them are found in Yunnan, Guizhou, Sichuan Provinces, etc. High REEs abundances are confirmed in the Zhijin phosphorite deposit in Guizhou Province and with total REEs resource over 3 Mt. The collophanite and apatite are the main host phase for both REEs and P, and the collophanite has complex chemical composition. There are still controversies for the mineral and chemical composition of collophanite. Based on detailed petrological, mineralogical, SEM/EDS, XRD, FIB-TEM and LA-ICP-MS results of phosphorites in Zhijin deposit, this paper discuss the mineral composition of phosphorites and the origin of the complex chemical composition of collophanite. The results show that the most phosphorites in the deposit show the pelletal texture, which is composed of phosphorous pellets and carbonate cement. The mineral composition of the phosphorous pellet is very complex, including mainly fluorapatite and dolomite, and with minor quartz, dolomite, pyrite (some oxidized into limonite), muscovite, solid bitumen and barite. The mineral composition of the cement is mainly dolomite, with minor quartz, pyrite, barite, and trace amounts of zircon, rutile, and liebigite (possibly formed by oxidation of other uranium minerals). The FIB-TEM results show that the cryptocrystalline part of the outer layer of phosphorus pellet is composed of nanoscale mineral aggregates including mainly nanoscale fluorapatite, and small amount of nanoscale dolomite, pyrite and organic matter. The mineral composition of collophanite is similar to that of phosphorus pellet. The discovery of nanoscale fluorapatite, dolomite, pyrite, and organic matter in phosphorite provides reliable evidence for explaining the chemical complexity of collophanite. The discovery of solid bitumen and liebigite in phosphorites, as well as high REEs content in organic matter, also provides new evidence for an alternative occurrence of U and REEs in phosphorites. [ABSTRACT FROM AUTHOR]