Self-Repairable and Flexible Polymer Network Electrolyte with Enhanced Lithium-Ion Conduction for Lithium Metal Batteries

Developing high-performance functional polymer-based electrolytes is important for realizing next generation safe lithium metal batteries. In this study, a new type of quasi-solid polymer network electrolyte (SIPH-x-y%) was prepared by combining synthesized polymer network (SIPH) containing urethane bond linked ionic liquids (ILs), polyethylene glycol (PEG), and disulfide bond moieties, lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI), and glyme type additive. It was found that SIPH-20-40% was mechanically flexible, self-healable, and showed high ionic conductivity of 2.67×10⁻⁴ S cm⁻¹. Also, SIPH-20-40% possesses a high lithium ion transference number of 0.43 and good electrochemical stability. These properties enabled the SIPH-20-40% electrolyte membrane to support Li/Li symmetrical cell to cycle stably during long term Li plating and stripping. The Li/SIPH-20-40%/LFP showed high delivered specific capacity and good stability (166.1 mAh g⁻¹ after 106 cycles at 0.2 C). Such glyme doped polymer network electrolyte provides new experimental findings for developing polymer-based electrolyte with excellent mechanical integrity and battery related properties.     

Bisnitronyl nitroxides bridged by tetra(ethyleneoxy) sensing metal ions spectroscopically and electrochemically

Compound 1 containing two nitronyl nitroxide units bridged by tetra(ethyleneoxy) was designed and synthesized for sensing metal ions, by taking the features of nitronyl nitroxides: a chromophore showing absorption in visible range, reversible oxidation/reduction and coordination to metal ions. The absorption spectrum of 1 was altered markedly upon mixing with a few rare earth metal ions and some transition metal ions. Moreover, the oxidation potential of 1 was shifted to more positive range in the presence of metal ions including Pb²⁺, Ba²⁺, and Ca²⁺. Thus, compound 1 can sense metal ions both spectroscopically and electrochemically.     

The Double Ringel-Hall Algebras of Valued Quivers

This paper is devoted to the study of the structure of the double Ringel-Hall algebra D(Λ) for an infinite dimensional hereditary algebra A, which is given by a valued quiverΓover a finite field, and also to the study of the relations of D(Λ)-modules with representations of valued quiverΓ.     

Directed Evolution of a Tryptophan 2,3‐Dioxygenase for the Diastereoselective Monooxygenation of Tryptophans

Herein, we report an engineered enzyme that can monooxygenate unprotected tryptophan into the corresponding 3a‐hydroxyhexahydropyrrolo[2,3‐b]indole‐2‐carboxylic acid (HPIC) in a single, scalable step with excellent turnover number and diastereoselectivity. Taking advantage of directed evolution, we analyzed the stepwise oxygen‐insertion mechanism of tryptophan 2,3‐dioxygenases, and transformed tryptophan 2,3‐dioxygenase from Xanthomonas campestris into a monooxygenase for oxidative cyclization of tryptophans. It was revealed that residue F51 is vital in determining the product ratio of HPIC to N′‐formylkynurenine. Our reactions and purification procedures use no organic solvents, resulting in an eco‐friendly method to prepare HPICs for further applications.     

Directional growth of Al−Mg<Subscript>2</Subscript>Si eutectic alloy in the SZ2 unmanned spaceship

This paper reports the investigation results on directional growth of Al−Mg₂Si eutectic alloy in the SZ2 unmanned spaceship. The analysis shows that microgravity has influence on the directional growth of Al−Mg₂Si eutectic alloy. The eutectic colony in space-grown sample is larger than that in ground-grown sample, and the directional effect is not so good as that of terrestrial sample. But there is no obvious difference in the lamellar thickness between these samples, and lamellar interspacing in space sample is smaller than that grown on the ground. A simple discussion is done on the gravity effect on the directional growth of Al−Mg₂Si eutectic alloy.     

Production of light alkenes with low CO2 emission from gas phase oxidative cracking (GOC) of hexane

Compared with non-oxidative pyrolysis of hexane, the rupture of C-C bonds of hexane in the GOC process becomes rather easy due to the change of thermodynamics and kinetics of the reaction with introduction of oxygen. CO predominates in the COx produced, and the ratio CO/CO₂ can be as high as 16. The GOC process could be operated in an autothermic way, which would minimize energy consumption of the whole process and greatly decrease the CO₂ emission. GOC seems to be an environmentally benign and promising alternative route for light alkenes production using heavy feedstock. This revised version was published online in August 2006 with corrections to the Cover Date.     

人工神经网络的光学实现

本文讨论了光学神经网络的优势及其所面临的主要问题,简述了它近十年来的发展．光互连是光学实现神经网络最具吸引力的技术,光电混合集成的灵巧象素器件又融合了电子器件灵活、可编程、易控制的特点．二者的结合是当前光学神经网络发展的主要趋势,它们为神经网络的进一步发展和应用,为超大规模神经网络的实现和应用提供了一种很有前途的方案．     

静高压熔态淬火Al70Co15Ni10Tb5合金中十次准晶的相关晶体相C4和C5

 使用静高压熔态淬火方法，在Al₇₀Co₁₅Ni₁₀Tb₅合金中截获到两个新的十次准晶相关相C₄和C₅。其晶胞参数分别为：底心正交晶体（C₄），α=1.38 nm，b=1.60 nm，c=2.0 nm；简单正交晶体（C₅），α=1.20 nm，b=1.60 nm，c=2.30 mn。对二者的高分辨象进行了分析和研究，发现他们有着密切的关系，且可以认为是Penros拼图有序化的结果。