Triple-function Hydrated Eutectic Electrolyte for Enhanced Aqueous Zinc Batteries

Aqueous rechargeable zinc-ion batteries (ARZBs) are impeded by the mutual problems of unstable cathode, electrolyte parasitic reactions, and dendritic growth of zinc (Zn) anode. Herein, a triple-functional strategy by introducing the tetramethylene sulfone (TMS) to form a hydrated eutectic electrolyte is reported to ameliorate these issues. The activity of H₂O is inhibited by reconstructing hydrogen bonds due to the strong interaction between TMS and H₂O. Meanwhile, the preferentially adsorbed TMS on the Zn surface increases the thickness of double electric layer (EDL) structure, which provides a shielding buffer layer to suppress dendrite growth. Interestingly, TMS modulates the primary solvation shell of Zn²⁺ ultimately to achieve a novel solvent co-intercalation ((Zn-TMS)²⁺) mechanism, and the intercalated TMS works as a “pillar” that provides more zincophilic sites and stabilizes the structure of cathode (NH₄V₄O₁₀, (NVO)). Consequently, the Zn||NVO battery exhibits a remarkably high specific capacity of 515.6 mAh g⁻¹ at a low current density of 0.2 A g⁻¹ for over 40 days. This multi-functional electrolytes and solvent co-intercalation mechanism will significantly propel the practical development of aqueous batteries.     

雷电波分析与比较研究

本文对双指数雷电流模型和 IEC1 3 1 2—— 1推荐的雷电流模型进行了分析和研究 ,计算了这两种雷电流模型的雷电流参数。在此基础上 ,用 FFT方法分析了雷电流的频谱分布     

基于多小波的GPS相位观测值周跳探测

阐述了周跳探测的重要性,分析了多小波在信号处理方面比单小波更有优势,基于此,利用多小波变换模极大值与信号奇异性之间的关系模型,写出了多小波在GPS周跳探测中的具体操作步骤。最后应用于GPS双差观测量,实验结果表明多小波变换在GPS相位观测值周跳探测中的有效性。     

Synthesis of chiral β-3-amino-2-hydroxyalkanoates and 3-alkyl-3-hydroxy-β-lactams by double asymmetric induction

Reactions of chiral (2S)-enolates of dioxolan-4-ones, derived from lactic, mandelic, and phenyllactic acids, with aliphatic (S_S)- and (S_R)-tert-butylsulfinyl aldimines afforded conformationally restrained C2-disubstituted N,O-orthogonally protected 3-amino-2-hydroxyalkanoates in the form of N-sulfinyl protected 1′-aminodioxolan-4-ones. The product distribution showed that there is significant kinetic selectivity, due to the presence of ‘matched’ and ‘mismatched’ components, between the (S)- or (R)-tert-butylsulfinyl aldimines and the (2S)-enolates of the 1,3-dioxolan-4-ones. Selective methoxide-induced removal of the acetal group of the N-sulfinyl-1′-aminodioxolanones yielded the corresponding N-sulfinyl protected methyl alkanoates. In addition, the selective acid-induced removal of the sulfinyl group of the N-sulfinyl-1′-aminodioxolanones provided the corresponding N-unprotected 1′-aminodioxolanones, whose base-induced cyclization afforded the corresponding β-lactams.     

Double Michael addition of nitromethane to divinyl ketones: A remarkably positive effect of additive

An efficient double Michael addition of nitromethane to divinyl ketones was established in good to high yields (75–99%). A wide range of cyclohexanones were obtained with excellent diastereocontrol (up to >20:1 dr) and enantioinduction (91–99% ee) in a one-pot fashion. The involvement of basic additive significantly enhanced the reactivity of this cascade sequence.     

碳酸氢铵制纯碱的研究

本文对“中间盐”复分解制碱法进行了研究。“中间盐”的加入不能使两个三盐共饱和点在干盐图上发生明显的移动,但能使三盐介稳平衡点的介稳期延长,从而使得用碳酸氢铵和食盐通过复分解制碱成为可能。     

PBFC-PI量子动力学方法及应用

对多原子体系的量子动力学计算非常重要, 然而, 对含六原子以上的分子体系进行精确量子动力学计算仍具挑战性. 面向过程的基函数定制(PBFC)-并行迭代(PI)方法是一种高效的量子动力学方法, 已应用于对含九原子的丙二醛异构体系的氢迁移速率的精确量子计算. 本综述首先阐明了PBFC的基本思想, 之后重点回顾了PBFC-PI方法的具体内容、 该方法与其它方法的结合及其应用方面的新进展. 应用这些方法实现了对单氢迁移、 协同双氢迁移和分步双氢迁移3种类型基准体系的大规模并行计算, 有助于获得对氢迁移过程的新认识.     

X射线荧光光谱铝环-双层压片法测定土壤中常量和微量元素

本文提出用铝环-双层压片法制片,经验系数法校正吸收-增强效应,对少量土壤样品中的常量和微量元素进行了定量测定。取样量为500 mg,制样与测量精确度好于5%,用本法对标样的分析表明,分析值与推荐值基本一致,本法具有简单、快速、成本低的特点,适用于少量样品的分析。     

Spectroelectrochemical and Voltammetric Studies of L‐DOPA

The electrooxidation of L -dopa at GC electrode was studied by in situ UV-vis spectroelectrochemistry (SEC) and cyclic voltammetry. The mechanism of electrooxidation and some reaction parameters were obtained. The results showed that the whole electrooxidation reaction of L -dopa at glassy carbon (GC) electrode was an irreversible electrochemical process followed by a chemical reaction in neutral solution (EC mechanism). The spectroelectrochemical data were treated by the double logarithm method together with nonlinear regression, from which the formal potential E⁰=228 mV, the apparent electron-transfer number of the electrooxidation reaction αn=0.376 (R=0.99, SD=0.26), the standard electrochemical rate constant k⁰=(3.93±0.12)×10⁻4 cm s⁻¹ (SD=1.02×10⁻²), and the formation equilibrium constant of the following chemical reaction k_c=(5.38±0.34)×10⁻¹ s⁻¹ (SD=1.02×10⁻²) were also obtained.     

Halogen bonding-driven formation of supramolecular macrocycles and double helix

Halogen bonding has been used to hold two hydrogen bonded aromatic amide foldamers to form supramolecular macrocycles.