Spectroscopic and Computational Insight into the Intermolecular Interactions between Zwitter‐Type Ionic Liquids and Water Molecules

Geometric and conformational changes of zwitter‐type ionic liquids (ZILs) due to hydrogen‐bonding interactions with water molecules are investigated by density functional theory (DFT), two‐dimensional IR correlation spectroscopy (2D IR COS), and pulsed‐gradient spin‐echo NMR (PGSE NMR). Simulation results indicate that molecular structures in the optimized states are strongly influenced by hydrogen bonding of water molecules with the sulfonate group or imidazolium and pyrrolidinium rings of 3‐(1‐methyl‐3‐imidazolio)propanesulfonate ( 1 ) and 3‐(1‐methyl‐1‐pyrrolidinio)propanesulfonate ( 2 ), respectively. Concentration‐dependent 2D IR COS reveals kinetic conformational changes of the two ZIL–H₂O systems attributable to intermolecular interactions, as well as the interactions of sulfonate groups and imidazolium or pyrrolidinium rings with water molecules. The dramatic changes in the ¹H self‐diffusion coefficients elucidate the formation of proton‐conduction pathways consisting of ZIL networks. In ZIL domains, protons are transferred by a Grotthuss‐type mechanism through formation, breaking, and restructuring of bonds between ZILs and H₂O, leading to an energetically favorable state. The simulation and experimental investigations delineated herein provide a perspective to understanding the interactions with water from an academic point of view as well as to designing ILs with desired properties from the viewpoint of applications.     

Slow light in a simple metamaterial structure constructed by cut and continuous metal strips

Recently, slow light in metamaterials has been investigated based on the coupling between two quasi-bound states, in classic analogue of electromagnetically induced transparency in atomic systems. Here we demonstrate the feasibility in achieving slow light in metamaterials, based on the mechanism of coupling between a quasi-bound state and a continuum state. The theoretical prediction by a two-particle model is in good agreement with the experimental result in the metamaterial composed of the cut and continuous metal strips. The present work illustrates the versatility of metamaterials, implying the great potential in many applications.     

基于PCA的变压器故障红外监测应用研究

变压器作为电力系统中非常重要的输变电设备,其运行状况直接影响到整个系统运行的安全水平。根据红外光谱仪所测得信息,通过傅里叶变换可得到各故障特征气体红外吸收信息;依据Lambert-Beer定律并结合所测信息,采用主成分分析法就可以对各故障特征气体进行定性与定量分析,判别当前变压器的运行状况。对于故障运行的电力变压器,及时发现并解除存在的故障或故障隐患对整个系统的安全运行具有重要意义。     

A novel zirconocene/ultradispersed diamond black powder supported catalytic system for ethylene polymerization

A novel carrier of ultradispersed diamond black powder (UDDBP) was used to support metallocene catalyst. Al₂O₃ was also used as carrier in order to compare with UDDBP. Supported catalysts for ethylene polymerization were synthesized by two different reaction methods. One way was direct immobilization of the metallocene on the support, the other was adsorption of MAO onto the support followed by addition of the metallocene. Four supported catalysts Cp₂ZrCl₂/UDDBP, Cp₂ZrCl₂/Al₂O₃, Cp₂ZrCl₂/MAO/UDDBP and Cp₂ZrCl₂/Al₂O₃/MAO were obtained. The content of the zirconium in the supported catalyst was determined by UV spectroscopy. The activity of the ethylene polymerization catalyzed by supported catalyst was investigated. The influence of Al/Zr molar ratio and polymerization temperature on the activity was discussed. The polymerization rate was also observed.     

1，2—二氯丙烷裂解反应光窗结焦机理的研究

有机化合物在光窗上的结焦严重地影响激光引发化学反应及光学原位实时探测。本文报道在1，2－二氯丙烷反应系统中，光窗结焦现象同时存在于激光引发反应及热反应过程中，对光窗在300℃条件 下的结焦机理研究表明，少量氧气在光窗结焦过程中起关键作用。结焦前驱体的红外光谱研究表明，前驱体的可能结构为1－丙炔－1，3－二醇的缩聚体。该化合物极易通过缩聚反应形成更大的分子，最终导致光 窗结焦。对系统及反应物进行彻底除氧，光窗结焦现象大为改善。     

Sequential actions of cobalt nanoparticles and palladium(II) catalysts: three-step one-pot synthesis of fenestranes from an enyne and an alkyne diester

A three-step one-pot synthesis of fenestranes from a readily available enyne and an alkyne diester has been carried out with cobalt nanoparticles and palladium(II) as catalysts.     

基于实验的反演识别方法及其在材料力学性能研究中的应用

本文介绍了基于实验的反演识别方法,综述了该方法在材料力学以及界面力学性能研究中的应用.内容包括:讨论了基于实验反演识别整体化策略与若干关键技术,比较了几种识别算法的优缺点,给出了在金属基复合材料界面力学损伤与破坏及考虑时间效应的粘接界面力学模型与实验表征方面的应用,简介了在其它材料力学性能研究等方面取得的进展.最后,对该实验分析方法发展趋势进行简要评述.