搜索到372篇“ INTERCONVERSION“的相关文章
Stimuli-Responsive Interconversion between Poly-NHC-Based Organometallic Assemblies and Their Self-Aggregated Dimers
2024年
Comprehensive Summary Poly-NHC-based organometallic assemblies 3-PF6,3-SbF6 and 3-OTf were obtained and verified by NMR spectroscopy,ESI mass spectrometry and single-crystal X-ray diffraction analyses.Controllable structural interconversion was observed between the poly-NHC-based organometallic assemblies and their self-aggregated dimers in solution affected by concentration,solvent and metal ion.1H NMR spectra of assembly 3-PF6 in CD3CN at different concentrations demonstrated controllable structural interconversion,and 19F NMR spectrum of assembly 3-PF6 at high concentration further evidenced the presence of the free hexafluorophosphate anion and encapsulated hexafluorophosphate anion for its two sets of signals.In addition,single-crystal X-ray diffraction analysis provided clear evidence that in the solid state,two assemblies 3-PF6 were vertically stuck,forming a self-aggregated dimer with an encapsulated hexafluorophosphate anion.Investigating the reversible structural interconversion is beneficial for revealing the intrinsic nature on the atom level and paving the way to design the stimuli-responsive functional system.
Guang-Feng JinYing-Feng Han
关键词:STIMULI-RESPONSIVE
“义位←→空义位”:语义变异路径互逆转化及其修辞加工
2024年
本文比对《现代汉语词典》第1-7版承载语义变异的目标语言单位发生在词义系统内外的变异现象,以自主构拟的“义位←→空义位”双向转化的解释框架,依次解释:分属词汇身份和非词汇身份的“义位→空义位”语义变异承载体的信息结构和修辞加工;“空义位→义位”语义变异承载体的信息结构和修辞加工;实现“空义位→义位”词汇化的阶段性完成,可能是发生在词义系统内外新一轮意义再生产的开始。发生在词义系统内外的语义变异,是开放性的连续统。从词到非词的“突变”和从非词到词“渐变”的不同条件下,语用规则优先和语言规则优先分别支持语义变异的双向运动。希望从不同的方向,揭示自然语言的语义修辞化变异和修辞用法的词汇化沉淀复杂的表象背后可认知、可推导的简单规则。
谭学纯
关键词:信息结构
过渡金属氧化物中新奇量子态与电荷-自旋互转换研究进展
2023年
为了满足信息技术时代下海量数据的高效存储及处理,具有低功耗、非易失性的自旋电子器件受到极大关注.能够高效产生自旋流的自旋源材料是新型自旋-轨道力矩器件的重要组成部分.近二十年来,在探索具有高效产生自旋流的材料体系,以及理解材料相关物理机制两方面都取得了较大的进展.最近,在过渡金属氧化物中涌现出许多与产生自旋流密切相关的新奇量子态,成为自旋源的新兴材料体系被广泛研究.研究结果表明,过渡金属氧化物具有对电子结构高度敏感、显著且灵活可调的电荷-自旋转换效率,具有巨大的应用潜力.本文主要综述了过渡金属氧化物中新奇的电子能带结构及其与电荷-自旋互转换的关联机制,并对未来的发展趋势进行了展望.
劳斌郑轩李晟汪志明
关键词:过渡金属氧化物
金属间化合物电催化剂在氢电转换器件应用中的研究进展
2023年
人类对可持续能源的高度重视,使得绿色环保的氢能成为研究热点。能量转换和存储技术(如燃料电池和电解水)可实现氢能源和电力的相互转换,但实现这些技术的前提是需要开发高效稳定的催化剂。结构有序的金属间化合物具有确定的组成和可调控的几何效应和电子效应的优势,已被探索作为能量转换和存储技术的有效电催化剂,金属间化合物表面均匀的活性位点分布也有利于研究催化剂活性和结构之间联系(即构效关系)的理想模型。本综述首先介绍了氢电转换装置催化剂所面临的挑战以及金属间化合物在电催化中的优势,其次从活性和稳定性的角度重点论述金属间化合物在氢电转换装置中的研究进展,最后总结并展望了金属间化合物电催化剂未来的发展前景。
梁锦辉梁乐程崔志明
关键词:金属间化合物电催化
High-density oxygen-doped nano-TaN enables robust polysulfide interconversion in Li−S batteries
2023年
To tackle undesirable shuttle reaction and sluggish reaction kinetics in lithium–sulfur(Li–S)batteries,we develop a porous and high-density oxygen-doped tantalum nitride nanostructure(nano-TaNO)as an efficient catalyst through delicate tailoring.Benefiting from well-defined interior and surface nanopore channels,the nano-TaNO favors abundant sulfur storage,easy electrolyte infiltration and good electrons/Li+transport.More importantly,high-density O dopant in nano-TaNO not only provides high conductivity,but also promotes polysulfide adsorption/conversion via Li–O chemical interactions and the generation of S3∗−radicals to activate additional evolution path from S8 to Li_(2)S.Consequently,the nano-TaNObased cathode exhibits excellent specific capacity and cyclability even under high sulfur loading condition.These interesting findings suggest the great potential of tantalum nitride and a high amount of anion doping engineering in manipulating intermediates and building high-performance Li−S rechargeable batteries.
Shuang YuYonggui ZhangShuo YangKuikui XiaoDong CaiHuagui NieZhi Yang
关键词:TANHIGH-DENSITY
Light-driven interconversion of Pd_(2)L_(4)cage and mononuclear PdL_(2)mediated by the isomerization of azobenzene ligand
2023年
The lantern-shaped cage Pd_(2)L_(4)and tweezer-like PdL_(2)can be synthesized from the trans-and cis-isomer of an azobenzene-containing ligand,respectively,which were characterized by^(1)H,^(13)C,^(1)H-^(1)H COSY,DOSY NMR spectroscopies,high-resolution ESI-MS and density function theory(DFT)calculations.The interconversion of Pd_(2)L_(4)and PdL_(2)can be achieved via the cis-trans isomerization of the azobenzene unit on the ligand upon alternative irradiation of light 365 nm or 420 nm.
Jinkang ZhuXujin ChenXin JinQiaochun Wang
关键词:AZOBENZENEISOMERIZATION
Photoinduced Cu^(+)/Cu^(2+)interconversion for enhancing energy conversion and storage performances of CuO based Li-ion battery
2023年
Pursuing appropriate photo-active Li-ion storage materials and understanding their basic energy storage/conversion principle are pretty crucial for the rapidly developing photoassisted Li-ion batteries(PA-LIBs).Copper oxide(CuO)is one of the most popular candidates in both LIBs and photocatalysis.While CuO based PA-LIBs have never been reported yet.Herein,one-dimensional(1D)CuO nanowire arrays in situ grown on a three-dimensional(3D)copper foam support were employed as dualfunctional photoanode for both‘solar-to-electricity’and‘electricity-to-chemical’energy conversion in the PA-LIBs.It is found that light energy can be indeed stored and converted into electrical energy through the assembled CuO based PA-LIBs.Without external power source,the photo conversion efficiency of CuO based photocell reaches about 0.34%.Impressively,at a high current density of 4000 m A g^(-1),photoassisted discharge and charge specific capacity of CuO based PA-LIBs respectively receive 64.01%and 60.35%enhancement compared with the net electric charging and discharging process.Mechanism investigation reveals that photogenerated charges from CuO promote the interconversion between Cu^(2+)and Cu^(+)during the discharging/charging process,thus forcing the lithium storage reaction more completely and increasing the specific capacity of the PA-LIBs.This work can provide a general principle for the development of other high-efficient semiconductor-based PA-LIBs.
Qiuman ZhangMeng WeiQianwen DongQiongzhi GaoXin CaiShengsen ZhangTeng YuanFeng PengYueping FangSiyuan Yang
羟基樟脑调控的氨基酸S/R构型相互转化
2023年
为解决当前通过纯化学法进行氨基酸S/R构型转化中存在的手性分子结构复杂、分子质量大以及耗费等当量重金属盐的问题,提出一种利用结构简单的2-羟基樟脑和3-羟基樟脑进行氨基酸S/R构型转化的新方法。通过对碱、溶剂和反应温度的筛选,建立最优反应体系,然后对不同侧链的外消旋以及光学纯氨基酸的构型转化进行研究。结果表明,以叔丁醇钾为碱,异丙醇为溶剂,在40℃下反应获得最佳转化效果,其能够兼容具有不同芳环和脂肪侧链的氨基酸,高效进行氨基酸S/R构型的相互转化,展现出优秀的立体选择性,且羟基樟脑可循环利用;机理分析表明,拆分的高立体选择性由热力学控制。新方法所用手性试剂结构简单并可循环使用,无需将氨基酸合成特定的反应底物,反应转化率和立体选择性高,为氨基酸纯化学S/R构型转化提供了一种新的途径。
余伟董思凡李傲齐崔斌李昊龙秦源韩天佼范士明
关键词:有机合成化学氨基酸樟脑手性
一种正、负和零泊松比相互转换的新策略
2022年
针对正、负和零泊松比值难以调节的问题,本文基于曲杆/板组成的内凹式十边形多孔结构,提出了一种转换策略。采用数值模拟和实验相结合的方法验证了在不同胞壁曲率下,结构的泊松比不同(范围包括正、负和零)。研究发现:结构的泊松比绝对值随着有效真实应变的增大而逐渐减小,随后出现了相反的泊松比值。对这种现象进行了分析,并提出了曲率效应影响机制。
陈帅王兵朱绍伟
关键词:多孔结构负泊松比
Electrocatalytic CO_(2)and HCOOH interconversion on Pd-based catalysts
2022年
Electrochemical energy storage and conversion toward sustainable carbon neutrality cycle is of great interest in today's society.In this perspective,we highlight the interconversion between carbon dioxide and formic acid by means of electrocatalytic CO_(2)reduction reaction(CO_(2)RR)and formic acid oxidation reaction(FAOR)as an effective way to achieve that goal.In line with the distinctive catalytic nature of Pd to reversibly drive both FAOR and CO_(2)RR,we first illustrate the intimate mechanistic relation between these two reversed reactions over Pd surfaces.Next,recent advances in developing Pd-based bifunctional catalysts and relevant optimization strategies are briefly summarized,including geometric structure engineering with preferential facet exposure,construction of crystallographic ordering intermetallic,electronic structure manipulation through metal or metalloid doping to fine tune the binding strength for active and poisoning intermediates.At the end,our viewpoints on the design principles at both microscopic and macroscopic scales are offered toward an efficient CO_(2)and HCOOH interconversion loop.
Guiru ZhangXianxian QinChengwei DengWen-Bin CaiKun Jiang

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