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金属异头碳效应 被引量:1
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作者 李懿伦 张香归 +1 位作者 袁耀锋 叶克印 《大学化学》 CAS 2023年第5期119-123,共5页
异头碳效应是有机化学中经典立体电子效应的重要组成部分。异头碳效应可以解释吡喃糖中异头碳上电负性较大的取代基倾向于占据直立键,而非立体位阻更具优势的平伏键的现象。本文简要回顾了异头碳效应的发展历史及其重要应用,重点介绍了... 异头碳效应是有机化学中经典立体电子效应的重要组成部分。异头碳效应可以解释吡喃糖中异头碳上电负性较大的取代基倾向于占据直立键,而非立体位阻更具优势的平伏键的现象。本文简要回顾了异头碳效应的发展历史及其重要应用,重点介绍了有机糖化学前沿的金属异头碳效应。当吡喃糖中异头碳上连接金属元素时,可以通过改变金属的种类、价态、配体以及底物结构有效调控金属异头碳效应。通过科研反哺本科教学,有助于化学相关专业学生进一步加深对金属异头碳效应这一新兴研究领域的理解和认识。 展开更多
关键词 邻位交叉效应 异头碳效应 立体电子效应 构象
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全氟立方烷的笼状立体电子效应
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作者 李懿伦 袁耀锋 叶克印 《大学化学》 CAS 2023年第11期126-130,共5页
立体电子效应是有机化学基础理论的重要组成部分。其中,邻位交叉效应和异头碳效应已经被深入研究并纳入了基础有机化学的教学实践之中。近年来,随着全氟立方烷分子被准确预测和成功合成,一种崭新的笼状电子效应引发了广泛关注。本文简... 立体电子效应是有机化学基础理论的重要组成部分。其中,邻位交叉效应和异头碳效应已经被深入研究并纳入了基础有机化学的教学实践之中。近年来,随着全氟立方烷分子被准确预测和成功合成,一种崭新的笼状电子效应引发了广泛关注。本文简要回顾了立体电子效应的发展及其重要应用,着重介绍了全氟立方烷独特的笼状电子效应并对其合成工作进行了深入讨论。结合当前国内外有机化学研究前沿,通过科研反哺教学,有助于化学相关专业学生培养国际化视野、拓宽知识面,并进一步加深对立体电子效应的理解与认识。 展开更多
关键词 立体电子效应 有机合成 全氟立方烷
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硫-氟的邻位交叉效应 被引量:2
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作者 李懿伦 余意 +1 位作者 袁耀锋 叶克印 《大学化学》 CAS 2022年第7期104-108,共5页
乙烷分子中相邻的两个氢原子被氟取代以后,它的最优构象就从全交叉式转变为邻位交叉,这就是邻位交叉效应影响分子构象最具代表性的一个例子。本文简要回顾了含氟邻位交叉效应的发展历史与重要应用,重点介绍了物理有机科研前沿的硫-氟邻... 乙烷分子中相邻的两个氢原子被氟取代以后,它的最优构象就从全交叉式转变为邻位交叉,这就是邻位交叉效应影响分子构象最具代表性的一个例子。本文简要回顾了含氟邻位交叉效应的发展历史与重要应用,重点介绍了物理有机科研前沿的硫-氟邻位交叉效应。结合当前最新的科研成果,验证了通过改变硫原子的电正性可以达到有效调控邻位交叉效应这一重要策略。通过科研反哺教学,有助于进一步加深对硫-氟邻位交叉效应的理解和认识。 展开更多
关键词 邻位交叉效应 立体电子效应 构象
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Sandwich structured graphene-wrapped FeS-graphene nanoribbons with improved cycling stability for lithium ion batteries 被引量:5
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作者 Lei li Caitian Gao +7 位作者 Anton Kovalchuk Zhiwei Peng Gedeng Ruan Yang Yang Huilong Fei Qifeng Zhong yilun li James M. Tour 《Nano Research》 SCIE EI CAS CSCD 2016年第10期2904-2911,共8页
Sandwich structured graphene-wrapped FeS-graphene nanoribbons (G@FeS-GNIKs) were developed. In this composite, FeS nanoparticles were sandwiched between graphene and graphene nanoribbons. When used as anodes in lith... Sandwich structured graphene-wrapped FeS-graphene nanoribbons (G@FeS-GNIKs) were developed. In this composite, FeS nanoparticles were sandwiched between graphene and graphene nanoribbons. When used as anodes in lithium ion batteries (L1Bs), the G@FeS-GNR composite demonstrated an outstanding electrochemical performance. This composite showed high reversible capacity, good rate performance, and enhanced cycling stability owing to the synergy between the electrically conductive graphene, graphene nanoribbons, and FeS. The design concept developed here opens up a new avenue for constructing anodes with improved electrochemical stability for LIBs. 展开更多
关键词 lithium ion battery iron sulfide graphene nanoribbons graphene energy storage
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Recent Advances on the Corrosion Resistance of Low-Density Steel:A Review
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作者 Chao liu yilun li +1 位作者 Xuequn Cheng Xiaogang li 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2022年第7期1055-1067,共13页
This paper reviews the previous literature on the alloy composition design of low-density steel(LDS),focusing on the eff ect of Al,Mn,Ni,and other alloy elements on the formation of the steel matrix and second phase,a... This paper reviews the previous literature on the alloy composition design of low-density steel(LDS),focusing on the eff ect of Al,Mn,Ni,and other alloy elements on the formation of the steel matrix and second phase,and provides classifi cation.The microstructure of LDS after processing includes the matrix structure,к-carbide,and B2(FeAl,NiAl,or MnAl)phase of ferritic LDS,austenitic LDS,and dual-phase LDS.The infl uence of alloy elements on the corrosion resistance of LDS is derived from the addition of Al and Mn for metallurgy.Additionally,the infl uence of Cr and Mo addition on the corrosion resistance improvement was studied.The electrochemical properties of the corrosion process in LDS are discussed.Further,the microstructure of LDS aff ects the corrosion resistance properties including pitting corrosion,hydrogen embrittlement,and SCC(stress corrosion cracking).Finally,future research directions are proposed. 展开更多
关键词 Low-density steel Alloy element adjustment MICROSTRUCTURE Corrosion resistance
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Energy Security Planning for Hydrogen Fuel Cell Vehicles in Large-Scale Events:A Case Study of Beijing 2022 Winter Olympics
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作者 Pinxi Wang Qing Xue +3 位作者 Jun Yang Hao Ma yilun li Xu Zhao 《Automotive Innovation》 EI CSCD 2022年第2期209-220,共12页
Energy security planning is fundamental to safeguarding the traffic operation in large-scale events.To guarantee the promo-tion of green,zero-carbon,and environmental-friendly hydrogen fuel cell vehicles(HFCVs)in larg... Energy security planning is fundamental to safeguarding the traffic operation in large-scale events.To guarantee the promo-tion of green,zero-carbon,and environmental-friendly hydrogen fuel cell vehicles(HFCVs)in large-scale events,a five-stage planning method is proposed considering the demand and supply potential of hydrogen energy.Specifically,to meet the requirements of the large-scale events’demand,a new calculation approach is proposed to calculate the hydrogen amount and the distribution of hydrogen stations.In addition,energy supply is guaranteed from four aspects,namely hydrogen produc-tion,hydrogen storage,hydrogen delivery,and hydrogen refueling.The emergency plan is established based on the overall support plan,which can realize multi-dimensional energy security.Furthermore,the planning method is demonstrative as it powers the Beijing 2022 Winter Olympics as the first“green”Olympic,providing both theoretical and practical evidence for the energy security planning of large-scale events.This study provides suggestions about ensuring the energy demand after the race,broadening the application scenarios,and accelerating the application of HFCVs. 展开更多
关键词 Hydrogen fuel cell vehicles Large-scale events Energy security plan Hydrogen calculation Layout of hydrogen refueling station
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