检索结果-南通市图书馆

Chiral transfer amidst one-dimensional linear polymers and twodimensional network covalent organic frameworks:Striking a fine balance between helicity and crystallinity

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5726-5734页

作者： Xinlin Zha Mengjuan Zuo Guilin Xu Zhong Yan Haining You Yi Xiong ying liu yingying Li Liyan Yang Ke liu Mufang Li Tao Zhao Dong Wang College of chemistry and Chemical Engineering Donghua UniversityShanghai 201620China key laboratory of Textile Fiber and Products Ministry of EducationWuhan Textile UniversityWuhan 430200China

The current landscape of chiral covalent organic frameworks(COFs)predominantly centered on constructing asymmetric molecular-scale chirality,often introducing an inherent contradiction to the COF symmetry and limiting ***,we overcome these challenges by achieving chiral transfer between one-dimensional(1D)imine linear polymers(LPs)and two-dimensional(2.)networkβ-ketoenamine COFs composed of achiral *** successfully synthesize several 1D imine LPs with mesoscopic helical chirality,comprising achiral C2.symmetric terephthalaldehyde and diamine linkers in a chiral supramolecular transcription *** the irreversible tautomerism mechanism within the linker replacement approach,terephthalaldehyde(TPA)units in these helical 1D LPs are substituted with C3-symmetric 1,3,5-triformylphloroglucinol(TP),yielding the corresponding 2. networkβ-ketoenamine *** and helicity of the resultantβ-ketoenamine COFs intimately hinge on reaction conditions,including the aldehyde stoichiometry of Tp and TPA,as well as the quantity and concentration of the catalyst *** optimized conditions,the nucleation and growth were precisely governed,achieving a harmonious equilibrium of crystallinity and helicity within the generated 2. networkβ-ketoenamine COFs,even with covalent bond rupture,recombination,and topological transition(from[C2.C2.to[C3+C2.).Impressively,the ground state chirality inherent to helical 1D LPs seamlessly transfers to helical 2. networkβ-ketoenamine *** study not only offers new perspectives on the development of chiral functional COFs,but also provides fresh insights into the precise control of COFs'microscopic morphology.

关键词： chiral covalent organic frameworks chiral transfer dimensional transformation helicity

IN SITU INTERFEROMETRIC STUDY ON THE GELATION PROCESS OF POLYACRYLIC ACID GELS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2000年第4期18卷 373-377页

作者： ying Guan Qiang Chen Xian-min Zhang yu-xing Peng Jian Xu Polymer Physics {2., Center for molecular Science, institute of chemistry, Chinese Academy of sciences, beijing 100080, china Department of Information & Electronic Engineering, Zhejiang University, Hangzhou 31002., china Chengdu institute of organic chemistry, Chinese Academy of sciences, Chengdu 610041, china 中科院化学所高分子物理及化学国家重点实验室北京浙江大学浙江杭州中科院成都有机化学所四川成都

In situ interferometry was used to investigate the gelation process of polyacrylic acid (PAA) gels. The basic principle of the in situ interferometry technique is illustrated. It can give sufficient information for non-destructive and successful investigation of the whole gelation process. The effect of initiator concentration on the gelation process was studied. The polymerization rate of AA increases with increasing initiator concentration. The error arising from the thermal effect in the gelation process can be neglected.

关键词： in situ interferometry gelation polyacrylic acid

Phase separation of ploy(ethylene glycol) + n-butanol mixture induced by supercritical CO_2

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第6期18卷 738-740页

作者： Min Qiang Hou, Shu Guang Liang, Ji yuan Song, Xiao Yong Li, Zhao Fu Zhang, Tao Jiang, Bu Xing Han beijing {2. laboratory for molecular sciences, institute of chemistry, Chinese Academy of sciences, beijing 100080, china beijing national {2. for molecular sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The phase behavior of supercritical (SC) CO2.+ PEG 1000 (PEG with average molecular weight of 1000 g/mol) + n-butanol system was studied. It was demonstrated that SC CO2.could induce phase separation of PEG 1000 + n-butanol system under suitable conditions. This hints that SC CO2.has potential applications in the separation of mixtures of PEG + organic compound.

关键词： PEG1000 CO2 n-Butanol Phase behavior Separation

Theoretical investigations on the growth of graphene by oxygenassisted chemical vapor deposition

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 4645-4650页

作者： Xiaoli Sun Chaojie yu yujia Yang Zhihao Li Jianjian Shi Wanjian Yin Zhongfan {2. beijing Graphene institute(BGI) Beijing 100095China School of Physics and Electronics Shandong Normal UniversityJinan 250014China College of Energy Soochow Institute for Energy and Materials InnovationsLight Industry Institute of Electrochemical Power SourcesSUDA-BGI Collaborative Innovation CenterSoochow UniversitySuzhou 215006China School of Electronic Engineering Chengdu Technological UniversityChengdu 611730China Center for Nanochemistry Beijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Recently,graphene has drawn considerable attention in the field of electronics,owing to its favorable conductivity and high carrier *** to the industrialization of graphene is its high-quality microfabrication via chemical vapor ***,many problems remain in its preparation,such as the not fully understood cracking mechanism of the carbon source,the mechanism of its substrate oxidation,and insufficient defect repair *** help close this capability gap,this study leverages density functional theory to explore the role of O in graphene *** effects of Cu substrate oxidation on carbon source cracking,nucleation barriers,crystal nucleus growth,and defect repairs are *** was found to reduce energy change during dehydrogenation,rendering the process ***,the adsorbed O in graphene or its Cu substrate can promote defect repair and edge growth.

关键词： density functional theory oxygen-assisted graphene growth chemical vapor deposition Cu substrate

Architecture and Properties of Several molecular Aggregate Structures

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Architecture and Properties of Several Molecular Aggregate S...

Architecture and Properties of Several molecular Aggregate Nanostructures

中国化学会第六届全国结构化学学术会议

作者： yu-Liang Li CAS key laboratory of organic solids,{2. national laboratory for molecular sciences (BNLMS),institute of chemistry,Chinese Academy of sciences,{2. 100190,P.R.{12.

＜正＞We have designed and synthesized functional molecules with structural features that favor assembly into aggregate nanostructures via combination of intermolecular interactions and self-assembly techniques. These ordered low dimensions aggregate nanostructures as prepared are based on a variety of molecular materials including in{2. and {2. semi-conductor,carbon materials and *** have also

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Architecture and Properties of Several Molecular Aggregate N...

FABRICATION OF SELF-ASSEMBLY DNA-C_(60) MULTILAYER FILMS

第六届全国物理无机化学会议

作者： yuliang Li CAS key laboratory of organic solids,{2. national laboratory for molecular sciences (BNLMS),institute of chemistry,Chinese Academy of sciences,{2. 100190,P.R.{12.

＜正＞We have designed and synthesized functional molecules with structural features that favor assembly into aggregate nanostructures via combination of intermolecular interactions and self-assembly *** large-areas ordered molecular aggregate nanostructures are based on a variety of molecular structures such as perylenes,anthracenes,porphyrins,polydiacetylenes,fullerenes and their *** have also developed new

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2002年第6期20卷 591-593页

作者： Shu-guang Yang Yong-jun Zhang Xin-hua Dai Wen-hong Tang Chun-yan liu Wei-xiao Cao yu-liang Li Jian Xu State {2. laboratory of Polymer Physics and chemistry, institute of chemistry, Chinese Academy of sciences,beijing 100080, china Technology institute of Physics and chemistry Chinese Academy of sciences, beijing 100101, china College of chemistry and {12. Engineering Peking University beijing 100871, china institute of chemistry Chinese Academy of Sciences State Key Laboratory of Polymer Physics and Chemistry 北京 100080 Technology institute of Physics and chemistry Chinese Academy of Sciences 北京 100101 College of chemistry and molecular Engineering Peking University 北京 100871

Electrostatic layer-by-layer self-assembly multilayer films were successfully fabricated from C-60-ethylenediamine adduct (C-60-EDA) and DNA. Under visible light irradiation, DNA is ready to be cleaved and the films a... 详细信息

关键词： self-assembly photo-induced cleavage DNA C-60

Two-dimensional perovskite oxide high-κ dielectric for high-performance phototransistors

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2024年第13期69卷 2001-2003页

作者： Zhongfan liu Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Technology Innovation Center of Graphene Metrology and Standardization for State Market Regulation Beijing Graphene InstituteBeijing 100095China

Field-effect transistors are essential components of modern ***,the continued scaling of electronic and optoelectronic devices is bringing silicon-based technologies close to their physical limits,causing issues such as short-channel effects[1].Two-dimensional(2.)semiconductors provide an attractive solution for transistors to extend Moore’s law because of their ultrathin thickness and immunity to short-channel effects[2..To fulfill the potential of 2. semiconductors,gate dielectrics need to be simultaneously engineered to build future 2.-material-based *** insulators with high dielectric constants(j)exhibit lower equivalent oxide thickness,which can ensure efficient gate control over channels and low gate leakage[3].Therefore,tremendous efforts have been made in searching for novel high-j dielectrics.

关键词： dielectric oxide dimensional

An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china chemistry 2024年第9期67卷 2998-3003页

作者： Qi liu Xue-Dong Li Liang Cheng Li liu beijing national {2. for molecular sciences(BNLMS) CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of sciences Beijing 100049China

The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral ***,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination *** this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent *** addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis *** methodology provided a straightforward and sustainable access to a broad range of biaryl-2.carboxylic acid and in excellent yields(up to 92.)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关键词： br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion