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Science China Chemistry 2024年第11期67卷 3833-3843页

作者： Zhaodong Zhu Jingjing Wu Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs School of Chemistry and Chemical Engineering Zhangjiang Institute for Advanced Study Shanghai Jiao Tong University

Based on rational design, benzoyl cyanide, a well-known ionic acylating reagent, has been developed as a general radical acylating reagent for benzylic site-selective acylation reactions for the first time. Using visible-light photoredox-catalyzed single electron transfer(SET) and hydrogen atom transfer(HAT) strategies, two different direct benzylic C–H acylation reactions with high atom economy have been developed. This newly developed radical acylating reagent could also be used to achieve three component acyltrifluoromethylation of styrenes, which is usually challenging to achieve by other means. All of these reactions proceed under mild nickel-free and NHC-free conditions with high functional group tolerance. In addition, based on our detailed mechanistic experiments, the process of radical-radical cross-coupling mechanism was suggested for these transformations.

关键词： photoredox catalysis benzylic C–H acylation radical acylating reagent HAT catalysis acyltrifluoromethylation

The chance of sodium titanate anode for the practical sodium-ion batteries

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Chinese Journal of Chemical Engineering 2024年第8期72卷 226-244页

作者： Feng Chen Haoyu Li Xianyan Qiao Ruoyang Wang Changyan Hu Ting Chen Yifan Niu Benhe Zhong Zhenguo Wu Xiaodong Guo School of Chemical Engineering Sichuan UniversityChengdu 610065China institute for advanced study Chengdu UniversityChengdu 610106China Chengdu No.7 High School Chengdu 6100412China

Supporting sustainable green energy systems,there is a big demand gap for grid energy *** storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alternative to the lithium-ion batteries equivalent in large-scale energy storage due to their natural abundance and prospective inexpensive *** various anode materials of SIBs,beneficial properties,such as outstanding stability,great abundance,and environmental friendliness,make sodium titanates(NTOs),one of the most promising anode materials for the rechargeable ***,there are still enormous challenges in application of NTO,owing to its low intrinsic electronic conductivity and collapse of *** research on NTOs is still in its infancy;there are few conclusive reviews about the specific function of various modification ***,we summarize the typical strategies of optimization and analysis the fine structures and fabrication methods of NTO anodes combined with the application of in situ characterization *** work provides effective guidance for promoting the continuous development,equipping NTOs in safety-critical systems,and lays a foundation for the development of NTO-anode materials in SIBs.

关键词： Sodium titanates Sodium-ion batteries Modification methods Electronic materials Electrochemistry Synthesis

The pseudospectrum and spectrum(in)stability of quantum corrected Schwarzschild black hole

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 55-75页

作者： Li-Ming Cao Jia-Ning Chen Liang-Bi Wu Libo Xie Yu-Sen Zhou School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China Peng Huanwu Center for Fundamental Theory Hefei 230026China Interdisciplinary Center for Theoretical study and Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

In this study,we investigate the pseudospectrum and spectrum(in)stability of quantum corrected Schwarzschild black ***,we use the hyperboloidal framework to cast the quasinormal mode(QNM)problem into an eigenvalue problem associated with a non-selfadjoint operator,and then the spectrum and pseudospectrum are ***,the invariant subspace method is exploited to improve the computational efficiency for *** investigation into the spectrum(in)stability entails two main *** the one hand,we calculate the spectra of the quantum corrected black hole,then by the means of the migration ratio,the impact of the quantum correction effect on the Schwarzschild black hole has been *** results indicate that the so-called“migration ratio instability”will occur for small black holes with small angular momentum number *** the eikonal limit,the migration ratios remain the same for each *** the other hand,we study the spectrum(in)stability of the quantum corrected black hole by directly adding some particular perturbations into the effective potential,where perturbations are located at the event horizon and null infinity,*** are two interesting observations under the same perturbation energy ***,perturbations at infinity are more capable of generating spectrum instability than those at the event ***,we find that the peak distribution can lead to the instability of QNM spectrum more efficiently than the average distribution.

关键词： quasinormal modes pseudospectrum hyperboloidal coordinate

Special Unipotent Representations of Simple Linear Lie Groups of Type A

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Acta Mathematica Sinica,English Series 2024年第3期40卷 707-716页

作者： Dan BARBASCH Jia Jun MA Bin Yong SUN Chen Bo ZHU Department of mathematics Cornell UniversityIthacaNY 14853USA School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China Department of mathematics Xiamen University Malaysia CampusSepangSelangor Darul Ehsan43900Malaysia institute for advanced study in mathematics&New Cornerstone Science Laboratory Zhejiang UniversityHangzhou 310058P.R.China Department of mathematics National University of Singapore10 Lower Kent Ridge RoadSingapore 119076

Let G be a special linear group over the real,the complex or the quaternion,or a special unitary *** this note,we determine all special unipotent representations of G in the sense of Arthur and Barbasch-Vogan,and show... 详细信息

关键词： Special unipotent representations unitary representations coherent continuation Weyl group representations

Combination of methylthio-chemistry with living crystallization-driven self-assembly toward uniformπ-conjugated nanostructures with antibacterial activity,surface tailorability,tunable morphology and dimension

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Science China Chemistry 2024年第7期67卷 2341-2352页

作者： Chuyu Duan Binbin Xu Ruru Li Xiaoyu Huang Shaoliang Lin Chun Feng Shanghai Key Laboratory of advanced Polymeric Materials School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Key Laboratory of Fluorine and Nitrogen Chemistry and advanced Materials Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Living crystallization-driven self-assembly(CDSA)provides robust access to uniformπ-conjugated nanostructures(CNSs)from block copolymers(BCPs)containing a crystallineπ-conjugated segment with controlled dimension,morphology and composition,which show appealing applications in biomedicine,photocatalysis and *** further expand the application spectrum of these CNSs,the development of facile strategies toward diverse CNSs with varying structures/functionalities is highly ***,BCPs consisting of oligo(p-phenylene ethynylene)-b-poly(polypropyl-3-methanethiol acrylate)(OPE_(9)-bPMTPA35and OPE_(9)-b-PMTPA_(58);the subscript represents the number of repeat unit of each block)consisting of a crystallineπ-conjugated core-forming OPE_(9)segment and a corona-forming PMTPA block are *** efficient“click-type”alkylation of methylthio groups,OPE_(9)-b-PMTPA with varying contents of sulfonium unit is *** ribbon-like micelles with different widths and lengths can then be generated in a controlled manner via the self-seeding approach of living ***,negatively charged polymeric and Ag nanoparticles can be immobilized on sulfonium/methylthio-containing shells by taking advantage of electrostatic attraction and coordination interaction,***,the ribbon-like micelles with positively charged shells exhibit antibacterial activity against *** the ease of modification of PMTPA-based shell and attractive opto-electronic/photocatalytic properties ofπ-conjugated units,the combination of methylthio-chemistry and living CDSA opens a new avenue to generate multi-functional CNSs for widespread applications from biomedicine to photocatalysis.

关键词： crystallization-driven self-assembly block copolymer π-conjugated nanostructure methylthio-chemistry

Achieving structurally stable O3-type layered oxide cathodes through site-specific cation-anion co-substitution for sodium-ion batteries

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Journal of Energy Chemistry 2024年第6期93卷 411-418,I0011页

作者： Yihao Shen Chen Cheng Xiao Xia Lei Wang Xi Zhou Pan Zeng Jianrong Zeng Liang Zhang institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123JiangsuChina institute for advanced study School of Mechanical EngineeringChengdu UniversityChengdu 610106SichuanChina Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Jiangsu Key Laboratory of advanced Negative Carbon Technologies Soochow UniversitySuzhou 215123JiangsuChina

O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical ***,challenges persist in the form of uncontrollable phase transitions and intricate Na^(+)diffusion pathways during cycling,resulting in compromised structural stability and reduced capacity over *** study introduces a special approach employing site-specific Ca/F co-substitution within the layered structure of O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) to effectively address these ***,the strategically site-specific doping of Ca into Na sites and F into O sites not only expands the Na^(+)diffusion pathways but also orchestrates a mild phase transition by suppressing the Na^(+)/vacancy ordering and providing strong metal-oxygen bonding strength,*** as-synthesized Na_(0.95)Ca_(0.05)Ni_(0.5)Mn_(0.5)O_(1.95)F_(0.05)(NNMO-CaF)exhibits a mild O3→O3+O'3→P3 phase transition with minimized interlayer distance variation,leading to enhanced structural integrity and stability over extended *** a result,NNMO-CaF delivers a high specific capacity of 119.5 mA h g^(-1)at a current density of 120 mA g^(-1)with a capacity retention of 87.1%after 100 *** study presents a promising strategy to mitigate the challenges posed by multiple phase transitions and augment Na^(+)diffusion kinetics,thus paving the way for high-performance layered cathode materials in sodium-ion batteries.

关键词： Sodium-ion batteries O3-type layered oxides Site-specific co-doping Phase transition

Highly efficient tunable photodetector with a bipolar response in van der Waals heterojunctions

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Science China(Technological Sciences) 2024年第2期67卷 639-646页

作者： SHI ChaoFan ZHANG Shi XIAO KeNing ZHANG LiBo HAN Li ZHU YuLin TANG WeiWei LIU ChangLong LI GuanHai CHEN XiaoShuang College of Physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences Hangzhou310024China State Key Laboratory of Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

The heterojunction integration of two-dimensional(2D)materials via van der Waals(vdW)forces,unencumbered by lattice and processing constraints,constitutes an efficacious approach to enhance the overall optoelectronic performance of photodetectors,due to an assortment of distinctive light-matter ***,vdW heterojunction photodetectors based on transition metal dichalcogenides(TMDs)face an inevitable trade-off between low dark currents and high responsivity,curtailing the application potential of myriad novel optoelectronic components in sensing,spectral,and communication *** this study,we present the successful actualization of a highly sensitive,self-powered,and gate-tunable bipolar response *** mechanisms underlying photocurrent generation were scrutinized via bias-,power-,and position-dependent mapping photoresponse measurements,identifying the photovoltaic effect,which is attributable to the Schottky junction’s built-in electric field,as the predominant *** prototype Au-WS2-graphene photodetector exhibits a remarkable light on/off ratio of 1.2×10^(6),a specific detectivity of 6.12×10^(11)cm H^(z1/2)W^(-1)with 20μs response time at 638 *** wide gate-tunable responsivity provides an adjustability scope,ranging from 0.9 to 3.1 A W^(-1).Notably,the device demonstrates an exceptional linear photocurrent response,with a linear dynamic range(LDR)value approximating 130 dB,which significantly surpasses that of other photodetectors based on TMDs.

关键词： WS2/graphene van der Waals heterojunction gate-tunable bipolar response

Learning to select the recombination operator for derivative-free optimization

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Science China mathematics 2024年第6期67卷 1457-1480页

作者： Haotian Zhang Jianyong Sun Thomas Back Zongben Xu School of mathematics and Statistics Xi’an Jiaotong UniversityXi’an710049China Leiden institute of advanced Computer Science Leiden UniversityLeiden2333 CANetherlands

Extensive studies on selecting recombination operators adaptively,namely,adaptive operator selection(AOS),during the search process of an evolutionary algorithm(EA),have shown that AOS is promising for improving EA's performance.A variety of heuristic mechanisms for AOS have been proposed in recent decades,which usually contain two main components:the feature extraction and the policy *** feature extraction refers to as extracting relevant features from the information collected during the search *** policy setting means to set a strategy(or policy)on how to select an operator from a pool of operators based on the extracted *** components are designed by hand in existing studies,which may not be efficient for adapting optimization *** this paper,a generalized framework is proposed for learning the components of AOS for one of the main streams of EAs,namely,differential evolution(DE).In the framework,the feature extraction is parameterized as a deep neural network(DNN),while a Dirichlet distribution is considered to be the policy.A reinforcement learning method,named policy gradient,is used to train the *** case studies,the proposed framework is applied to two DEs including the classic DE and a recently-proposed DE,which result in two new algorithms named PG-DE and PG-MPEDE,*** on the Congress of Evolutionary Computation(CEC)2018 test suite show that the proposed new algorithms perform significantly better than their ***,we prove theoretically that the considered classic methods are the special cases of the proposed framework.

关键词： evolutionary algorithm differential evolution adaptive operator selection reinforcement learning deep learning

Regulating the crystal phase of bismuth-based semiconductors for promoted photocatalytic performance

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Science China Chemistry 2024年第6期67卷 1839-1864页

作者： Zhaohui Wu Mei-Chi Chong Shiying Zhang Junshan Li Yongfa Zhu Hunan Key Laboratory of Applied Environmental Photocatalysis Changsha UniversityChangsha410022China Department of Chemistry Tsinghua UniversityBeijing100084China institute for advanced study Chengdu UniversityChengdu610106China

Numerous bismuth-based semiconductors(BBSs)with sophisticated and desirable structures used as photocatalysts for efficient photocatalytic degradation of water organic contaminants have attracted considerable ***,regulating the crystal phases and phase transition of BBSs for promoted photocatalytic performance is ***,the unique crystal structure and band structure features of each typical BBSs,and the vital roles on phase controlling of each phase were systematically presented based on the classification of ***,the critical factors for the phase transition of BBSs and intrinsic driving forces endowed by phases of BBSs for enhanced photocatalytic performance of organic contaminants removal were also *** review will provide systematical guidelines and horizons for regulating the crystal phase and phase transition of BBSs,promoting photocatalytic degradation and mineralization of organic contaminants.

关键词： bismuth-based semiconductors phase regulation photocatalytic performances organic contaminants

Facile semisynthesis of histone H3 enables nucleosome probes for investigation of histone H_(3)K79 modifications

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Chinese Chemical Letters 2024年第10期35卷 321-324页

作者： Kun Zou Yihang Xiao jinyu Yang Mingxuan Wu Department of Chemistry Zhejiang UniversityHangzhou 310027China Department of Chemistry School of ScienceWestlake UniversityHangzhou 310030China institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China

Histone H3K79 modifications are essential to regulate chromatin structure and gene transcription,but understanding of the molecular mechanisms is *** H3K79 is at globular domain,short histone peptide cannot mimic H3K79 in ***,reconstituted nucleosome-based chemical tools are ideally used to investigate H3K79 *** consequence,H3K79-modified histone H3 with additional chemical handles are required,but such synthesis is challenging and *** we report a facile semisynthesis method that enables multifunctional histone H3 readily available.H3K79-containing fragment is short for straight peptide synthesis that was later ligated to recombinant expressed H3 fragments for full-length product in large *** a result,nucleosomes with H3K79 modifications as well as photo-reactive group and affinity tag were obtained to investigate potential binding *** believe this method that enhances synthetic accessibility of nucleosome probes will accelerate understanding of the underexplored H3K79 modifications.

关键词： Histone H3K79 modifications Methylation Succinylation Semisynthesis Nucleosome probes