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NHC-mediated photocatalytic para-selective C–H acylation of aryl alcohols: regioselectivity control via remote radical spiro cyclization

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science China Chemistry 2025年

作者： Tinglei Zhang Lala Wang Xiaolin Peng Tianhui Liao Dongmei Chen Ting Tu Donghan Liu Ziye Cheng Shiqing Huang Shi-Chao Ren Xinglong Zhang Yonggui Robin Chi State Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Qiannan Medical College for Nationalities School of Chemistry Chemical Engineering and Biotechnology Nanyang Technological University Department of Chemistry The Chinese University of Hong Kong institute of high performance computing Agency for Science Technology and Research

Friedel-Crafts reaction and transition-metal catalysis represent primary methodologies for arene acylation; however, suffer from certain limitations, such as electronic effect-dependent reactivity, regioselectivity issues, the necessity of directing group, and relatively exceptionally limited exploration in meta-and para-acylations. N-heterocyclic carbene(NHC) catalysis has recently emerged as a promising alternative strategy for arene acylation, offering distinct regioselectivity profiles that are challenging to achieve through known methods. Herein, an NHC-mediated photo-catalytic para-selective C–H acylation of aryl alcohols is disclosed. The reaction employs a remote radical-induced temporary spiro cyclization strategy, proceeding via tandem radical dearomatization, radical acylation, rearomatization processes. Combined experimental and computational mechanistic studies support the proposed reaction pathway and observe an exclusive para-selectivity regardless of the nature of the substituents on the substrates. Despite the less satisfactory yields, the current method exhibits non-electronic nature-based reactivity and regioselectivity, enabling quick access to acylated arenes that are difficult or impossible for reported methods.

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Mechanistic insight into the synergy between nickel single atoms and nanoparticles on N-doped carbon for electroreduction of CO2

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Journal of Energy Chemistry 2025年第1期100卷 327-336页

作者： Mingdong Sun Wenwen Guan Cailing Chen Chao Wu Xiaoling Liu Biao Meng Tao Chen Yu Han Jun Wang Shibo Xi Yu Zhou State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University Advanced Membranes and Porous Materials Center Physical Sciences and Engineering Division King Abdullah University of Science and Technology institute of Sustainability for Chemicals Energy and Environment A*STAR (Agency for Science Technology and Research) College of Materials science and Engineering Sichuan University

The synergy of single atoms （SAs） and nanoparticles （NPs） has demonstrated great potential in promoting the electrocatalytic carbon dioxide reduction reaction （CO2RR）;however,the rationalization of the SAs/NPs proportion remains one challenge for the catalyst ***,a Ni2+-loaded porous poly（ionic liquids）(PIL) precursor synthesized through the free radical self-polymerization of the ionic liquid monomer,1-allyl-3-vinylimidazolium chloride,was pyrolyzed to prepare the Ni,N co-doped carbon materials,in which the proportion of Ni SAs and NPs could be facilely modulated by controlling the annealing *** catalyst Ni-NC-1000 with a moderate proportion of Ni SAs and NPs exhibited high efficiency in the electrocatalytic conversion of CO2into *** Ni K-edge X-ray absorption near-edge structure （XANES） spectra and theoretical calculations were conducted to gain insight into the synergy of Ni SAs and *** charge transfer from Ni NPs to the surrounding carbon layer and then to the Ni SAs resulted in the electron-enriched Ni SAs active *** the electroreduction of CO2,the coexistence of Ni SAs and NPs strengthened the CO2activation and the affinity towards the key intermediate of*COOH,lowering the free energy for the potential-determining*CO2→*COOH step,and therefore promoted the catalysis efficiency.

关键词： Activation energy

Laser assisted phase transformation of carbon-based transition metal oxide electrode for high-performance supercapacitor application

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science China Chemistry 2025年

作者： Mingzhen Xiu Jianghong Zhang Yu Lu Xun Cao Kang Huang Siyu Zhu Bowei Zhang Yu Liang Chunwang Zhao Junsheng Wu Yizhong Huang School of Materials science and Engineering Nanyang Technological University Energy Research institute Interdisciplinary Graduate Programme Nanyang Technological University institute of Sustainability for Chemicals Energy and Environment Agency for Science Technology and ResearchSingapore institute of Advanced Materials and Technology University of Science and Technology Beijing School of Materials science and Technology Shenyang University of Chemical Technology School of Materials science and Hydrogen Energy Foshan University

Transitional metal oxides have a wide range of applications due to their superior *** enhanced performance of metal oxide relies on their desirable oxidation states,which is challenging to achieve and requires complex *** study demonstrates a facile strategy enabling rapid phase transformation of transition metal *** approach involves synthesis of a tetragonal Mn3O4/carbon cloth composite using the liquid plasma discharge deposition （LPDD） technique,followed by laser irradiation with the presence of ethylene glycol under an N2gas *** resulting face-centered cubic MnO/carbon cloth electrode exhibits an excellent capacitance of 1,125 F g-1at 2 A g-1,with remarkable capacitance retention of 95%after10,000 *** approach can be extended to other transition metals including Co,Cu,Cr,Fe,Ni,and *** simulations reveal the significance of ethylene glycol and the underlying mechanism associated with the phase transformation of transition metal *** present study offers a powerful technique for the phase transformation of transition metal oxide which can guide the development of new electrode materials with enhanced electrochemical properties for high-performance energy storage applications.

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3D TEM study on hollow α-Fe2O3 nanostructures and nanorings

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Progress in Natural science:Materials International 2019年第6期29卷 685-689页

作者： Ming Lin Enyi Ye Jia Zhang institute of Materials Research and Engineering A*STAR (Agency for Science Technology and Research) institute of high performance computing A*STAR (Agency for Science Technology and Research)

Controlled synthesis of hollow structures with non-spherical holes is significant in fabricating nanomaterials with well-defined geometries and specific catalytic and electrochemical properties. Here we report the synthesis of uniform hexagonal bipyramid hematite(α-Fe2O3) nanoparticles with hollow and faceted interior via directional etching process in solution. The delicate hollow structures were investigated by electron tomography and growth mechanism was revealed unambiguously. The three-dimensional visualization demonstrates the outside surfaces of hematite particles are enclosed by six {104} and twelve {113} planes, due to the stabilizing effect of the F-anions on the exposed surfaces. The concurrent etching process is a reverse process of crystal growth and leads to the dissolution occurring at the edges and tips of the hexagonal bipyramid particles, resulting in the perforated crystals with exposed {102} internal facets or overetched nanorings with hexagonal *** nanoscale growth and etching process still strictly follows the bulk crystal growth mechanism, thus shedding light on the synthesis of other nanoparticle with controlled morphologies and porous structures.

关键词： Tomography Hexagonal bipyramid Dissolution Facet control Phase transformation

Hypervelocity impact induced shock acoustic emission waves for quantitative damage evaluation using in situ miniaturized piezoelectric sensor network

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Chinese Journal of Aeronautics 2019年第5期32卷 1059-1070页

作者： Menglong LIU Qiang WANG Qingming ZHANG Renrong LONG Fangsen CUI Zhongqing SU institute of high performance computing A*STAR (agency for science Technology and Research) School of Automation Nanjing University of Posts and Telecommunications State Key Laboratory of Explosion science and Technology Beijing Institute of Technology institute of high performance computing (A*STAR agency for science Technology and Research) Department of Mechanical Engineering The Hong Kong Polytechnic University

Manmade debris and natural meteoroids, travelling in the Low Earth Orbit at a speed of several kilometers per second, pose a severe safety concern to the spacecraft in service through the HyperVelocity Impact(HVI). To address this issue, an investigation of shock Acoustic Emission(AE) waves induced by HVI to a downscaled two-layer Whipple shielding structure is performed,to realize a quantitative damage evaluation. Firstly a hybrid numerical model integrating smoothparticle hydrodynamics and finite element is built to obtain the wave response. The projectiles, with various impact velocities and directions, are modelled to impact the shielding structure with different thicknesses. Then experimental validation is carried out with built-in miniaturized piezoelectric sensors to in situ sense the HVI-induced AE waves. A quantitative agreement is obtained between numerical and experimental results, demonstrating the correctness of the hybrid model and facilitating the explanation of obtained AE signals in experiment. Based on the understanding of HVI-induced wave components, assessment of the damage severity, i.e., whether the outer shielding layer is perforated or not, is performed using the energy ratio between the regions of ‘‘high frequency" and ‘‘low frequency" in the acquired AE signals. Lastly, the direct-arrival fundamentalsymmetric wave mode is isolated from each sensing signal to be input into an enhanced delay-andsum algorithm, which visualizes HVI spots accurately and instantaneously with different sensor network configuration. All these works demonstrate the potential of quantitative, in situ, and real time HVI monitoring using miniaturized piezoelectric sensor network.

关键词： Acoustic Emission(AE) Damage detection Hypervelocity impact Piezoelectric sensor Whipple shielding assembly

Modulating the thermal conductivity of silicon nanowires via surface amorphization

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science China(Technological sciences) 2014年第4期57卷 699-705页

作者： LIU XiangJun ZHANG Gang PEI QingXiang ZHANG YongWei institute of high performance computing

We perform non-equilibrium molecular dynamics calculations to study the heat transport in crystalline-core amorphous-shell silicon nanowires(SiNWs).It is found that the thermal conductivity of the core-shell SiNWs is closely related to the cross-sectional area ratio of amorphous *** shell amorphization,an 80%reduction in thermal conductivity compared to crystalline SiNWs with the same size can be achieved,due to the non-propagating heat diffusion in the amorphous *** contrast to the strong temperature-dependent thermal conductivity of crystalline SiNWs,the core-shell SiNWs only show weak temperature *** addition,an empirical relation is proposed to accurately predict the thermal conductivity of the core-shell SiNWs based on the rule of *** present work demonstrates that SiNWs with an amorphized shell are promising candidates for thermoelectric applications.

关键词： thermal conductivity thermoelectric molecular dynamics silicon nanowire

Breakup of spherical vesicles caused by spontaneous curvature change

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Acta Mechanica Sinica 2012年第6期28卷 1545-1550页

作者： Ping Liu Ju Li Yong-Wei Zhang institute of high performance computing Department of Nuclear science and Engineering Massachusetts Institute of Technology

We present our theoretical analysis and coarse- grained molecular dynamics （CGMD） simulation results to describe the mechanics of breakup of spherical vesi- cles driven by changes in spontaneous curvature. System- atic CGMD simulations reveal the phase diagrams for the breakup and show richness in breakup morphologies. A the- oretical model based on Griffith fracture mechanics is devel- oped and used to predict the breakup condition.

关键词： Molecular dynamics Bending modulus Phasediagram. Fracture

Thermal properties of two-dimensional materials

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Chinese Physics B 2017年第3期26卷 59-70页

作者：张刚张永伟 institute of high performance computing A*STAR Singapore

Two-dimensional （2D） materials, such as graphene, phosphorene, and transition metal dichalcogenides （e.g., MoS2 and WS2）, have attracted a great deal of attention recently due to their extraordinary structural, mechanical, and physical properties. In particular, 2D materials have shown great potential for thermal management and thermoelectric energy generation. In this article, we review the recent advances in the study of thermal properties of 2D materials. We first review some important aspects in thermal conductivity of graphene and discuss the possibility to enhance the ultra-high thermal conductivity of graphene. Next, we discuss thermal conductivity of MoS2 and the new strategy for thermal management of MoS2 device. Subsequently, we discuss the anisotropic thermal properties of phosphorene. Finally, we review the application of 2D materials in thermal devices, including thermal rectifier and thermal modulator.

关键词： thermal conduction two-dimensional materials

Collaborative Knowledge Infusion for Low-Resource Stance Detection

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Big Data Mining and Analytics 2024年第3期7卷 682-698页

作者： Ming Yan Tianyi Zhou Joey W.Tsang Ivor Centre for Frontier AI Research and Institute of High-Performance ComputingAgency for Science Technology and ResearchSingapore 138632Singapore

Stance detection is the view towards a specific target by a given context(***,commercial reviews).Target-related knowledge is often needed to assist stance detection models in understanding the target well and making detection ***,prevailing works for knowledge-infused stance detection predominantly incorporate target knowledge from a singular source that lacks knowledge verification in limited domain *** low-resource training data further increase the challenge for the data-driven large models in this *** address those challenges,we propose a collaborative knowledge infusion approach for low-resource stance detection tasks,employing a combination of aligned knowledge enhancement and efficient parameter learning ***,our stance detection approach leverages target background knowledge collaboratively from different knowledge sources with the help of knowledge ***,we also introduce the parameter-efficient collaborative adaptor with a staged optimization algorithm,which collaboratively addresses the challenges associated with low-resource stance detection tasks from both network structure and learning *** assess the effectiveness of our method,we conduct extensive experiments on three public stance detection datasets,including low-resource and cross-target *** results demonstrate significant performance improvements compared to the existing stance detection approaches.

关键词： parameter-efficient learning low-resource stance detection knowledge infusion