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Topologically engineering of π-conjugated macrocycles: Tunable emission and photochemical reaction toward multi-cyclic polymers

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Chinese Chemical Letters 2024年第10期35卷 259-266页

作者： Yi Liu Peng Lei Yang Feng Shiwei Fu Xiaoqing Liu Siqi Zhang Bin Tu Chen Chen Yifan Li Lei Wang qing-dao zeng Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional Materials College of Materials Science and Engineering Shenzhen University CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology (NCNST) Institute of Critical Materials for Integrated Circuits Shenzhen Polytechnic University

The topology of conjugated macrocycles had significant impacts on their photo-physical and photochemical properties. Herein, a series of π-conjugated macrocycles with diverse topology were synthesized via intramolecular McMurry coupling. Their chemical structure and macrocyclic topology were unambiguously confirmed via NMR, MALDI-TOF mass spectra, crystal analysis and scanning tunneling microscopy(STM). Depending on the structural topology and structural rigidity, these cyclic compounds display obviously distinctive emission behavior and photochemical reactions in the solution and in the solid *** phenylene vinylene macrocycle(denoted as MST) exhibiting aggregation-induced emission behavior, was more vulnerable to photo-cyclization in solution and triplet sensitizer promoted photodimerization due to lower strain and more flourishing intramolecular motions. After UV light irradiation,relatively more flexible MST could yield the anti-dimer via triplet excimer on the HOPG surface confirmed by STM investigation. By contrast, highly constrained bicyclic analogue(named as DMTPE) with central tetraphenylethene core, displayed high emission quantum yields of 68% both in solution and in the solid state, and was relatively inert to photochemical reactions and yield syn-dimer on the surface via singlet excimer involved [2 + 2] photo-dimerization. Based on the solution-mediated photo-polymerization of MST moiety, multicyclic porous carbon-rich ribbon connected with four-membered ring was successfully constructed and validated via STM imaging.

关键词： Aggregation-induced emission Conjugated macrocycle Multicyclic ribbon Photochemistry Scanning tunneling microscopy

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Construction of two-dimensional(2D) H-bonded supramolecular nanostructures studied by STM

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Chinese Chemical Letters 2013年第3期24卷 177-182页

作者： Jing Xu qing-dao zeng National Center for Nanoscience and Technology(NCNST)

In this review, a group ot two-dimensional （2D） hydrogen-bonded supramolecular networks developed in our laboratory are discussed. Our attention is mainly focused on：（1） recognition of Fe3＋ through twocomponent molecular networks; （2） site-selective fabrication of 2D fullerene arrays; and （3） fabrication of the nanoporous structure regulated by photoisomerization reaction process. It is envisioned that special supramolecular nanostructures, through H-bonding interactions, can be constructed or reconstructed to be further investigated toward the research of multi-component systems, molecule recognition, single molecular switches, and host-guest supramolecular chemistry.

关键词： Scanning tunneling microscopy (STM)Self-assemblySupramolecular networkHydrogen bonds

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Photo-regulation of 2D supramolecular self-assembly：On-surface photochemistry studied by STM

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Chinese Chemical Letters 2017年第4期28卷 729-737页

作者： Hong-Liang Dai Yan-Fang Geng qing-dao zeng Chen Wang CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology (NCNST) Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

During the past few years,regulation and controlling of the two-dimension（2D） self-assembled supramolecular structure on surface have drawn increasing attention in nanoscience and *** stimuli have been widely used to regulate these 2D *** various external stimuli approaches,photo-regulation as one of the most outstanding means of regulation has been extensively studied because different wave bands can lead to molecular conformation variation and new bonds to gain new *** this review,the photo-regulated self-assembled structure on solid surface as well as the photo-reactions of different molecules substituted with photo-sensitive groups are introduced to give us an insight into on-surface photochemistry,which plays an important role on the nano-devices ***,these photo-sensitive behaviors as well as the formed structures on surface were probed at sub-molecule level by unique scanning tunneling microscopy（STM） technique.

关键词： Scanning tunneling microscopy(STM) Photochemistry Light irradiation 2D self-assembly Molecular template

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Formation of heterocaryotic and homonuclear bridged–dimeric complexes on surface

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Chinese Chemical Letters 2016年第4期27卷 602-606页

作者： Yan-Fang Geng Shi-Li Wu Jing Xu Hong-Liang Dai Xiao-Kang Li Ke Deng qing-dao zeng CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscienceand Technology (NCNST) Beijing 100190 China Key Laboratory of Organo-pharmaceutical Chemistry. Gannan Normal University Ganzhou 341000 China

The formation of coordinated dimeric complexes bridged by axial ligands on surface is observed with the help of a 1,3,5-tris（10-carboxydecyloxy）benzene（TCDB） template through scanning tunneling microscopy（STM）. STM images of molecular adlayers of zinc tetraphenylporphyrin（Zn TPP）, zinc phthalocyanine（Zn Pc）, and their mixture are reported. Zn TPP and Zn Pc can spontaneously form highly an ordered structure with a 1：1 molar ratio, which is different from that of individual Zn Pc. The coordinated bimolecular complexes bridged with axial ligands, simply as Zn Pc–DPP–Zn TPP and Zn Pc–DPE–Zn Pc, are presented and the corresponding surface structures are compared. Zn Pc and Zn TPP can be connected by an axial ligand DPP and formed assembled structures out of surface. Two types of arrays with entirely new structure are obtained for the Zn Pc–DPE–Zn Pc complex. These bridged hybrid complexes provide an example of design of self-organized crystals on the basis of coordination through non-covalent interactions.

关键词： Coordinated dimeric complexes Zinc tetraphenylporphyrin(ZnTPP) Zinc phthalocyanine(ZnPc) Scanning tunneling microscopy(STM) Axial ligands

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Switching,explosion,and chaos of multi-wavelength soliton states in ultrafast fiber lasers

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 82-90页

作者： Zhi-zeng Si Yue-Yue Wang Chao-qing Dai College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityLin’an 311300China

Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are *** this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are *** generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three *** and negative dispersion lead to different group velocities of *** presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an *** an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental *** work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.

关键词： multi-wavelength fiber laser soliton explosion chaos state switching real-time dynamics

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El Niño and the AMO Sparked the Astonishingly Large Margin of Warming in the Global Mean Surface Temperature in 2023

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Advances in Atmospheric Sciences 2024年第6期41卷 1017-1022页

作者： Kexin LI Fei ZHENG Jiang ZHU qing-Cun zeng International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China

In 2023,the majority of the Earth witnessed its warmest boreal summer and autumn since *** 2023 will indeed turn out to be the warmest year on record and what caused the astonishingly large margin of warming has become one of the hottest topics in the scientific community and is closely connected to the future development of human *** analyzed the monthly varying global mean surface temperature(GMST)in 2023 and found that the globe,the land,and the oceans in 2023 all exhibit extraordinary warming,which is distinct from any previous year in recorded *** on the GMST statistical ensemble prediction model developed at the Institute of Atmospheric Physics,the GMST in 2023 is predicted to be 1.41℃±0.07℃,which will certainly surpass that in 2016 as the warmest year since 1850,and is approaching the 1.5℃ global warming *** to 2022,the GMST in 2023 will increase by 0.24℃,with 88%of the increment contributed by the annual variability as mostly affected by El Niñ***,the multidecadal variability related to the Atlantic Multidecadal Oscillation(AMO)in 2023 also provided an important warming background for sparking the GMST *** a result,the GMST in 2023 is projected to be 1.15℃±0.07℃,with only a 0.02℃ increment,if the effects of natural variability—including El Niño and the AMO—are eliminated and only the global warming trend is considered.

关键词： record-breaking temperature global mean surface temperature El Niño AMO global warming

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High Speed Sintering:Assessing the Influence of Energy Input on Microstructure and Mechanical Properties of Polyether Block Amide(PEBA)Parts

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Chinese Journal of Polymer Science 2024年第5期42卷 675-682,I0004,I0010页

作者： Jiang-Tao Sun Zhi-Yong Fan Yi-Wei Mao Wei Li Wei Zhu dao-Sheng Cai qing-Song Wei State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430074China National Engineering Research Centre for High Efficiency Grinding Hunan UniversityChangsha410082China Wuhan EasyMFG Technology CO. LTDWuhan430074China

High speed sintering,a new powder-bed fusion additive manufacturing technology,utilizes infrared lights(IR)to intensely heat and melt polymer *** presence of defects such as porosity,which is associated with particle coalescence,is highly dependdent on the level of energy *** study investigate the influcence of energy input on porosity and its subsequent effects on the mechanical properties and microstructures of PEBA *** parts were manufactured with a variety of lamp powers,resulting in a range of energy input levels spanning from low to ***,they underwent testing using Archimedes’method,followed by tensile *** porosity,mechanical characteristics,and energy input exhibit a strong correlation;inadequate energy input was the primary cause of pore *** the reduced IR light power resulted in the following outcomes:porosity,ultimate tensile strength,and elongation of 1.37%,7.6 MPa,and 194.2%,*** the energy input was further increased,the porosity was reduced to as low as 0.05%and the ultimate tensile strength and elongation were increased to their peak values of 233.8%and 9.1 MPa,respectively.

关键词： High speed sintering Additive manufacturing Energy input Powder bed fusion PEBA

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Reliability of DC-link capacitor in pulsed power supply for accelerator magnet

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Nuclear Science and Techniques 2024年第9期35卷 28-40页

作者： Jie Wang Da-qing Gao Wan-zeng Shen Hong-Bin Yan Li-Jun Mao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Capacitors are widely used in pulsed magnet power supplies to reduce ripple voltage,store energy,and decrease power *** this study,DC-link capacitors in pulsed power supplies were *** deriving an analytical method for the capacitor current on the H-bridge topology side,the root-mean-square value of the capacitor current was calculated,which helps in selecting the DC-link *** proposed method solves this problem quickly and with high *** current reconstruction of the DC-link capacitor is proposed to avoid structural damage in the capacitor’s current measurement,and the capacitor’s hotspot temperature and temperature rise are calculated using the FFT *** test results showed that the error between the calculated and measured temperature increases was within 1.5℃.Finally,the lifetime of DC-link capacitors was predicted based on Monte Carlo *** proposed method can evaluate the reliability of DC-link capacitors in a non-isolated switching pulsed power supply for accelerators and is also applicable to film capacitors.

关键词： Aluminum electrolytic capacitor DC-link current DC–DC power converter Hotspot temperature

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A Low Cost, Green Sustainable and Biodegradable Biomass-based Fluorine-free Water and Oil Repellent

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Chinese Journal of Polymer Science 2024年第4期42卷 480-491页

作者： Zhi-Wei Shen Shu-Feng Hu Chen zeng Wei-qing Kong Mei-Fang Zhu State Key Laboratory for Modification of Chemical Fibers&Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510630China

With the global ban on plastics intensifying, the substitution of plastic with paper has garnered increasing attention. However, the inadequate water and oil repellency of pulp molding hinders its practical applications. Currently, the common method to enhance the oil and water repellency of pulp molding is by adding fluorinated water and oil repellents. Nevertheless, fluorinated compounds are environmentally and physiologically harmful. Therefore, the development of fluorine-free, water and oil repellent alternatives is crucial. In this study, chitosan and stearic acid were utilized as the first and second layers of the oil and water repellent coatings, respectively. The coated samples exhibited favorable water repellency, with a water contact angle of 116.4°, and excellent oil repellency, achieving a 12/12 rating on the kit scale. Importantly, the samples did not exhibit any leakage after being soaked in hot water and hot oil at 95±5℃ for 30 min, demonstrating remarkable performance as a barrier against hot water and oil. Moreover, the coated samples displayed outstanding mechanical properties, thermal stability, biodegradability, and recyclability. The approach presented in this study is simple, cost-effective, environmentally friendly, and represents a promising technique for producing fluoride-free, oil-and water-resistant pulp molding products.

关键词： Biomass Fluoride-free Oil-andwater-resistant Plasticfree

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Two-Dimensional Functional Nano-Structure Construction:STM Reveals

Two-Dimensional Functional Nano-Structure Construction:STM R...

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中国化学会第六届全国结构化学学术会议

作者： Xue-Mei Zhang,Chen Wang,qing-dao zeng~* National Center for Nanoscience and Technology,Beijing,100190

＜正＞Supramolecular architectures formed by the self-assemblies of functional molecular building blocks are attracting considerable interest due to their potential applications in nanoscience and *** the past years,scanning tunneling microscopy（STM） imaging is widely used for characterising assembling structure of organic monolayer at the noble metal or HOPG substrate in UHV or at ambient temperature.

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