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Impact of Polymer matrix on Polymer Mechanochromism from Excited State Intramolecular Proton Transfer

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Chinese Journal of Chemistry 2024年第6期42卷 611-616页

作者： Yu Wu Xin Cheng Huan Hu Shui Hu Zhimin ma Zhiyong ma Beijing Advanced Innovation Center for Soft matter Science and Engineering Beijing State Key Laboratory of Organic-Inorganic CompositesCollege of Chemical EngineeringBeijing University of Chemical TechnologyBeijing100029 China Center of Advanced Elastomer materials College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029 China College of Engineering Peking UniversityBeijing100871 China

Mechanochromic polymers based on non-covalent changes have attracted much attention ***,we report the impact of inter/intramolecular hydrogen bonds on polymer mechanochromism from the excited state intramolecular proton transfer (ESIPT) ***-NH2-OH and PhMz=2A are designed and obtained by simple and high-yield synthesis,and are connected into polyurethane and poly(methyl acrylate-co-2-ethylhexyl acrylate),*** the initial state,the PhMz-NH2-OH@PU sample shows blue fluorescence from the excited enol form (E*) excitons,owing to intermolecular hydrogen bonds that interrupt the ESIPT reactions but the PhMz=2A@Pma-2-EA sample expresses cyan fluorescence belonging to the excited keto form (K*) emission,implying that the intramolecular hydrogen bonds ***,under stretching,external force can tune the emission of the PhMz=2A@Pma-2-EA sample from K* to E* *** external force can putatively still promote a bond rotation,ESIPT reactions remain equivalently interrupted in both the relaxed and stressed states in a hydrogen-bond donating *** calculation confirms the force-induced increase in dihedral angle for the transition of ESIPT-on/***,PhMz-NH2-OH@PU and PhMz=2A@Pma-2-EA showed disparate initial ESIPT states and further different responses/sensitivity to *** study reports a novel and efficient strategy for enriching mechanochromic investigation and extending the applications of ESIPT reactions.

关键词： Polymer mechanochromism Excited state intramolecular proton transfer Hydrogen bonding Supramolecular chemistry Elastomers

Bionic soft robotic gripper with feedback control for adaptive grasping and capturing applications

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Frontiers of Mechanical Engineering 2024年第1期19卷 129-148页

作者： Tingke WU Zhuyong LIU Ziqi ma Boyang WANG Daolin ma Hexi YU Department of Engineering Mechanics School of Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Hydrodynamics Shanghai Jiao Tong UniversityShanghai 200240China

Robots are playing an increasingly important role in engineering *** robots have promising applications in several fields due to their inherent advantages of compliance,low density,and soft interactions.A soft gripper based on bio-inspiration is proposed in this *** analyze the cushioning and energy absorption mechanism of human fingertips in detail and provide insights for designing a soft gripper with a variable stiffness *** investigate the grasping modes through a large deformation modeling approach,which is verified through *** characteristics of the three grasping modes are quantified through testing and can provide guidance for robotics ***,the adaptability of the soft gripper is verified by grasping multi-scale and extremely soft ***,a cushioning model of the soft gripper is proposed,and the effectiveness of cushioning is verified by grasping extremely sharp objects and living ***,we validate the advantages of the variable stiffness of the soft gripper,and the results show that the soft robot can robustly complete assemblies with a gap of only 0.1 *** to the unstructured nature of the engineering environment,the soft gripper can be applied in complex environments based on the abovementioned experimental ***,we design the soft robotics system with feedback capture based on the inspiration of human catching *** feasibility of engineering applications is initially verified through fast capture experiments on moving *** design concept of this robot can provide new insights for bionic machinery.

关键词： soft bionic gripper variable stiffness structure large deformation modeling feedback control soft robotic system

Theoretical study of aromaticity reversal in dimethyldihydropyrene derivatives

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Chinese Journal of Structural Chemistry 2024年第5期43卷 8-10页

作者： Fangwen Peng Zhen Luo Yingjin ma Haibo ma School of Chemistry and Chemical Engineering Nanjing UniversityNanjing210023China Computer Network Information Center Chinese Academy of SciencesBeijing100190China Qingdao Institute for Theoretical and Computational Sciences School of Chemistry and Chemical EngineeringShandong UniversityQingdaoShandong266237China

Aromaticity has always been an intriguing chemistry topic,which is considered to have close relations with materials'stability and chemical reactivity due to special energy *** conjugated cycles,Hückel's rule,proposed in 1931,suggests that annulenes having[4n+2]and[4n]πelectrons present aromatic and antiaromatic characters with closed and open electronic configurations,respectively[1].

关键词： Hückel aromatic reactivity

Tuning Surface Molecular Design of Porous Carbon for Blue Energy Harvesting

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Research 2024年第1期2023卷 651-662页

作者： Jian Yu Zhong-Lin Wang Tianwei ma Department of Civil and Environmental Engineering University of Hawaii at MānoaHonoluluHI 96822USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Engineering Texas A&M University-Corpus ChristiCorpus ChristiTX 78412USA

Capacitive mixing is a promising blue energy technology due to its membrane-free electricity generation and long electrode life ***,because of limited performance,existing systems do not lend themselves to practical *** it is a crucial factor directly influencing electrode behavior,surface chemistry has largely been overlooked in capacitive ***,we show that manipulating surface functionalization alone can tune the responses of electrodes to produce a high voltage rise without altering the pore structure of the *** findings reveal that the spontaneous electrode potential of a surface-modified carbon electrode shifts negatively proportional to the surface charge due to the surface groups,which explains why and how manipulating the surface chemistry can improve the power generation capacity.

关键词： electrode Porous mixing

Deployment analysis of composite thin-walled lenticular tubes with effect of storage time and temperature

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Chinese Journal of Aeronautics 2024年第1期37卷 162-172页

作者： Jinfeng DENG Ning AN Qilong JIA Xiaofei ma School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Xi’an Institute of Space Radio Technology Xi’an 710100China

Composite Thin-walled Lenticular Tube(CTLT)is increasingly utilized in small satellites missions as a lightweight,foldable,and rollable structural material that facilitates the construction of large deployable *** CTLT is initially flattened and coiled around a central hub for storage before launch,during which elastic energy is stored as deformation energy,allowing it to be self-deployed on demand for use in *** work presents a comprehensive investigation into the coiling,storage and deployment behaviors of CTLT that wraps around a central hub.A nonlinear explicit dynamic finite element model was developed with both deformable CTLT and rigidbodies mechanisms including the central hub and guide rollers,as well as the complex interactions among *** coiling mechanics characteristics such as stored strain energy and rotational moment were presented and validated against experimental data in the ***,the dynamic deployment behaviors were analyzed in terms of two different deployment methods,namely,controlled deployment and free *** effect of material property change during storage was also discussed through numerical experiments.

关键词： Composite deployable structures Deployment dynamics Finite element method Stress relaxation Thin-walled booms

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

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National Science Review 2024年第4期11卷 111-122页

作者： Rui Zhang Qi Meng Zhi-Ming ma Academy of mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional *** to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

Non-Fully Conjugated Photovoltaic materials with Y-Series Acceptor Backbone for High-Performance Organic Solar Cells

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Chinese Journal of Chemistry 2024年第11期42卷 1307-1318页

作者： Hairui Bai Qunping Fan Ruijie ma Xia Guo Wei ma maojie Zhang State Key Laboratory for Mechanical Behavior of materials Xi’an Jiaotong UniversityXi’anShaanxi710049 China National Engineering Research Center for Colloidal materials School of Chemistry&Chemical EngineeringShandong UniversityJinanShandong250100 China Department of Electronic and Information Engineering Research Institute for Smart Energy(RISE)The Hong Kong Polytechnic UniversityKowloon999077 Hong KongChina

In the last few years,organic solar cells(OSCs)have made significant progress in photovoltaic performance,mainly due to the innovative development of active layer materials,especially Y-series and related derivatives as acceptors which have become the key factor that boosts the power conversion ***,to achieve high-performance OSCs,an emerging molecular design strategy of applying flexible alkyl units as linkers to construct non-fully conjugated acceptors has been developed and addressed great *** review highlights the non-fully conjugated photovoltaic materials with Y-series backbone that enable high-performance *** OSCs have been achieved by some representative non-fully conjugated material *** related molecular design strategies are discussed in ***,a brief summary and future prospect are provided in advancing the non-fully conjugated photovoltaic materials with Y-series backbone towards the brighter future.

关键词： Organic solar cells All-polymer solar cells Non-fully conjugated photovoltaic materials Power conversion efficiency Polymer acceptors Organicel ectronics

Armoring lithium metal anode with soft±rigid gradient interphase toward high-capacity and long-life all-solid-state battery

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Green Energy & Environment 2024年第8期9卷 1279-1289页

作者： Rui Zhang Biao Chen Yuhan ma Yue Li Junwei Sha Liying ma Chunsheng Shi Naiqin Zhao School of materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional materials Tianjin University Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Department of Chemical and Biomolecular Engineering National University of Singapore Collaborative Innovation Centre of Chemical Science and Engineering

Solid polymer electrolytes （SPEs） are highly promising for realizing high-capacity,low-cost,and safe Li metal ***,the Li dendritic growth and side reactions between Li and SPEs also plague these ***,a fluorinated lithium salt coating （FC） with organicinorganic gradient and soft-rigid feature is introduced on Li surface as an artificial protective layer by the in-situ reaction between Li metal and fluorinated carboxylic *** FC layer can improve the interface stability and wettability between Li and SPEs,assist the transport of Li ions,and guide Li nucleation,contributing to a dendrite-free Li deposition and long-lifespan Li metal *** symmetric cell with FC-Li anodes exhibits a high areal capacity of 1 mah cm-2at 0.5 ma cm-2,and an ultra-long lifespan of 2000 h at a current density of 0.1 m A ***,the full cell paired with the LiFePO4cathode exhibits improved cycling stability,remaining 83.7%capacity after 500 cycles at 1 *** matching with the S cathode,the FC layer can prevent the shuttle effect,contributing to stable and high-capacity Li-S *** work provided a promising way for the construction of stable all-solid-state lithium metal batteries with prolonged lifespan.

关键词： All-solid-state battery Solid polymer electrolyte Li metal anode Li nucleation Interface stability

Greedy is Good:Constrained Non-submodular Function maximization via Weak Submodularity

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Journal of the Operations Research Society of China 2024年第3期12卷 627-648页

作者： ma-Jun Shi Wei Wang School of Statistics Xi’an University of Finance and EconomicsXi’an710100ShaanxiChina School of mathematics and Statistics Xi’an Jiaotong UniversityXi’an710049ShaanxiChina

The widely used greedy algorithm has been recently shown to achieve near-optimal theoretical guarantees for the problems of constrained monotone non-submodular function maximization,with competitive performances in *** this paper,we investigate the problems of maximizing monotone non-submodular set functions under three classes of independent system constraints,including p-matroid intersection constraints,p-extendible system constraints and p-system *** prove that the greedy algorithm yields an approximation ratio ofγ/p+γfor the former two problems,andξγ/p+ξγfor the last problem,which further has been improved toγ/p+γ,whereγ,ξdenote the submodularity ratio and the diminishing returns ratio of set function *** addition,we also show that the greedy guarantees have a further refinement of for all the problems mentioned above,whereαis the generalized curvatureξ/p+αγof set ***,we show that our greedy algorithm does yield competitive practical performances using a variety of experiments on synthetic data.

关键词： Non-submodular function p-matroid intersection p-extendible system p-system Greedy algorithm