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Acta Mechanica Solida Sinica 2022年第6期35卷 1021-1029页

作者： Xin fan nan Wu Yongshou Liu Qing Guo School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710129China

This paper aims to solve the resonance failure probability and develop an effective method to estimate the effects of variables and failure modes on failure probability of axially functionally graded material(FGM)pipe conveying ***,the natural frequency of axially FGM pipes conveying fluid is calculated using the differential quadrature method(DQM).A variable sensitivity analysis(VSA)is introduced to measure the effect of each random variable,and a mode sensitivity analysis(MSA)is introduced to acquire the importance ranking of failure ***,an active learning Kriging(ALK)method is established to calculate the resonance failure probability and sensitivity indices,which greatly improves the application of resonance reliability analysis for pipelines in engineering *** on the resonance reliability analysis method,the effects of fluid velocity,volume fraction and fluid density of axially FGM pipe conveying fluid on resonance reliability are *** results demonstrate that the proposed method has great performance in the anti-resonance analysis of pipes conveying fluid.

关键词： Resonance reliability analysis Simply supported pipe conveying fluid Differential quadrature method Variable sensitivity analysis Mode sensitivity analysis Active learning Kriging model

Trimetallic mesoporous PdCuRu for efficient formate electrosynthesis from polyethylene terephthalate recycling

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Science China Chemistry 2025年

作者： Yuting Li Huiqin yao Lizhi Sun Shu Han Xiaoxiang Xu Guangyin fan Ben Liu College of Chemistry and Materials Science Sichuan Normal University Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University School of Basic Medical Sciences Ningxia Medical University Department of Otorhinolaryngology-Head and Neck Surgery Zhongnan Hospital of Wuhan University

Electrochemical recycling of waste polyethylene terephthalate（PET） plastics represents a green and sustainable route to produce valuable fuels and address serious environmental issues. Despite some encouraged achievements, their progress is still slower because of the lack of highly active and selective electrocatalysts. Here, we reported an efficient PET recycling route with trimetallic PdCuRu mesoporous nanospheres（MSs） as a high-performance electrocatalyst that achieved selective electrosynthesis of valuable formate from PET hydrolysate（PETH） electrooxidation. Penetrated metal mesopores and trimetallic compositions of PdCuRu MSs synergistically optimized electronic structures of Pd sites and changed chemisorption properties of intermediates, which disclosed a high formate Faradic efficiency of 97% and impressive yield rate of 0.49 mmol h-1cm-2in an alkaline solution. Meanwhile, this electrocatalyst held good electrocatalytic stability, retaining high formate Faradic efficiency and yield rate even being performed for 10 cycles, which highlighted its potential applications for practical PET recycling. Our study provides a powerful strategy for designing high-performance electrocatalysts toward selective electro-synthesis of valuable fuels from various waste plastics.

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Synthetic control of chiral pore surfaces in covalent organic frameworks for enantioselective separation of chiral drugs

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Science China Chemistry 2025年

作者： Shiguo Fu Xiaofeng Zhang Kaixuan Wang Linfeng Chen fan Xia Yong Cui yan Liu School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Faculty of Materials Science and Chemistry China University of Geosciences

Enantioselective separations of racemates using porous materials are highly attractive and significant in both fundamental research and technological applications. However, achieving controlled chiral pore surfaces to create the necessary driving force for enantiomer discrimination poses a fundamental challenge. Herein, we demonstrate that chiral covalent organic frameworks(COFs) possess the essential characteristics for effective enantioseparations through synthetic control over pore surfaces. We synthesized three 3D chiral COFs (CCOFs) featuring abundant chiral recognition sites on the pore walls via the condensation of enantiopure dialdehyde of 2,2′-dihydroxy-1,1′-binaphthyl and tetraamine. All CCOFs with high stability exhibit an 11-fold interpenetrated framework with tubular open channels, decorated with dihydroxyl or diethoxyl groups. The CCOFs with dihydroxyl groups serve as solid adsorbents for the adsorptive separation and solid-phase extraction of various chiral 1-phenylethanol-derived enantiomers, particularly racemic drugs, achieving up to 98%enantiomeric excess. In contrast, the CCOF with diethoxy groups is unable to resolve the racemates. These CCOF materials can be recycled and reused without any apparent loss of performance. Density functional theory (DFT) calculations reveal that the enantiospecific recognition arises from the well-organized chiral inner sphere and multiple chiral host-guest interactions.

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Co@C-N as an electronic mediator anchored with Cu2O nanoparticles enables efficient photoreduction of CO2 to CO with nearly 100% selectivity

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Science China Chemistry 2025年

作者： Xingbin Pan Xiuzheng Deng Jingshan fan Jiangchuan Liu Changhai Liu Zhongyu Li Qian Liang Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology CNPC-CZU Innovation Alliance School of Petrochemical Engineering Changzhou University School of Materials Science & Engineering Changzhou University

Solar-driven CO2conversion into value-added chemical provides an attractive strategy for sustainable development. However,the enhanced CO2photoreduction performance with target product selectivity remains a major challenge. Here, we develop a novel strategy involving Cu2O nanoparticles in situ grown on the surface of ZIF-67-derived Co@C-N nanocages （CC） to create abundant active sites and appropriate heterointerfaces. A remarkable CO selectivity of 95.7%with a yield of 117.39μmol g-1h-1and an apparent quantum efficiency as high as 1.88%at 420 nm was obtained over CC-60 catalyst in pure water, which was 87.6times higher than that of pure Cu2O. Theoretical calculations and experiments indicated that Co@C-N nanocages as charge mediator not only rapidly trap photogenerated electrons to promote charge separation efficiency, but also regulate the d-band center of Cu atoms to move to the Fermi energy level, thereby optimizing the reaction kinetics to facilitate the highly selective conversion of the key intermediate *CO desorption to CO.

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Experimental Investigation of Heat Storage and Heat Transfer Rates during Melting of nano-Enhanced Phase Change Materials (NePCM) in a Differentially-Heated Rectangular Cavity

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Journal of Thermal Science 2020年第2期29卷 503-511页

作者： LI Zirui HU nan TU Jing fan Liwu Institute of Thermal Science and Power Systems School of Energy EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China

In this work, an experimental study of melting heat transfer of nano-enhanced phase change materials(NePCM) in a differentially-heated rectangular cavity was performed. Two height-to-width aspect ratios of the cavity, i.e., 0.9 and 1.5, were investigated. The model Ne PCM samples were prepared by dispersing graphene nanoplatelets(GNP) into 1-tetradecanol, having a nominal melting point of 37℃, at loadings up to 3 wt.%. The viscosity was found to have a more than 10-fold increase at the highest loading of GNP. During the melting experiments, the wall superheat at the heating boundary was set to be 10℃ or 30℃. It was shown that with increasing the loading of GNP, both the heat storage and heat transfer rates during melting decelerate to some extent, at all geometrical and thermal configurations. This suggested that the use of NePCM in such cavity may not be able to enhance the heat storage rate due to the dramatic growth in viscosity, which deteriorates significantly natural convective heat transfer during melting to overweigh the enhanced heat conduction by only a decent increase in thermal conductivity. This also suggested that the numerically predicted melting accelerations and heat transfer enhancements, as a result of the increased thermal conductivity, in the literature are likely overestimated because the negative effects due to viscosity growth are underestimated.

关键词： aspect ratio graphene nanoplatelets latent heat storage melting heat transfer phase change material rectangular cavity

Determination of Soil Parameters in Apple-Growing Regions by Near-and Mid-Infrared Spectroscopy

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Pedosphere 2011年第5期21卷 591-602页

作者： DONG Yi-Wei yaNG Shi-Qi XU Chun-Ying LI Yu-Zhong BAI Wei fan Zhong-nan WANG ya-nan LI Qiao-Zhen Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences Beijing 100081 (China) Key Laboratory of Agro-Environment and Climate Change Ministry of Agriculture Beijing 100081 (China) Key Laboratory of Dryland Farming and Water-Saving Agriculture Ministry of Agriculture Beijing 100081 (China)

Soil quality monitoring is important in precision *** study aimed to examine the possibility of assessing the soil parameters in apple-growing regions using spectroscopic methods.A total of 111 soil samples were collected from 11 typical sites of apple orchards,and the croplands surrounding ***-infrared(NIR) and mid-infrared(MIR) spectra,combined with partial least square regression,were used to predict the soil parameters,including organic matter(OM) content,pH,and the contents of As,Cu,Zn,Pb,and *** matter and pH were closely correlated with As and the heavy *** NIR model showed a high prediction accuracy for the determination of OM,pH,and As,with correlation coefficients(r) of 0.89,0.89,and 0.90,*** predictions of these three parameters by MIR showed reduced accuracy,with r values of 0.77,0.84,and 0.92,*** heavy metals could also be measured by spectroscopy due to their correlation with organic *** NIR and MIR had high correlation coefficients for the determination of Cu,Zn,and Cr,with standard errors of prediction of 2.95,10.48,and 9.49 mg kg-1 for NIR and 3.69,5.84,and 6.94 mg kg-1 for MIR,*** content behaved differently from the other *** NIR and MIR underestimated Pb content,with r values of 0.67 and 0.56 and standard errors of prediction of 3.46 and 2.99,*** and Zn had a higher correlation with OM and pH and were better predicted than Pb and ***,NIR spectra could accurately predict several soil parameters,metallic and nonmetallic,simultaneously,and were more feasible than MIR in analyzing soil parameters in the study area.

关键词： heavy metals partial least square regression prediction accuracy soil quality spectroscopic method

Eigenvector-based analysis of cluster synchronization in general complex networks of coupled chaotic oscillators

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Frontiers of physics 2023年第4期18卷 321-335页

作者： Huawei fan ya Wang Xingang Wang School of Science Xi’an University of Posts and TelecommunicationsXi’an 710121China School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062China

Whereas topological symmetries have been recognized as crucially important to the exploration of synchronization patterns in complex networks of coupled dynamical oscillators,the identification of the symmetries in largesize complex networks remains as a ***,even though the topological symmetries of a complex network are known,it is still not clear how the system dynamics is transited among different synchronization patterns with respect to the coupling strength of the *** propose here the framework of eigenvector-based analysis to identify the synchronization patterns in the general complex networks and,incorporating the conventional method of eigenvalue-based analysis,investigate the emergence and transition of the cluster synchronization *** are able to argue and demonstrate that,without a prior knowledge of the network symmetries,the method is able to predict not only all the cluster synchronization states observable in the network,but also the critical couplings where the states become stable and the sequence of these states in the process of synchronization *** efficacy and generality of the proposed method are verified by different network models of coupled chaotic oscillators,including artificial networks of perfect symmetries and empirical networks of non-perfect *** new framework paves a way to the investigation of synchronization patterns in large-size,general complex networks.

关键词： cluster synchronization complex networks network symmetry coupled oscillators

Orthogonal Solubility in Fully Conjugated Donor-Acceptor Block Copolymers： Compatibilizers for Polymer/Fullerene Bulk-Heterojunction Solar Cells

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Chinese Journal of Polymer Science 2017年第2期35卷 207-218页

作者： Shi-fan Wang ya-nan Liu Jie yang 陶友田 yan Guo Xu-dong Cao 张志国 Yong-fang Li 黄维 Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM)Nanjing Tech University (Nanjing Tech) Institute of Chemistry Chinese Academy of Sciences Department of Biomedical Engineering College of Engineering and Applied Sciences

Donor-acceptor （D-A） type fully conjugated block copolymer systems have been rarely reported due to the challenges in synthetic approaches to prepare well-defined low-polydispersity products. In this work, fully conjugated block copolymers are synthesized in a one-pot reaction through Stille coupling polycondensation, by utilizing the end-functional polymer copolymerization method. End-functional P3HT are copolymerized with AA （2,7-dihromo-9-（heptadecan-9-yl）-9H- carbazole） and BB （4,7-bis（5-（trimethylstannyl）thiophen-2-yl）benzo[c][1,2,5]thiadiazole, TBT） type monomers, respectively. The orthogonal solubility between the very soluble P3HT donor and the insoluble PCDTBT acceptor block improves the purity of block copolymers as well as distinct nano-scale phase-separation compared with other reports on miscibility of donor and acceptor polymer block. Further purification via preparative GPC is carried out to remove the excess of unreacted P3HT and free PCDTBT as well as to achieve low polydispersity of block copolymers. The chemical structure of the P3HT- b-PCDTBT block copolymers are verified via IH-NMR, and further confirmed by FTIR spectra. The block copolymer shows broad absorption and moderate optical band gap of 1.8 eV. Furthermore, the fully conjugated block copolymer films exhibit significant fine structures, much smoother film morphology compared to P3HT/PCDTBT polymer blends. By adding a small amount of block copolymer P3HT-b-PCDTBT as a compatibilizer into the bulk-heterojunction of P3HT：PC61BM blends, polymer solar ceils with an 8% increase of short circuit current （Jse） and 10% increase of power conversion efficiency （PCE） are achieved owing to the improvement of the active-layer film morphology. To the best of our knowledge, this is the first report on donor-acceptor type fully conjugated block copolymer as an effective ternary additive in polymer： fullerene bulk heterojunction solar cells.

关键词： Block copolymers Donor Acceptor Bulk heterojunction solar cells Compatibilizer

A convenient,highly-efficient method for preparation of hydroxyl-terminated isotactic poly(propylene) and functional di-block copolymer

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Chinese Chemical Letters 2014年第4期25卷 596-600页

作者： ya-nan Ye Pei-Yuan Li Yong-Gang Shangguan Zhi-Sheng Fu Qiang Zheng Zhi-Qiang fan MOE Key Laboratory of Macromolecular Synthesis and Functionalization.Department of Polymer Science and Engineering Zhejiang University

Both terminated functional isotactic polypropylene （iPP） and block copolymers containing iPP segment are desirable for commercial applications. This paper provides a convenient, highly-efficient method to prepare hydroxyl-terminated isotactic polypropylene （iPP-t-OH） and functional di-block copolymer containing the iPP segment through a combination of coordination polymerization and coupling reaction. The coordination polymerization was catalyzed by TiCI4/MgCI2/AIEt3 catalyst system using ZnEt2 as chain transfer agent. Further, the Zn-terminated iPP was oxidized and subsequently hydrolyzed to provide iPP-t-OH. Soxhlet extraction and 13C NMR were used to calculate the isotacticity of iPP-t-OH. The degree of polymerization and the number of hydroxyl groups at the chain end of iPP-t-OH were measured by GPC and 1H NMR. Despite the high molecular weight and heterogeneous reaction, iPP-t-OH is effectively linked with PEG-t-NCO to produce di-block copolymers. DSC analysis of the di-block copolymer shows an obvious decrease in Tm and To, which indicated that PEG was successfully linked to the terminal end of iPP.

关键词： Hydroxyl-terminated isotacticpoly(propylene) Di-block copolymer Functionality Coupling reaction

Chiral phosphoramidite ligand-modulated palladium auto-tandem catalysis for asymmetric dehydrogenative dienylation of imines with α-alkenes

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Science China Chemistry 2025年

作者： Zhong-Sheng Nong Hao-fan Qian Ying-Chun Chen Pu-Sheng Wang Liu-Zhu Gong Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of China Key Laboratory of Drug Targeting and Drug Delivery System (Sichuan University) Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University School of Materials and Chemistry Southwest University of Science and Technology

The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community. Transition metal-catalyzed asymmetric functionalization of allylic C–H bond represents a unique alternative toward this goal. However, enantioselective dehydrogenative transformation of olefins to value-added optically enriched molecules remains yet to be discovered. Here, we report a highly enantioselective dehydrogenative dienylation of imines with unactivated α-alkenes driven by the synergistic action of palladium complex and carboxylic acid. Chiral phosphoramidite ligands turned out to be superior in modulating the performance of palladium autotandem catalysis and allowed a broad range of α-alkenes and imines to be transformed into chiral dienylamines. Mechanistic studies suggest that the dienes could be in situ generated from α-alkenes through a palladium(0)-mediated dehydrogenative process in the presence of excess benzoquinone oxidants, and then participated in the Pd-chiral phosphoramidite-catalyzed intermolecular vinylogous-type addition to the imines activated by the carboxylic acid co-catalyst. Notably, the second β-H elimination occurring in the dienylation event might be the turnover-limiting step.

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