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Preparing cyclic polymers at high concentrations via self-folding cyclization technique by adjusting the contents of hydrophilic units in linear precursors

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Chinese Chemical Letters 2024年第2期35卷 283-288页

作者： Hao Zha Zuowei Wang Chao Liu chunyan hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Cyclic polymers are a class of polymers that feature endless topology,and the synthesis of cyclic polymers has attracted the attention of many ***,cyclic polymers were efficiently constructed by self-folding cyclization technique at high *** poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate))(P(OEGA-co-DDA))precursors with different ratios of hydrophilic and hydrophobic moieties were synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization using a bifunctional chain transfer agent with two anthryl end *** amphiphilic linear precursors underwent the self-folding process to generate polymeric nanoparticles in *** irradiating the aqueous solution of the nanoparticles with 365 nm UV light,cyclic polymers were synthesized successfully via coupling of anthryl *** effects of the ratios of hydrophilic and hydrophobic moieties in linear P(OEGA-co-DDA)copolymers and polymer concentration on the purity of the obtained cyclic polymers were explored in detail via ^(1)H nuclear magnetic resonance(^(1)H NMR),dynamic light scattering(DLS),UV‒visible(vis)analysis,three-detection size exclusion chromatography(TD-SEC)and transmission electron microscopy(TEM).It was found that by adjusting the content of the hydrophilic segments in linear precursors,single chain polymeric nanoparticles(SCPNs)can be generated at high polymer ***,cyclic polymers with high purity can be constructed *** method overcomes the limitation of traditional ring-closure method,which is typically conducted in highly dilute conditions,providing an efficient method for the scalable preparation of cyclic polymers.

关键词： Cyclic polymers Self-folding cyclization technique Single chain polymeric nanoparticles RAFT polymerization Direct visualization

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Efficient synthesis of bottle-brush polymers enabled by selective photoactivation strategy in NIR-induced PET-RAFT polymerization

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Science China Chemistry 2024年第7期67卷 2353-2361页

作者： Hao Zha Lin Cheng Zuowei Wang Chao Liu chunyan hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Bottle-brush polymers possessing densely grafted side chains have special properties that are distinct from linear ***,an efficient method for preparing bottle-brush polymers based on a selective photoactivation strategy in the photoinduced electron/energy transfer reversible addition-fragmentation chain transfer(PET-RAFT)polymerization was developed.A methacrylate monomer 2-(2-(dodecylthiocarbonothioylthio)propionate)ethyl methacrylate(DTPEMA)containing a 2-(dodecylthiocarbonothioylthio)propionate(DTP)unit with a secondary R group was *** the unique selectivity of metal naphthalocyanine photocatalyst zinc 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine(ZnTtBNc)toward trithiocarbonate with tertiary R group,the PET-RAFT polymerization of DTPEMA catalyzed by ZnTtBNc was performed under near infrared(NIR)light(λ_(max)=760 nm)irradiation at room temperature,using 4-cyano-4-[(dodecylsulfanylthiocarbonyl)-sulfanyl]pentanoic acid(CDTPA)with a tertiary R group as a chain transfer agent(CTA).Proton nuclear magnetic resonance(1H NMR)and gel permeation chromatography(GPC)results demonstrated that the DTP units in the side chains were inert during the *** grafting poly(methyl acrylate)(PMA)from PDTPEMA via thermal-initiated RAFT polymerization,welldefined P(DTPEMA-g-PMA)bottle-brush polymers could be ***,the film prepared from the bottle-brush polymer exhibited excellent scratch self-healing property due to the interlocking of side chains.

关键词： bottle-brush polymers PET-RAFT polymerization selective photoactivation scratch self-healing

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Scalable preparation and direct visualization of cyclic polymers via self-folding cyclization technique

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Science China Chemistry 2022年第12期65卷 2558-2566页

作者： Hualong Zhang Hao Zha Chao Liu chunyan hong CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei230026China

Cyclic polymers exhibit distinct properties compared with their linear counterparts due to the lack of chain ***,the scalable synthesis of cyclic polymers remains a major challenge,especially for ring-closure ***,we report a novel strategy for large-scale preparation of cyclic polymers,which relies on the prior self-folding of anthracene-telechelic amphiphilic random copolymers(poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate)),P(OEGA-co-DDA))into single-chain polymeric nanoparticles(SCPNs)in *** ultraviolet(UV)-induced cyclization occurs in the hydrophobic *** formation of SCPNs leads to a shortened distance between the end groups of the linear precursors and spatially separated cyclization loci,and significantly enhances the efficiency of UV-induced *** self-folding technique permits access to the synthesis of cyclic polymers not only with high molecular weights(M_(n)>10^(5) g/mol),but also in a decent scale(40 g/L),breaking through the limitations of ring-closure ***,the dense pendants of the copolymers can magnify the macromolecules by increasing the mass density along the backbones,thus making the polymers more readily detectable by the *** transmission electron microscopy(TEM)and atomic force microscopy(AFM)images allow us to observe the topological structures directly and provide crucial evidence to confirm the cyclization.

关键词： cyclic polymer scalable preparation direct visualization self-folding cyclization technique

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Template-Directed Fabrication of Anatase TiO2 Hollow Nanoparticles and Their Application in Photocatalytic Degradation of Methyl Orange

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Chinese Journal of Chemistry 2017年第6期35卷 1016-1022页

作者： Jie Chang Wenjian Zhang chunyan hong CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China Hefei Anhui 230026 China

Polymerization-induced self-assembly （PISA） was used to fabricate polymeric nanoparticles via reversible ad- dition-fragmentation chain transfer （RAFT） dispersion polymerization of benzyl methacrylate （BzMA） using di- block copolymer poly（glycerol monomethacrytate）-block-poly（2-dimethylaminoetbyl methacrylate）（PGMMA- PDMAEMA-CTA） as the macro RAFT agent. The dispersion of polymeric nanoparticles with a final concentration of about 210 mg/g （solid content of 21%） was obtained via this efficient method （PISA）. The resultant polymeric nanoparticles consisting of corona-shell-core three layers with weak polyelectrolyte PDMAEMA as the shell were used as sacrificial template to fabricate TiO2 hollow nanoparticles. The negatively charged titanium precursor was absorbed into the PDMAEMA shell via the electrostatic interaction, and hydrolyzed to form polymer/TiO2 hybrid nanoparticles. Anatase TiO2 hollow nanoparticles were formed after removing the polymeric templates by calcina- tion at 550 ℃. The experiments of photocatalytic degradation of methyl orange showed that the resultant anatase TiO2 hollow nanoparticles had high photocatalytic activity and good reusability.

关键词： polymerization-induced self-assembly RAFT dispersion polymerization TiO2 hollow nanoparticles

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Two tandem multicomponent reactions for the synthesis of sequence-defined polymers

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Science China Chemistry 2015年第11期58卷 1734-1740页

作者： Lu Yang Ze Zhang Bofei Cheng Yezi You Decheng Wu chunyan hong Key Laboratory of Soft Matter Chemistry Chinese Academy of Sciences Department of Polymer Science and Engineering University of Science and Technology of China Beijing National Laboratory for Molecular Sciences State Key Laboratory of Polymer Physics & Chemistry Institute of Chemistry Chinese Academy of Sciences

Multicomponent polymerizations have become powerful tools for the construction of sequence-defined polymers. Although the Passerini multicomponent reaction has been widely used in the synthesis of sequence-defined polymers, the tandem usage of the Passerini multicomponent reaction and other multicomponent reactions in one-pot for the synthesis of sequence-defined polymers has not been developed until now. In this contribution, we report the tandem usage of the Passerini three-component reaction and the three-component amine-thiol-ene conjugation reaction in one pot for the synthesis of sequence-defined polymers. The Passerini reaction between methacrylic acid, adipaldehyde, and 2-isocyanobutanoate was carried out, affording a new molecule containing two alkene units. Subsequently, an amine and a thiolactone were added to the reaction system, whereupon the three-component amine-thiol-ene conjugating reaction occurred to yield a sequence-defined polymer. This method offers more rapid access to sequence-defined polymers with high molecular diversity and complexity.

关键词：多组分反应合成序列串联使用定义合成聚合物分子多样性聚合物合成甲基丙烯酸

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A New Class of Strong Orthogonal Arrays of Strength Three

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Journal of Systems Science & Complexity 2024年第3期37卷 1233-1250页

作者： WANG chunyan LIU Min-Qian YANG Jinyu Center for Applied Statistics and School of Statistics Renmin University of ChinaBeijing 100872China School of Statistics and Data Science LPMC&KLMDASRNankai UniversityTianjin 300071China

Strong orthogonal arrays(SOAs) were recently introduced and studied as a class of spacefilling designs for computer experiments. To surely realize better space-filling properties, SOAs of strength three or higher are desirable. In addition, orthogonality is also an important property for designs of computer experiments, because it guarantees that the estimates of the main effects are uncorrelated. This paper first provides a systematic study on the construction of(nearly) orthogonal strength-three SOAs with better space-filling properties. The newly proposed strength-three SOAs enjoy almost the same space-filling properties of strength-four SOAs, and can accommodate much more columns than the latter. Moreover, they are(nearly) orthogonal and flexible in run sizes. The construction methods are straightforward to implement, and their theoretical supports are well established. In addition to the theoretical results, many designs are tabulated for practical needs.

关键词： Computer experiment orthogonality space-filling property strong orthogonal array

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Mode Switching and Consistency Control for Electric-Hydraulic Hybrid Steering System

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Automotive Innovation 2024年第1期7卷 166-181页

作者： Zhongkai Luan Wanzhong Zhao chunyan Wang College of Energy and Power Engineering 29 Yudao St.Nanjing 210016China

Electric-hydraulic hybrid power steering(E-HHPS)system,a novel device with multiple modes for commercial electric vehicles,is designed to realize both superior steering feel and high energy ***,inconsistent steering perfor-mance occurs in the mode-switching process due to different dynamic characteristics of electric and hydraulic components,which even threatens driving *** this paper,mode-switching strategy and dynamic compensation control method are proposed for the E-HHPS system to eliminate the inconsistency of steering feel,which comprehensively considers ideal assistance characteristics and energy consumption of the ***,the influence of disturbances on system stability is analyzed,and H_(∞)robust controller is employed to guarantee system robustness and *** experimental results dem-onstrate that the proposed strategy can provide a steering system with natural steering feel without apparent inconsistency and effectively minimize energy consumption.

关键词： Hydraulic hybrid steering system Steering feel Consistency Mode switch Robust control

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Summer Atmospheric Water Cycle under the Transition Influence of the Westerly and Summer Monsoon over the Yarlung Zangbo River Basin in the Southern Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第5期41卷 830-846页

作者： Qianhui MA chunyan ZHANG Donghai WANG Zihao PANG School of Atmospheric Sciences Sun Yat-sen UniversityGuangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesKey Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Guangdong Meteorological Data Center Guangdong Meteorological ServiceGuangzhou 510080China National Observation and Research Station of Coastal Ecological Environments in Macao Macao Environmental Research InstituteMacao University of Science and TechnologyMacao SAR 999078China National Meteorological Information Center China Meteorological AdministrationBeijing 100081China

This study compares the summer atmospheric water cycle,including moisture sources and consumption,in the upstream,midstream,and downstream regions of the Yarlung Zangbo River Basin in the southern Tibetan *** evolutions of moisture properties under the influence of the westerly and summer southerly monsoon are examined using 5-yr multi-source measurements and ERA5 reanalysis *** that moisture consumption in this study is associated with clouds,precipitation,and diabatic *** to the midstream and downstream regions,the upstream region has less moisture,clouds,and precipitation,where the moisture is brought by the *** early August,the vertical wet advection over this region becomes enhanced and generates more high clouds and *** midstream region has moisture carried by the westerly in June and by the southerly monsoon from July to *** higher vertical wet advection maximum here forms more high clouds,with a precipitation peak in early *** downstream region is mainly affected by the southerly-driven wet *** rich moisture and strong vertical wet advection here produce the most clouds and precipitation among the three regions,with a precipitation peak in late *** height of the maximum moisture condensation is different between the midstream region(325 hPa)and the other two regions(375 hPa),due to the higher upward motion maximum in the midstream *** diabatic heating structures show that stratiform clouds dominate the upstream region,stratiform clouds and deep convection co-exist in the midstream region,and deep convection systems characterize the downstream region.

关键词： Yarlung Zangbo River Basin atmospheric water cycle constrained variational analysis moisture source and consumption

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Isotopic characteristics and source analysis of atmospheric ammonia during agricultural periods in the Xichuan area of the Danjiangkou Reservoir

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Journal of Environmental Sciences 2024年第2期136卷 460-469页

作者： Xiaoshu Chen Tongqian Zhao chunyan Xiao Xiaoming Guo Feihong Chen Institute of Resources and Environment Henan Polytechnic UniversityJiaozuo 454000China

Nitrogen deposition is an important means of exogenous nitrogen input in reservoir *** activities around the reservoir lead to a sharp increase in the concentration of ammonia in the atmosphere,which poses a threat to the reservoir water *** the contribution of agricultural ammonia release to atmospheric NH_(x)(gaseous NH_(3)and particulate NH_(4)^(+)),in the reservoir area can provide a theoretical foundation for local reactive nitrogen *** collected atmospheric NH_(3)and NH_(4)^(+)samples during the agricultural periods and analyzed the isotopic characteristics of atmospheric NH_(x)and the contribution rates of different ammonia sources in the Xichuan area of the Danjiangkou *** results showed that the initialδ~(15)N values of NH_(3)(-30.0‰to–7.2‰)and particulate NH_(4)^(+)(–33‰to+4.9‰for finer and coarser particles,respectively)are different,and their contribution ratios from dissimilar ammonia sources are also different,among which NH_(4)^(+)is more susceptible to meteorological ***,since the atmospheric NH_(x)in the Xichuan area is mainly gaseous NH_(3),the final sources of atmospheric ammonia nitrogen source depend on gaseous NH_(3).Agricultural sources(59%-74%)were the main NH_(3)sources in this *** them,the fertilizer use emission was dominant;it had the highest contribution rate in summer during the agricultural period and a more prominent impact in areas with less human *** regulation of the application of high-ammonia releasing fertilizer,especially during the agricultural period in summer,is an effective way to reduce the threat of atmospheric ammonia to water health.

关键词： Danjiangkou reservoir Atmospheric ammonia nitrogen Isotope Ammonia source analysis Agricultural sources

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A new nonfullerene acceptor with an extended π conjugation core enables ternary organic solar cells approaching 19%efficiency

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Nano Research 2024年第5期17卷 4062-4068页

作者： chunyan Liu Nailiang Qiu Zhengjin Li Yan Lu School of Materials Science and Engineering Tianjin Key Laboratory for Photoelectric Materials and DevicesKey Laboratory of Display Materials and Photoelectric DevicesMinistry of EducationTianjin University of TechnologyTianjin 300384China School of Chemistry Chemical Engineering and MaterialsJining UniversityQufu 273155China

In organic solar cells(OSCs),it is an effective way to improve the power conversion efficiency(PCE)by adding a guest component with appropriate absorption and energy levels in the host ***,a new nonfullerene acceptor(NFA)named TBF-2Cl was developed by the strategy of expanding theπconjugated core of 2,2’-(((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b’]dithiophene-2,7-diyl)bis(methaneylylidene))bis(5,6-dichloro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(IDT-4Cl)with two benzene *** increase of benzene units,TBF-2Cl exhibits higher lowest unoccupied molecular orbital(LUMO)level of-3.75 eV than that of one benzene unit based NFA IDT-4Cl and fluorene core based NFA F-2Cl,which facilitates enhancing the open-circuit voltage(V_(oc))of ternary ***,TBF-2Cl film shows a medium optical bandgap with the absorption range from 500-800 nm,being well complementary with the wide bandgap polymer donor D18 and narrow bandgap NFA ***,a remarkable PCE of 18.92%with a high short-circuit current density(J_(sc))of 27.40 mA·cm^(-2),a fill factor(FF)of 0.749,especially an outstanding V_(oc) of 0.922 V was achieved for the optimal ternary device based on D18:TBF-2Cl:CH-6F,surpassing the binary counterpart(17.08%).The findings provide insight into the development of new guest acceptors for obtaining more efficient OSCs.

关键词： medium optical bandgap high lowest unoccupied molecular orbital(LUMO)level the third component ternary organic solar cell high open-circuit voltage

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