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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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Optimizing large optical contrast in Ge-Se-Te films via high-throughput method

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Progress in Natural science:Materials International 2025年第1期35卷 222-228页

作者： Qiqi Chen Guoxiang Wang Zijun Liu Yixiao Gao Chenjie Gu Tiefeng Xu Xiang Shen Yimin Chen Laboratory of Infrared Material and Devices & Key Laboratory of Photoelectric Materials and Devices of Zhejiang Province Advanced Technology Research InstituteNingbo University Department of Microelectronic Science and Engineering School of Physical Science and Technology Ningbo University Ningbo Solartrum Co.Ltd.

Chalcogenide phase-change materials（PCMs） have attracted great attentions due to their potential applications in reconfigurable photonic devices. The Ge2Sb2Te5and GeTe PCMs exhibit significant difference in refractive index（Δn） between amorphous and crystalline states, but they suffer from high optical loss. The binary Sb2S3and Sb2Se3PCMs, however, show low optical loss but small Δn. This encourages us to develop the novel materials,which are desired to combine large Δn and low optical loss. Instead of traditional trial-and-error screening method, we here used an efficient high-throughput method to optimize the PCMs' candidates for reconfigurable photonic devices in Ge-Se-Te chalcogenides. The crystallization temperature and difference in optical bandgap were detected, and then the component of Ge25Se7Te68, which also exhibits ultralow optical loss of 1.2 × 10-6（in amorphous state） and large Δn of 1.32 at 1550 nm, was optimized. This Te-rich Ge-Se-Te film can be a candidate for the applications of programmable reconfigurable photonic circuits.

关键词： Chalcogenide phase-change films High-throughput Reconfigurable photonics Refractive index

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Study on the theoretical and mechanism of CaF_(2)-catalyzed vacuum carbothermal reduction of MgO

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Journal of Magnesium and Alloys 2025年第2期13卷 731-745页

作者： Tingzhuang Ma Bin Yang Yang Tian Neng Xiong Baoqiang Xu Guozheng Zha Rong Yu Dong Liang Lipeng Wang Dong Wang Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province Kunming University of Science and TechnologyKunming 650093China Yunnan province Engineering Research Center of Aluminium Industry Kunming University of Science and TechnologyKunming 650093China National Engineering Research Center of Vacuum Metallurgy Kunming University of Science and TechnologyKunming 650093China Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China IME Institute of Process Metallurgy and Metal Recycling RWTH Aachen UniversityAachen 52056Germany

The increasing demand for magnesium as a next-generation structural material highlights the significance of incorporating CaF_(2)as a catalyst to enhance the efficiency of vacuum carbothermal reduction of magnesium(VCTRM).This study investigates the thermodynamic theory and catalytic mechanism of CaF_(2)in the VCTRM *** reduction experiments and molecular dynamics simulations were conducted to gain a comprehensive understanding of the *** calculations indicate that in vacuum carbothermal reduction,the primary reaction occurs between MgO and *** shows that CaF_(2)'s catalytic action primarily involves F^(-),Ca^(2+),and melt *** experiments demonstrate that the addition of CaF_(2)significantly increases the reduction ***,the mass loss rate increases with both the quantity of CaF_(2)added and the holding time,stabilizing at additions over 5%.Experiments conducted at temperatures above the melting point of CaF_(2)exhibited a pronounced catalytic *** resultant magnesium showed optimal structure and crystallization,with a purity of 87.84%.Notably,while CaF_(2)remained in the residue,it was not detected in the condensate,confirming its catalytic *** dynamics simulations revealed that molten CaF_(2)sabotages the structure of magnesium oxide,with F^(-)dispersing onto the surface of MgO,thus enhancing the reaction between MgO and C to form ***,no chemical reaction was observed between C,MgO,and CaF_(2).The occurrence of the carbothermal reduction reaction at high temperatures depends on the concentration of the reducing agent C,with CaF_(2)influencing the reaction *** research elucidates the theoretical and mechanistic foundations of CaF_(2)-catalyzed VCTRM,aligning with the green energy-saving concept and significantly advancing the green and efficient VCTRM process.

关键词： vacuum carbothermal reduction of magnesium Thermodynamic theory Catalytic mechanism Molecular dynamics simulation Magnesium Green energy-saving

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Constraining the Earth-mass Primordial Black Hole Mergers Model of the Non-repeating FRBs Using the First CHIME/FRB Catalog

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Research in Astronomy and Astrophysics 2024年第9期24卷 76-82页

作者： Min Meng Qiu-Ju Huang Can-Min Deng Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China

In this paper,we upgrade the constraints for the Earth-mass primordial black hole mergers model based on the first Canadian Hydrogen Intensity Mapping Experiment(CHIME)/fast radio burst(FRB)*** the null hypothesis that the observed non-repeating FRBs originate from Earth-mass primordial black hole mergers,we find that how the charges were distributed in the primordial black hole population is well described by a double powerlaw function with typical charge value of law function with typical charge value of q_(c)/10^(-5)=1.60_(-0.28)^(+0.28),where the power-law index α_(1)=2.33_(-0.18)^(+0.15) for q

关键词： black hole physics (stars:)gamma ray burst:general (cosmology:)dark matter

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Microstructure dependence of electrochemical corrosion resistance for rapidly solidified Ti_(50)Al_(48)Mo_(2)alloy

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Journal of Materials science & technology 2024年第18期185卷 58-68页

作者： Chonghao Sun Ruilin Xiao Kelun Liu Ying Ruan Bingbo Wei MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions School of Physical Science and TechnologyNorthwestern

The rapid solidification of undercooled liquid Ti_(50)Al_(48)Mo_(2)alloy was achieved by the electromagnetic lev-itation(EML)*** small and medium undercoolings,primary(βTi)dendrite reacted with sur-rounding liquid to drive a peritectic transformation into the(αTi)*** solutal Mo and Al segrega-tions were located within the dendrite center and the grain boundary during peritectic transformation,consequently B2 phase in the dendrite center andγphase at the grain boundary *** under-cooling exceeded 253 K,the peritectic transformation was completely inhibited,and the formation of the B2 phase andγphase was completely *** ultrafine eutectoid structure was formed and a complete solute trapping effect was *** solute distribution facilitated the forma-tion of thicker passivation film with lower defect density and higher film resistance on the alloy ***,this weakened micro-galvanic effect reduced the susceptibility to pitting corrosion,and conse-quently the corrosion resistance of the alloy was improved.

关键词： Ti-Al based alloys Electromagnetic levitation technique Undercooling Rapid solidification Passivation film

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Room-temperature ferrimagnetism and size-modulated electronic structures in two-dimensional cluster-based metal-organic frameworks

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science China Chemistry 2024年第4期67卷 1334-1340页

作者： Jing Cheng Xingxing Li Jinlong Yang Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of ChinaHefei 230026China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique ***,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in ***,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly *** this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(MOFs)Fe_(n)-(pyz)(n=1-6)by utilizing Fenmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic *** 2D cluster-based MOFs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of Fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine *** particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of Fe_(n)clusters in Fe_(n)-(pyz)(n=1-6)MOFs results in diverse functional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half ***,these 2D assembled MOFs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.

关键词： metal-organic framework two-dimensional material half metal bipolar magnetic semiconductor magnet

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Boosting oxygen reduction in acidic media through integration of Pt-Co alloy effect and strong interaction with carbon defects

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Nano Research 2024年第9期17卷 7900-7908页

作者： Nannan Ji Haoyun Sheng Shilong Liu Yangyuan Zhang Hongfei Sun Lingzhi Wei Ziqi Tian Peng Jiang Qianwang Chen Jianwei Su Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid MaterialsAnhui UniversityHefei 230601China Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201China Hefei National Laboratory for Physical Science at Microscale Department of Materials Science&EngineeringUniversity of Science and Technology of ChinaHefei 230026China International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China

Optimization of Pt atom utilization efficiency is critical for the development of proton-exchange-membrane fuel *** we aim to develop an efficient oxygen reduction reaction(ORR)catalyst with a low Pt content through the concurrent modification of Pt-Co alloy catalysts and carbon *** the present study,ultrafine Pt-Co alloy nanoparticles are successfully synthesized and stabilized by topological carbon defects via adopting the ammonia thermal *** the low Pt loading,the obtained catalyst exhibits an impressive half-wave potential of 0.926 V versus the reversible hydrogen electrode in 0.1 M HClO_(4)***,the durability testing using the timed-current method demonstrates a tiny loss of only 3.6%after 12 *** experimental results and theoretical calculations demonstrate that topological carbon defects significantly enhance the charge transfer processes at the alloy/carbon interface,contributing to the strong electronic metal-support interactions between the Pt-Co alloy nanoparticles and topological carbon *** interactions,along with the alloy effect,play a crucial role in promoting the ORR performance in acidic media.

关键词： electrocatalysis oxygen reduction reaction Pt-Co alloy electronic interaction topological carbon defects

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Possibilities for the synthesis of superheavy element Z=121 in fusion reactions

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Nuclear science and Techniques 2024年第6期35卷 90-100页

作者： Ming-Hao Zhang Yu-Hai Zhang Ying Zou Xiu-Xiu Yang Gen Zhang Feng-Shou Zhang The Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China School of Physical Science and Technology Guangxi UniversityNanning 530004China National Laboratory of Heavy Ion Accelerator of Lanzhou Center of Theoretical Nuclear PhysicsLanzhou 730000China

Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental *** synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 *** influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in *** reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.

关键词： Superheavy nuclei Dinuclear system model Fusion reaction Evaporation residue cross section

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Synthesis of energetic materials by microfluidics

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Defence technology(防务技术) 2025年第2期44卷 306-319页

作者： Shuo Liu Chuanyu Zhang Yanlan Wang Xueyong Wei School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049China School of Instrument Science and Technology Xi'an Jiaotong UniversityXi'an 710049China Science and Technology on Applied Physical Chemistry Laboratory Xi'an 710061China

Energetic materials,characterized by their capacity to store and release substantial energy,hold pivotal significance in some fields,particularly in defense ***,with its ability to manipulate fluids and facilitate droplet formation at the microscale,enables precise control of chemical *** scholarly endeavors have increasingly harnessed microfluidic reactors in the realm of energetic materials,yielding morphologically controllable particles with enhanced uniformity and explosive ***,crucial insights into microfluidic-based methodologies are dispersed across various publications,necessitating a systematic ***,this review addresses this gap by concentrating on the synthesis of energetic materials through ***,the methods based on micro-mixing and droplets in the previous papers are summarized and the strategies to control the critical parameters within chemical reactions are discussed in ***,the comparison in terms of advantages and disadvantages is *** demonstrated in the last section regarding perspectives,challenges such as clogging,dead zones,and suboptimal production yields are non-ignoble in the promising fields and they might be addressed by integrating sound,optics,or electrical energy to meet heightened *** comprehensive overview aims to consolidate and analyze the diverse array of microfluidic approaches in energetic material synthesis,offering valuable insights for future research directions.

关键词： Microfluidic technology Energetic materials synthesis Micro-mixing Micro-droplets

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The co-excitation of electrostatic ion-cyclotron wave and ion-Bernstein-like wave launched from a grid

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Plasma science and technology 2025年第3期27卷 1-9页

作者： Hongyu SUN Jinxiu MA Yaodong ZHAO Wan TAO Qi LIU School of Physical Sciences and CAS Key Laboratory of Geospace Environment University of Science and Technology of ChinaHefei 230026People’s Republic of China

Electrostatic ion-cyclotron wave(EICW)and ion-Bernstein wave(IBW)are two typical normal modes of plasma propagating vertically to a magnetic *** modes satisfy the extreme conditionsω《k_(||)v_(te)andω》k_(||)v_(te),whereω,k_(||),and v_(te)are the wave angular frequency,wave number parallel to the magnetic field,and the electron thermal *** these extremities,there exist IBW-like waves that have not been *** this paper,the co-excitation of the EICW and IBW-like wave in an experiment is *** is shown that,in an argon(Ar)discharge,the EICW appears in the fundamental and second harmonic frequency bands of the ioncyclotron *** contrast,the IBW-like wave appears in the higher harmonic frequency bands and in the case of a relatively strong magnetic *** a helium(He)discharge,the IBW-like wave is excited in the fundamental frequency band,but the wave behaviour becomes complicated in the harmonic frequency *** measured dispersion relations of the excited EICW are in agreement with the results of the fluid and kinetic models in some range of frequencies,but those of the excited IBW-like wave are only in qualitative agreement with the kinetic model of the *** study is important for identifying the IBW-like mode that may have potential application in plasma heating via Landau damping.

关键词： electrostatic ion-cyclotron wave ion-Bernstein-like wave dispersion relation

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