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Flavor mixing and solution structures in Dyson–Schwinger equations for a two-flavor system

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Communications in Theoretical Physics 2024年第10期76卷 64-77页

作者： Xue-ao Chao Yu-xin liu Department of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University Collaborative Innovation Center of Quantum Matter Center for High Energy Physics Peking University

We solved the Dyson–Schwinger(DS) equations for a two-flavor system with symmetry to study its flavor mixing effects. Initially, we employed the point interaction model and bare vertex approximation to reveal the structure of the solutions. Using the point interaction model, the DS equations can be solved analytically, and we found that these solutions can be classified into three groups, each forming an ellipse. These solutions exhibit SO(2) symmetry, while the original SU(2)symmetry at the Lagrangian level is dynamically broken to SO(2), corresponding to the emergence of flavor mixing effects. However, this flavor mixing effect does not manifest in the final physical *** utilizing the system's SO(2) symmetry, we can diagonalize the propagators of the DS equations,eliminating the flavor mixing effect but causing the originally degenerate masses at the Lagrangian level to split. These mass eigenstates have identical quantum numbers but different masses. If we can correspond these to quark particles of different generations, we can explain why the three generations of quarks have different masses and obtain the corresponding quark mass spectrum. Finally, we provide the corresponding numerical results using a more realistic interaction model.

关键词： dynamic symmetry breaking Dyson-Schwinger equation flavor change mass splitting

Polyolefin vitrimers bearing acetoacetate functionality

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Science China Chemistry 2024年第11期67卷 3861-3867页

作者： Zihao Wang Yue liu Wenmin Pang ao Chen Min Chen Chinese Academy of Sciences (CAS) Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education Anhui University

Polyolefin vitrimers are polymer networks bearing reversible covalent crosslinking points, enabling them to be reprocessed and recycled. In this contribution, a series of polyolefin vitrimers were designed based on the acetoacetate-functionalized polyolefin copolymers, which were produced through the direct copolymerization of ethylene with polar comonomers using a phosphinesulfonate palladium catalyst. The pendant acetoacetate group could mediate several characteristic reactions, such as the Michael addition reaction, ketone-amine condensation and metal coordination reaction. As such, structurally adjustable polyolefin vitrimers can be accessed by introducing various dynamic crosslinking bonds, including disulfide exchange, transamination of vinylogous urethane and labile metal coordination bond. The utilization of different crosslinking reactions and the mole ratio of crosslinkers significantly impact the material properties of the resultant polymers. Specifically, the generated polyolefin vitrimers demonstrated excellent reprocessability and closed-loop recycling properties. The study in this work provides an efficient strategy to access various polyolefin vitrimers.

关键词： polyolefin vitrimers acetoacetate group polar monomer olefin copolymerization

Incombustible solid polymer electrolytes:A critical review and perspective

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Journal of Energy Chemistry 2024年第6期93卷 264-281,I0007页

作者： Kai Wu Jin Tan Zhenfang liu Chenguang Bao ao Li Qi liu Baohua Li College of Materials Science and Engineering Hunan UniversityChangsha 413000HunanChina Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 055GuangdongChina

Since the advent of the solid-state batteries,employing solid polymer electrolytes(SPEs)to replace routine flammable liquid electrolytes is regarded to be one of the most promising solutions in pursing highenergy-density battery *** with superior thermal stability,good processability,and high mechanical modulus obtain increasing ***,SPE-based batteries are not impenetrable due to their decomposition and combustibility under extreme *** believe incorporating appropriate flame-retardant additives/solvents/fragments into SPEs can intrinsically reduce their flammability to solve the battery safety *** this review,the recent research progress of incombustible SPEs,with special emphasis on flame-retardant structural design,is ***,a brief introduction of flame-retardant mechanism,evaluation index for safety of SPEs,and a detailed overview of the latest advances on diverse-types SPEs in various battery systems are *** deep insight into thermal ru naway process,the free-standing incombustible GPEs,and the ratio nal design of pouch cell structures may be the main directions to motivate revolutionary next-generation for safety batteries.

关键词： Non-flammable electrolyte Solid polymer electrolyte High safety electrolyte Solid state electrolyte Solid state battery

Europium-bearing organic framework with excellent X-ray scintillating luminescence

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Journal of Rare Earths 2024年第2期42卷 251-255,I0001页

作者： Yugang Zhang Lanhua Chen Xia Wang Wei liu Shu'ao Wang State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou215123China School of Environmental and Materials Engineering Yantai UniversityYantai264005China

Two europium-bearing organic frameworks,termed as EuTPO-1 and EuTPO-2(H_(3)TPO=tris(4-carboxylphenyI)-phosphineoxide),are reported in this work.A series of characterizations of EuTPO-1and EuTPO-2,such as X-ray crystallography and photoluminescence spectroscopy,was performed to expatiate their structure and physicochemical *** of them are constructed by dimers of the europium-oxygen subunit of [Eu_(2)O_(16)] and TPO *** from high X-ray stopping attenuation and excellent luminescence efficiency,they emit sufficient luminescence when irradiated with ***,they possess stable light outputs when exposed to high humidities and strong radiation dose,outperforming the commercial scintillator CsI:*** result paves the way for developing new scintillator and enriches the compound of europium-bearing organic framework with X-ray scintillating luminescence.

关键词： Metal-organic frameworks Scintillating material Luminescence efficiency Rare earths

Efficient piezo-assisted near-infrared-light-driven Cr(Ⅵ)reduction over Bi_(2)S_(3) nanowires transformed from ultrathin Bi_(2)WO_(6) nanosheets

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Rare Metals 2024年第9期43卷 4333-4343页

作者： Qiang Zhang Yuan-Hao Cheng Wei liu Hui-Nan Che Yan-Hui ao Key Laboratory of Integrated Regulation and Resource Development On Shallow Lakes Ministry of EducationCollege of EnvironmentHohai UniversityNanjing 210098China

The utilization of piezo-photocatalytic technol ogy for environmental remediation under full spectrum solar light is promising but still ***,one dimensional Bi_(2)S_(3)nanowires,which can utilize both mechanical energy and near-infrared(NIR)light to remov hexavalent chromium(Cr(Ⅵ))efficiently,were synthe sized by a restrained growth *** reaction rat constants of Cr(Ⅵ)reduction in piezo-photocatalyti process under NIR(800–2500 nm)reached 0.334 min^(-1)which were 3.2 and 12.4 times as that of single piezo and photocatalytic *** formation of polarized electri fields and one-dimensional structure allow ultrafast sepa ration of charge carriers,thereby promoting the catalyti ***,due to the strong penetrability o NIR light,the piezo-photocatalysis performance in turbid solutions under NIR light(0.188 min^(-1))was even com parable to that under visible light(0.186 min^(-1)).Thi study provides a new concept on the development of piezo photocatalytic technology for environmental remediation by utilization of NIR light and natural mechanical energy.

关键词： Piezo-photocatalysis NIR light Bi_(2)S_(3)nanowires Cr(Ⅵ)

Elaborative collection of condensed combustion products of solid propellants:Towards a real Solid Rocket Motor(SRM)operational environment

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Chinese Journal of Aeronautics 2024年第1期37卷 77-88页

作者： Wenchao ZHANG Zhimin FAN Dongliang GOU Yao SHU Peijin liu Aimin PANG Wen ao National Key Laboratory of Solid Rocket Propulsion Northwestern Polytechnical UniversityXi’an 710072China Science and Technology on Aerospace Chemical Power Laboratory Xiangyang 441003China

A novel constant-pressure and constant-quenching distance Condensed Combustion Products(CCPs)collection system was developed,coupled with a timing control system,to collect the CCPs formed in the course of burning of aluminum-based composite *** effects of adiabatic graphite plating,collection zone,quenching distance,time series of collection,and propellant burning rate on the microscopic morphology,particle size distribution and unburned aluminum content of CCPs were *** was verified that the graphite plating can provide a high-fidelity high-temperature environment for propellant *** combustion efficiency is improved by 2.44% compared to the bare propellant *** time series of collection has a significant effect on the combustion efficiency of aluminum,and the combustion efficiency of aluminum in the thermal state(1.2-2.4 s)is 2.75% higher than that in the cold state(0-1.2 s).Similarly,the characteristics of the CCPs in different collection zones are *** the quenching distance of 5 mm,the combustion efficiency of aluminum in the core zone(85.39%)is much lower than that in the outer zone(92.07%),while the particle size of the CCPs in the core zone(172μm)is larger than that in the outer zone(41μm).This indicates that the core zone is more likely to produce large-sized and incompletely burned agglomerates during the propellant combustion *** burning rates also lead to a significant difference in particle size distribution and combustion *** burning rates result in higher combustion efficiency.A detailed sequence of the elaborative collection process of CCPs is proposed,mainly including the setting of ignition delay time,burning rate,working pressure,plating length and time series of *** findings of this study are expected to provide a reliable tool for the evaluation of the combustion efficiency of solid propellants.

关键词： Composite propellants Condensed combustion products Aluminum Combustion efficiency Particle size distribution

Using Longitudinal Fins to Improve the Melting Performance of Stearic Acid in Thermal Energy Storage Devices

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Journal of Thermal Science 2024年第5期33卷 1672-1687页

作者： YAN Suying liu Yiran ao Ci ZHao Xiaoyan ZHANG Na ZHANG Ruiying AHMADI Mohammad Hossein School of Energy and Power Engineering Inner Mongolia University of TechnologyHohhot 010051China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China School of Materials Science and Engineering Inner Mongolia University of TechnologyHohhot 010051China Faculty of Mechanical Engineering Shahrood University of TechnologyShahroodIran

The heat transfer efficiency of a thermal energy storage unit(TESU)can be improved by the addition of novel longitudinal fins.A series of TESUs are analyzed using the finite volume method(FVM)to determine the effect of fin angle on the heat transfer *** the fin angle increases,the TES rate first increases,then decreases,reaching a maximum rate at 60°,where the melting time is less by 30.9%,28.58%,21.99%,9.02%,and 18.1%than at 0°,15°,30°,45°,and 80°,*** addition,it is found that the melting time of the phase change material is significantly greater at the bottom of the *** time percentage of this stage decreases as the fin angle increases through these percentages by 7%,14%,23%,33%,and 20%,***,the response surface methodology(RSM)is applied to optimize the longitudinal fin by minimizing the total melting *** analysis concludes that a fin angle of 58.68°reduces the complete melting time of the stearic acid by 44%below the time at 0°.These findings fill a gap in knowledge of the effect on melting performance of the design angle of longitudinal fins and provide a reference for the design of horizontally placed longitudinal finned thermal energy storage units.

关键词： thermal energy storage melting rate enhancement longitudinal fins fin angle phase change materials

Photoluminescence and photothermal conversion in boric acid derived carbon dots for targeted microbial theranostics

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Chinese Chemical Letters 2024年第9期35卷 232-237页

作者： Yiqiao Chen ao liu Biwen Yang Zhenzhen Li Binggang Ye Zhouyi Guo Zhiming liu Haolin Chen Department of Anesthesiology General Hospital of Southern Theater Command of People’s Liberation ArmyGuangzhou 510010China MOE Key Laboratory of Laser Life Science&Guangdong Provincial Key Laboratory of Laser Life Science College of BiophotonicsSouth China Normal UniversityGuangzhou 510631China Healthy Medical Engineering Technology Research Center Guangdong Food and Drug Vocational CollegeGuangzhou 510520China

Theranostic carbon dots(CDs)have attracted widespread attention recently due to their tunable optical properties and diverse *** fluorescent imaging application,the photothermal property endows CDs with the potential for microbial ***,realization of the effective conversion between fluorescence and heat in one CD system has rarely been ***,we provide a simple strategy for targeted microbial theranostics based on 4-carboxyphenylboronic acid-derived CDs(PCBA-CDs)which possess concentration-dependent photoluminescence/photothermal *** lower concentrations,PCBA-CDs show bright and stable fluorescent signals ranging from blue to *** fluorescence intensity gradually decreases with increasing concentration,while on the contrary,the photothermal effect of PCBA-CDs ascends progressively due to the rearrangement of electronic transitions in aggregated ***-CDs also demonstrate high affinity to the polysaccharide structures on the surface of microbe which allows rapid microbial fluorescence imaging as well as specific photothermal ablation of pathogens in skin wounds using PCBA-CDs at lower and higher concentrations,*** study supplies a facile nanotheranostic strategy for just-in-time microbial management using bioactive CDs.

关键词： Theranostic carbon dots Fluorescence imaging Phenylboronic acid Photothermal therapy Nanotheranostic

Texture and Se vacancy optimization induces high thermoelectric performance in Bi_(2)Se_(3) flexible thin films

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Rare Metals 2024年第6期43卷 2796-2804页

作者： Dong-Wei ao Wei-Di liu Yue-Xing Chen Fan Ma Yi-Jie Gu Zhuang-Hao Zheng School of Machinery and Automation Weifang UniversityWeifang 261061China Australian Institute for Bioengineering and Nanotechnology The University of QueenslandBrisbane 4072Australia Shenzhen Key Laboratory of Advanced Thin Films and Applications Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China School of Materials Science and Engineering Inner Mongolia University of TechnologyHohhot 010051China

Bi_(2)Se_(3)-based flexible thin film with high thermoelectric performance is promising for the waste heat recovery *** this work,a novel post-selenization method is employed to prepare n-type Bi_(2)Se_(3)flexible thin films with highly textured *** strengthened texture and Se vacancy optimization can be simultaneously achieved by optimizing the selenization *** highly oriented texture leads to the increased carrier mobility and results in a high electric conductivity of~290.47 S·cm^(-1)at 623 ***,a high Seebeck coefficient(>110μW·K-1)is obtained due to the reduced carrier concentration,induced by optimizing vacancy ***,a high power factor of 3.49μW·cm^(-1)·K^(-2)at 623 K has been achieved in asprepared highly-bendable Bi_(2)Se_(3)flexible thin films selenized at 783 *** study introduces an effective post-selenization method to tune the texture structure and vacancies of Bi_(2)Se_(3)flexible thin films,and correspondingly achieves high thermoelectric performance.

关键词： Thermoelectric Bi_(2)Se_(3) Flexible thin film Post-selenization