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Dynamical switchable quantum nonreciprocity induced by off-resonant chiral two-photon driving

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 31-37页

作者： Da-Wei Liu Zi-hao Li Shi-Lei chao ying Wu Liu-Gang Si School of Physics and Institute for Quantum Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

Optical nonreciprocity,which refers to the direction-dependent emission,scattering and absorption of photons,plays a very important role in quantum engineering and quantum information ***,we propose an all-optical approach to achieve the optical dynamical switchable quantum nonreciprocity by an off-resonant chiral two-photon driving in a single microring cavity,which differs from the conventional nonreciprocal *** is shown that the optical field with time-dependent statistical properties can be generated and the nonreciprocity flips periodically,with switchable photon blockade and photon-induced tunneling *** find that the dynamical system is robust and immune to the parameter variations,which loosens the parameter range of ***,the time window for one-way quantum information is sufficiently wide and *** work opens a new idea for the current quantum nonreciprocal research,which can facilitate a memory functionality and be used for future inmemory superconducting quantum *** other nonreciprocal quantum devices,i.e.,dynamical switchable nonreciprocal squeezing and entanglement,may be inspired by our method,which is expected to have important applications in future quantum technology.

关键词： dynamical switchable nonreciprocity single-photon source chiral two-photon driving

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

Grain-boundary segregation and grain growth in nanocrystalline substitutional solid solution alloys

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Journal of Materials Science & Technology 2024年第1期168卷 239-249页

作者： Fawei Tang chao Hou hao Lu Zhi Zhao Xiaoyan Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were *** on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been *** study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.

关键词： Substitutional solid solution Grain boundary segregation Thermal stabilization Solute concentration Grain size

Path-Following Control With Obstacle Avoidance of Autonomous Surface Vehicles Subject to Actuator Faults

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 956-964页

作者： Li-ying hao Gege Dong Tieshan Li Zhouhua Peng the School of Marine Electrical Engineering Dalian Maritime UniversityDalian 116026China the School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731the Navigation CollegeDalian Maritime UniversityDalian 116026 the Yangtze Delta Region Institute(Huzhou) Huzhou 313001China

This paper investigates the path-following control problem with obstacle avoidance of autonomous surface vehicles in the presence of actuator faults,uncertainty and external *** surface vehicles inevitably suffer from actuator faults in complex sea environments,which may cause existing obstacle avoidance strategies to *** reduce the influence of actuator faults,an improved artificial potential function is constructed by introducing the lower bound of actuator efficiency *** nonlinear state observer,which only depends on measurable position information of the autonomous surface vehicle,is used to address uncertainties and external *** using a backstepping technique and adaptive mechanism,a path-following control strategy with obstacle avoidance and fault tolerance is designed which can ensure that the tracking errors converge to a small neighborhood of *** with existing results,the proposed control strategy has the capability of obstacle avoidance and fault tolerance ***,the comparison results through simulations are given to verify the effectiveness of the proposed method.

关键词： Actuator faults autonomous surface vehicle(ASVs) improved artificial potential function nonlinear state observer obstacle avoidance

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

Enhancing force sensing in a squeezed optomechanical system with quantum nondemolition measurement

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Communications in Theoretical Physics 2024年第1期76卷 49-60页

作者： Shi-Lei chao Zi-hao Li Xin-You Lü School of Physics Huazhong University of Science and Technology430074 WuhanChina

A theoretical scheme is proposed to enhance the sensitivity of force sensors with quantum nondemolition measurement(QND)in an optomechanical setup assisted by four-tone optical driving and an optical parametric amplifier(OPA).With the help of special drive,the system can be simplified as the typical type of QND for force sensing,so that the backaction noise can be evaded to surpass the standard quantum ***,the added noise can be suppressed owing to the modified optical susceptibility resulting from the *** introducing two oscillators coupling with two charged bodies respectively,the signal can be enhanced with the nonlinearity caused by Coulomb interaction,while the noise presents an exponential ***,considering the homodyne detection effect,the range of system parameters and frequency bands will be *** present investigation may provide a route toward simultaneously evading backaction noise,reducing the mechanical thermal noise,and enhancing the external signal,which can be an alternative design for sensitive devices.

关键词： force sensing optical parametric amplifier quantum non-demolition measurement optomechanical system

An Improved Thermal Conductivity Measurement Scheme for Macroscopic Graphitic Films Using the Laser Flash Method

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Journal of Thermal Science 2024年第4期33卷 1480-1490页

作者： ZHANG Peijuan MING Xin LIU yingjun WANG Xuelong SHI Hang hao Yuanyuan LU Jiahao LIU Zheng LAI Haiwen ZHANG ying GAO Weiwei XU Zhen GAO chao MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringKey Laboratory of Adsorption and Separation Materials&Technologies of Zhejiang ProvinceZhejiang UniversityHangzhou310027China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan030032China Special Equipment Safety Supervision and Inspection Institute of Jiangsu Province National Graphene Products Quality Inspection and Testing Center(Jiangsu)Wuxi214174China Hangzhou Gaoxi Technol Co. LtdHangzhou311113China China Academy of Aerospace Aerodynamics Beijing100074China

Achieving efficient thermal management urges to exploit high-thermal-conductivity materials to satisfy the boosted demand of heat *** is critical to adopt standardized characterization protocols to evaluate the intrinsic thermal conductivity of thermal management ***,for the most representative laser flash method,the lack of standard measurement methodology and systematic description on the thermal diffusivity and influencing factors has led to significant deviations and confusion of the thermal conduction performance in the emerging thermal management ***,the measurement error factors of thermal diffusivity by the common laser flash analyzer(LFA)are *** high-thermal-conductivity graphitic film(GF)as a typical case,the key factors are analyzed to guide the measurement protocol of related carbon-based thermal management *** basic principle of the LFA measurement,actual pre-processing conditions,instrument parameters setting,and data analysis are elaborated for accurate ***,the graphene thick films and common isotropic materials are also extended to meet various thermal measurement *** on the existing practical problems,we propose a feasible test flow to achieve a unified and standardized thermal conductivity measurement,which is beneficial to the rapid development of carbon-based thermal management materials.

关键词： thermal management graphitic film laser flash method thermal conductivity thermal diffusivity

Warhead fragments motion trajectories tracking and spatio-temporal distribution reconstruction method based on high-speed stereo photography

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Defence Technology（防务技术） 2024年第7期37卷 162-172页

作者： Pengyu Hu Jiangpeng Wu Zhengang Yan Meng He chao Liang hao Bai Xi'an Modern Control Technology Research Institute Xi'an710065China Xi'an OET Science and Technology Co. LtdXi'an710076China

High speed photography technique is potentially the most effective way to measure the motion parameter of warhead fragment benefiting from its advantages of high accuracy,high resolution and high ***,it faces challenge in dense objects tracking and 3D trajectories reconstruction due to the characteristics of small size and dense distribution of fragment *** address these challenges,this work presents a warhead fragments motion trajectories tracking and spatio-temporal distribution reconstruction method based on high-speed stereo ***,background difference algorithm is utilized to extract the center and area of each fragment in the image ***,a multi-object tracking(MOT)algorithm using Kalman filtering and Hungarian optimal assignment is developed to realize real-time and robust trajectories tracking of fragment *** reconstruct 3D motion trajectories,a global stereo trajectories matching strategy is presented,which takes advantages of epipolar constraint and continuity constraint to correctly retrieve stereo correspondence followed by 3D trajectories refinement using polynomial ***,the simulation and experimental results demonstrate that the proposed method can accurately track the motion trajectories and reconstruct the spatio-temporal distribution of 1.0×10^(3)fragments in a field of view(FOV)of 3.2 m×2.5 m,and the accuracy of the velocity estimation can achieve 98.6%.

关键词： Warhead fragment measurement High speed photography Stereo vision Multi-object tracking Spatio-temporal reconstruction

MXene-derived quantum dots based photocatalysts:Synthesis,application,prospects,and challenges

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Chinese Chemical Letters 2024年第6期35卷 123-133页

作者： hao Deng Yuxin Hui chao Zhang Qi Zhou Qiang Li hao Du Derek hao Guoxiang Yang Qi Wang School of Environmental Science and Engineering Zhejiang Gongshang UniversityHangzhou 310018China Instrumental Analysis Center of Zhejiang Gongshang University Hangzhou 310018China Centre for Technology in Water and Wastewater(CTWW) School of Civil and Environmental EngineeringUniversity of Technology Sydney(UTS)UltimoNSW 2007Australia

In recent years,the emerging two-dimensional material-MXenes has attracted widespread attention in the field of photocatalysis due to its high conductivity,suitable Fermi level,tunable elemental composition,and excellent photoelectric *** zero-dimensional quantum dots(MQDs)derived from 2D MXenes not only inherit the characteristics of MXenes but also exhibit better performance due to the quantum size *** on the above excellent physical and chemical properties,MQDs are often used as co-catalysts of photocatalysts,and show excellent co-catalytic *** the same time,compared with other cocatalysts(precious metals,metal oxides,metal sulfides),it has the advantages of low cost and high ***,understanding the status of MQDs in the field of photocatalysis is crucial for their further *** this review,we summarized the synthesis and modification methods of MQDs in recent years,as well as their photocatalytic applications in H_(2) production,CO_(2) reduction,N_(2) fixation,pollutant degradation,and other *** addition,the challenges and prospects faced by MQDs are also proposed,providing theoretical guidance for the further development of MQD-based photocatalysts.

关键词： MXenes Quantum dots Photocatalysis Composites Environment purification