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Dative B–N bonds weaven toward two-dimensional purely organic materials for single crystals

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Science China Chemistry 2025年第1期68卷 12-14页

作者： wei-Lei Zhou Siwei Wang Yong Chen College of Chemistry and Materials Science Inner Mongolia Key Laboratory of Chemistry for Nature Products and Synthesis for Functional MoleculesInnovation Team of Optical Functional Molecular DevicesInner Mongolia Minzu UniversityTongliao 028000China College of Chemistry Nankai UniversityTianjin 300071China

Molecular topology is one of the important topics to study and understand the relationship between molecular structure and properties^([1]).Particularly,two-dimensional(2D)materials with extremely high surface area and ultra-thin morphology have attracted considerable attention due to their unexpected properties in materials and chemistry^([2,3]).

关键词： bonds purely dimensional

No-go guide for the Hubble tension:Late-time or local-scale new physics

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 73-85页

作者： Lu Huang Shao-Jiang Wang Wang-wei Yu CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of Sciences(CAS)Beijing100190China Asia Pacific Center for Theoretical Physics(APCTP) Pohang37673Korea Max-Planck-Institut für Gravitationsphysik(Albert-Einstein-Institut) HannoverD-30167Germany Leibniz Universität Hannover Hannover30167Germany

The standard model of modern cosmology might be cracked by the recent persistent hot debate on the Hubble-constant(H_(0))tension,which manifests itself as the sound-horizon(r_(s))tension or absolute-magnitude(M_(B))tension if deeming the origin of the Hubble tension from modifying the early or late Universe,*** this study,we achieve a fully model-independent constraint(fitting a model-independent global parameterization to a model-independent inverse distant ladder with a modelindependent high-redshift calibration)on late-time models with strong evidence against homogeneous new physics over theΛ-cold-dark-matter(ΛCDM)*** using this model-independent constraint to calibrate sufficiently local supernovae with corresponding late-time models extrapolated below the homogeneity scale,we find surprisingly that,although both H_(0)tension and MB tension are absent in our local Universe,a combination of H_(0)and M_(B)as the intercept a B of the magnitude-redshift relation exhibits 3~7σtension even for theΛCDM *** aBtension seems to call for local-scale inhomogeneous new physics disguised as local observational systematics.

关键词： Hubble constant inverse distance ladder local Universe

Applications of in-situ solid-state nuclear magnetic resonance in methanol to olefins reaction

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Science China Chemistry 2025年第1期68卷 134-151页

作者： Jing Niu Shutao Xu Yingxu wei Zhongmin Liu National Engineering Research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

The methanol-to-olefins(MTO)reaction offers an alternative pathway for the production of low-carbon olefins from non-oil *** research has been impeded by a lack of comprehensive understanding of its underlying mechanism,despite the significant progress made in ***-situ solid-state nuclear magnetic resonance(ss NMR)spectroscopy has emerged as a pivotal tool,offering crucial insights into key species under real-time operando ***,the host–guest interaction between zeolites or surface species residing on zeolites and the reactant/active intermediates is revealed by the combination of in-situ^(13)C MAS NMR and 2D correlation ***,recent technological advancements in hyperpolarization(HP)methods,including HP^(129)Xe NMR and dynamic nuclear polarization(DNP),have significantly improved the sensitivity of ssNMR,enabling detailed structural and kinetic analysis as well as the detection of trace *** this feature article,we summarized recent advancements in(in-situ)ssNMR spectroscopy applied to MTO reaction processes,encompassing mechanistic investigations at various stages and the intricate host–guest *** theoretical insights into the dynamic evolution of MTO reactions lay a solid foundation for the optimization of catalytic processes and the development of efficient catalysts,thereby advancing the techniques towards more sustainable and economical production route for olefins.

关键词： MTO zeolites in-situ ssNMR reactive intermediates reaction mechanism

Three-dimensional fracture of UO_(2)ceramic pellets by phase field modeling

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 165-176页

作者： wei Xiong Xuan Ye Hongzhang Cheng Xiaoming Liu Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Fracture is the primary failure type for the UO_(2)ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes of heat conduction,heat transfer,and mechanical deformation with the cohesive phase field framework,we proposed a high-precision modeling of quasistatic cracking of three-dimensional(3D)UO_(2)ceramic fuel pellets under high temperature and *** simulation results agree well with the experimental results,indicating that the proposed method has the potential to capture 3D crack modes in the interested time ***,we studied the relation of the 3D fracture patterns of fuel pellets with the peak power *** was found that the power level plays a critical role in determining the competition between radial and circumferential cracks,as well as transverse penetrating cracks.

关键词： phase field method nuclear fuel pellet coupled thermo-mechanical model thermal fracture

A six-variable quasi-3D isogeometric approach for free vibration of functionally graded graphene origami-enabled auxetic metamaterial plates submerged in a fluid medium

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 157-176页

作者： wei CHEN Zhihong TANG Yufen LIAO Linxin PENG College of Civil Engineering University of South China College of Civil Engineering and Architecture Guangxi University Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education Guangxi University

This paper presents, for the first time, an effective numerical approach based on the isogeometric analysis(IGA) and the six-variable quasi-three dimensional(3D)higher-order shear deformation theory(HSDT) to study the free vibration characteristics of functionally-graded(FG) graphene origami(GOri)-enabled auxetic metamaterial(GOEAM) plates submerged in a fluid medium. The plate theory incorporates the thickness stretching and the effects of transverse shear deformation without using any shear correction factors. The velocity potential function and Bernoulli's equation are used to derive the hydrodynamic pressure acting on the plate surface. Both horizontally and vertically immersed plate configurations are considered here in the form of inertia *** plates are composed of multilayer GOEAMs, with the GOri content varying through the plate's thickness in a layer-wise manner. This design results in graded auxetic *** material properties are evaluated by mixing rules and a genetic programming(GP)-assisted micromechanical model. The governing equations of motion for the FG-GOEAM plates immersed in a fluid medium are derived by Hamilton's principle. After validating the convergence and accuracy of the present model, a comprehensive parametric study is carried out to examine the effects of the GOri content, GOri distribution pattern, GOri folding degree, fluid level, immersed depth, and geometric parameter on the natural frequencies of the FG-GOEAM plates. The results show that the natural frequencies for the four GOri distribution patterns increase with the increase in the layer number when the lay number is fewer than 10, and then stabilize after the layer number reaches ***, in general, the natural frequency of the FG-GOEAM plate in a vacuum or fluid increases when the GOri content increases, while decreases when the GOri folding degree increases. Some additional findings related to the numerical results are presented in the conclusions. It is belie

关键词： free vibration functionally-graded (FG) graphene origami (GOri)-enabled auxetic metamaterial (GOEAM) plate hydrodynamic pressure isogeometric analysis (IGA) O321 quasi-three dimensional (3D) higher-order shear deformation theory (HSDT)

Spectroscopic Features of Quantum Many-Body Scar States

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Chinese Physics Letters 2025年第2期42卷 26-30页

作者： Wenjie wei Long Zhang Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China Hefei National Laboratory Hefei 230088China

We studied the dynamic correlations of non-integrable systems with quantum many-body scar(QMBS)states generated by a ladder *** ladder operator's spectral function has an exact δ-function peak induced by the QMBS *** a concrete example,we show that in the one-dimensional(1D)spin-1 Affleck-Kennedy-Lieb-Tasaki model,the spectral function of two-magnon excitations exhibits a characteristic bowtie shape composed of aδ-function resonance peak at momentum k=π and a continuum spectrum *** two-magnon excitations can be observed via resonant inelastic X-ray scattering spectroscopy on quasi-1D nickelates and other spin-1 antiferromagnetic ***,the findings of this study pave the way for detecting(approximate)QMBS states in realistic materials.

关键词： materials. excitation ladder

Recent progress on artificial intelligence-enhanced multimodal sensors integrated devices and systems

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Journal of Semiconductors 2025年第1期46卷 179-192页

作者： Haihua Wang Mingjian Zhou Xiaolong Jia Hualong wei Zhenjie Hu wei Li Qiumeng Chen Lei Wang College of Integrated Circuit Science and Engineering Nanjing University of Posts and TelecommunicationsNanjing 210023China Nantong Institute of Nanjing University of Posts and Telecommunications Nantong 226021China

Multimodal sensor fusion can make full use of the advantages of various sensors,make up for the shortcomings of a single sensor,achieve information verification or information security through information redundancy,and improve the reliability and safety of the *** intelligence(AI),referring to the simulation of human intelligence in machines that are programmed to think and learn like humans,represents a pivotal frontier in modern scientific *** the continuous development and promotion of AI technology in Sensor 4.0 age,multimodal sensor fusion is becoming more and more intelligent and automated,and is expected to go further in the *** this context,this review article takes a comprehensive look at the recent progress on AI-enhanced multimodal sensors and their integrated devices and *** on the concept and principle of sensor technologies and AI algorithms,the theoretical underpinnings,technological breakthroughs,and pragmatic applications of AI-enhanced multimodal sensors in various fields such as robotics,healthcare,and environmental monitoring are *** a comparative study of the dual/tri-modal sensors with and without using AI technologies(especially machine learning and deep learning),AI-enhanced multimodal sensors highlight the potential of AI to improve sensor performance,data processing,and decision-making ***,the review analyzes the challenges and opportunities afforded by AI-enhanced multimodal sensors,and offers a prospective outlook on the forthcoming advancements.

关键词： sensor multimodal sensors machine learning deep learning intelligent system

PINN for solving forward and inverse problems involving integrable two-dimensional nonlocal equations

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Communications in Theoretical Physics 2025年第2期77卷 15-22页

作者： Xi Chen wei-Qi Peng School of Mathematics China University of Mining and Technology School of Mathematical Sciences Ocean University of China

In this paper, the physics informed neural network(PINN) deep learning method is applied to solve two-dimensional nonlocal equations, including the partial reverse space y-nonlocal Mel'nikov equation, the partial reverse space-time nonlocal Mel'nikov equation and the nonlocal twodimensional nonlinear Schr?dinger(NLS) equation. By the PINN method, we successfully derive a data-driven two soliton solution, lump solution and rogue wave solution. Numerical simulation results indicate that the error range between the data-driven solution and the exact solution is relatively small, which verifies the effectiveness of the PINN deep learning method for solving high dimensional nonlocal equations. Moreover, the parameter discovery of the partial reverse space-time nonlocal Mel'nikov equation is analysed in terms of its soliton solution for the first time.

关键词： two dimensional nonlocal equations PINN soliton solution rogue wave inverse problems

Intricate interplay between shear stress and extrusion temperature in Mg−Al composite rods

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 105-125页

作者： Jian-xing ZHAO Chao-wei ZENG Ting YUAN wei PENG Zhen-wei SUN Ou ZHANG Hong-jun HU College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China

The Mg−Al composite rods of aluminum core-reinforced magnesium alloy were prepared by the extrusion−shear(ES)process,and the microstructure,deformation mechanism,and mechanical properties of the Mg−Al composite rods were investigated at different extrusion temperatures and shear *** experimental results show that the proportion of dynamic recrystallization(DRX)and texture for Al and Mg alloys are controlled by the combination of temperature and shear *** texture type of the Al alloys exhibits slight variations at different *** the increase of temperature,the DRX behavior of Mg alloy shifts from discontinuous DRX(DDRX),continuous DRX(CDRX),and twin-induced DRX(TDRX)dominant to CDRX,the dislocation density in Mg alloy grains decreases significantly,and the average value of Schmid factor(SF)of the basalslip system *** particular,partial grains exhibit a distinct dominant slip system at 390℃.The hardness and thickness of the bonding layer,as well as the yield strength and elongation of the Mg alloy,reach their maximum at 360℃as a result of the intricate influence of the combined temperature and shear stress.

关键词： Mg−Al composite rod texture evolution deformation mechanism intermetallic compound extrusion−shear process