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Journal of Systems Science & Complexity 2024年第2期37卷 545-566页

作者： SUN Junchao CHEN Yong TANG Xiaoyan School of mathematical Sciences Key Laboratory of Mathematics and Engineering Applications(Ministry of Education)&Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

The multiple patterns of internal solitary wave interactions(ISWI)are a complex oceanic *** remote sensing techniques indirectly detect these ISWI,but do not provide information on their detailed structure and ***,the authors considered a three-layer fluid with shear flow and developed a(2+1)Kadomtsev-Petviashvili(KP)model that is capable of describing five types of oceanic ISWI,including O-type,P-type,TO-type,TP-type,and *** learning models,particularly physics-informed neural networks(PINN),are widely used in the field of fluids and internal solitary ***,the authors find that the amplitude of internal solitary waves is much smaller than the wavelength and the ISWI occur at relatively large spatial scales,and these characteristics lead to an imbalance in the loss function of the PINN *** solve this problem,the authors introduce two weighted loss function methods,the fixed weighing and the adaptive weighting methods,to improve the PINN *** successfully simulated the detailed structure and dynamics of ISWI,with simulation results corresponding to the satellite *** particular,the adaptive weighting method can automatically update the weights of different terms in the loss function and outperforms the fixed weighting method in terms of generalization ability.

关键词： Internal solitary wave interactions KP equation PINN method weighted loss function method

Direct visualization of laser-driven dynamic fragmentation in tin by in situ x-ray diffraction

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Matter and Radiation at Extremes 2024年第5期9卷 109-114页

作者： Jing Yang Xinxin Wang Liang Xu Qiannan Wang Yi Sun Jiangtao Li Lin Zhang Yinghua Li Yuying Yu Pei Wang Qiang Wu Jianbo Hu laboratory for Shock Wave and Detonation physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621900China laboratory of Computational physics Institute of Applied Physics and Computational MathematicsBeijing 100094China

We present a novel method for investigating laser-driven dynamic fragmentation in tin using in situ X-ray *** experimental results demonstrate the feasibility of the method for simultaneously identifying the phase and temperature of fragments through analysis of the diffraction ***,we observe a deviation from the widely accepted isentropic release assumption,with the temperature of the fragments being found to be more than 100 K higher than expected,owing to the release of plastic work during dynamic *** findings are further verified through extensive large-scale molecular dynamics simulations,in which strain energies are found to be transferred into thermal energies during the nucleation and growth of voids,leading to an increase in *** findings thus provide crucial insights into the impact-driven dynamic fragmentation phenomenon and reveal the significant influence of plastic work on material response during shock release.

关键词： dynamic release diffraction

Non-centrosymmetric topological phase probed by non-linear Hall effect

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National Science Review 2024年第6期11卷 180-188页

作者： Naizhou Wang Jing-Yang You Aifeng Wang Xiaoyuan Zhou Zhaowei Zhang Shen Lai Yuan-Ping Feng Hsin Lin Guoqing Chang Wei-bo Gao Division of physics and Applied physics School of Physical and Mathematical Sciences Nanyang Technological University Department of physics National University of Singapore Low Temperature physics laboratory College of Physics and Center for Quantum Materials and Devices Chongqing University Centre for Advanced 2D Materials National University of Singapore Institute of physics Academia Sinica The Photonics Institute and Centre for Disruptive Photonic Technologies Nanyang Technological University

Non-centrosymmetric topological material has atracted intense atention due to its superior characteristics as compared with the centrosymmetric one, although probing the local quantum geometry in non-centrosymmetric topological material remains challenging. The non-linear Hall（NLH） effect provides an ideal tool to investigate the local quantum geometry. Here, we report a non-centrosymmetric topological phase in ZrTe5, probed by using the NLH effect. The angle-resolved and temperature-dependent NLH measurement reveals the inversion and ab-plane mirror symmetries breaking at <30 K, consistently with our theoretical calculation. Our findings identify a new non-centrosymmetric phase of ZrTe5and provide a platform to probe and control local quantum geometry via crystal symmetries.

关键词： non-linear Hall effect topological insulator ZrTe5

The exchange interaction between neighboring quantum dots:physics and applications in quantum information processing

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Journal of Semiconductors 2024年第10期45卷 20-34页

作者： Zheng Zhou Yixin Li Zhiyuan Wu Xinping Ma Shichang Fan Shaoyun Huang School of Electronics Beijing Key Laboratory of Quantum Devices Key Laboratory for the Physics and Chemistry of Nanodevices Peking UniversityBeijing 100871China

Electron spins confined in semiconductor quantum dots(QDs)are one of potential candidates for physical implementation of scalable quantum information processing *** coupling based inter exchange interaction between QDs is crucial in achieving single-qubit manipulation,two-qubit gate,quantum communication and quantum *** review first provides a theoretical perspective that surveys a general framework,including the Helter−London approach,the Hund−Mulliken approach,and the Hubbard model,to describe the inter exchange interactions between semiconductor quantum *** electrical method to control the inter exchange interaction in a realistic device is proposed as *** the significant achievements of inter exchange interaction in manipulating single qubits,achieving two-qubit gates,performing quantum communication and quantum simulation are *** last part is a summary of this review.

关键词： exchange interaction quantum dots tunnel coupling quantum computation

MONOTONICITY CORRECTIONS FOR NINE-POINT SCHEME OF DIFFUSION EQUATIONS

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Journal of Computational Mathematics 2024年第5期42卷 1305-1327页

作者： Wang Kong Zhenying Hong Guangwei Yuan Zhiqiang Sheng School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key laboratory of mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjing 211106China laboratory of Computational physics Institute of Applied Physics and Computational MathematicsBeijing 100088China HEDPS Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China

In this paper,we present a nonlinear correction technique to modify the nine-point scheme proposed in[SIAM ***.,30:3(2008),1341-1361]such that the resulted scheme preserves the *** first express the flux by the cell-centered unknowns and edge unknowns based on the stencil of the nine-point ***,we use a nonlinear combination technique to get a monotone *** order to obtain a cell-centered finite volume scheme,we need to use the cell-centered unknowns to locally approximate the auxiliary *** present a new method to approximate the auxiliary unknowns by using the idea of an improved multi-points flux *** numerical results show that the new proposed scheme is robust,can handle some distorted grids that some existing finite volume schemes could not handle,and has higher numerical accuracy than some existing positivity-preserving finite volume schemes.

关键词： Monotonicity corrections Diffusion equation Improved MPFA Distorted meshes

Recent advances in protein conformation sampling by combining machine learning with molecular simulation

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Chinese physics B 2024年第3期33卷 80-87页

作者：唐一鸣杨中元姚逸飞周运谈圆王子超潘瞳熊瑞孙俊力韦广红 Department of physics State Key Laboratory of Surface Physicsand Key Laboratory for Computational Physical Sciences (Ministry of Education)Shanghai 200438China

The rapid advancement and broad application of machine learning(ML)have driven a groundbreaking revolution in computational *** of the most cutting-edge and important applications of ML is its integration with molecular simulations to improve the sampling efficiency of the vast conformational space of large *** review focuses on recent studies that utilize ML-based techniques in the exploration of protein conformational *** first highlight the recent development of ML-aided enhanced sampling methods,including heuristic algorithms and neural networks that are designed to refine the selection of reaction coordinates for the construction of bias potential,or facilitate the exploration of the unsampled region of the energy ***,we review the development of autoencoder based methods that combine molecular simulations and deep learning to expand the search for protein ***,we discuss the cutting-edge methodologies for the one-shot generation of protein conformations with precise Boltzmann ***,this review demonstrates the promising potential of machine learning in revolutionizing our insight into the complex conformational ensembles of proteins.

关键词： machine learning molecular simulation protein conformational space enhanced sampling

Color-kinematics duality and dual conformal symmetry for a four-loop form factor in N=4 SYM

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Science China(physics,Mechanics & Astronomy) 2024年第4期67卷 64-71页

作者： Guanda Lin Gang Yang Siyuan Zhang CAS Key laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental physics and mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical physics Asia-Pacific Beijing/Hangzhou 310024China

We obtain the integrand of full-color four-loop three-point form factor of the stress-tensor supermultiplet in N=4 SYM,based on the color-kinematics(CK)duality and generalized unitarity *** result not only manifests all dual Jacobi relations via CK duality but also contains 133 free *** suggests the constructibility of the form factor at even higher loops via CK *** also find that the planar form factor has a hidden dual conformal symmetry in the lightlike limit of the operator momentum,which is checked up to four loops.

关键词： S-matrix supersymmetric model perturbative calculations

Classification of high-ordered topological nodes towards Moiré flat bands in twisted bilayers

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Science China(physics,Mechanics & Astronomy) 2024年第9期67卷 133-147页

作者： Fan Cui Congcong Le Qiang Zhang Xianxin Wu Jiangping Hu Ching-Kai Chiu Beijing National laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China RIKEN Interdisciplinary Theoretical and mathematical Sciences(iTHEMS) Wako 351-0198Japan CAS Key laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Kavli Institute of Theoretical Sciences University of Chinese Academy of SciencesBeijing 100190China New Cornerstone Science laboratory Beijing 100190China

At magic twisted angles,Dirac cones in twisted bilayer graphene(TBG)can evolve into flat bands,serving as a critical playground for the study of strongly correlated *** chiral symmetry is introduced,rigorous mathematical proof confirms that the flat bands are locked at zero energy in the entire Moiré Brillouin zone(BZ).Yet,TBG is not the sole platform that exhibits this absolute band *** to this flatness phenomenon are topological nodes and their specific locations in the *** this study,considering twisted bilayer systems that preserve chiral symmetry,we classify various ordered topological nodes in base layers and all possible node locations across different ***,we constrain the node locations to rotational centers,such as Γ and M points,to ensure the interlayer coupling retains equal strength in all *** this classification as a foundation,we systematically identify the conditions under which Moiré flat bands ***,through the extension of holomorphic functions,we provide proof that flat bands are locked at zero energy,shedding light on the origin of the band ***,beyond Dirac cones,numerous twisted bilayer nodal platforms can host flat bands with a degeneracy number of more than two,such as four-fold,six-fold,and *** multiplicity of degeneracy in flat bands might unveil more complex and enriched correlation physics.

关键词： twisted bilayer systems high-ordered topological nodes Moriéflat bands high degeneracy

A polarized^(3)He system based on metastability-exchange optical pumping

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Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 72-81页

作者： Yuting Wang Liangyong Wu Kaiyuan Zhang Mei Peng Siyu Chen Haiyang Yan State Key laboratory of Nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China Institute of Nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Key laboratory of Nuclear physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Key laboratory of Neutron physics Institute of Nuclear Physics and ChemistryChina Academy of Engineering PhysicsMianyang 621900China

Hyperpolarized^(3)He nuclei have emerged as a significantly important approach in quantum precision measurement techniques,with extensive applications in fundamental physics,magnetometry,metrology,and *** this study,we report on the design and implementation of a^(3)He polarization system at the China Mianyang Research Reactor(CMRR),utilizing the metastabilityexchange optical pumping(MEOP)*** employed a Merritt coil system consisting of four square coils to furnish a uniform holding *** deployed a 2 W fiber laser to pump the metastable^(3)He atoms and conducted free induction decay(FID)detection of the polarized^(3)He nuclei using both pickup coil and optical *** the optical method,we used a50 m W linearly polarized distributed Bragg reflector(DBR)laser as the *** applied transverse light absorption polarimetry to measure the absolute nuclear polarization of the ground-state^(3)*** have developed cell fabrication capabilities at the CMRR,and cells at various pressures ranging from 100 to 1000 Pa have been fabricated and *** a typical borosilicate cell with 100 Pa pressure,the absolute polarization is measured as Pn≈70%,and the transverse relaxation time is estimated as T2≈0.5 ***,we constructed a few aluminosilicate cells,each carefully filled with pure^(3)He at a pressure of 100 ***,we conducted a comprehensive evaluation of their performance in the context of MEOP.

关键词： metastability exchange optical pumping polarized^(3)He magnetic resonance

Microwave-Assisted Confining Growth and Liquid Exfoliation of sp^(3)-Hybrid Carbon Nitride Nano/Micro-Crystals

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Energy & Environmental Materials 2024年第6期7卷 399-408页

作者： Chenglong Shen Qing Lou Kaikai Liu Guangsong Zheng Runwei Song Jinhao Zang Xigui Yang Xing Li Lin Dong Chongxin Shan Henan Key laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and Laboratory of Zhongyuan LightZhengzhou UniversityZhengzhou 450052China

As one promising carbon-based material,sp^(3)-hybrid carbon nitride has been predicted with various novel physicochemical ***,the synthesis of sp^(3)-hybrid carbon nitride is still limited by the nanaoscale,low crystallinity,complex source,and expensive ***,we have presented a facile approach to the sp^(3)-hybrid carbon nitride nano/micro-crystals with microwave-assisted confining growth and liquid ***,the carbon nitride nano/micro-crystals can spontaneously emerge and grow in the microwave-assisted polymerization of citric acid and urea,and the liquid exfoliation can break the bulk disorder polymer to retrieve the highly crystalline carbon nitride nano/*** obtained carbon nitride nano/micro-crystals present superior blue light absorption strength and surprising photoluminescence quantum yields of 57.96%in ethanol and 18.05%in solid *** experimental characterizations and density functional theory calculations reveal that the interface-trapped localized exciton may contribute to the excellent intrinsic light emission capability of carbon nitride nano/micro-crystals and the interparticle staggered stacking will prevent the aggregation-caused-quenching ***,the carbon nitride nano/micro-crystals are demonstrated to be potentially useful as the phosphor medium in light-emitting-diode for interrupting blue light-induced eye *** work paves new light on the synthesis strategy of sp^(3)-hybrid carbon nitride materials and thus may push forward the development of multiple carbon nitride research.

关键词： confining growth density functional theory liquid exfoliation luminescence sp^(3)-hybrid carbon nitride