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Materials design and preparation of ultrathin two-dimensional metal halide perovskites

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Nano Research 2024年第7期17卷 6231-6246页

作者： Xiaomin Zhang Sihan Zhao Junran Zhang Lin Wang School of Flexible Electronics(Future Technologies)and Institute of Advanced Materials Key Laboratory of Flexible ElectronicsJiangsu National Synergetic Innovation Center for Advanced MaterialsSchool of Physical and Mathematical SciencesNanjing Tech UniversityNanjing 211816China

Metal halide perovskites(MHPs)have emerged as highly promising candidates for the next generation of photonics and optoelectronic devices,owing to their prominent optical and excitonic properties,as well as the convenience of ***,ultrathin two-dimensional(2D)MHPs,which are generally prepared by exfoliation,solution growth,and chemical vapor deposition method,have attracted dramatically increasing attentions owing to their combined features of ultrathin 2D morphology and superior performance of *** the growing interest in ultrathin 2D MHPs,there is currently a lack of a comprehensive and systematic overview of the distinct advantages offered by each growth method for producing these *** review critically assesses the preliminary studies on the materials design and preparation of ultrathin ***,it explores heterostructures based on ultrathin MHPs and offers insights into the challenges and opportunities that lie ahead for this enticing class of 2D materials.

关键词： ultrathin perovskites material preparation exfoliation solution growth chemical vapor deposition

Synthesis of hierarchically porous carbon materials by zinc salts-assisted carbonization of biomass and organic solid wastes

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Particuology 2024年第1期84卷 45-52页

作者： Le-Le Zhang Lei Tong Yanwei Ding Wanqun Zhang Hai-Wei Liang Hefei National Research Center for physical sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei230026China

Hierarchically porous carbons(HPCs)with multimodal pores have attracted considerable attention due to their unique physical and chemical properties and various application potentials in heterogeneous catalysis,environmental treatment,and energy storage and ***,we report a general and simple zinc salts-assisted method for the synthesis of HPCs with varied porosity and chemical func-tionalities by the direct carbonization of diverse biomass and *** the carbonization,zinc salts are thermally decomposed into nanoparticles that serve as in-situ templates to introduce nanopores in *** prepared HPCs exhibit high specific surface areas(up to 2432 m2 g-1),large pore volumes(up to 4.30 cm^(3)g^(-1)),and broad pore size ***,the zinc salts can be recovered and recycled,supporting the sustainable production of HPCs on large *** prepared HPCs-supported catalysts with atomically dispersed metal sites exhibit promising electrocatalytic performance for the oxygen reduction reaction.

关键词： Hierarchical porous carbon Zinc salts Biomass Wastes Electrocatalysis

THE RIEMANN PROBLEM FOR ISENTROPIC COMPRESSIBLE EULER EQUATIONS WITH DISCONTINUOUS FLUX

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Acta Mathematica Scientia 2024年第1期44卷 37-77页

作者：孙印正屈爱芳袁海荣 department of Mathematics Shanghai Normal UniversityShanghai200234China School of mathematical sciences and Shanghai Key Laboratory of Pure Mathematics and mathematical Practice East China Normal UniversityShanghai200241China

We consider the singular Riemann problem for the rectilinear isentropic compressible Euler equations with discontinuous flux,more specifically,for pressureless flow on the left and polytropic flow on the right separated by a discontinuity x=x(t).We prove that this problem admits global Radon measure solutions for all kinds of initial *** over-compressing condition on the discontinuity x=x(t)is not enough to ensure the uniqueness of the ***,there is a unique piecewise smooth solution if one proposes a slip condition on the right-side of the curve x=x(t)+0,in addition to the full adhesion condition on its *** an application,we study a free piston problem with the piston in a tube surrounded initially by uniform pressureless flow and a polytropic *** particular,we obtain the existence of a piecewise smooth solution for the motion of the piston between a vacuum and a polytropic *** indicates that the singular Riemann problem looks like a control problem in the sense that one could adjust the condition on the discontinuity of the flux to obtain the desired flow field.

关键词： compressible Euler equations Riemann problem Radon measure solution delta shock discontinuous flux wave interactions

Observations on spontaneous chiral symmetry breaking and the mass gap of QCD in finite volume

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Communications in Theoretical Physics 2024年第9期76卷 44-49页

作者： Xiaolan Meng Bolun Hu Yi-Bo Yang University of Chinese Academy of sciences School of Physical Sciences CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Fundamental Physics and mathematical sciences Hangzhou Institute for Advanced StudyUCAS International Centre for Theoretical Physics Asia-Pacific

We present a lattice quantum chromodynamics(QCD) simulation with 2 + 1 + 1 flavor full QCD ensembles using near-physical quark masses and different spatial sizes L, at a ～ 0.055 *** results show that the scalar and pesudoscalar 2-point correlator with a valence pion mass of approximately 230 MeV become degenerated at L ≤ 1.0 fm, and such an observation suggests that the spontaneous chiral symmetry breaking disappears effectively at this point. At the same time, the mass gap between the nucleon and pion masses remains larger than ΛQCDin the entire L ∈ [0.2, 0.7] fm range.

关键词： chiral symmetry breaking confinement lattice QCD

Integralinput-to-statestability ystemswithsmalldelays Integral input-to-state stability of systems with small delays

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Control Theory and Technology 2024年第3期22卷 455-467页

作者： R.H.Harsha Nawarathna Yuandan Lin Yuan Wang department of mathematical sciences Florida Atlantic UniversityBoca RatonFL 33431USA

We consider how small delays affect the integral-input-to-state stability(iss)property for a *** result is similar to the input-to-state stability(Iss)result obtained in[1]:the iss property will be preserved in a practical and semi-global manner if the delay interval is small ***,since the iss quantifies the robust stability in terms of a generalized Li norm of the inputs instead of a generalized Loo norm of the inputs for the Iss case,the techniques and proofs for the Iss case do not apply to the iss case *** the proofs in[1]are based on the Lyapunov-Razumikhin approach,our proofs are based on the iss-Lyapunov functions for the zero-delay *** addition to the interest by its own in showing how the iss property is affected by small delays,the result also serves to the study of the iss property for singularly perturbed systems.

关键词： Integral-input-to-state stability Nonlinear systems Small delays Lyapunov method

通过声学系统实现三维平坦朗道能级:从理论到实践

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科学通报 2024年第23期69卷 3339-3341页

作者：程哲宇张柏乐 School of physical and mathematical sciences Nanyang Technological UniversitySingapore 637371Singapore

1930年, 22岁的朗道考虑过二维自由电子气在磁场下运动的问题.计算表明,此时电子的本征能量会劈裂成无色散的平坦能级,称为朗道能级,这个熟知的结论已经被写在朗道的著作中^([1]),并且之后也是量子霍尔效应的基石^([2]).正如同大部分量... 详细信息

1930年, 22岁的朗道考虑过二维自由电子气在磁场下运动的问题.计算表明,此时电子的本征能量会劈裂成无色散的平坦能级,称为朗道能级,这个熟知的结论已经被写在朗道的著作中^([1]),并且之后也是量子霍尔效应的基石^([2]).正如同大部分量子力学书籍所述,朗道能级起源于二维自由电子气.由于自由电子之间无相互作用,自由电子气是研究系统对外场响应的理想平台.

关键词：朗道能级量子霍尔效应自由电子气量子力学本征能量声学系统外场响应相互作用

Gender-Based Analysis of User Reactions to Facebook Posts

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Big Data Mining and Analytics 2024年第1期7卷 75-86页

作者： Yassine El Moudene Jaafar Idrais Rida El Abassi Abderrahim Sabour mathematical Engineering and Computer Science Laboratory Faculty of SciencesIbn Zohr UniversityAgadir 8706Morocco department of Computer Science mathematical−High School of Technology Ibn Zohr UniversityAgadir 8706Morocco

Online Social Networks(OSNs)are based on the sharing of different types of information and on various interactions(comments,reactions,and sharing).One of these important actions is the emotional reaction to the *** diversity of reaction types available on Facebook(namely FB)enables users to express their feelings,and its traceability creates and enriches the users’emotional identity in the virtual *** paper is based on the analysis of 119875012 FB reactions(Like,Love,Haha,Wow,Sad,Angry,Thankful,and Pride)made at multiple levels(publications,comments,and sub-comments)to study and classify the users’emotional behavior,visualize the distribution of different types of reactions,and analyze the gender impact on emotion *** of these can be achieved by addressing these research questions:who reacts the most?Which emotion is the most expressed?

关键词： profiling knowledge extraction data mining emotion mining social media data crawling Facebook reactions gender

A chaotic hierarchical encryption/watermark embedding scheme for multi-medical images based on row-column confusion and closed-loop bi-directional diffusion

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Chinese Physics B 2024年第2期33卷 228-237页

作者：张哲祎牟俊 Santo Banerjee 曹颖鸿 School of Information Science and Engineering Dalian Polytechnic UniversityDalian 116034China department of mathematical sciences Politecnico di TorinoTorino 10129Italy

Security during remote transmission has been an important concern for researchers in recent *** this paper,a hierarchical encryption multi-image encryption scheme for people with different security levels is designed,and a multiimage encryption(MIE)algorithm with row and column confusion and closed-loop bi-directional diffusion is adopted in the *** ensuring secure communication of medical image information,people with different security levels have different levels of decryption keys,and differentiated visual effects can be obtained by using the strong sensitivity of chaotic *** highest security level can obtain decrypted images without watermarks,and at the same time,patient information and copyright attribution can be verified by obtaining watermark *** experimental results show that the scheme is sufficiently secure as an MIE scheme with visualized differences and the encryption and decryption efficiency is significantly improved compared to other works.

关键词： chaotic hierarchical encryption multi-medical image encryption differentiated visual effects row-column confusion closed-loop bi-directional diffusion transform domain watermark embedding

Escape probability for isotropic emitters near Kerr black hole with astrometric

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Communications in Theoretical Physics 2024年第5期76卷 128-133页

作者： Yu-Xuan Han Qing-Hua Zhu Qing-Guo Huang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of physical sciences University of Chinese Academy of SciencesNo.19A Yuquan RoadBeijing 100049China department of Physics Chongqing UniversityChongqing 401331China School of Fundamental Physics and mathematical sciences Hangzhou Institute for Advanced Study UCASHangzhou 310024China

The paper investigates the escape probability for isotropic emitters near a Kerr black *** propose a new approach to obtain the escape probability in a general manner,going beyond previous case-by-case *** approach is based on studies of the black hole shadow with astrometric observable and can be applied to emitters with an arbitrary 4-velocities and locations,even to the emitters outside of the equatorial *** also consider representative examples illustrating how escape probabilities vary with distance,velocity,and inclination ***,this new approach provides an effective method for studying escape probabilities near Kerr black holes.

关键词： Kerr black hole photon escape probability isotropic emitters