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Limit Theorems for Critical galton-Watson Processes with Immigration Stopped at Zero

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Acta Mathematica Sinica,English Series 2024年第2期40卷 435-450页

作者： Dou Dou LI Mei zhang Xian yu zhang College of Statistics and Data Science Faculty of ScienceBeijing University of TechnologyBeijing 100124P.R.China Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

In this paper,we consider a critical galton-Watson branching process with immigration stopped at zero *** precise estimation on the probability generating function of the n-th population are obtained,and the tail prob... 详细信息

关键词： Branching immigration critical life period limit theorems

Physics of cavitation near particles

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Journal of Hydrodynamics 2024年第1期36卷 102-118页

作者： Jia-xin yu Xiao-yu Wang Jun-wei Shen Jin-sen Hu Xiang-qing zhang Da-qing He yu-ning zhang Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China

The combined effect of cavitation and silt abrasion presents a great challenge and threat to secure the operation and the efficiency of hydraulic machineries working in sediment-laden *** present paper critically reviews the current research progress on the interaction mechanisms of the bubbles and the ***,the analytical models including boundary treatment methods for predicting the jet dynamics of the bubble collapse near particles are ***,the bubble collapsing dynamics,jet dynamics and shock wave characteristics near particles are revealed both experimentally and ***,the bubble-particle-wall system is investigated with a focus on microjets.

关键词： Cavitation bubble particle jet shock wave

Silicon dioxide-protection boosting the peroxidase-like activity of fe single-atom catalyst for combining chemo-photothermal therapy

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Nano Research 2024年第6期17卷 4924-4933页

作者： yu Fan yu Yi Hongpan Rong Jiatao zhang Beijing Key Laboratory of Construction-Tailorable Advanced Functional Materials and green Applications School of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 100081China CAS Center for Excellence in Nanoscience CAS KeyLaboratory for Biomedical Effects of Nanomaterials and NanosafetyNational Center for Nanoscience and Technology(NCNST)Beijing 100190China Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering Ministry of Industry and Information TechnologySchool of Chemistry&Chemical EngineeringBeijing Key Laboratory of Construction-Tailorable Advanced Functional Materials and Green ApplicationsSchool of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China

Carbon-based single-atom catalysts(SACs)have been widely studied in the field of biomedicine due to their excellent catalytic ***,carbon-based SACs usually aggregate during pyrolysis,which leads to the reduction of catalytic ***,we describe a method to improve the monodispersion of SACs using silicon dioxide as a protective *** decoration of silicon dioxide serves as a buffer layer for individual nanoparticles,which is not destroyed during the pyrolysis process,ensuring the single-particle dispersion of the nanoparticles after *** approach increased the hydroxyl groups on the surface of fe-SAC(fe-SAC-SE)and improved its water solubility,resulting in a four times enhancement of the peroxidase(POD)-like activity of fe-SAC-SE(58.4 U/mg)than that of non-protected SACs(13.9 U/mg).The SiO_(2)-protection approach could also improve the catalytic activities of SACs with other metals such as Mn,Co,Ni,and Cu,indicating its generality for SACs *** advantage of the high POD-like activity,photothermal properties,and large specific surface area of fe-SAC-SE,we constructed a synergistic therapeutic system(fe-SAC-SE@DOX@PEg)for combining the photothermal therapy,catalytic therapy,and *** was verified that the photothermal properties of fe-SAC-SE@DOX@PEg could effectively improve its POD-like activity,exhibiting excellent tumor-killing performance at the cellular *** work may provide a general approach to improve the performances of SACs for disease therapy and diagnosis.

关键词： single-atom catalysts peroxidase-like activity SiO2-protection photothermal therapy catalytic therapy chemotherapy

Quantum Spin Exchange Interactions to Accelerate the Redox Kinetics in Li–S Batteries

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Nano-Micro Letters 2024年第5期16卷 370-383页

作者： yu Du Weijie Chen yu Wang yue yu Kai guo gan Qu Jianan zhang Key Laboratory of Advanced Energy Catalytic and Functional Materials Preparation of Zhengzhou City College of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001People’s Republic of China

Spin-engineering with electrocatalysts have been exploited to suppress the“shuttle effect”in Li–S *** selec-tion,spin-dependent electron mobility and spin potentials in activation barriers can be optimized as quantum spin exchange interactions lead-ing to a significant reduction of the electronic repulsions in the orbitals of ***,we anchor the MgPc molecules on fluorinated carbon nanotubes(MgPc@FCNT),which exhibits the single active Mg sites with axial *** to the density functional theory calculations,the electronic spin polarization in MgPc@FCNT not only increases the adsorption energy toward LiPSs intermediates but also facilitates the tunneling process of electron in Li–S *** a result,the MgPc@FCNT provides an initial capacity of 6.1 mAh cm^(-2) even when the high sulfur loading is 4.5 mg cm^(-2),and still maintains 5.1 mAh cm^(-2) after 100 *** work provides a new perspective to extend the main group single-atom catalysts enabling high-performance Li–S batteries.

关键词： Metal phthalocyanines Spin polarization Electrocatalysis Li–S batteries

A Note on gradient Estimates for Elliptic Equations with Discontinuous Coefficients

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 1-10页

作者： yu PENg Xiandong SUN Huichun zhang Department of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China.

The authors will use a method in metric geometry to show an L^(P)-estimate for gradient of the weak solutions to elliptic equations with discontinuous coefficients,even the BMO semi-norms of the coefficients are not *... 详细信息

关键词： L^(p)-Estimate Elliptic equation Discontinuous coefficients

Derivation of Expanded Isospectral-Nonisospectral Integrable Hierarchies via the Column-vector Loop Algebra

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 778-800页

作者： Hai-fe.g WANg yu-fe.g zhang School of Science Jimei UniversityXiamen 361021China School of Mathematics China University of Mining and TechnologyXuzhou 221116China

A scheme for generating nonisospectral integrable hierarchies is *** on the method,we deduce a nonisospectral hierarchy of soliton equations by considering a linear spectral *** follows that the corresponding expanded isospectral and nonisospectral integrable hierarchies are deduced based on a 6 dimensional complex linear space ■.By reducing these integrable hierarchies,we obtain the expanded isospectral and nonisospectral derivative nonlinear Schr?dinger *** using the trace identity,the biHamiltonian structure of these two hierarchies are also ***,some symmetries and conserved quantities of the resulting hierarchy are discussed.

关键词： expanded isospectral-nonisospectral integrable hierarchies column-vector loop algebra bi-Hamiltonian structure symmetry

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Research on Bast Fiber Extracted from the White Bark of Three Species in the genus Broussonetia

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Chinese Journal of Polymer Science 2024年第6期42卷 729-738页

作者： Shan-Shan Jin Si-Nong Wang Yan-Yan Huang Jing-yu zhang Peng Liu Hui yu Hong-Dong zhang yu-Liang Yang Institute for Preservation and Conservation of Chinese Ancient Books Fudan University LibraryFudan UniversityShanghai200433China State key laboratory of Molecular Engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China

Against the backdrop of a global paper resource shortage,there is a growing need to identify fast-growing tree species capable of producing long-lasting *** plant species namely Broussonetia kazinoki,Broussonetia papyrifera and hybrid paper mulberry,belong to the Broussonetia genus,were collected from China to study their white bark suitability for pulp and *** chemical composition revealed that the holocellulose content in Broussonetia kazinoki and Broussonetia papyrifera was more than 80%.The molecular weight distribution of several holocellulose/α-cellulose is observed by gPC,which allows us to better observe the changes of various components on the molecular *** yield,lignin,whiteness,and molecular weight of the pulps obtained by NaOH treatment were *** microscope was used to characterize the fiber length-width ratio and ***,the improvement of the fiber rigidity method based on the Kratky-Porod chain model makes it more theoretical and further reveals the influencing factors of fiber *** study demonstrates the high potentiality of these three species for papermaking applications.

关键词： Broussonetia genus Cellulose Alkaline pulping Kratky-Porod chain model Fiber rigidity

Hard carbon for sodium storage:Mechanism and performance optimization

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Nano Research 2024年第7期17卷 6038-6057页

作者： Yongxin Wang Meng Li yu zhang Naiqing zhang State Key Laboratory of Urban Water Resource and Environment School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Due to the shortage of lithium resource reserves and the pressure of rising prices,sodium-ion batteries have regained the attention of the public,and shown great potential for application in the fields of grid energy storage and low-speed vehicles to achieve the purpose of complementing lithium-ion batteries,so it is imperative to promote the commercial application of sodiumion *** sodium-ion battery anode materials,hard carbon is the material most likely to be used ***,there is still much work to be done before its *** review provides a comprehensive overview of the current research status from the following three ***,the microstructure and sodium storage active sites of hard carbon are ***,the mechanism of sodium storage in hard carbon is investigated,which can be broadly categorized into four model,“insertion–filling”,“adsorption–insertion”,“adsorption–filling”,and“multistage”.Finally,from the perspective of improving the electrochemical performance of hard carbon,the performance improvement strategies proposed in recent years are *** with the performance of hard carbon commercial products of some enterprises,the future development goal of hard carbon is prospected,hoping that all sectors of society can work hard for this common goal.

关键词： sodium-ion battery hard carbon mechanism performance optimization

Artificial Intelligence Based Multi-Scenario mmWave Channel Modeling for Intelligent High-Speed Train Communications

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China Communications 2024年第3期21卷 260-272页

作者： zhang Mengjiao Liu yu Huang Jie He Ruisi zhang Jingfan yu Chongyang Wang Chengxiang School of Microelectronics Shandong UniversityJinan 250101China The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China The National Mobile Communications Research Laboratory School of Information Science and EngineeringSoutheast UniversityNanjing 210096China The Purple Mountain Laboratories Nanjing 211111China

A large amount of mobile data from growing high-speed train(HST)users makes intelligent HST communications enter the era of big *** corresponding artificial intelligence(AI)based HST channel modeling becomes a *** paper provides AI based channel characteristic prediction and scenario classification model for millimeter wave(mmWave)HST ***,the ray tracing method verified by measurement data is applied to reconstruct four representative HST *** setting the positions of transmitter(Tx),receiver(Rx),and other parameters,the multi-scenarios wireless channel big data is ***,based on the obtained channel database,radial basis function neural network(RBF-NN)and back propagation neural network(BP-NN)are trained for channel characteristic prediction and scenario ***,the channel characteristic prediction and scenario classification capabilities of the network are evaluated by calculating the root mean square error(RMSE).The results show that RBF-NN can generally achieve better performance than BP-NN,and is more applicable to prediction of HST scenarios.

关键词： artificial intelligence channel characteristic prediction HST channel millimeter wave scenario classification