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Intersections of Homogeneous Cantor Sets with Their Translations

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Acta Mathematica Sinica,English Series 2008年第8期24卷 1313-1318页

作者： mei feng DAI Nonlinear Scientific Research Center Faculty of Science Jiangsu University Zhenjiang 212013 P. R. China

We pursue the study on homogeneous Cantor sets with their translations. We get the fractal structure of intersection I（t）, and find that the Hausdorff measure of these sets forms a discrete spectrum whose non-zero values come only from shifting numbers with the coding of t. Concretely, a very brief calculation formula of the measure with the coding of t is given.

关键词： homogeneous Cantor set intersection fractal structure discrete spectrum

Preparation of Entangled Atomic States Through Resonant Atom-Field Interaction

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Communications in Theoretical Physics 2006年第2期45卷 347-349页

作者： CHEN mei-feng Department of Electronic Science and Applied Physics Fuzhou University Fuzhou 350002 China

A scheme is proposed for the generation of two-atom maximally entangled states and multi-atom maximally entangled states of W class. The scheme is based on the simultaneous resonant interaction of atoms with a single-mode cavity field. It does not require accurate adjustment of the interaction time. The time needed to complete the generation does not increase with the number of the atom.

关键词： resonant interaction two-atom entangled state atomic W state

Generation of Four-Photon Coherent State via Degenerate Raman Interaction

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Communications in Theoretical Physics 2006年第1期45卷 154-156页

作者： CHEN mei-feng Department of Electronic Science and Applied Physics Fuzhou University Fuzhou 350002 China

A scheme is presented for generating a four-photon coherent state via the degenerate Raman interaction. The scheme does not need classical fields to manipulate the atoms. Its another advantage is that the atomic spontaneous emission can be neglected. Therefore, the coherence of the system may be better maintained. The scheme can be generalized to generate superposition of 2^n coherent states and superposition of 2^n two-mode coherent states. The coherent states in each mode are on a circle symmetrically.

关键词： four-photon coherent state Raman interaction

The Relationship between the Nonexistence of Generalized Bent Functions and Diophantine Equations

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Acta Mathematica Sinica,English Series 2011年第6期27卷 1173-1186页

作者： feng mei LIU Qin YUE National Key Laboratory on Information Assurance Technology Sub-box 21 Box 7227 Beijing 100072 P. R. China Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing 210016 P. R. China

Two new results on the nonexistence of generalized bent functions are presented by using properties of the decomposition law of primes in cyclotomic fields and properties of solutions of some Diophantine equations, an... 详细信息

关键词： Generalized bent function integral basis Diophantine equation

Spatial differentiation pattern of interregional migration in ethnic minority areas of Yunnan Province, China

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Journal of Mountain Science 2021年第11期18卷 3041-3057页

作者： ZHAO mei-feng WANG De-gen School of Geographic and Environmental Sciences Tianjin Normal UniversityTianjin 300387China School of Architecture Soochow UniversitySuzhou 215123China

Interregional migration has broad and far-reaching impacts on regional urbanization process in ethnic minority areas of Southwest *** previous literature of interregional migration paid less attention on the ethnic minority areas with fragile geographical feature and marginal socio-economic context in the developing world due to the dearth of reliable *** on the 2015 national 1%population sampling survey at the village/community scale,taking Yulong Naxi Autonomous County,Yunnan Province,China as the case study,this paper analyzed the spatial differentiation *** results showed that:(1)migration in Yulong Naxi Autonomous County exhibited obvious spatial differentiation characteristics in terms of population aggregation,population loss,migration direction,and migration activity;(2)the overall spatial differentiation of migration exhibited a"layer+sector"pattern in Yulong Naxi Autonomous County:the first layer was active areas with net inflows(60 km to the seat of the county government),comprised of inactive areas and active areas with net outflows;(3)the spatial differentiation pattern of migration was highly correlated with the regional contexts including the regional economic development,regional transportation accessibility and regional social development,while regional physical geographical factors had insignificant relationships with the migration pattern.

关键词： Interregional migration Spatial differentiation pattern Regional contexts Ethnic minority area Southwest China

Dynamical Behavior of SEIR-SVS Epidemic Models with Nonlinear Incidence and Vaccination

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 282-303页

作者： Xiao-mei feng Li-li LIU feng-qin ZHANG School of Mathematics and Informational Technology Yuncheng UniversityYuncheng 044000China School of Mathematics and Informational Sciences Shaanxi Normal UniversityXi'an 710062China Complex Systems Research Center Shanxi UniversityTaiyuan 030006China Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention Shanxi UniversityTaiyuan 030006China

For some infectious diseases such as mumps,HBV,there is evidence showing that vaccinated individuals always lose their immunity at different rates depending on the inoculation *** this paper,we propose an age-structured epidemic model using a step function to describe the rate at which vaccinated individuals lose immunity and reduce the age-structured epidemic model to the delay differential *** the age-structured model,we consider the positivity,boundedness,and compactness of the semiflow and study global stability of equilibria by constructing appropriate Lyapunov ***,for the reduced delay differential equation model,we study the existence of the endemic equilibrium and prove the global stability of ***,some numerical simulations are provided to support our theoretical results and a brief discussion is given.

关键词： vaccination age-structured epidemic model delay differential equation model stability Lyapunov functional

Microstructure and mechanical properties of Ti-Cu amorphous coating synthesized on pure Cu substrate by mechanical alloying method

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Rare Metals 2020年第10期39卷 1222-1228页

作者： Cheng Chen Xiao-mei feng Yi-fu Shen School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing 211800China College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Mechanical alloying method was applied to fabricate coating with amorphous structure on pure Cu *** microstructure,the phase composition and the mechanical properties including microhardness and wear resistance of the coating were,respectively,characterized and *** results show that the coating is rough but *** has favorable adhesion to the *** coating is made up of an inner composite layer and an outer amorphous *** microhardness and the wear resistance of the pure Cu substrate are improved because of the bilayer *** formation mechanism of the coating was *** as-synthesized coating is considered to be effective to strengthen the surface of pure Cu substrate.

关键词： Coating Amorphous Mechanical alloying Surface reinforcement

Conservation Laws of Differential Equations in Finance

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Communications in Theoretical Physics 2005年第6X期44卷 967-968页

作者： QIN Mao-Chang mei feng-Xiang SHANG mei School of Science Chongqing Technology and Business University Chongqing 400067 China School of Science Beijing Institute of Technology Beijing 100081 China

Conservation laws of some differential equations in fiance are studied in this paper. This method does not involve the use or existence of a variational principle. As an alternative, linearize the given equation and find adjoint equation of the linearized equation, the conservation laws can be constructed directly from the symmetries and adjoint symmetries of the associated linearized equation and its adjoint equation.

关键词： conservation law adjoint equation finance

Characteristics and implications of stress state in a gold mine in Ludong area, China

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1363-1372页

作者： Peng Li mei-feng Cai Qi-feng Guo Sheng-jun Miao School of Civil and Resource Engineering University of Science and Technology Beijing Key Laboratory of High-Efficient Mining and Safety of Metal Mines (Ministry of Education of China) University of Science and Technology Beijing Beijing Key Laboratory of Urban Underground Space Engineering University of Science and Technology Beijing

In this study, we obtained information from twenty-one measurement points on the stress magnitudes and orientations of a gold mine in the Ludong area. We used the overcoring technique with an improved hollow inclusion strain gauge and then analyzed the distribution characteristics of the in situ stress field. The results indicate that the stress field is characterized by σH > σh > σv and σH > σv > σh(where σH, σh, and σv are the maximum horizontal, minimum horizontal, and vertical principal stresses, respectively). The regional stress field is dominated by horizontal principal stress. The σH, σh, and σv values show a gradual increasing trend with depth. The σH is predominantly oriented in the NWW–SEE or near-EW direction. We also confirmed the correspondence between the measured stress field and the regional geological structure. In addition, based on the measured stress data, we discuss the implications of the in situ stress with respect to fault activity in the mine area.

关键词： in situ stress measurement improved hollow inclusion strain gauge stress field geological structure fault activity