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Global Classical Solutions to the Equations of Two-dimensional MHD Transverse Flow

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1371-1384页

作者： Yi peng shi State Key Laboratory for Turbulence and Complex System Peking University Beijing 100871 P. R. China

A new method for constructing the symmetric form for the hyperbolic systems is introduced. Then a new symmetric form of the equations of MHD transverse flow is constructed by adding an additional equation. With this new form, we obtain the local existence of smooth solution including the case that the initial density may tend to the vacuum state at infinity. Furthermore, the uniformly a priori estimation for the classical solutions is established and the global smooth solutions for a kind of initial data are obtained.

关键词： MHD transverse flow global classical solution

Magnetoelectric multiferroicity and quantum paraelectricity in hexaferrites

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Science China(Physics,Mechanics & Astronomy) 2019年第4期62卷 1-13页

作者： shi-peng Shen Young Sun Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences

Multiferroic materials with coexisting ferroelectric and magnetic orders have attracted tremendous research interests because of their intriguing fundamental physics as well as potential applications in the next-generation multifunctional devices. Hexaferrites with conical magnetic structures are among the most promising single-phase multiferroics because strong magnetoelectric effects can be achieved in them from low temperatures up to room temperature in low magnetic fields. In this review, after briefly introducing the background on multiferroics and classification of hexaferrites, we summarize recent progress in multiferroic hexaferrites, including the mechanisms of spin-induced ferroelectricity, the magnetoelectric phase diagram, giant direct and converse magnetoelectric effects. Furthermore, we present a new mechanism of magnetic-ion-induced displacive polarization in hexaferrites, which leads to quantum paraelectricity and quantum electric-dipole liquid in M-type hexaferrites.

关键词： magnetoelectric effect hexaferrite quantum paraelectricity

PRICING OF LIBOR FUTURES BY MARTINGALE METHOD IN COX-INGERSOLL-ROSS MODEL

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Journal of Systems Science & Complexity 2010年第2期23卷 261-269页

作者： Ping LI peng shi Guangdong HUANG Xiaojun shi BeiHang University Beijing 100191 China. Northern Illinois University Illinois 60115 USA School of Information Engineering China Geosciences University Beijing 100083 China. BeiHang University Beijing 100083 China.

This paper considers the pricing of LIBOR futures in the Cox-Ingersoll-Ross(CIR)modelunder Pozdnyakov and Steele(2004)'s martingale framework for futures *** the CIR modelfor short term interest rate,we prove that there exists a unique futures price process associated withthe terminal value and the standard financial market,and that this unique futures price process has amartingale ***,a general closed-form pricing formula for LIBOR futures contractsis obtained in the CIR model.

关键词： Cox-Ingersoll-Ross model futures pricing LIBOR futures martingale.

CONVERGENCE ANALYSIS OF MORLEY ELEMENT ON ANISOTROPIC MESHES

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Journal of Computational Mathematics 2006年第2期24卷 169-180页

作者： shi-peng Mao Shao-chun Chen ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China Department of Mathematics Zhengzhou University Zhengzhou 450052 China

The main aim of this paper is to study tile convergence of a nonconforming triangular plate element-Morley element under anisotropic meshes. By a novel approach, an explicit bound for the interpolation error is derived for arbitrary triangular meshes （which even need not satisfy the maximal angle condition and the coordinate system condition ）, the optimal consistency error is obtained for a family of anisotropically graded finite element meshes.

关键词： Anisotropic meshes Interpolation error Consistency error Morley element.

Molecular and evolutionary analyses of formyl peptide receptors suggest the absence of VNO-specific FPRs in primates

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Journal of Genetics and Genomics 2010年第12期37卷 771-778页

作者： Hui Yang peng shi State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of SciencesKunming 650223China

Formyl peptide receptors (FPRs) were observed to expand in rodents and were recently suggested as candidate vomeronasal chemo-sensory receptors. Since vomeronasal chemosensory receptors usually underwent positive selection and evolved concordantly with the vomeronasal organ (VNO) morphology, we surveyed FPRs in primates in which VNO morphology is greatly diverse and thus it would provide us a clearer view of VNO-FPRs evolution. By screening available primate genome sequences, we obtained the FPR repertoires in representative primate species. As a result, we did not find FPR family size expansion in primates. Further analyses showed no evolution-ary force variance between primates with or without VNO structure, which indicated that there was no functional divergence among pri-mates FPRs. Our results suggest that primates lack the VNO-specific FPRs and the FPR expansion is not a common phenomenon in mammals outside rodent lineage, regardless of VNO complexity.

关键词： formyl peptide receptor vomeronasal chemosensory receptor primates

Cooperative control for heterogeneous multi-agent systems: progress, applications, and challenges

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Science China(Information Sciences) 2024年第5期67卷 318-320页

作者： Bing YAN peng shi Jonathon CHAMBERS School of Electrical and Mechanical Engineering Faculty of Science Engineering and TechnologyThe University of Adelaide School of Engineering College of Science and Engineering University of Leicester

Cooperative control for heterogeneous multi-agent systems(MASs) is a critical and rapidly evolving field in modern automation and robotics. Characterized by the integration of agents with diverse capabilities and func... 详细信息

关键词： Multi agent systems

Application of Adaptive Fuzzy Spiking Neural P Systems in Fault Diagnosis of Power Systems

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Chinese Journal of Electronics 2014年第1期23卷 87-92页

作者： TU Min WANG Jun peng Hong shi peng School of Electrical and Information Engineering Xihua University Center for Radio Administration and Technology Development Xihua University Department of Computing and Mathematical Sciences University of Glamorgan PontypriddCF37 1DL UK School of Engineering and Science Victoria University MelbourneVic 8001 Australia

Adaptive fuzzy spiking neural P systems(AFSN P systems) are a novel kind of computing models with parallel computing and learning ability. Based on our existing works, AFSN P systems are applied to deal with the fault diagnosis problems of power systems and the uncertainty of action messages about protective relays and breakers, and a new fault diagnosis model of power systems is proposed with simple reasoning process and fast speed with parallel processing capabilities. The effectiveness of the fault diagnosis model is verified by some examples of fault diagnosis. Furthermore, the learning ability of AFSN P systems can be applied to adjust the weights in the fault diagnosis model automatically.

关键词： Membrane computing Spiking neural P systems Fault diagnosis Power systems

Rural transformation,income growth,and poverty reduction by region in China in the past four decades

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Journal of Integrative Agriculture 2023年第12期22卷 3582-3595页

作者： shi peng-fei HUANG Ji-kun China Center for Agricultural Policy School of Advanced Agricultural SciencesPeking UniversityBeijing 100871P.R.China Research Center for Rural Economy Ministry of Agriculture and Rural AffairsBeijing 100810P.R.China

China has experienced rapid rural transformation in the past four *** the rapid transformation is a significant rise in rural household income and a substantial fall in rural *** paper examines the evolutions of and the relationships between rural transformation(high-value agriculture and rural non-farm employment)and its outcomes(per capita rural income and rural poverty incidence)using provincial-level *** results show that 31 provinces/autonomous regions/municipalities have undergone significant rural transformation,but the level and speed of rural transformation differed ***,an increased level of rural transformation is often associated with higher per capita rural income and reduced rural poverty ***,a category of provincial rural transformation based on high-value agriculture and rural non-farm employment is also *** further discuss the likely impacts of institutions,policies,and investments(IPIs)on rural transformation and conclude with policy implications.

关键词： rural transformation high-value agriculture non-farm employment income poverty China

Adaptive connected hierarchical optimization algorithm for minimum energy spacecraft attitude maneuver path planning

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Astrodynamics 2023年第2期7卷 197-209页

作者： Hanqing He peng shi Yushan Zhao School of Astronautics Beihang UniversityBeijing 102206China

Space object observation requirements and the avoidance of specific attitudes produce pointing constraints that increase the complexity of the attitude maneuver path-planning *** deal with this issue,a feasible attitude trajectory generation method is proposed that utilizes a multiresolution technique and local attitude node adjustment to obtain sufficient time and quaternion nodes to satisfy the pointing *** nodes are further used to calculate the continuous attitude trajectory based on quaternion polynomial interpolation and the inverse dynamics ***,the characteristic parameters of these nodes are extracted to transform the path-planning problem into a parameter optimization problem aimed at minimizing energy *** problem is solved by an improved hierarchical optimization algorithm,in which an adaptive parameter-tuning mechanism is introduced to improve the performance of the original algorithm.A numerical simulation is performed,and the results confirm the feasibility and effectiveness of the proposed method.

关键词： hierarchical optimization algorithm(HOA) adaptive parameters tuning attitude control minimum energy control pointing constraint