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Science China(Physics,Mechanics & Astronomy) 2013年第3期56卷 573-580页

作者： ma LiangCai ZHANG JianMin XU KeWei College of Physics and Information Technology Shaanxi Normal University School of Physics and Electrical Information Engineering Ningxia University State Key Laboratory for Mechanical Behavior of materials Xi'an Jiaotong University

By using the first-principles calculations,we have systematically investigated the adsorption of atomic oxygen on Cu(111) surface for a wide range of coverages Θ(from 0.11 to 1.00 ML) and adsorption *** found that the fcc-hollow site is the most stable site for oxygen *** adsorption energy decreases with increasing oxygen coverage due to the increasing repulsive interaction in the overlayer O *** for coverage of 1.00 ML,the oxygen-induced lateral relaxations and bucklings are found in the outermost three Cu layers,and the hillock-like as well as ridge-like bucklings are also found for Θ=0.25 ML and Θ=0.75 ML as well as Θ=0.50 ML,*** an increasing oxygen coverage,the work function increases and the surface dipole moment *** transfer from the first layer Cu atoms to O adatoms indicates the O-Cu bond having some degree of ionic character,while the hybridization between O 2p and Cu 3d orbitals implies that it also has some degree of covalence ***,with the increasing oxygen coverage,more Cu 3d and O 2p states are empty thus weakening the binding of O/Cu(111) system,but increase in the PDOS at the Fermi *** implies an enhancement in the metallic character of the O/Cu(111) system.

关键词： adsorption oxygen relaxation electronic structures first-principles calculation

LIMIT THEOREMS FOR β-LAGUERRE AND β-JACOBI ENSEMBLES

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Acta mathematica Scientia 2022年第5期42卷 2025-2039页

作者： Naqi HUANG Yutao ma Faculty of Electrical Engineering Mathematics and Computer ScienceDelft University of TechnologyMekelweg 42628 CD DelftThe Netherlands School of mathematical Sciences&Laboratory of mathematics and Complea Systems of Ministry of Education Beijing Normal UniversityBeijing 100875China

We use tridiagonal models to study the limiting behavior of β-Laguerre and β-Jacobi ensembles,focusing on the limiting behavior of the extremal eigenvalues and the central limit theorem for the two *** the central limit theorem of β-Laguerre ensembles,we follow the idea in[1]while giving a modified version for the generalized *** we use the total variation distance between the two sorts of ensembles to obtain the limiting behavior of β-Jacobi ensembles.

关键词： beta-ensembles largest and smallest eigenvalues central limit theorem total variationdistance

Development of Bionic UAVs Cluster Technology

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第S1期35卷 1-8页

作者： ma Chunyao Feng Zhuoqun Zheng Xiangming College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

With the wider use of UAV in various fields,the raising task complexity and the increasing environmental uncertainties,the higher requirements for UAV technology are put *** bionic UAV cluster system has the potential advantages of good stealth performance,strong environmental adaptability,wide expansion of task and high operational *** has excellent prospects in future information warfare,electronic warfare and conventional combat *** reviewing the development of bionic UAV cluster technology,this paper summarizes and analyzes the latest research progresses of the key technologies such as aerodynamic mechanism and aerodynamic configuration design,driving mechanism design,autonomous flight control,adaptive networking and cluster control of bionic aircrafts.

关键词： bionic UAV aerodynamic mechanism structure design ad-hoc networks cluster control

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0/1背包问题竞争决策算法

计算机工程与应用 2008年第3期44卷 14-16,38页

作者：宁爱兵马良上海理工大学管理学院上海200096

竞争决策算法是在分析大自然生物世界特别是人类的各种竞争机制和决策原理的基础上,利用竞争造就优化、决策左右结果的特性来到达优化目的的新型寻优算法。在考虑0/1背包问题特点的基础上给出了用竞争决策算法求解0/1背包问题的算法,经... 详细信息

竞争决策算法是在分析大自然生物世界特别是人类的各种竞争机制和决策原理的基础上,利用竞争造就优化、决策左右结果的特性来到达优化目的的新型寻优算法。在考虑0/1背包问题特点的基础上给出了用竞争决策算法求解0/1背包问题的算法,经过大量数据测试和验证,获得了较好的结果。

关键词：竞争决策算法 0/1背包问题竞争力函数决策函数资源交换规则竞争决策均衡

Data-based prediction and causality inference of nonlinear dynamics

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Science China mathematics 2018年第3期61卷 403-420页

作者： Huanfei ma Siyang Leng Luonan Chen School of mathematical Sciences Soochow University Institute of Industrial Science The University of Tokyo Key Laboratory of Systems Biology Innovation Center for Cell Signaling NetworkInstitute of Biochemistry and Cell Biology Shanghai Institutes for Biological SciencesChinese Academy of Sciences

Natural systems are typically nonlinear and complex, and it is of great interest to be able to reconstruct a system in order to understand its mechanism, which cannot only recover nonlinear behaviors but also predict future dynamics. Due to the advances of modern technology, big data becomes increasingly accessible and consequently the problem of reconstructing systems from measured data or time series plays a central role in many scientific disciplines. In recent decades, nonlinear methods rooted in state space reconstruction have been developed, and they do not assume any model equations but can recover the dynamics purely from the measured time series data. In this review, the development of state space reconstruction techniques will be introduced and the recent advances in systems prediction and causality inference using state space reconstruction will be presented. Particularly, the cutting-edge method to deal with short-term time series data will be focused ***, the advantages as well as the remaining problems in this field are discussed.

关键词： nonlinear system prediction causality inference time series data

Abiotic contribution to total soil CO_2 flux across a broad range of land-cover types in a desert region

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Journal of Arid Land 2017年第1期9卷 13-26页

作者： ma Jie LIU Ran LI Yan State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Fukang National Field Scientific Observation and Research Station for Desert Ecosystems Chinese Academy of Sciences

As an important component of ecosystem carbon（C） budgets, soil carbon dioxide（CO2） flux is determined by a combination of a series of biotic and abiotic processes. Although there is evidence showing that the abiotic component can be important in total soil CO2 flux（R（total））, its relative importance has never been systematically assessed. In this study, after comparative measurements of CO2 fluxes on sterilized and natural soils, the R（total） was partitioned into biotic flux（R（biotic）） and abiotic flux（R（abiotic）） across a broad range of land-cover types（including eight sampling sites： cotton field, hops field, halophyte garden, alkaline land, reservoir edge, native saline desert, dune crest and interdune lowland） in Gurbantunggut Desert, Xinjiang, China. The relative contribution of R（abiotic） to R（total）, as well as the temperature dependency and predominant factors for R（total）, R（biotic） and R（abiotic）, were analyzed. Results showed that R（abiotic） always contributed to R（total） for all of the eight sampling sites, but the degree or magnitude of contribution varied greatly. Specifically, the ratio of R（abiotic） to R（total） was very low in cotton field and hops field and very high in alkaline land and dune crest. Statistically, the ratio of R（abiotic） to R（total） logarithmically increased with decreasing R（biotic）, suggesting that R（abiotic） strongly affected R（total） when R（biotic） was low. This pattern confirms that soil CO2 flux is predominated by biotic processes in most soils, but abiotic processes can also be dominant when biotic processes are weak. On a diurnal basis, R（abiotic） cannot result in net gain or net loss of CO2, but its effect on transient CO2 flux was significant. Temperature dependency of R（total） varied among the eight sampling sites and was determined by the predominant processes（abiotic or biotic） of CO2 flux. Specifically, R（biotic） was driven by soil temperature while R（abiotic） was regulated by the change in soil temperature（ΔT）. Namely

关键词： soil CO2 flux biotic flux abiotic flux temperature dependence Gurbantunggut Desert

Generalized Block markov Superposition Transmission over Free-Space Optical Links

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China Communications 2017年第9期14卷 80-93页

作者： Jinshun Zhu Shancheng Zhao Xiao ma School of Electronics and Information Technology Sun Yat-sen University College of Information Science and Technology Jinan University School of Data and Computer Science Sun Yat-sen University Guangdong Key Laboratory of Information Security Technology Sun Yat-sen University

In free-space optical(FSO) communications, the performance of the communication systems is severely degraded by atmospheric turbulence. Channel coding and diversity techniques are commonly used to combat channel fading induced by atmospheric turbulence. In this paper, we present the generalized block markov superposition transmission(GBMST) of repetition codes to improve time diversity. In the GBMST scheme, information sub-blocks are transmitted in the block markov superposition manner, with possibly different transmission memories. Based on analyzing an equivalent system, a lower bound on the bit-error-rate(BER) of the proposed scheme is presented. Simulation results demonstrate that, under a wide range of turbulence conditions, the proposed scheme improves diversity gain with only a slight reduction of transmission rate. In particular, with encoding memory sequence(0, 0, 8) and transmission rate 1/3, a diversity order of eleven is achieved under moderate turbulence conditions. Numerical results also show that, the GBMST systems with appropriate settings can approach the derived lower bound, implying that full diversity is achievable.

关键词： atmospheric turbulence channel block markov superposition transmission(BMST) free-space optical communications gamma-gamma channel model sliding-window decoding algorithm time diversity

Global asymptotic tracking of asymmetrical underactuated surface vessels with parameter uncertainties

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控制理论与应用（英文版） 2013年第4期11卷 608-614页

作者： Wenjing XIE Hailing SUN Baoli ma School of Automation Science and Electrical Engineering Beihang University

In this work, we investigate the tracking control problem of asymmetrical underactuated surface vessels with parameter uncertainties. The tracking error model is first derived via appropriate coordinate transformations, and is considered as a cascade structure composed of two subsystems. The Lyapunov redesign approach is employed to construct the control laws separately to stabilize the two subsystems with unknown model parameters. The cascade system theory is applied to prove the global uniform asymptotic convergence of the state trajectory to the reference one provided the desired yaw velocity is not vanishing. The effectiveness of the proposed control laws is verified by simulation examples.

关键词： Asymmetrical underactuated surface vessels Trajectory tracking Parameter uncertainties Lyapunovredesign

Recent progress on the design and fabrication of micromotors and their biomedical applications

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Bio-Design and manufacturing 2018年第4期1卷 225-236页

作者： Wensen Jiangl Liang ma Xiaobin Xul School of materials Science and Engineering Tongji UniversityShanghai 201804China State Key Laboratory of Fluid Power and Mechatronic Systems &School of Mechanical Engineering Zhejiang UniversityHangzhou 310058China

The advancement in the micro-/nanofabrication techniques has greatly facilitated the development of micromotors.A variety of micromotors have been invented with powerful functions,which have attracted a broad range of interests from chemistry, physics,mechanics,biology and *** this paper,we reviewed recent progress in micromotors and highlighted representative *** mechanisms of micromotors by internal and external energy sources were *** described general fabrication strategies of the popular micromotors (wire,tubular,helical and Janus)including bottom-up and top-down *** the application section,we primarily focused on the biological applications,such as biological cargo delivery, biosensing and *** last,we discussed the current challenges and provided future prospects.

关键词： Micromotor Nanomotor Electric tweezers Drug delivery Nanorobot Micromachine

Numerical simulation of martian historical dynamo:Impact of the Rayleigh number on the dynamo state

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Science China Earth Sciences 2009年第3期52卷 402-410页

作者： WANG TianYuan KUANG WeiJia ma ShiZhuang Laboratory for Computational Geodynamics Graduate University of Chinese Academy of SciencesBeijing 100049China Planetary Geodynamics Laboratory NASA Goddard Space Flight CenterGreenbeltMD 20771USA

The observed mars remnant magnetism suggests that there was an active dynamo in the martian core. We use the MoSST core dynamics model to simulate the martian historical dynamo, focusing on the variation of the dynamo states with the Rayleigh number Ra (a non-dimensional parameter describing the buoyancy force in the core). Our numerical results show that the mean field length scale does not vary monotonically with the Rayleigh number, and the field morphology at the core mantle boundary changes with Rayleigh number. In particular, it drifts westward with a speed decreasing with Rayleigh number.

关键词： mars magnetic field Rayleigh number dynamo