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Cooperative guidance law with maneuverability awareness:A decentralized solution

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Chinese Journal of Aeronautics 2024年第7期37卷 450-457页

作者： Shuyang xu xun song Chaoyong LI College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Beijing Institute of Electronic System Engineering Beijing 100074China

In this paper,we propose a cooperative guidance law aimed to achieve coordinated impact angles with limited observation on target *** primary challenge lies in establishing an appropriate communication graph among all missiles and devising an algorithm to estimate target acceleration information during *** address this,we propose a specific communication topology and employ a numerical integration-based estimation ***,a distributed algorithm is introduced to facilitate consensus on target acceleration *** upon these foundations,we design an optimal-control-based distributed guidance law for each *** of the proposed guidance law is validated through numerical simulations.

关键词： Cooperative guidance Target maneuver estimation Distributed estimation Consensus Optimal control

Systematic study on the proton radioactivity of spherical proton emitters

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Nuclear Science and Techniques 2023年第4期34卷 93-101页

作者： Dong-Meng Zhang lin-Jing Qi De-Xing Zhu Yang-Yang xu song Luo Xiao-Hua Li School of Nuclear Science and Technology University of South ChinaHengyang 421001China National Exemplary Base for International Sci&Tech.Collaboration of Nuclear Energy and Nuclear Safety University of South ChinaHengyang 421001China Cooperative Innovation Center for Nuclear Fuel Cycle Technology&Equipment University of South ChinaHengyang 421001China Key Laboratory of Low Dimensional Quantum Structures and Quantum Control Hunan Normal UniversityChangsha 410081China

In this study, based on a two-potential approach, we systematically investigated the proton radioactivity half-lives of spherical proton emitters with 69≤Z≤81 from the ground and/or isomeric state, choosing the nuclear potential to be a modified Woods–Saxon potential that contains the isospin effect of the daughter nucleus. It was found that the calculated half-lives could reproduce the experimental data well. Furthermore, we extended this model to predict the half-lives of 17 protonemitting candidates whose radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020. For comparison, the unified fission model, Coulomb potential and proximity potential model, universal decay law for proton emission, and new Geiger–Nuttall law were also used. All the predicted results are consistent with each other.

关键词： Proton radioactivity Spherical nuclei Two-potential approach Modified Woods–Saxon potential Half-lives

Meristem control of leaf patterning

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Science China(Life Sciences) 2015年第3期58卷 315-316页

作者： xu lin National Laboratory of Plant Molecular Genetics Shanghai Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences

Plant organs are derived from stem *** a leaf primordium initiates growth from the shoot apical meristem（SAM）,it establishes adaxial-abaxial（dorsal-ventral）*** polarity essentially allows the leaf to become a flat structure with the lamina expanding along the juxtaposition,i.e.,the middle domain,between the adaxial and abaxial domains.

关键词： polarity expanding dorsal lamina shoot essentially capturing organs auxin ventral

A robust output-feedback adaptive dynamic surface control for linear systems with input disturbance

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控制理论与应用（英文版） 2013年第2期11卷 261-267页

作者： Mingchao song Yan lin School of Automation Beihang University

In this paper, a robust output-feedback adaptive control is proposed for linear time-invariant （LTI） single- input single-output （SISO） plants with unmeasurable input disturbance. Using dynamic surface control （DSC） technique, it is shown that the explosion of complexity problem in backstepping control can be eliminated. Furthermore, the proposed adaptive DSC scheme has the following merits： 1） by introducing an initialization technique, the L~ performance of system tracking error can be guaranteed even if the plant high-frequency gain is unknown and the input disturbance exists, and 2） the adaptive law is necessary only at the first design step, which significantly reduces the design procedure. It is proved that with the proposed scheme, all the closed-loop signals are semiglobally uniformly ultimately bounded. Simulation results are presented to demonstrate the effectiveness of the proposed scheme.

关键词： Dynamic surface control Backstepping control Adaptive control Output-feedback Transient perfor-

Modification on static responses of a nano-oscillator by quadratic optomechanical couplings

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Science China(Physics,Mechanics & Astronomy) 2014年第5期57卷 880-886页

作者： ZHANG lin song ZhangDai School of Physics and Information Technology Shanxi Normal University

A quadratic coupling enabled parametric oscillation in an optomechanical system is used to modify the nonlinear static responses of a mechanical oscillator with a normal linear coupling. The mean value study showed that the modification of the static response on a mechanical oscillator is extremely sensitive and useful, which can readily enhance or suppress the nonlinear displacement response from a bistability case to singlet or triplet well case, freely bifurcating the equilibrium position from one to two or three. The static equilibria structure and the stability regions for mean-value controls on nano-oscillator were analyzed trader the possible modification parameters.

关键词： cavity optomechanics quadratic coupling static response

Numerical studies on the degeneration of internal waves induced by an initial tilted pycnocline

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Acta Oceanologica Sinica 2014年第7期33卷 27-39页

作者： lin Zhenhua song Jinbao Institute of Oceanology Chinese Academy of Sciences Key Laboratory of Ocean Circulation and Waves (KLOCAW) Chinese Academy of Sciences

The pycnocline in a closed domain is tilted by external wind forcing and tends to restore to a level posi- tion when the wind falls. An internal seiche oscillation exhibits if the forcing is weak, otherwise internal surge and internal solitary waves emerge, which serve as a link to cascade energy to small-scale processes. A two-dimensional non-hydrostatic code with a turbulence closure model is constructed to extend previous laboratory studies. The model could reproduce all the key phenomena observed in the corresponding labo- ratory experiments. The model results further serve as a comprehensive and reliable data set for an in-depth understanding of the related dynamical process. The comparative analyses indicate that nonlinear term favors the generation of internal surge and subsequent internal solitary waves, and the linear model predicts the general trend reasonably well. The vertical boundary can approximately reflect all the incoming waves, while the slope boundary serves as an area for small-scale internal wave breaking and energy dissipation. The temporal evolutions of domain integrated kinetic and potential energy are also analyzed, and the results indicate that about 20% of the initial available potential energy is lost during the first internal wave breaking process. Some numerical tactics such as grid topology and model initialization are also briefly discussed.

关键词： internal wave numerical model wave breaking energy dissipation

Optimization of contact-mode triboelectric nanogeneration for high energy conversion efficiency

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Science China(Information Sciences) 2018年第6期61卷 78-86页

作者： Huamin CHEN Yun xu lin BAI Jian LI Tong LI Chen ZHAO Jiushuang ZHANG Guofeng song Institution of Semiconductors Chinese Academy of Sciences College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences

The rapid growth of flexible and wearable electronics makes it an urgent requirement to develop mobile and sustainable energy sources for these devices. Triboelectric nanogenerator(TENG) stands out for its outstanding performance. However, high output performance and energy conversion efficiency TENG still remains one of the most crucial barriers for practical applications. In this paper, we systematically analyze the relationship of maximum instantaneous output power and energy conversion efficiency with the material parameters, structural parameters and experimental parameters. Firstly, we obtain the explicit equations for the transferred charge, output voltage, output current and maximum instantaneous power from the contactmode model and governing equation. Then it is deeply studied how the material parameters, structure parameters and experimental condition can influence the output performance. Finally, the relationship of energy conversion efficiency with the TENG parameters is investigated to provide guidance for rational design of TENG. The high efficiency energy source could greatly promote the development of flexible electronics.

关键词： flexible electronics triboelectric nanogenerator output performance energy efficiency

Preparation of Mo_2C nanoparticles dispersion-strengthened copper-based composite by EB-PVD

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Rare Metals 2014年第5期33卷 568-572页

作者： Xiao Li Guang-Ping song Fan-Yu Bu Bin xu Bai-Yang Lou Zhan lin College of Materials Science and Engineering Zhejiang University of Technology Center for Composite Materials and Structures Harbin Institute of Technology

In this research, a nano-Mo2 C particle dispersion-strengthened copper alloy was prepared by a novel method, i.e., electron beam physical vapor deposition（EBPVD） which has advantages of simple technical process and low cost compared with the conventional mechanical alloying method. And the microstructure and properties of the material were investigated. The results show that the copper matrix is composed of columnar crystals with the average width of 7 lm, and the size of Mo2 C dispersoid is1–7 nm. The ultimate tensile strength of the material is486 MPa, and the electrical conductivity is 82 % IACS. As the temperature increases from 293 to 573 K, the material becomes more brittle.

关键词： Electron beam physical vapor deposition Dispersion-strengthened copper ODS In-situ

Effect of climate change on seasonal water use efficiency in subalpine Abies fabri

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Journal of Mountain Science 2017年第1期14卷 142-157页

作者： SUN Xiang-yang WANG Gen-xu HUANG Mei HU Zhao-yong song Chun-lin Institute of Mountain Hazards and Environment Chinese Academy of Sciences Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Abies fabri is a typical subalpine dark coniferous forest in southwestern China. Air temperature increases more at high elevation areas than that at low elevation areas in mountainous regions,and climate change ratio is also uneven in different seasons. Carbon gain and the response of water use efficiency(WUE) to annual and seasonal increases in temperature with or without CO_2 fertilization were simulated in Abies fabri using the atmospheric-vegetation interaction model(AVIM2). Four future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5(CMIP5) were selectively investigated. The results showed that warmer temperatures have negative effects on gross primary production(GPP) and net primary production(NPP) in growing seasons and positive effects in dormant seasons due to the variation in the leaf area index. Warmer temperatures tend to generate lower canopy WUE and higher ecosystem WUE in Abies fabri. However,warmer temperature together with rising CO_2 concentrations significantlyincrease the GPP and NPP in both growing and dormant seasons and enhance WUE in annual and dormant seasons because of the higher leaf area index(LAI) and soil temperature. The comparison of the simulated results with and without CO_2 fertilization shows that CO_2 has the potential to partially alleviate the adverse effects of climate warming on carbon gain and WUE in subalpine coniferous forests.

关键词： Climate change Carbon gain Water use efficiency Atmospheric-vegetation interaction model