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Science china(Information Sciences) 2025年第1期68卷 306-321页

作者： Cuijuan ZHANG Lianghao JI Shasha YANG Xing GUO Huaqing LI Chongqing Key Laboratory of Image Cognition Chongqing University of Posts and Telecommunications Key Laboratory of Intelligent Perception and Computing of Anhui Province Anqing Normal University College of Electronic and Information Engineering Southwest University

This study uses event-triggered(ET) and reinforcement learning methods to investigate the optimal consensus control problem for cooperative-competitive multiagent systems. It proposes a novel distributed ET control strategy, which relies on a prioritized experience replay(PER) policy. This strategy not only conserves communication resources but also ensures acceptable system performance. To implement the proposed method, actor-critic(AC) dual-structured neural networks(NNs) are used to approximate the value function and control policy. In the AC NNs, the weight estimates for the NNs are updated at the moment of event triggering, resulting in a nonperiodic weight adjustment pattern. This approach decreases the computational cost in comparison with the traditional ET mechanism. The PER-based ET mechanism makes full use of valid historical data and effectively establishes a balance between system performance and communication resource ***, it does not require the following two conditions in most existing studies:(1) requirement of the system dynamics model to be known, and(2) persistent excitation. In addition, Zeno behavior is excluded from this study. Finally, a simulation is conducted to confirm the validity of the suggested approach.

关键词： multiagent systems event-triggered mechanism prioritized experience replay dual-structured neural networks optimal consensus control

Nonequilibrium Thermodynamic and Dissipative Structure Mechanism of Fluidized Beds

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 90-93页

作者： Maozhan Qi Li Wang Xuezi Ni (Mechanical Engineering School, University of Science and Technology Beijing, Beijing 100083, china) Mechanical Engineering School University of Science and Technology Beijing Beijing 100083 China

Fluidized beds are nonlinear dynamic systems that exchange mass and energy with outside. They are governed not only byfluid dynamics, but by thermodynamics, especially the second law of thermodynamics as well. According to Prigogine's dissipative structure theory, the following have been concluded: (l) a fixed bed is on thermodynamic blanch, and bubbling, turbulent and fast beds areon the dissipatve structure branches. (2) Entropy in fluidized beds is divided into tWo parts: entropy production and entropy flux. The latter increases with gas velocity and decreases with pressure of the systems. That means the entropy of a system may reduce and the systemwith higher gas velocity behaves as dissipative structure characteristics. (3) For a giVen velocity, a fluidized bed operates stably on thewhole, but it is unstable to local gas-solid phases. The unstable phases are described by fluid dynamic equations, While the minimum ofsystem energy function assures whole stability of the system. (4) A transition criterion of a bubbling bed is derived from Prigogine's stability theory.

关键词： fluidized bed nonequilibrium thermodynamics dissipative structure energy extremum

First-principles study on structural stability of 3d transition metal alloying magnesium hydride

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中国有色金属学会会刊：英文版 2006年第1期16卷 23-32页

作者：周惦武彭平刘金水陈律胡艳军 School of Materials Science and Engineering Hunan University Changsha 410082 China

A first-principles plane-wave pseudopotential method based on the density functional theory was used to investigate the energy and electronic structure of magnesium hydride (MgH2) alloyed by 3d transition metal elements. Through calculations of the negative heat formation of magnesium hydride alloyed by X (X denotes 3d transition metal) element, it is found that when a little X (not including Sc) dissolves into magnesium hydride, the structural stability of alloying systems decreases, which indicates that the dehydrogenation properties of MgH2 can be improved. After comparing the densities of states(DOS) and the charge distribution of MgH2 with or without X alloying, it is found that the improvement for the dehydrogenation properties of MgH2 alloyed by X attributes to the fact that the weakened bonding between magnesium and hydrogen is caused by the stronger interactions between X (not including Cu) and hydrogen. The calculation results of the improvement for the dehydrogenation properties of MgH2-X (X=Ti, V, Mn, Fe, Co, Ni, Cu) systems are in agreement with the experimental results. Hence, the dehydrogenation properties of MgH2 are expected to be improved by addition of Cr, Zn alloying elements.

关键词： MgH2 镁合金合金化结构稳定性密度功能理论电子结构热加工

Structural stability of intermetallic compounds of Mg-Al-Ca alloy

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中国有色金属学会会刊：英文版 2007年第2期17卷 250-256页

作者：周惦武刘金水张健彭平 State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University School of Materials Science and Engineering Hunan University

A first-principles plane-wave pseudopotential method based on the density functional theory was used to investigate the energetic and electronic structures of intermetallic compounds of Mg-Al-Ca alloy, such as Al2Ca, Al4Ca and Mg2Ca. The negative formation heat, the cohesive energies and Gibbs energies of these compounds were estimated from the electronic structure calculations, and their structural stability was also analyzed. The results show that Al2Ca phase has the strongest alloying ability as well as the highest structural stability, next Al4Ca, finally Mg2Ca. After comparing the density of states of Al2Ca, Al4Ca and Mg2Ca phases, it is found that the highest structural stability of Al2Ca is attributed to an increase in the bonding electron numbers in lower energy range below Fermi level, which mainly originates from the contribution of valence electron numbers of Ca(s) and Ca(p) orbits, while the lowest structural stability of Mg2Ca is resulted from the least bonding electron numbers near Fermi level.

关键词：金属间化合物 Mg-Al-Ca合金结构稳定性电子结构

Theoretical Investigation on the Abstraction Reaction of H with (CH_3)_3SiH

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Chemical Research in Chinese Universities 2002年第1期18卷 47-51页

作者： ZHANG Qing-zhu WANG Ming-gang WANG Shao-kun ZHANG Miao LIU Chuan-pu GU Yue-shu Department of Chemistry Shandong UniversityJinan 250100P.R.China

The abstraction reaction of H with (CH_3)_3SiH was investigated at the high levels of ab initio molecule orbital theory. The geometries were optimized at the MP2 level with 6-31G( d ) basis set, and G2MP2 level was used for the final energy calculations. The theoretical analysis provides the conclusive evidence that the main process is the hydrogen abstraction from the Si-H bond, leading to the formation of H_2 and silyl radicals; the hydrogen abstraction from the C-H bond has a higher barrier and is difficult to react. The kinetics was calculated with canonical variational transition-state theory (CVT) over the temperature range 200-1 000 K, and the theoretical rate constants match well with the later experimental values.

关键词： Reaction mechanism Variational transition state Tunneling effect Rate constant

Characteristics of alternating current hopping conductivity in DNA sequences

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Chinese Physics B 2009年第8期18卷 3591-3596页

作者：马松山徐慧王焕友郭锐 School of Physical Science and Technology Central South University Department of Physics Xiangnan University

This paper presents a model to describe alternating current （AC） conductivity of DNA sequences, in which DNA is considered as a one-dimensional （1D） disordered system, and electrons transport via hopping between localized states. It finds that AC conductivity in DNA sequences increases as the frequency of the external electric field rises, and it takes the form of σac（ω） - ω2 ln^2（1/ω）. Also AC conductivity of DNA sequences increases with the increase of temperature, this phenomenon presents characteristics of weak temperature-dependence. Meanwhile, the AC conductivity in an offdiagonally correlated case is much larger than that in the uncorrelated case of the Anderson limit in low temperatures, which indicates that the off-diagonal correlations in DNA sequences have a great effect on the AC conductivity, while at high temperature the off-diagonal correlations no longer play a vital role in electric transport. In addition, the proportion of nucleotide pairs p also plays an important role in AC electron transport of DNA sequences. For p 〈 0.5, the conductivity of DNA sequence decreases with the increase of p, while for p ≥ 0.5, the conductivity increases with the increase of p.

关键词： DNA sequences AC hopping conductivity off-diagonal correlations

Quantum logic operations on two distant atoms trapped in two optical-fibre-connected cavities

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Chinese Physics B 2011年第12期20卷 88-94页

作者：张英俏张寿 Yeon Kyu-Hwang Yu Seong-Cho Department of Physics College of ScienceYanbian University BK21 Physics program and Department of Physics College of Natural SciencesChungbuk National UniversityCheongjuChungbuk361-763Republic of Korea

Based on the coupling of two distant three-level atoms in two separate optical cavities connected with two optical fibres, schemes on the generation of several two-qubit logic gates are discussed under the conditions of △ = δ- 2v cos πk/2 〉〉 g/2 and v-g. Discussion and analysis of the fidelity, gate time and experimental setups show that our schemes are feasible with current optical cavity, atomic trap and optical fibre techniques. Moreover, the atom-cavityfibre coupling can be used to generate an N-qubit nonlocal entanglement and transfer quantum information among N distant atoms by arranging N atom cavity assemblages in a line and connecting each two adjacent cavities with two optical fibres.

关键词： quantum logic gate cavity QED optical fibre

Studies on the Electrochemical Behavior of Bleomycin at a Co/GC Ion Implantation Modified Electrode and Its Application

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Chemical Research in Chinese Universities 2001年第4期17卷 362-367页

作者： HU Jing-bo LI Qi-long Department of Chemistry Beijing Normal UniversityBeijing 100875P.R.China

In a 0. 10 mol/L HAc-NaAc buffer solution (pH = 4. 59), a sensitive reduction peak of bleomycin was observed by linear sweep voltammetry at a Co/GC ion implantation modified electrode. The peak potential was-0. 73 V(iw. SCE). The peak current was proportional to the concentration of bleomycin over the range of 5.0 × 10-8-1.0× 10-6 and 1.0× 10-6-1. 0 × 10-5 mol/L with a detection limit of 2.0 × 10-8 mol/L. The electrochemical behavior of the reduction peak of bleomycin at the Co/GC modified electrode was studied by linear sweep and cyclic voltammetry and applied to the determination of bleomycin in urine. This method is simple, rapid and reliable. The reduction process is quasi-reversible. The experiments of AES and XPS showed that Co was surely implanted into the surface of GCE and the depth distribution of Co was in good agreement with Gooses normal distribution; the implanted Co at GCE improved the electrocatalytic activity.

关键词： Co/GC ion implantation modified electrode Electrochemical behavior Linear sweep voltammetry Bleomycin

Integration of spatial attractions between and within pixels for sub-pixel mapping

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Journal of Systems Engineering and Electronics 2012年第2期23卷 293-303页

作者： Qunming Wang Liguo Wang Danfeng Liu College of Information and Communications Engineering Harbin Engineering UniversityHarbin 150001E R.China

As a promising technique to enhance the spatial reso- lution of remote sensing imagery, sub-pixel mapping is processed based on the spatial dependence theory with the assumption that the land cover is spatially dependent both within pixels and be- tween them. The spatial attraction is used as a tool to describe the dependence. First, the spatial attractions between pixels, sub- pixel/pixel spatial attraction model （SPSAM）, are described by the modified SPSAM （MSPSAM） that estimates the attractions accord- ing to the distribution of sub-pixels within neighboring pixels. Then a mixed spatial attraction model （MSAM） for sub-pixel mapping is proposed that integrates the spatial attractions both within pix- els and between them. According to the expression of the MSAM maximumising the spatial attraction, the genetic algorithm is em- ployed to search the optimum solution and generate the sub-pixel mapping results. Experiments show that compared with SPSAM, MSPSAM and pixel swapping algorithm modified by initialization from SPSAM （MPS）, MSAM can provide higher accuracy and more rational sub-pixel mapping results.

关键词： remote sensing imagery sub-pixel mapping mixed spatial attraction model (MSAM) genetic algorithm (GA).

Theoretical study on phase conjugation in weakly injected vertical-cavity surface-emitting lasers

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Chinese Physics B 2008年第5期17卷 1821-1825页

作者：张伟利潘炜罗斌李孝峰邹喜华王梦遥 School of Information Science & Technology Southwest Jiaotong University

This paper gives a detailed theoretical investigation on phase conjugation induced by nearly degenerate fourwave mixing in single mode vertical-cavity surface-emitting lasers （VCSELs） with weak optical injection. Considering VCSELs that can work in linearly polarized or elliptically polarized states, it derives the theoretical expression of the conjugated field by small signal analysis based on the vectoral rate equations-the spin-flip model. For linearly polarized state, VCSELs show similar conjugate spectra to edge-emitting semiconductor lasers. For the elliptically polarized state, dichroism and birefringence parameters as well as the spin-flip rate can change the conjugate spectra. Especially, when frequency detuning of the probe and pump waves is between the positive and negative relaxation oscillation frequency, changes are evident. For specific values of parameters, conjugate efficiency between 20 dB to 40 dB are obtained.

关键词： phase conjugate VCSELs polarization four-wave mixing