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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第9期14卷 733-742页

作者： zheng-wei zhu School of Information Engineering Southwest University of Science and Technology Mianyang 621010 China

The trajectory of a shipbome radar target has a certain complexity, randomness, and diversity. Tracking a strong maneuvering target timely, accurately, and effectively is a key technology for a shipbome radar tracking system. Combining a variable structure interacting multiple model with an adaptive grid algorithm, we present a variable structure adaptive grid inter- acting multiple model maneuvering target tracking method. Tracking experiments are performed using the proposed method for five maneuvering targets, including a uniform motion - uniform acceleration motion target, a uniform acceleration motion - uni- form motion target, a serpentine locomotion target, and two variable acceleration motion targets. Experimental results show that the target position, velocity, and acceleration tracking errors for the five typical target trajectories are small. The method has high tracking precision, good stability, and flexible adaptability.

关键词： Shipbome radar Target tracking Variable structure Interacting multiple model Adaptive grid algorithm

Parameter influence on electron collection efficiency of a bare electrodynamic tether

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Science China(Information Sciences) 2018年第2期61卷 24-35页

作者： Gangqiang LI zheng H.zhu Department of Earth and Space Science and Engineering York University Department of Mechanical Engineering York University

This study develops a coupled multiphysics finite element method for the dynamic analysis of a bare flexible electrodynamic tether. Contrary to the existing methods, the new method discretizes and solves the orbital motion limited equation and the dynamic equation of an elastic flexible tether ***, the new method is verified via comparison with the existing methods in a straight tether ***, the number of tether elements, tether bending deformation, and two design parameters at the cathodic end affecting the electrical current are investigated. It is determined that the tether bending deformation and the two parameters i.e., the impedance ZT and ΦPWhave a significant impact on the electron collection efficiency of an electrodynamic tether system. The results indicate that the proposed method should be applied in the refined mission analysis.

关键词： multiphysics coupled finite element electrodynamic tether electron collection efficiency

Tracing the behaviour of hexachlorobenzene in a paddy soil-rice system over a growth season

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Journal of Environmental Sciences 2008年第1期20卷 56-61页

作者： YANG Hua zheng Minghui zhu Yongguan Research Center for Eco-Environrnental Sciences Chinese Academy of Sciences Beijing 100085 China.

Hexachlorobenzene （HCB）, a persistent organic pollutant （POP）, has been found in paddy soils. To improve the understanding of HCB contamination in paddy soils, a laboratory simulative study was carried out to investigate the behavior of HCB in a paddy soil and rice plants. This study was divided into three experiments. First, an experiment aimed to examine the evaporation of HCB in paddy soil. In the second experiment, rice was planted in 10 mg/kg HCB contaminated soil and after pot culture at 3, 6, 9, and 27 weeks （at maturity）, both soil and plant samplings were scheduled to be sampled. The soil samples comprised rhizosphere soil, nortrhizosphere soil, and unplanted contaminated soil, whereas plant samples included shoots, roots, and rice grains （dehusked）. Lastly, in this part, HCB in xylem saps was designed to be examined. The results showed that （1） the HCB translocation from paddy soil to rice by vaporization; （2） the HCB concentration in rice grains was surprisingly high; （3） the observed HCB decrease in rice rhizosphere offers a potential means for in situ HCB degradation; （4） HCB might not be transported along transpiration in rice.

关键词： HCB paddy soil rice rhizosphere xylem sap

P-Twisted Affine Lie Algebras and Their Associated Vertex Algebras

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Communications in Theoretical Physics 2008年第7期50卷 7-12页

作者： DING Lu zheng zhu-Jun Institute of Applied Mathematics Academy of Mathematics and Systems Science the Chinese Academy of Sciences Beijing 100080 China School of Mathematical Sciences South China University of Technology Guangzhou 510641 China Institute of Mathematics Henan University Kaifeng 475001 China

For any finite-dimensional semisimple Lie algebra g, a Z＋-graded vertex algebra is construsted on the vacuum representation Vk（g[θ]of g[θ]）,which is a one-dimentionM central extension of 8-invariant subspace on t... 详细信息

关键词： p-twisted affine Lie algebra vertex algebra

Preparation and application in electromagnetic absorption of ZnO/FeNiMo composite

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Rare Metals 2014年第5期33卷 573-577页

作者： Xia-Lian zheng zheng-Hou zhu Xiao-Min Li School of Materials Science and Engineering Nanchang University Physics Science and Engineering Technology Institute Yichun College

In order to increase the absorbing ability and expand the absorbing bandwidth, ZnO and FeNiMo particles were established as absorbers, and wax as adhesive, and the electromagnetic parameters were tested using a vector network analyzer, then the absorbing properties were calculated by means of transmission line theory. The ZnO/FeNiMo composite has excellent microwave absorption properties of a minimum reflection loss value-27.8 dB at 15.98 GHz for a thickness of 1.5 mm and a broad absorption bandwidth of 13.46–18 GHz（RL 〈-10 dB）.

关键词： ZnO FeNiMo Absorbing materials Absorbing property Reflection loss

The absorbing properties of Fe_(73.5) Cu_1 Nb_3Si_(13.5)B_9 amorphous powder/S-glass fiber-reinforced epoxy composite panels

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Rare Metals 2013年第3期32卷 294-298页

作者： Xia-Lian zheng zheng-Hou zhu Xiao-Min Li School of Materials Science and Engineering Nanchang University Physics Science and Engineering Technology Institute Yichun College

Fe73.5Cu1Nb3Si13.5B9 （or FeCuNbSiB） powder/ S-glass fiber-reinforced epoxy composite panels were pre- pared by mold pressing method. Metallographic analysis shows that the amorphous powders are evenly distributed between the layers of S-glass fibers. The effects of the Fe- CuNbSiB powder mass fraction on the complex permittivity, complex permeability, and microwave absorption of the composite panels have been studied in the frequency range of 2.6-18.0 GHz. The complex permittivity of the composite panels with different mass fractions of the FeCuNbSiB powders shows several peaks in the 2.6-18.0 GHz fre- quency range. The complex permeability of the composites decreases with the increasing frequency in the frequency range of 8-18 GHz. The composite with FeCuNbSiB/epoxy mass ratio of 2.5：1.0 has excellent microwave absorption properties of a minimum reflection loss value -30.5 dB at 10.93 GHz for a thickness of 2 mm. A reflection loss exceeding -10 dB can be obtained in a broad frequency range of 3.2-18.0 GHz with a thickness of 1.15-5.00 mm. For the FeCuNbSiB composites, the magnetic loss is the dominant term for microwave absorption. The FeCuNbSiB powders are a possible candidate for high-performance microwave absorption filler.

关键词： Amorphous powders Composites Permeability Permittivity Absorbing properties

Physical modeling of gas-liquid interfacial fluctuation in a thick slab continuous casting mold with argon blowing

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International Journal of Minerals,Metallurgy and Materials 2010年第6期17卷 704-708页

作者： Shu-guo zheng Miao-yong zhu School of Materials and Metallurgy Northeastern University Shenyang 110004 China

Combining with the physical model of level fluctuation in a thick slab continuous casting mold with the cross-section of 1500 mm×280 mm and argon blowing, the rationalities of estimating the level fluctuation by three traditional quantitative approaches were discussed, and the effects of gas flowrate, casting speed, and the immersion depth of submerged entry nozzle （SEN） on the level fluctuation were also investigated. As a result, it seems that three traditional quantitative approaches are not very suitable for estimating the level fluctuation in a mold with argon blowing, so a new approach for estimating level fluctuation in the mold with argon blowing was presented. The experimental results show that the level fluctuation is mainly in the region around the nozzle wall. When the casting speeds are larger than a certain value, there is the escape of large bubbles near the nozzle wall, which causes an obvious increase of level fluctuation. Furthermore, optimal process parameters, viz., the gas flowrate of 6 NL/min, the casting speed of 1.1 m/min, and the immersion depth of 170 mm, are presented to restrain the level fluctuation by a physical model.

关键词： slabs continuous casting molds level fluctuation modelling

Libration and end body swing stabilization of a parallel partial space elevator system

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Chinese Journal of Aeronautics 2021年第3期34卷 187-199页

作者： Gefei SHI Gangqiang LI zheng H.zhu School of Aeronautics and Astronautics Sun Yat-Sen UniversityGuangzhou 510275China Department of Mechanical Engineering York UniversityTorontoOntario M3J 1P3Canada

This paper studies the libration and stabilization of a parallel partial space elevator system in circular orbits. The system is made up of two paralleled partial space elevators, each of which consists of one main satellite, one end body and a climber moving along the tether between *** libration characteristics of the elevator are studied through numerical analysis by a new dynamic model, and a novel control strategy is proposed to stabilize the swing of the end body by projecting the climber speeds only. Optimal control method is used to implement the new control strategy in the case where the climbers move in opposite direction. The simulation results validate the effectiveness of the proposed control strategy whose application will neither sacrifice the transport efficiency nor exacerbate libration significantly.

关键词： Libration stabilization Nonlinear dynamics Optimal control Parallel partial space elevator Space tether

Orbital radius keeping of floating partial space elevator in cargo transposition

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Astrodynamics 2023年第3期7卷 259-269页

作者： Gefei Shi zheng H.zhu School of Aeronautics and Astronautics Sun Yat-sen UniversityGuangzhou510275China Department of Mechanical Engineering York University4700 Keele StreetTorontoOntarioM3J 1P3Canada

A floating partial space elevator(PSE)is a PSE with a floating main *** work aims to keep the orbital radius of the main satellite of a floating PSE in cargo transposition without the use of thrusts.A six-degree-of-freedom two-piece dumbbell model was built to analyze the dynamics of a floating *** adjusting the climber’s moving speed and rolling of the end body,the main satellite’s orbital radius can be kept.A novel control strategy using a proportional shrinking horizon model predictive control law containing a self-stability modified law is proposed to stabilize both the orbital and libration states to regulate the speed of only the *** results validated the proposed control *** system provides a successful approach to the desired equilibrium by the end of the transposition.

关键词： floating partial space elevator(PSE) self-stability modified law shrinking horizon model predictive control

Motion Control in Saccade and Smooth Pursuit for Bionic Eye Based on Three-dimensional Coordinates

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Journal of Bionic Engineering 2017年第2期14卷 336-347页

作者： Qingbin Wang Wei Zou De Xu zheng zhu Research Center of Precision Sensing and Control Institute of Automation Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100190 China

Saccade and smooth pursuit are two important functions of human eye. In order to enable bionic eye to imitate the two functions, a control method that implements saccade and smooth pursuit based on the three-dimensional coordinates of target is proposed. An optimal observation position is defined for bionic eye based on three-dimensional coordinates. A kind of motion planning method with high accuracy is developed. The motion parameters of stepper motor consisting of angle acceleration and turning time are computed according to the position deviation, the target＇s angular velocity and the stepper motor＇s current angular velocity in motion planning. The motors are controlled with the motion parameters moving to given position with desired angular velocity in schedule time. The experimental results show that the bionic eye can move to optimal observation positions in 0.6 s from initial location and the accuracy of 3D coordinates is improved. In addition, the bionic eye can track a target within the error of less than 20 pixels based on three-dimensional coordinates. It is verified that saccade and smooth pursuit of bionic eye based on three-dimensional coordinates are feasible.

关键词： bionic eye saccade smooth pursuit motion planning observation position