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False-target image synthesizer for countering ISAR via inverse dechirping

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Journal of Systems Engineering and Electronics 2016年第1期27卷 99-110页

作者： Xizhang Wei Shaokun Xu Bo peng zhen Liu School of Electronic Science and Engineering National University of Defense Technology Changsha 410073 China Unit 63891 of the PLA Luoyang 471003 China

For real-time jamming signal generation in deceiving inverse synthetic aperture radar（ISAR）,the target characteristics modulation is always processed in the expensive field programmable gate array（FPGA）.Due to the large computational complexity of the traditional modulating operation,the size and structure of simulated false-target are *** regard to the principle of dechirping in range compression of linear frequency modulated（LFM） radar,a novel algorithm named ＂inverse dechirping＂ is proposed for target characteristics *** algorithm only needs one complex multiplier in the FPGA to generate the jamming signal when the radar signal is intercepted,which can be obtained by multiplication of radar signal samplings and the equivalent dechirped target echo in the time *** the complex synthesis of dechirped target echo can be realized by cheap digital signal processor（DSP） within the interpulse time,the overall cost of the jamming equipment will be reduced and the false-target size will not be limited by the scale of *** simulations are performed to verify the correctness and effectiveness of the proposed algorithm.

关键词： radar jamming inverse dechirping inverse synthetic apeture radar(ISAR).

Comparative studies of adsorbed CO and methanol electrooxidation on carbon supported Pt and PtRu catalysts in acid solution

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Rare Metals 2006年第3期25卷 274-280页

作者： peng Cheng ZHANG zhen CHENG Xuan ZHANG Ying Department of Applied Chemistry South China University of Technology Guangzhou 510641 China Department of Chemistry State Key Laboratory for Physical Chemistry of Solid Surfaces Xiamen University Xiamen 361005 China Department of Materials Science and Engineering Xiamen University Xiamen 361005 China

Physicochemical characterization of commercial Pt/C and PtRu/C catalysts was carried out by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Comparative studies of methanol electrooxidation on carbon supported Pt and PtRu catalysts in acid solution were performed by means of an electrochemical method. The experimental results showed that PtRu/C not only had a higher electrocatalytic activity for the electrocatalytic oxidation of methanol than Pt/C, but also for the electrocatalytic oxidation of adsorbed CO. Alloy formation of Ru with Pt modified not only the characteristics of H2 adsorption on the surface of catalyst but also the characteristics of CO adsorption on the sur face of catalyst. The interaction of CHaOH with Ru was a temperature-activated process requiring elevated temperature.

关键词： electrochemistry methanol oxidation cyclic voltammetry electrocatalyst

Motion compensation algorithm in narrowband imaging for mid-course targets

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Journal of Systems Engineering and Electronics 2017年第1期28卷 40-50页

作者： Xizhang Wei zhen Liu Xiaofeng Ding Bo peng School of Electronic Science and Engineering National University of Defense TechnologyChangsha 410073China Unit 31006 of the PLA Beijing 100086China

Imaging precession targets based on the narrowband radar to distinguish the real warhead from mid-course targets is a new technique in missile defense systems. Aiming at the typical mid-course flying scene, this paper describes the principle of the narrowband imaging method, and analyzes the influence on the narrowband imaging by the target translational motion. Then the precision qualification is deduced for both the distance compensation and the velocity compensation, and the conclusion that the velocity compensation is more appropriate for the motion compensation in the narrowband imaging is given. Furthermore, this paper proposes a motion compensation algorithm for the narrowband radar which reduces the interference of the signal phase chaos caused by the rebuilt real signal phase, thus realizing the precise translational motion compensation of the narrowband signal. Finally, the effectiveness of this method is proved by both theoretic analysis and experiment results. © 1990-2011 Beijing Institute of Aerospace Information.

关键词： Radar Radar imaging

An efficient formulation based on the Lagrangian method for contact–impact analysis of flexible multi-body system

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Acta Mechanica Sinica 2016年第2期32卷 326-334页

作者： peng Chen Jin-Yang Liu Jia-zhen Hong Department of Engineering Mechanics School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiaotong University

In this paper,an efficien formulation based on the Lagrangian method is presented to investigate the contact–impact problems of f exible multi-body ***,the penalty method and the Hertz contact law are the most commonly used methods in engineering ***,these methods are highly dependent on various non-physical parameters,which have great effects on the simulation ***,a tremendous number of degrees of freedom in the contact–impact problems will influenc thenumericalefficien *** of these two problems,a formulation combining the component mode synthesis method and the Lagrangian method is presented to investigate the contact–impact problems in fl xible multi-body system ***,the finit element meshing laws of the contact bodies will be studied preliminarily.A numerical example with experimental verificatio will certify the reliability of the presented formulationincontact–***,aseries of numerical investigations explain how great the influenc of the finit element meshing has on the simulation *** the limitations of the element size in different regions are summarized to satisfy both the accuracy and efficien y.

关键词： Multi-body dynamics Contact–impact analysis Lagrangian method Component mode synthesis

Contact-impact formulation for multi-body systems using component mode synthesis

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Acta Mechanica Sinica 2013年第3期29卷 437-442页

作者： peng Chen Jin-Yang Liu Jia-zhen Hong Department of Engineering Mechanics School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University

The efficiency and accuracy are two most concerned issues in the modeling and simulation of multi-body systems involving contact and impact. This paper proposed a formulation based on the component mode synthesis method for planar contact problems of flexible multi-body systems. A flexible body is divided into two parts： a contact zone and an un-contact zone. For the un-contact zone, by using the fixed-interface substructure method as reference, a few low-order modal coordinates are used to replace the nodal coordinates of the nodes, and meanwhile, the nodal coordinates of the local impact region are kept unchanged, therefore the total degrees of freedom （DOFs） are greatly cut down and the computational cost of the simulation is significantly reduced. By using additional constraint method, the impact constraint equations and kinematic constraint equations are derived, and the Lagrange equations of the first kind of flexible multi-body system are obtained. The impact of an elastic beam with a fixed half disk is simulated to verify the efficiency and accuracy of this method.

关键词： Contact-impact analysis · Flexible multi-body system · Component mode synthesis

Double-stranded DNA-nucleic acid dye complex-sensitized biocatalytic photosynthesis:Base pairing-switched regeneration of nicotinamide cofactor

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Journal of Energy Chemistry 2024年第7期94卷 618-624页

作者： zhen Dong Yanying Wang Dan Li peng Wu College of Chemistry Sichuan UniversityChengdu 610064SichuanChina Analytical&Testing Centre State Key Laboratory of Hydraulics and Mountain River EngineeringSichuan UniversityChengdu 610064SichuanChina School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007HenanChina

Photo-biocatalysis,the combination of photosensitization and biocatalysis,is an emerging solution for sunlight-based renewable *** is thus important to develop light antennas with both good light har-vesting and efficient electron ***,the intriguing electrical conductivity of dsDNA and its host effect(for nucleic acid dyes to harvest light)were explored simultaneously to develop a dsDNA-based light antenna for *** SYBR Green I(SG)as the example of the nucleic acid dye,the proposed SG-dsDNA system was found to be capable for visible-light-driven reduced nicotinamide adenine dinucleotide(NADH)regeneration,and the turnover frequency of which(1.35 min^(-1))exceeded most of the existing photocatalytic *** SG can only be hosted by dsDNA,meanwhile dsDNA can be formed through hybridization between single strand DNA and its complementary strand,the pro-posed system adds an extra control of the photocatalytic activity(DNA base pairing-based switch).When integrating the SG-dsDNA system with NADH-dependent horse liver alcohol dehydrogenase(HLADH),successful synthesis of 2-phenylpropanol(a crucial intermediates of profens manufacturing)was achieved.

关键词： Photosynthesis dsDNA SYBRGreenI TICT 2-phenylpropanol

Semiconductor fibers for textile integrated electronic systems

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National Science Review 2024年第6期11卷 100-101页

作者： Yuanyuan zheng zhen Wang Peining Chen Huisheng peng State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceInstitute of Fiber Materials and Devices and Laboratory of Advanced Materials Fudan University

Over 5000 years of development, the functions of clothing have been mainly limited in warmth and modesty. With the development of smart fibers, fabrics are anticipated to revolutionize multidisciplinary applications, ... 详细信息

关键词： Fibers

Properties of quark matter in a new quasiparticle model with QCD running coupling

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Science China(Physics,Mechanics & Astronomy) 2016年第6期59卷 49-57页

作者： zhen Yan Lu Guang Xiong peng Jian Feng Xu Shi peng Zhang School of Physical Sciences University of Chinese Academy of Sciences Theoretical Physics Center for Science Facilities Institute of High Energy Physics

The running of the QCD coupling in the effective mass causes thermodynamic inconsistency problem in the conventional quasiparticle model. We provide a novel treatment which removes the inconsistency by an effective bag constant. The chemical potential dependence of the renormalization subtraction point is constrained by the Cauchy condition in the chemical potential space. The stability and microscopic properties of strange quark matter are then studied within the completely self-consistent quasiparticle model, and the obtained equation of state of quark matter is applied to the investigation of strange stars. It is found that our improved model can describe well compact stars with mass about two times the solar mass, which indicates that such massive compact stars could be strange stars.

关键词： quark matter quasiparticle model thermodynamic inconsistency

A hybrid deep learning and data assimilation method for model error estimation

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Science China Earth Sciences 2024年第12期67卷 3655-3670页

作者： Ziyi peng Lili lei Zhe-Min TAN Key Laboratory of Mesoscale Severe Weather Ministry of Educationand School of Atmospheric SciencesNanjing UniversityNanjing 210023China Department of Atmospheric and Oceanic Sciences Fudan UniversityShanghai 200438China

Forecast errors of numerical weather prediction consist of model errors and the growth of initial condition errors,while the initial condition is often optimized based on short-term *** it is difficult to untangle the initial condition error and model error,but it is essential to infer model errors not just for prediction but also for data assimilation(DA).A hybrid deep learning(DL)and DA method is proposed here,aiming to correct model *** uses a convolutional neural network(CNN)to extract characteristics of initial conditions and forecast errors,and then provides estimations for model *** CNN-based model error estimation method can consider the model error resulted from inaccurate model parameters,or simultaneously consider the model error and initial condition *** on the Lorenz05 model,offline and online experiments demonstrate that the CNN-based model error estimation method can effectively correct model errors resulted from inaccurate model parameters,including the forcing F,coupling coefficient c,and relative scale *** both online and offline model error estimations,simultaneously considering model errors and initial condition errors are beneficial to infer the model errors,compared to considering model errors ***,using the observations to verify the forecasts has advantages over using the analyses,to estimate the model *** observations can also achieve a faster convergence of model error estimation with online DA than using analyses.

关键词： Data assimilation Deep learning Model error