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Damage behavior of the KKV direct hit against fluid-filled submunition payload

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Defence Technology（防务技术） 2022年第11期18卷 2052-2064页

作者： Yang Zan Hai-fu Wang Yuan-feng zheng huan-guo Guo State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

The damage effects of fluid-filled submunition payload impacted by the kinetic kill vehicle(KKV)are investigated by simulations and ground-based *** simulations showed that the damage level and number of submunitions were significantly influenced by the diameter of the KKV compared with its *** on that,a high velocity penetrator formed by shaped charge explosion was used to simulate the direct hit experiment of a KKV impacting submunition *** results demonstrated that the damage modes of submunitions mainly included the slight damage,perforation and total smash,showing a good agreement with the *** understand the multiple damage modes of submunitions,the damage behavior of the submunitions in direct hit process were analyzed based on the AUTODYN-3D *** results presented that increased KKV diameter can increase the crater diameter and expand the damage volume,which will achieve a higher direct hit *** analysis indicated that there were other mechanical behaviors can enhance the damage to submunitions not lying in the KKV flight path,such as secondary debris kill,neighboring submunitions collision with each other,and high-speed fluid injection effect.

关键词： Kinetic kill vehicle Tactical ballistic missiles Submunition payload Direct hit Damage behavior

Feedback maximization of reliability of MDOF quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第9期10卷 1245-1251页

作者： lin-cong CHEN Rong-hua huan Wei-qiu ZHU Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

We studied the feedback maximization of reliability of multi-degree-of-freedom （MDOF） quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations. First, the partially averaged Ito equations are derived by using the stochastic averaging method for quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations. Then, the dynamical programming equation and its boundary and final time conditions for the control problems of maximizing the reliability is established from the partially averaged equations by using the dynamical programming principle. The nonlinear stochastic optimal control for maximizing the reliability is determined from the dynamical programming equation and control constrains. The reliability function of optimally controlled systems is obtained by solving the final dynamical programming equation. Finally, the application of the proposed procedure and effectiveness of the control strategy are illustrated by using an example.

关键词： Stochastic optimal control Dynamical programming Quasi integrable-Hamiltonian system Stochastic averaging Combined harmonic and white noise excitation Reliability

Measurement of K-Shell Ionization Cross Sections of Cr, Ni and Cu Atoms by 7.5-25 keV Electron Impact

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Chinese Physics Letters 2001年第11期18卷 1460-1462页

作者： AN Zhu TANG Chang-huan LUO zheng-Ming Key Laboratory for Radiation Physics and Technology of Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064

The K-shell ionization cross sections of Cr, Ni and Cu elements by 7.5-25 keV electron impact have been *** experimental data have also been compared with the theoretical predictions of the Hippler and Mayol-Salvat mo... 详细信息

关键词： keV Electron Ionization

Macroblock-level decoding and deblocking method and its pipeline implementation in H.264 decoder SOC design

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第1期8卷 36-41页

作者： WANG Shu-hui lin Tao lin zheng-hui Department of Electronic Engineering Shanghai Jiao Tong University Shanghai 200030 China

This paper presents a macroblock-level (MB-level) decoding and deblocking method for supporting the flexible macroblock ordering (FMO) and arbitrary slice ordering (ASO) bit streams in H.264 decoder and its SOC/ASIC implementation. By searching the slice containing the current macroblock in the bit stream and switching slices correctly, MBs can be decoded in the raster scan order, while the decoding process can immediately begin as long as the slice containing the current MB is available. This architectural modification enables the MB-level decoding and deblocking 3-stage pipeline, and saves about 20% of SDRAM bandwidth. Implementation results showed that the design achieves real-time decoding of 1080HD (1920×1088@30 fps) at a system clock of 166 MHz.

关键词： Flexible macroblock ordering (FMO) Arbitrary slice ordering (ASO) System-on-chip (SOC) Raster scan order Pipeline

The decadal abrupt change in the global land vapor pressure deficit

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Science China Earth Sciences 2023年第7期66卷 1521-1534页

作者： Mengqi CHENG Zhiyan ZUO Zouxing lin Qinglong YOU huan WANG Department of Atmospheric and Oceanic Sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China The Faculty Geography Resource Sciences Sichuan Normal UniversityChengdu 610101China Shanghai Frontiers Science Center of Atmosphere-Ocean Interaction Shanghai 200438China National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary Shanghai 202183China

The vapor pressure deficit(VPD) is an important variable used to characterize atmospheric *** paper analyses the spatial and temporal characteristics of the decadal abrupt change(DAC) in the global land VPD after 1980 using monthly scale data from the Climatic Research *** results show that 60.5% of the global land area underwent a significantly increased decadal abrupt change(IDAC) in the VPD,and the persistent IDAC of the VPD was obvious in the middle and low latitudes of Eurasia,Africa and parts of South America but not in central North America or Western *** 1980 to 2020,most regions experienced no more than two persistent IDACs,while more than two significant increases occurred mainly around the Mediterranean and in eastern South *** persistent IDAC occurred relatively early in the middle and low latitudes of Eurasia,Africa,and eastern South America and after 2000 in the high latitude regions,Eastern Europe,and near the Qinghai-Tibet *** regions where the persistent IDAC lasted longer than 10 years mainly included North Africa,West Asia,eastern South America,and parts of East Asia,indicating that the persistent increases in atmospheric aridity in these regions were *** general,the persistent IDAC that began in 1993–2000 was significantly more than that occurred in other periods and lasted longer than that before 1990,suggesting that the land area experiencing an abrupt increase has an expansion after the 1990s and that the role of water limitation in this persistent IDAC in Central Asia and most of China *** addition,the VPD showed another large-scale persistent IDAC over the global land region in 2009,indicating that global atmospheric aridity intensified over the last *** the same time,in a few global regions,the VPD has exhibited decreased decadal abrupt changes(DDACs) with durations shorter than 2 years.

关键词： Vapor pressure deficit Atmospheric aridity Decadal abrupt changes Spatial and temporal characteristics

Advancements in dynamic characteristics analysis of superconducting electrodynamic suspension systems: Modeling, experiment, and optimization

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Superconductivity 2024年第3期11卷 51-65页

作者： huan huang Haitao Li Tim Coombs Hanlin Zhu Yougang Sun Guobin lin Junqi Xu Jun zheng Key Laboratory of Railway Industry of Maglev Technology Tongji UniversityShanghai 201804China National Maglev Transportation Engineering R&D Center Tongji UniversityShanghai 201804China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China Department of Electrical Engineering University of CambridgeCambridge CB30FAUK Department of Electrical&Electronic Engineering University of BristolBristol BS81UBUK

Superconducting electrodynamic suspension (EDS) presents numerous advantages, including large suspension gaps, high lift-to-drag ratios, and lower requirements for track irregularities. Recent advancements in superconducting materials have further enhanced the feasibility of this technology, and hence multiple research institutions are actively developing and improving this high-speed rail technology. Superconducting EDS achieves passive suspension and guidance by the interaction between ground null-flux coils and onboard superconducting magnets, forming an electromechanical coupled system. Thus, electromechanical coupling modeling and equivalent experimental methods are essential in evaluating and optimizing this system. This article reviews the research on dynamic characteristics analysis of superconducting EDS, focusing on modeling and experimental methods. Firstly, it revisits the development history of superconducting EDS and the new opportunities brought by advancements in superconducting materials. Secondly, it discusses various modeling approaches for the suspension system, emphasizing their benefits and limitations. Thirdly, it describes equivalent experimental methods and their respective application scenarios. Then, it reviews important conclusions and possible optimization methods related to dynamic performance and electromechanical coupling research. Additionally, the sliding window method is introduced to improve computational efficiency in vehicle dynamics modeling. This article provides insights into the current state and future directions of superconducting EDS research, serving as a valuable reference for researchers and engineers.

关键词： Superconducting electrodynamic suspension Electromechanical coupling dynamics Equivalent experimental methods Electromagnetic damping Coil track irregularities

A New Upper Bound on the Order of Affine Sub-families of NFSRs

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Journal of Systems Science & Complexity 2020年第1期33卷 196-214页

作者： LIU Junying zheng Qunxiong lin Dongdai State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of SciencesBeijing 100093China School of Cyber Security University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Cryptology Beijing 100878China PLA Strategic Support Force Information Engineering University Zhengzhou 450002China

Nonlinear feedback shift registers(NFSRs)are widely used as building blocks in the design of stream *** NFSR(f)be an NFSR with the characteristic function f and let G(f)be the set of output sequences of NFSR(f).For a given NFSR(f),if there exists an affine Boolean function l such that G(l)?G(f),then G(l)is called an affine sub-family of NFSR(f).In this paper,by skillfully combining previous ideas,the authors give a new upper bound on the order of affine sub-families of NFSR(f).Compared with the four known bounds,the bound is better than three of them,and in some cases is also better than the rest one.

关键词： Affine sub-families families of NFSR sequences nonlinear feedback shift registers stream ciphers

Activated carbon fibers with manganese dioxide coating for flexible fiber supercapacitors with high capacitive performance

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Journal of Energy Chemistry 2019年第4期28卷 95-100页

作者： Huifang Li Jiachen Liang huan Li Xiaoyu zheng Ying Tao zheng-Hong huang Quan-Hong Yang Nanoyang Group School of Chemical Engineering and Technology Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Institute of Forensic Science Ministry of Public Security Laboratory of Advanced Materials School of Materials Science and Engineering Tsinghua University

Fiber supercapacitor(FSC)is a promising power source for wearable/stretchable electronics and high capacitive performance of FSCs is highly desirable for practice flexible ***,we report a composite of manganese dioxide(Mn O_2)and activated carbon fibers(ACFs)with high MnO_2mass loading and microporous structure(abbreviated as Mn O_2@ACF),which is used as a fiber electrode to produce a FSC with a high capacitive performance and a good *** MnO_2@ACF composite electrode in FSCs delivers an ultrahigh specific capacitance of 410 mF/cm^2at 0.1 mA/cm^2,corresponding to a high energy density of 36μWh/cm^2and high power density of 726μW/cm^*** high capacitive performance and simple fabrication method indicates that the Mn O_2@ACF composite is a very promising electrode material for flexible fiber supercapacitors.

关键词： Fiber supercapacitors Activated carbon fibers Mass loading Flexibility

A Mathematical Model of the Photosynthetic Carbon Metabolism Has Multiple Steady States Under the Same Parameter Conditions

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Acta Mathematicae Applicatae Sinica 2016年第3期32卷 591-604页

作者： Jin-ling ZHOU Zuo-huan zheng Xin-guang ZHU Institute of Science and Technology Zhejiang International Studies University. Hangzhou 310012 China Institute of Applied Mathematics Academy of Mathematics and Systems Sciences Chinese Academy of Sciences. Beijing 100080 China CAS-MPG Partner Institute for Computational Biology and Key Laboratory for Computational Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China

This paper analyzes a mathematical model of the photosynthetic carbon metabolism, which incorporates not only the Calvin-Benson cycle, but also another two important metabolic pathways： starch synthesis and photorespiratory pathway. Theoretically, the paper shows the existence of steady states, stability and instability of the steady states, the effects of CO2 concentration on steady states. Especially, a critical point is found, the system has only one steady state with C02 concentration in the left neighborhood of the critical point, but has two with C02 concentration in the right neighborhood. In addition, the paper also explores the influence of C02 concentration on the efficiency of photosynthesis. These theoretical results not only provide insight to the kinetic behaviors of the photosynthetic carbon metabolism, but also can be used to help improving the efficiency of photosynthesis in plants.

关键词： photosynthesis the efficiency of photosynthesis multiple steady states stability critical point