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A novel mechanism fusion data control method for slab camber in hot rolling

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Journal of Iron and Steel Research International 2023年第5期30卷 960-970页

作者： Le-bao song Dong Xu Peng-fei Liu Jin-hang Zhou Hui-qing Yan Jing-dong Li hai-nan He hai-jun Yu Xiao-chen Wang Quan Yang National Engineering Technology Research Center of Flat Rolling Equipment University of Science and Technology BeijingBeijing 100083China Xinjiang Joinworld Co. Ltd.Urumqi 830000XinjiangChina 2250 Hot Strip Mill Hunan Lianyuan Iron and Steel Co.Ltd.Loudi 417000HunanChina

For asymmetric plate shape,control over the hot rolling process mainly depends on the subjective judgement and personal experience of the operator as there are great deviations and much instability in hot ***,the intrinsic mechanisms and sensitivity affecting characteristic parameters and variables in the asymmetric rolling process remain ***,a novel mechanism fusion data control method for slab camber in hot rolling using dimensional analysis and data-driven technique was *** approach of dimensional analysis was used to establish a mathematical model and analyse the main parameters affecting the slab camber of the rough ***,the established mathematical model combined with the data-driven techniques was employed to accurately predict the slab bending ***,the superiority and effectiveness of the proposed model were demonstrated by a comparison with three regression ***,the proposed control strategy was successfully applied in a 1580 mm hot rolling industrial *** automatic control results show that the hit rate of slab cambers in different sizes from 10 to 30 mm is improved,and the quality stability of intermediate slab is significantly improved.

关键词： Mechanism model Dimensional analysis Data-driven technique Camber control Hot rolling

CHARACTERISTICS OF CORRELATION AND SPECTRUM BETWEEN WALL FLUCTUATING PRESSURE AND FLUCTUATING VELOCITY OF IMPINGING JET

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Journal of Hydrodynamics 2002年第3期14卷 21-28页

作者： Dai, Guang-qing Yang, Yong-Quan Yang, qing Wang, hai-Yun Hydraulics Lab. of High Speed Flows Sichuan Univ. Chengdu 610065 China

The correlation, between wall fluctuating pressure and fluctuating velocity, on the bed of plunging pool under the action of single and twin impinging jet, and their spectrum and turbulent scale are investigated in the paper by using 2-D LDA and the dynamic pressure scanning system of multiple points. It is found that the cross correlation between the horizontal fluctuating velocity and the fluctuating pressure of twin jet is bigger than that of single jet, and the spectrums of horizontal fluctuating velocity and fluctuating pressure obviously have approximately same dominant frequency. The relationship between the fluctuation pressure coefficient on wall and the turbulent intensity near the wall can be described with logarithmic curve.

关键词： Hydraulic structures Pressure Pressure measurement Turbulence Velocity

Optimal Synchronization Control of Heterogeneous Asymmetric Input-Constrained Unknown Nonlinear MASs via Reinforcement Learning

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IEEE/CAA Journal of Automatica Sinica 2022年第3期9卷 520-532页

作者： Lina Xia qing Li Ruizhuo song Hamidreza Modares Beijing Engineering Research Center of Industrial Spectrum Imaging School of Automation and Electrical EngineeringUniversity of Science and Technology Beijing IEEE the Department of Mechanical Engineering Michigan State University

The asymmetric input-constrained optimal synchronization problem of heterogeneous unknown nonlinear multiagent systems(MASs)is considered in the ***,a state-space transformation is performed such that satisfaction of symmetric input constraints for the transformed system guarantees satisfaction of asymmetric input constraints for the original ***,considering that the leader’s information is not available to every follower,a novel distributed observer is designed to estimate the leader’s state using only exchange of information among neighboring *** that,a network of augmented systems is constructed by combining observers and followers dynamics.A nonquadratic cost function is then leveraged for each augmented system(agent)for which its optimization satisfies input constraints and its corresponding constrained Hamilton-Jacobi-Bellman(HJB)equation is solved in a data-based *** specifically,a data-based off-policy reinforcement learning(RL)algorithm is presented to learn the solution to the constrained HJB equation without requiring the complete knowledge of the agents’*** of the improved RL algorithm to the solution to the constrained HJB equation is also ***,the correctness and validity of the theoretical results are demonstrated by a simulation example.

关键词： Asymmetric input-constrained heterogeneousnonlinear multiagent systems(MASs) Hamilton-Jacobi-Bellman(HJB)equation novel observer reinforcement learning(RL)

New types of topological superconductors under local magnetic symmetries

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National Science Review 2021年第5期8卷 85-90页

作者： Jinyu Zou qing Xie Zhida song Gang Xu Wuhan National High Magnetic Field Center & School of Physics Huazhong University of Science and Technology Department of Physics Princeton University

We classify gapped topological superconducting(TSC) phases of one-dimensional quantum wires with local magnetic symmetries, in which the time-reversal symmetry T is broken, but its combinations with certain crystalline symmetries, such as MxT, C2zT, C4zT and C6zT, are preserved. Our results demonstrate that an equivalent BDI class TSC can be realized in the MxT or C2zT superconducting wire,which is characterized by a chiral Zcinvariant. More interestingly, we also find two types of totally new TSC phases in the C4zT and C6zT superinducting wires, which are beyond the known AZ class, and are characterized by a helical Z~h invariant and Z~h ⊕Zcinvariants, respectively. In the Z~h TSC phase, Z pairs of Majorana zero modes(MZMs) are protected at each end. In the C6zT case, the MZMs can be either chiral or helical, and even helical-chiral coexisting. The minimal models preserving C4zT or C6zT symmetry are presented to illustrate their novel TSC properties and MZMs.

关键词： topological superconductor magnetic symmetry Majorana zero mode superconducting wire

Microcrack-and microvoid-related impact damage and ignition responses for HMX-based polymer-bonded explosives at high temperature

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Defence Technology（防务技术） 2022年第9期18卷 1602-1621页

作者： hai-jiao Xue Yan-qing Wu Kun Yang Yi Wu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing100081China

Investigating the damage and ignition behaviors of polymer-bonded explosive(PBX) under a coupled impact and high-temperature loading condition is required for the safe use of charged PBXs. An improved combined microcrack and microvoid model(CMM) was developed for better describing the thermal effects of deformation, damage, and ignition responses of PBXs. The main features of the model under typical dynamic loadings(i.e. uniaxial tension and compression, and lateral confinement) at different initial temperature were first studied. And then the effects of temperature on impact-shear sensitivity of HMX-based PBXs were investigated. The results showed that the ignition threshold velocity of shear-crack hotspots exhibits an increase from 260 to 270 to 315-325 m/s when initial temperature increases from 301 to 348 K;and then the threshold velocity decreases to 290-300 m/s with the initial temperature continually increasing to 378 K. The predicted ignition threshold velocity level of the explosives under coupled impact and high temperature loading conditions were consistent with the experimental data.

关键词： PBX Thermal-mechanical coupling Numerical simulation Impact Sensitivity

Chain damage effects of multi-spaced plates by reactive jet impact

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Defence Technology（防务技术） 2021年第2期17卷 393-404页

作者： Yuan-feng Zheng Cheng-hai Su Huan-guo Guo qing-bo Yu hai-fu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

Chain damage is a new phenomenon that occurs when a reactive jet impacts and penetrates multispaced *** reactive jet produces mechanical perforations on the spaced plates by its kinetic energy(KE),and then results in unusual chain rupturing effects and excessive structural damage on the spaced plates by its deflagration *** the present study,the chain damage behavior is initially demonstrated by *** reactive liners,composed of 26 wt%Al and 74 wt%PTFE,are fabricated through a pressing and sintering *** reactive liner thicknesses of 0.08 CD,0.10 CD and 0.12 CD(charge diameter)are chosen to carry out the chain damage *** results show a chain rupturing phenomenon caused by reactive *** constant reaction delay time and the different penetration velocities of reactive jets from liners with different thicknesses result in the variation of the deflagration position,which consequently determines the number of ruptured plates behind the ***,the finite-element code AUTODYN-3D has been used to simulate the kinetic energy only-induced rupturing effects on plates,based on the mechanism of behind armor debris(BAD).The significant discrepancies between simulations and experiments indicate that one enhanced damage mechanism,the behind armor blast(BAB),has acted on the ruptured ***,a theoretical model is used to consider the BAB-induced enhancement,and the analysis shows that the rupturing area on aluminum plates depends strongly upon the KE only-induced pre-perforations,the mass of reactive materials,and the thickness of plates.

关键词： Reactive materials Reactive jet Chain damage Behind armor blast

Numerical Investigation on Severe Slugging in A Catenary Riser

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China Ocean Engineering 2019年第5期33卷 628-635页

作者： QI Xiao-liang GAO song GUO hai-yan College of Engineering Ocean University of China Qingdao 266100 China Marine Design & Research Institute of China Shanghai 200240 China

A mathematical model is presented to study the main characteristics of severe slugging in a downward inclined pipeline followed by a catenary riser. In this model, both simplified transient model and phase distribution model are included so that the flow characteristics of each stage for severe slugging can be accurately reproduced, especially for blowout stage. The results show that the flow features of severe slugging can be simulated by the proposed mathematical model. A good agreement between the experimental data and the numerical results is observed. The model can predict the transient fluctuation of many respects, such as the superficial gas velocity at the bottom of the riser and the average velocity at the outlet of the riser.

关键词： severe slugging pipeline-riser system phase distribution transient fluctuation

Severe acute liver injury in patients with exertional heat stroke associated with poor short-term prognosis

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World Journal of Emergency Medicine 2022年第2期13卷 124-129页

作者： Chen Li hai-bin Su Hui Li Xin Li Hong-min Wang qing song Jin-hua Hu Senior Department of Hepatology the Fifth Medical Center of Chinese PLA General HospitalBeijing 100039China Department of Emergency the Third Medical Center of Chinese PLA General HospitalBeijing 100039China Department of Critical Care Medicine the First Medical Center of Chinese PLA General HospitalBeijing 100853China

Heat stroke is a potentially life-threatening condition characterized by a core temperature that exceeds the external temperature and is accompanied by central nervous system(CNS)abnormalities.[1]It has two forms,classical heat stroke and exertional heat stroke(EHS).EHS is usually experienced by athletes,military personnel,and outdoor laborers in hot and humid environments.

关键词： patients prognosis injury

Vertex-disjoint K_1+(K_1 ∪ K_2) in K_(1,4)-free Graphs with Minimum Degree at Least Four

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Acta Mathematica Sinica,English Series 2014年第4期30卷 661-674页

作者： Yun Shu GAO qing song ZOU School of Mathematics and Computer Science Ningxia University Department of Mathematics Xidian University

A graph is said to be K1,4-free if it does not contain an induced subgraph isomorphic to K1,4. Let κ be an integer with κ ≥ 2. We prove that if G is a K1,4-free graph of order at least llκ- 10 with minimum degree ... 详细信息

关键词： Forbidden graphs Vertex-disjoint subgraphs Minimum degree