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Analysis of temperature,stress,and displacement distributions of staves for a blast furnace

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International Journal of Minerals,Metallurgy and Materials 2009年第5期16卷 512-516页

作者： Xiao-jun ning Shu-sen Cheng ning-qiang Xie School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

The temperature of gas flow inside a blast furnace （BF） changes significantly when the blast furnace is under unstable operations, and the temperature and stress distributions of cooling staves （CS） for BF work the same pattern. The effect of gas temperature on the temperature, stress, and displacement distributions of the cooling stave were analyzed as the gas temperature inside the blast furnace rose from 1000 to 1600℃ in 900 s. The results show that both the temperature and temperature gradient of the hot side of CS increase when the gas flow temperature inside BF rises. The temperature gradient of the hot side of CS is greater than that of the other area of CS and it can reach 65℃/mm. In the vertical direction of the hot side of CS, closer to the central part of CS, the stress intensity is greater than that of the other area of the hot side of CS, which causes cracks on the hot side of CS in the vertical di- rection. As the gas temperature increases, the stress intensity rate near the fixed pin increases and finally reaches 45 MPa/s. Fatigues near the fixed pin and bolts are caused by great stress intensity rate and the area around the pin can be damaged easily. The edge of CS bends toward the cold side and the central part of CS shifts toward the hot surface.

关键词： blast furnace cool stave gas temperature numerical simulation

Robust decentralized H_∞ control of multi-channel systems with norm-bounded parametric uncertainties

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Journal of Systems Engineering and Electronics 2007年第4期18卷 871-878页

作者： Chen ning Gui Weihua School of Information Science and Engineering Central South Univ. Changsha 410083 P.R. China

A robust decentralized H∞ control problem for uncertain multi-channel systems is considered. The uncertainties are assumed to be time-invariant, norm-bounded, and exist in both the system and control input matrices. The dynamic output feedback is mainly dealt with. A necessary and sufficient condition for the uncertain multi-channel system to be stabilized robustly with a specified disturbance attenuation level is derived based on the bounded real lemma, which is reduced to a feasibility problem of a nonlinear matrix inequality （NMI）. A two-stage homotopy method is used to solve the NMI iteratively. First, a decentralized controller for the nominal system with no uncertainty is computed by imposing structural constraints on the coefficient matrices of the controller gradually. Then the decentralized controller is modified, again gradually, to cope with the uncertainties. On each stage, a variable is fixed alternately at the iterations to reduce the NMI to a linear matrix inequality （LMI）. A given example shows the efficiency of this method.

关键词： robust decentralized control parametric uncertainty homotopy method nonlinear matrix inequality LMI

Coupling Between Spin and Gravitational Field and Equation of Motion of Spin

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Communications in Theoretical Physics 2007年第3X期48卷 469-472页

作者： WU ning Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918-1 Beijing 100039 China

In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry cannog be directly applied to gauge theory of gravity. In gauge theory of gravity, based on the viewpoint of the coupling between the spin and gravitational field, an equation of motlon of the spin is deduced. In the post Newtonian approximation, it is proved that this equation gives the same result as that of the equation of parallel transport. So, in the post Newtonian approximation, gauge theory of gravity gives out the same prediction on the precession of orbiting gyroscope as that of general relativity.

关键词： precession of the orbiting gyroscopes classical tests of gauge theory of gravity gauge theory ofgravity equation of motion of the spin

Mechanism of Gravity Impulse

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Communications in Theoretical Physics 2006年第4X期46卷 639-642页

作者： WU ning Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918-1 Beijing 100049 China

It is well known that energy-momentum is the source of gravitational field. For a long time, it is generally believed that only stars with huge masses can generate strong gravitational field. Based on the unified theory of gravitational interactions and electromagnetic interactions, a new mechanism of the generation of gravitational field is studied. According to this mechanism, in some special conditions, electromagnetic energy can be directly converted into gravitational energy, and strong gravitational field can be generated without massive stars. Gravity impulse found in experiments is generated by this mechanism.

关键词： mechanism of generation of gravitational field gravity impulse quantum gravity unified theory of fundamental interactions

Modeling of co-current and counter-current bubble columns with an extended EMMS approach

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Particuology 2019年第3期17卷 126-135页

作者： Xiaoping Guan ning Yang State Key Laboratory of Multi-phase Complex System Institute of Process Engineering Chinese Academy of Sciences P.O. Box 353 Beijing 100190 China

Bubble columns can be operated in semi-batch, co-current or counter-current mode. This study attempts to extend the dual-bubble-size (DBS) model, viz., the energy-minimization multi-scale (EMMS) model for gas-liquid systems, to co-current and counter-current bubble columns. With the increase of superficial liquid velocity, the predicted total gas holdup and regime transition are in accordance with experiments. A DBS drag model was then developed and incorporated into the CFD simulation. The total gas holdup and local gas holdup radial distribution in both the co-current and counter-current bubble columns are well estimated. The findings in the present work demonstrate that developing closure laws through the stability condition is of great significance in modeling complicated multi-scale flow in bubble columns.

关键词： Co-current Counter-current Bubble columns CFD Drag model

Dynamic threshold for SPWVD parameter estimation based on Otsu algorithm

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Journal of Systems Engineering and Electronics 2013年第6期24卷 919-924页

作者： ning Ma Jianxin Wang School of Electronic Engineering and Optoelectronic Technology Nanjing University of Science and Technology

Time-frequency-based methods are proven to be effective for parameter estimation of linear frequency modulation （LFM） signals. The smoothed pseudo Winger-Ville distribution （SPWVD） is used for the parameter estimation of multi-LFM signals, and a method of the SPWVD binarization by a dynamic threshold based on the Otsu algorithm is proposed. The proposed method is effective in the demand for the estimation of different parameters and the unknown signal-to-noise ratio （SNR） circumstance. The performance of this method is confirmed by numerical simulation.

关键词： parameter estimation smoothed pseudo Winger-Ville distribution (SPWVD) dynamic threshold Otsu algorithm

Competitive access in multi-RAT systems with regulated interference constraints

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Science China(Information Sciences) 2017年第2期60卷 96-106页

作者： ning WEI Zhongpei ZHANG National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China

Deployment of multiple radio access technologies(RATs) at the same cell site enables the system to flexibly support different types of devices and services. Such multi-RAT systems call for an efficient utilization of the system resources as well as simplified management. In this paper, we take a user-centric approach and let each individual user equipment decide its own access strategy in a multi-RAT system with regulated interference constraints. The formulated problem is a generalized Nash equilibrium(GNE) problem. We show that there always exists a GNE but its uniqueness is not guaranteed. A closed form solution is provided to characterize a special class of the GNEs. We then propose a primal-dual algorithm with detailed convergence analysis for computing a GNE. The proposed algorithm may have practical implications in the design of multi-RAT systems.

关键词： 5G multi-RAT systems multiple access distributed algorithms generalized Nash equilibrium

Order-Preserved Preset-Time Cooperative Control:A Monotone System-Based Approach

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IEEE/CAA Journal of Automatica Sinica 2022年第9期9卷 1603-1611页

作者： Boda ning Qing-Long Han the Center for Smart Infrastructure and Digital Construction Swinburne University of TechnologyMelbourneVIC 3122Australia the School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourneVIC 3122Australia

This paper is concerned with order-preserved preset-time cooperative control of multi-agent systems with directed graphs.A novel monotone system-based approach is proposed to preserve the initial order of agents while guaranteeing the preset-time state ***,three different distributed controllers together with sufficient conditions are designed to realize leaderless consensus,leader-following consensus,and containment control,*** proposed controllers facilitate preset-time deployment of agents in practical scenarios with collision avoidance *** studies through a numerical example are carried out to illustrate the effectiveness of the proposed controllers.

关键词： Collision-avoidance consensus multi-agent systems preset-time control

Classical Gravitational Interactions and Gravitational Lorentz Force

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Communications in Theoretical Physics 2005年第5X期44卷 883-886页

作者： WU ning Institute of High Energy Physics the Chinese Academy of Sciences Beijing 100049 China

In quantum gauge theory of gravity, the gravitational field is represented by gravitational gauge *** field strength of gravitational gauge field has both gravitoelectric component and gravitomagnetic component. In classical level, gauge theory of gravity gives classical Newtonian gravitational interactions in a relativistic form. Besides,it gives gravitational Lorentz force, which is the gravitational force on a moving object in gravitomagnetic field The direction of gravitational Lorentz force is not the same as that of classical gravitational Newtonian force. Effects of gravitational Lorentz force should be detectable, and these effects can be used to discriminate gravitomagnetic field from ordinary electromagnetic magnetic field.

关键词： gravitational Lorentz force gravity gauge field quantum gravity