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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第5期9卷 664-671页

作者： Xiao-ke KU jian-zhong LIN Department of Mechanics Zhejiang University Hangzhou 310027 China College of Metrology Technology and Engineering China Jiliang University Hangzhou 310018 China

Lattice Boltzmann method was used to numerically investigate the motion and orientation distribution of cylindrical and cubic particles in pipe flow with high concentration and high particle to pipe size ratio. The transient impulse model of 3D collisions between particles and between particle and wall is proposed. The numerical results are qualitatively in agreement with and quantitatively comparable to the experiment data. The results show that the increases of both the cylindrical particle to pipe size ratio and the particle aspect ratio decrease the rotation about all axes. All rotations of cubic particles decrease with increasing the particle concentration. The cubic particles, rotating more drastically in the flow with large Reynolds number, rotate faster than the cylindrical particles with the same size. The cylindrical particles align with the flow direction more obviously with decreasing Reynolds numbers. However, the orientations of cubic particles are spread all over the range with no significant difference in magnitude, and the Reynolds numbers have no obvious effect on the orientations of cubic particles.

关键词： Particulate flow Angular velocity Orientation Lattice Boltzmann method

The role of Debye mass in the chiral crossover in a strong magnetic field

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Communications in Theoretical Physics 2022年第10期74卷 68-75页

作者： jia Zhang Xin-jian Wen Institute of Theoretical Physics State Key Laboratory of Quantum Optics and Quantum Optics DevicesShanxi UniversityTaiyuanShanxi 030006China

In this paper,the Debye mass of quarks is investigated in the Nambu–Jona-Lasinio model at zero and nonzero chemical *** a uniform plasma,the Debye mass usually behaves as a monotonous increasing function of the temperature,the chemical potential and the magnetic *** the fixed coupling interaction G,we find that the magnetic catalysis(MC)on the occurrence of the chiral restoration could be revealed by the susceptibility of the Debye mass dmD/dT at low chemical potential and by the quantity TdmD/dT in the region of moderate ***,the inverse MC is realized under a thermomagnetic coupling constant G(B,T)by the behavior of the Debye mass at both zero and nonzero chemical potentials.

关键词： chiral restoration strong magnetic field Debye mass Nambu-Jona-Lasinio

Robust global motion estimation

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Optoelectronics Letters 2007年第4期3卷 303-307页

作者： DING jia-rui LI zhong-jian AN Jin-wen College of Automation Nonhwestern Polytechnical UniversityXi’an710072China

A global motion estimation method based on robust statistics is presented in this paper. By using tracked feature points instead of whole image pixels to estimate parameters the process speeds up. To further speed up the process and avoid numerical instability, an alterative description of the problem is given, and three types of solution to the problem are compared. By using a two step process, the robustness of the estimator is also improved. Automatic initial value selection is an advantage of this method. The proposed approach is illustrated by a set of examples, which shows good results with high speed.

关键词：运动估计鲁棒性鲁棒统计学轨迹特征点

Effect of Coagulation and Diffusion on Nanoparticle Distribution in a Fully Developed Turbulent Boundary Layer

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Chinese Physics Letters 2012年第5期29卷 157-160页

作者： LIN jian-zhong CHEN zhong-Li Department of Mechanics Zhejiang UniversityHangzhou 310027 Institute of Fluid Mechanics China Jiliang UniversityHangzhou 310018

Nanoparticle distributions in a fully developed turbulent boundary layer are simulated numerically using the moment *** effects of Schmidt number and Damk(o)hler number on the nanoparticle distribution are *** is found that the particle number concentration and total particle mass increase from the wall to the *** difference of particle number concentration and total particle mass near the wall and near the outside becomes smaller with the increasing Schmidt number *** particle diameter and geometric standard deviation increase from the wall to the outside at a fixed Damk(o)hler number Da,and grow with the increase of Da at the same lateral position.

关键词： particle outside Boundary

Residual-Based False Data Injection Attacks Against Multi-Sensor Estimation Systems

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IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1181-1191页

作者： Haibin Guo jian Sun zhong-Hua Pang the National Key Laboratory of Autonomous Intelligent Unmanned Systems School of AutomationBeijing Institute of TechnologyBeijing 100081China the Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China the Key Laboratory of Fieldbus Technology and Automation of Beijing North China University of TechnologyBeijing 100144China

This paper investigates the security issue of multisensor remote estimation *** optimal stealthy false data injection(FDI)attack scheme based on historical and current residuals,which only tampers with the measurement residuals of partial sensors due to limited attack resources,is proposed to maximally degrade system estimation *** attack stealthiness condition is given,and then the estimation error covariance in compromised state is derived to quantify the system performance under *** optimal attack strategy is obtained by solving several convex optimization problems which maximize the trace of the compromised estimation error covariance subject to the stealthiness ***,due to the constraint of attack resources,the selection principle of the attacked sensor is provided to determine which sensor is attacked so as to hold the most impact on system ***,simulation results are presented to verify the theoretical analysis.

关键词： Cyber-physical systems(CPSs) false data injection(FDI)attacks remote state estimation stealthy attacks

Electro-oxidation process and mechanism of molybdenite decomposition under ultrasonic effect

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Rare Metals 2008年第6期27卷 566-570页

作者： jia Lijuan zhong Hong FU jiangang College of Chemistry and Chemical Engineering Central South University Changsha 410083 China

According to the characteristics and shortcomings of the traditional roasting process and the electro-oxidation process in the molybdenum metallurgical industry, the ultrasound electro-oxidation process was proposed to strengthen the oxidative decomposition or leaching of molybdenum. Laboratory work was carried out in an electrochemical cell with 15 mm electrode spacing at 25℃ under ultrasonic effect. The optimum conditions were found through experiments. The electro-oxidation mechanism of molybdenite decomposition under ultrasonic was investigated. A model of electro-oxidation mechanism of molybdenum under ultrasonic was given.

关键词： chemical metallurgy molybdenite leaching electron-oxidation ultrasonic

Micromorphology and physicochemical properties of hydrophobic blasting dust in iron mines

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International Journal of Minerals,Metallurgy and Materials 2019年第6期26卷 665-672页

作者： jian-guo Liu Long-zhe Jin jia-ying Wang Sheng-nan Ou Jing-zhong Guo Tian-yang Wang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of High-Efficient Mining and Safety of Metal Mines of the Ministry of Education University of Science and Technology BeijingBeijing 100083China Mine Emergency Technology Research Center University of Science and Technology BeijingBeijing 100083China College of Safety Engineering North China Institute of Science and TechnologyYanjiao 101601China

The micromorphology and physicochemical properties of hydrophobic blasting dust(HBD)from an iron mine were comprehensively analyzed by laser particle size analysis(LPSA),scanning electron microscopy(SEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The results show that the HBD particles can be classified into three types based on their particle size(PS):larger particles(PS>10μm),medium particles(1μm≤PS≤10μm),and nanoparticles(PS<1μm).The cumulative volume of respirable dust(PS≤10μm)was 84.45%.In addition,three shapes of HBD were observed by SEM:prism,flake,and *** particular,the small particles were mostly flaky,with a greater possibility of being ***,the body and surface chemical compounds of HBD were determined by XRD and XPS,*** adipate(C6H16N2O4)was the only organic compound in the body of HBD,but its mass fraction was only 13.4%.However,the content of organic C on the surface of HBD was 85.35%.This study demonstrated that the small-particle size and large amount of organic matter on the surface of HBD are the main reasons for its hydrophobicity,which can provide important guidance for controlling respirable dust in iron mines.

关键词： iron mine dust respirable dust hydrophobic blasting dust microstructure physicochemical properties particle size

Cathodic electrochemical behavior in Na_3AlF_6-Al_2O_3-LiF-based melts at tungsten electrode with various cryolite ratios

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Rare Metals 2018年第1期37卷 40-46页

作者： Shao-Hu Tao Yue-zhong Di jian-Ping Peng Ke-jia Liu Ying-Long Li Nai-Xiang Feng School of Metallurgy and Materials Northeastern University

The cathodic behavior at tungsten electrode in Na3AlF6-Al2O3-LiF-based melt with various cryolite ratios was investigated by means of potentiodynamic cathodic polarization, potentiostatic electrolysis, chronopotentiometry, and open-circuit chronopotentiometry. The results show that the formation process of Al-W intermetallic compound is controlled by both diffusion and charge transfer when the cryolite ratio is below 2.5, and is completely controlled by diffusion when cryolite ratio is above2.5. The deposition process of metal aluminum is completely charge-transfer controlled. Sodium vapor releases along with the deposition of metal aluminum as crylite ratio increases, which leads to a great influence on current efficiency. When the cryolite ratio is lower than 2.0, the critical cathodic current density of deposited aluminum at tungsten electrode is about 150 mA·cm^（-2）,but the current density is above 200 mA·cm^（-2） under other experimental conditions. A higher cryolite ratio can cause a higher cathodic overvoltage. The relative content of Al layer is higher with the decrease of cryolite ratio, and Al layer easily strips into the molten salt when the cryolite ratio is higher than 2.5.

关键词： LiF Cryolite ratio Aluminum electrolysis Cathodic electrochemistry

Tuning Surface Molecular Design of Porous Carbon for Blue Energy Harvesting

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Research 2024年第1期2023卷 651-662页

作者： jian Yu zhong-Lin Wang Tianwei Ma Department of Civil and Environmental Engineering University of Hawaii at MānoaHonoluluHI 96822USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Engineering Texas A&M University-Corpus ChristiCorpus ChristiTX 78412USA

Capacitive mixing is a promising blue energy technology due to its membrane-free electricity generation and long electrode life ***,because of limited performance,existing systems do not lend themselves to practical *** it is a crucial factor directly influencing electrode behavior,surface chemistry has largely been overlooked in capacitive ***,we show that manipulating surface functionalization alone can tune the responses of electrodes to produce a high voltage rise without altering the pore structure of the *** findings reveal that the spontaneous electrode potential of a surface-modified carbon electrode shifts negatively proportional to the surface charge due to the surface groups,which explains why and how manipulating the surface chemistry can improve the power generation capacity.

关键词： electrode Porous mixing

Robust control for constant thrust rendezvous under thrust failure

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Chinese Journal of Aeronautics 2015年第2期28卷 518-526页

作者： Qi Yongqiang jia Yingmin Wang jian College of Sciences China University of Mining and Technology School of Automation Science and Electrical Engineering Beihang University School of Environment Science and Spatial Informatics China University of Mining and Technology

A robust constant thrust rendezvous approach under thrust failure is proposed based on the relative motion dynamic model. Firstly, the design problem is cast into a convex optimization problem by introducing a Lyapunov function subject to linear matrix inequalities. Secondly, the robust controllers satisfying the requirements can be designed by solving this optimization problem. Then, a new algorithm of constant thrust fitting is proposed through the impulse compensation and the fuel consumption under the theoretical continuous thrust and the actual constant thrust is cal- culated and compared by using the method proposed in this paper. Finally, the proposed method having the advantage of saving fuel is proved and the actual constant thrust switch control laws are obtained through the isochronous interpolation method, meanwhile, an illustrative example is pro- vided to show the effectiveness of the proposed control design method.

关键词： Constant thrust Optimal fuel Rendezvous Robust controller Thrust failure