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A Reliability Allocation Method of CNC Lathes Based on Copula Failure Correlation Model

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Chinese Journal of Mechanical Engineering 2018年第6期31卷 128-136页

作者： Hao Wang yi-min Zhang Zhou Yang School of Mechanical Engineering and Automation Northeastern University Shenyang 110819 China Equipment Reliability Institute Shenyang University of Chemical Technology Shenyang 110142 China

The current research of reliability allocation of CNC lathes always treat CNC lathes as independent series systems. However, CNC lathes are complex systems in the actual situation. Failure correlation is rarely considered when reliabil?ity allocation is conducted. In this paper, drawbacks of reliability model based on failure independence assumption are illustrated, after which, reliability model of CNC lathes considering failure correlation of subsystems is established based on Copula theory, which is an improvement of traditional reliability model of series systems. As the failure time of CNC lathes often obeys Weibull or exponential distribution, Gumbel Copula is selected to build correlation model. After that, a reliability allocation method considering failure correlation is analyzed based on the model established before. Reliability goal is set first and then failure rates are allocated to subsystems according to the allocation vector through solving the correlation model. Reliability allocation is conducted for t = 1. A real case of a CNC lathe and a numerical case are presented together to illustrate the advantages of the reliability model established consider?ing failure correlation and the corresponding allocation method. It shows that the model accords to facts and real working condition more, and failure rates allocated to all the subsystems are increased to some extent. This research proposes a reliability allocation method which takes failure correlation among subsystems of CNC lathes into consid?eration, and costs for design and manufacture could be decreased.

关键词： CNC lathe Copula Failure correlation Reliability model Reliability allocation

Comparison of the mechanisms of microwave roasting and conventional roasting and of their effects on vanadium extraction from stone coal

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International Journal of minerals,Metallurgy and Materials 2015年第5期22卷 476-482页

作者： yi-zhong Yuan yi-min Zhang Tao Liu Tie-jun Chen College of Resources and Environmental Engineering Wuhan University of Science and Technology Hubei Provincial Engineering Technology Research Center of High efficient Cleaning Utilization for Shale Vanadium Resource

Experiments comparing microwave blank roasting and conventional blank roasting for typical vanadium-bearing stone coal from Hubei Province in central China, in which vanadium is present in muscovite, were conducted to investigate the effects of roasting tempera- ture, roasting time, H2SO4 concentration, and leaching time on vanadium extraction. The results show that the vanadium leaching efficiency is 84% when the sample is roasted at 800℃ for 30 min by microwave irradiation and the H2SO4 concentration, liquid/solid ratio, leaching temperature, and leaching time are set as 20vo1%, 1.5：1 mL.g-1, 95℃, and 8 h, respectively. However, the vanadium leaching efficiency achieved for the sample subjected to conventional roasting at 900℃ for 60 min is just 71% under the same leaching conditions. Scanning electron microscopy （SEM） analysis shows that the microwave roasted samples contain more cracks and that the particles are more porous compared to the conventionally roasted samples. According to the results of X-ray diffraction （XRD） and Fourier-transform infrared （FTIR） analyses, neither of these roasting methods could completely destroy the mica lattice structure under the experimental conditions; however, both methods deformed the muscovite structure and facilitated the leaching process. Comparing with conventional roasting, microwave roasting causes a greater deformation of the mineral structure at a lower temperature for a shorter roasting time.

关键词： vanadium metallurgy extraction stone coal microwave roasting leaching vanadium oxides

Exergy Analysis and Optimization of Ladle Furnace Refining Process

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Journal of Iron and Steel Research International 2010年第11期17卷 24-28页

作者： min yi JIANG Mao-fa School ofMaterials and Metallurgy Northeastern University Shenyang 110819 Liaoning China

To decrease energy consumption of ladle furnace, exergy analysis and optimization were conducted based on the ladle furnace refining process of modern clean steelmaking. Exergy analysis results showed that exergy loss induced by unavailable electric energy is the largest, and the electric energy efficiency is 46.20%. To cut down the unavailable electric energy, industrial experiments of submerged arc heating were carried out combined with slag composition modification. Results showed that submerged arc heating can be achieved within most heating period, average heating rate increased by 0. 5 ℃/min, unavailable electric energy decreased by 21. 730 MJ per ton steel, and electric energy efficiency was enhanced by 14.84 %. As the refining cycle was shortened, the exergy loss induced by heat elimination decreased from 19. 455 MJ per ton steel to 11. 066 MJ per ton steel.

关键词： LF exergy analysis exergy loss submerged arc heating

Numerical modeling method on the movement of water flow and suspended solids in two-dimensional sedimentation tanks in the wastewater treatment plant

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Journal of Environmental Sciences 2003年第1期15卷 31-37页

作者： ZENGGuang－ming JIANG－yi－min 等 DepartmentofEnvironmentalSciencesandEngineeeringofHumanUniversity Changsha410082China

Taking the distributing calculation of velocity and concentration as an example, the paper established a series of governing equations by the vorticity stream function method, and dispersed the equations by the finite differencing method. After figuring out the distribution field of velocity, the paper also calculated the concentration distribution in sedimentation tank by using the two dimensional concentration transport equation. The validity and feasibility of the numerical method was verified through comparing with experimental data. Furthermore, the paper carried out a tentative exploration into the application of numerical simulation of sedimentation tanks.

关键词： sedimentation tank numerical simulation vorticity stream function

Existence and Multiplicity of Solutions for Nonlocal Systems with Kirchhoff Type

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Acta Mathematicae Applicatae Sinica 2016年第1期32卷 35-54页

作者： Zhi-tao ZHANG yi-min SUN Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematics Northwest University

Firstly,we use Nehari manifold and Mountain Pass Lemma to prove an existence result of positive solutions for a class of nonlocal elliptic system with Kirchhoff *** a multiplicity result is established by cohomological index of Fadell and *** also consider the critical case and prove existence of positive least energy solution when the parameter β is sufficiently large.

关键词： Critical point Nehari manifold cohomological index

Dimensional Properties of Fractional Brownian Motion

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Acta Mathematica Sinica,English Series 2007年第4期23卷 613-622页

作者： Dong Sheng WU yi min XIAO Department of Statistics and Probability A-413 Wells Hall Michigan State University East Lansing MI 48824 USA

Let B^α = {B^α（t）,t E R^N} be an （N,d）-fractional Brownian motion with Hurst index α∈ （0, 1）. By applying the strong local nondeterminism of B^α, we prove certain forms of uniform Hausdorff dimension result... 详细信息

关键词： fractional Brownian motion Hausdorff dimension uniform dimension results strong local nondeterminism

Optical quantum simulation of Abelian gauge field using cold atomic ensembles coupled with arrays of optical cavities

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Science China(Physics,Mechanics & Astronomy) 2014年第12期57卷 2259-2265页

作者： LIU yi min LIU Rong Wan Department of Physics Shaoguan University

A potentially practical scheme is proposed to realize optical quantum simulation of artificial Abelian gauge field in a scalable architecture consisting of cold atomic ensembles with optical *** the present model,the collective excitations of cold atomic ensembles can be converted to the bosonic modes within the low-excitation limit,where the structure of two-dimension(2D)square plaquette enables the polaritons to move like a charged particle subjected to an external magnetic *** find that the energy spectrum of this hybrid system exhibits a shape of Hofstadter *** work provides a different perspective to the quantum simulation of condensed matter and many-body physics in the context of cavity quantum *** experimental feasibility are justified using the existing techniques.

关键词： gauge field quantum information processing cavity array

Adsorption properties of Ⅴ(Ⅳ) on resin-activated carbon composite electrodes in capacitive deionization

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International Journal of minerals,Metallurgy and Materials 2021年第11期28卷 1777-1787页

作者： Xiao-man Tian Shen-xu Bao yi-min Zhang School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key Laboratory of mineral Resources Processing and Environment Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources Hubei Provincial Engineering Technology Research Center of High Efficient Cleaning Utilization for Shale Vanadium ResourceWuhan University of Science and TechnologyWuhan 430081China

Composite electrodes prepared by cation exchange resins and activated carbon(AC)were used to adsorb Ⅴ(Ⅳ)in capacitive deionization(CDI).The electrode made of middle resin size(D860/AC M)had the largest specific surface area and mesoporous content than two other composite *** analysis showed that D860/AC M presents higher specific capacitance and electrical double layer capacitor than the others,and significantly lower internal diffusion ***,D860/AC M exhibits the highest adsorption capacity and rate of Ⅴ(Ⅳ)among three *** intra-particle diffusion model fits well in the initial adsorption stage,while the liquid film diffusion model is more suitable for fitting at the later *** pseudo-second-order kinetic model is suited for the entire adsorption *** adsorption of Ⅴ(Ⅳ)on the composite electrode follows that of the Freundlich *** analysis indicates that the adsorption of Ⅴ(Ⅳ)is an exothermic process with entropy reduction,and the electric field force plays a dominant role in the CDI *** work aims to improve our understanding of the ion adsorption behaviors and mechanisms on the composite electrodes in CDI.

关键词： capacitive deionization composite electrode vanadium electrochemical behavior kinetics

Vanadium(Ⅳ)solvent extraction enhancement in high acidity using di-(2-ethylhexyl)phosphoric acid with[Cl^(-)]present:an experimental and theoretical study

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Frontiers of Chemical Science and Engineering 2023年第1期17卷 56-67页

作者： Hong Liu yi-min Zhang Jing Huang Tao Liu School of Resource and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China State Environmental Protection Key Laboratory of mineral Metallurgical Resources Utilization and Pollution Control Wuhan University of Science and TechnologyWuhan 430081China Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Engineering Technology Research Center of High Efficient Cleaning Utilization for Shale Vanadium Resource Wuhan University of Science and TechnologyWuhan 430081China

Separation of vanadium from black shale leaching solution at low pH is very meaningful,which can effectively avoid the generation of alkali neutralization slag and the resulting vanadium *** this study,coordination mechanism of vanadium in acid leaching solution at low pH was investigated with the intervention of chloride *** the conditions of pH 0.8,di-(2-ethylhexyl)phosphoric acid concentration of 20%,phase ratio of 1:2,and extraction time of 8 min,the vanadium extraction could reach 80.00%.The Fourier transform infrared and electrospray ionization results reveal that,despite the fact that the chloride ion in the leachate could significantly promote vanadium extraction,the chloride ion does not enter the organic phase,indicating an intriguing *** Cl^(-)-V,SO_(4)^(2-)-V,and H_(2)O-V,the V-Cl bond is longer and the potential difference between coordinate ions and vanadium is ***,Vo^(2+)gets easily desorbed with chloride ions and enter the organic *** the same time,the hydrogen ions of di-(2-ethylhexyl)phosphoric acid also enter the water phase more easily,which reduces the pH required for the extraction reaction.

关键词： vanadium black shale solvent extraction high acidity extraction