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Square cavity flow driven by two mutually facing sliding walls

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第7期24卷 612-624页

作者： Bo AN Josep m.BERGADà Weimin SANG dong LI F.mELLIBOVSkY School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China National key Laboratory of Science and Technology on Aerodynamic Design and Research Xi'an 710072China key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyang 621000China Department of Fluid mechanics Universitat Politécnica de CatalunyaBarcelona 08034Spain Department of Physics Aerospace Engineering DivisionUniversitat Politécnica de CatalunyaBarcelona 08034Spain

We investigate the flow inside a 2D square cavity driven by the motion of two mutually facing walls independently sliding at different *** exploration,which employs the lattice Boltzmann method(LBm),extends on previous studies that had the two lids moving with the exact same speed in opposite *** there,here the flow is governed by two Reynolds numbers(Re_(T),Re_(B))associated to the velocities of the two moving *** convenience,we define a bulk Reynolds number Re and quantify the driving velocity asymmetry by a parameterα.Parameterαhas been defined in the rangeα∈[-π4,0]and a systematic sweep in Reynolds numbers has been undertaken to unfold the transitional dynamics path of the two-sided wall-driven cavity *** particular,the critical Reynolds numbers for Hopf and NeimarkSacker bifurcations have been determined as a function ofα.The eventual advent of chaotic dynamics and the symmetry properties of the intervening solutions are also analyzed and *** study unfolds for the first time the full bifurcation scenario as a function of the two Reynolds numbers,and reveals the different flow topologies found along the transitional path.

关键词： Two-sided wall-driven cavity Velocity ratios Transitions Flow topology Energy cascade

超临界循环流化床锅炉深度调峰时水冷壁流动不稳定特性计算分析

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西安交通大学学报 2025年第1期59卷 68-77,92页

作者：李维腾郭泽瑞韩磊杨冬西安交通大学动力工程多相流国家重点实验室西安710049

针对深度调峰时超临界循环流化床锅炉水冷壁管道内的汽液两相流动不稳定问题,提出了一种适用于不同工况的频域法数学模型。通过对质量、能量、动量方程进行小扰动线性化后经拉普拉斯变换得到了用于描述管道内汽液流体流动稳定性的传递函... 详细信息

针对深度调峰时超临界循环流化床锅炉水冷壁管道内的汽液两相流动不稳定问题,提出了一种适用于不同工况的频域法数学模型。通过对质量、能量、动量方程进行小扰动线性化后经拉普拉斯变换得到了用于描述管道内汽液流体流动稳定性的传递函数,通过图解奈奎斯特图的方法判断管内工质流动的稳定性。然后,通过该模型计算了某350 mW超临界循环流化床锅炉水冷壁管段的不稳定边界并研究了不同参数对流动不稳定特性的影响。计算结果表明:所选回路在20%和50%锅炉最大连续蒸发量负荷发生流动不稳定时,热负荷分别为76.09 kW·m^(-2)和113.52 kW·m^(-2),水冷壁管道流动稳定且安全;入口过冷度对临界热流密度的影响呈非单值性;增大质量流速使流体的进口和出口密度差减小,有利于流动的稳定;增大入口节流系数,可以抑制入口处流量的脉动,有利于流动的稳定;在不同的工况条件下,改变管段倾斜角度会对流动稳定性产生不同的影响。

关键词：深度调峰流动不稳定性频域法超临界循环流化床锅炉

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Strain Growth in Containment Vessels

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Transactions of Tianjin University 2006年第B09期12卷 193-198页

作者： dong Q LI Q m ZHENG J Y School of mechanical Aerospace and Civil Engineering The University of Manchester PO Box 88 Manchester M60 1QD UK Institute of Chemical machinery Zhejiang University Hangzhou 310027 China

Strain growth is a phenomenon observed in containment vessels subjected to internal blast loading. The elastic response of the vessel may become larger in a later stage compared to its response during the initial stage. The dynamic responses of infinitely long cylindrical containment vessels subjected to uniformly-distributed internal blast loading are studied using LS-DYNA. The development of bending modes and the interaction between the breathing mode and bending modes are observed. The methodology developed for dynamic elastic buckling analysis is employed to study the strain growth phenomenon in explosion containment vessels. It is shown that the dynamic instable vibration of a containment vessel is the basic mechanism of strain growth.

关键词： strain growth containment vessel dynamic response impulsive loading

On maximal non-selfadjoint reflexive algebras associated with a double triangle lattice

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Science China mathematics 2015年第11期58卷 2373-2386页

作者： dong AiJu WANG dong School of mathematics and Computer Engineering Xi'an University of Arts and Science Academy of mathematics and Systems Science Chinese Academy of Sciences Department of mathematics and Statistics University of New Hampshire

We show that the reflexive algebra Alg(L) given by a double triangle lattice L in a finite factor m(with L" = m) is maximal non-selfadjoint in the class of all weak operator closed subalgebras with the same diagonal subalgebra Alg(L) ∩ Alg(L)^+.Our method can be used to prove similar results in finite-dimensional matrix *** a consequence,we give a new proof to the main theorem by Hou and Zhang(2012).

关键词： kadison-Singer algebra kadison-Singer lattice reflexive algebra double triangle lattice factorof type II1

Equivalence of a Bit Pixel Image to a Quantum Pixel Image

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Communications in Theoretical Physics 2015年第11期64卷 501-506页

作者： Carlos Ortega Laurel dong Shi-Hai m.Cruz-Irisson ESImE-Culhuacan Instituto Politicnico Nacional CIDETEC Instituto Politecnico NacionalUPALM

We propose a new method to transform a pixel image to the corresponding quantum-pixel using a qubit per pixel to represent each pixels classical weight in a quantum image matrix *** qubits are linear superposition,changing the coefficients level by level to the entire longitude of the gray scale with respect to the base states of the ***,these states are just bytes represented in a binary matrix,having code combinations of 1 or 0 at all pixel *** method introduces a qubit-pixel image representation of images captured by classical optoelectronic methods.

关键词： qubit pixel quantum image processing image represe

On-the-fly dopant redistribution in a silicon nanowire p-n junction

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Nano Research 2017年第8期10卷 2845-2855页

作者： dong-II moon myeong-Lok Seol Jin-Woo Han m. meyyappan Center for Nanotechnology NASA Ames Research Center Moffett Field CA 94035 USA

Dopant redistribution in a silicon nanowire （SiNW） p-n junction is found to occur owing to self-heating effects. A SiNW is doped to form back-to-back diodes and is thermally isolated by an oxide layer on its bottom side and by air on the other sides. When a high level of current flows, the inner body temperature is found to increase enough to cause dopant diffusion and even to reach the silicon melting point due to Joule heating. This experimentally observed electrothermal behavior is also validated through numerical simulation. The conductivity change is dependent on the total power density and the change becomes permanent once the device suffers self-heating beyond a threshold point. Finally, the dopant redistribution is directly visualized using scanning capacitance microscopy for the first time.

关键词： nanowire degradation Joule heating dopant redistribution scanning capacitance microscopy

Simultaneous removal of chromium and arsenate from contaminated groundwater by ferrous sulfate:Batch uptake behavior

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Journal of Environmental Sciences 2011年第3期23卷 372-380页

作者： Xiaohong Guan Haoran dong Jun ma Irene m. C. Lo State key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China Department of Civil and Environmental Engineering The Hong Kong University of Science and Technology Hong Kong 999077 China

Chromium and/or arsenate removal by Fe（Ⅱ） as a function of pH, Fe（Ⅱ） dosage and initial Cr（Ⅵ）/As（Ⅴ） ratio were examined in batch tests. The presence of arsenate reduced the removal efficiency of chromium by Fe（Ⅱ）, while the presence of chromate significantly increased the removal efficiency of arsenate by Fe（Ⅱ） at pH 6-8, In the absence of arsenate, chromium removal by Fe（Ⅱ） increased to a maximum with increasing pH from 4 to 7 and then decreased with a further increase in pH. The increment in Fe（Ⅱ） dosage resulted in an improvement in chromium removal and the improvement was more remarkable under alkaline conditions than that under acidic conditions. Chromium removal by Fe（Ⅱ） was reduced to a larger extent under neutral and alkaline conditions than that under acidic conditions due to the presence of 10 μtmol/L arsenate. The presence of 20 μmol/L arsenate slightly improved chromium removal by Fe（Ⅱ） at pH 3.9-5,8, but had detrimental effects at pH 6.7-9.8. Arsenate removal was improved significantly at pH 4-9 due to the presence of 10μmol/L chromate at Fe（Ⅱ） dosages of 20-60 μmol/L. Elevating the chromate concentration from 10 to 20μmol/L resulted in a further improvement in arsenate removal at pH 4.0-4.6 when Fe（Ⅱ） was dosed at 30-60 μmol/L.

关键词： chromium removal arsenate removal ferrous iron groundwater treatment

Corrosion protection of NiNb metallic glass coatings for 316SS by magnetron sputtering

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Journal of materials Science & Technology 2021年第20期79卷 88-98页

作者： L.Jiang Z.Q.Chen H.B.Lu H.B.ke Y.Yuan Y.m.dong X.k.meng School of Chemistry and Life Sciences Suzhou University of Science and TechnologySuzhou 215009China Institute of materials Engineering National Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210009China Songshan Lake materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China Institute of materials Engineering Nanjing UniversityNantong 226019China College of Chemistry and Chemical Engineering Nantong UniversityNantong 226019China

metallic glasses(mGs)appear as promising anti-corrosion coating materials due to their microstructural and physicochemical ***,we proposed magnetron sputtered NiNb thin film mG coatings(mGCs)with different structures and compositions for corrosion protection of 316 stainless steel in an aggressive saline *** properties of monolayered Ni_(50)Nb_(50) and Ni_(60)Nb_(40),as well as the multilayered Ni_(50)Nb_(50)/Ni_(60)Nb_(40)(at.%)mGCs,were characterized in terms of morphology and microstructural properties,as well as the anticorrosion *** the NiNb mGCs presented compact structure and the monolayered coatings exhibited preferable adhesion properties in comparison with the multilayered *** electrochemical tests and XPS results imply that the monolayered Ni_(50)Nb_(50) mGC with high Nb content resisted corrosion mainly due to the formation of stable passive film that contained abundant Nb_(2)O_(5) species,whereas the Ni_(60)Nb_(40) mGC with high Ni content showed week corrosion protection performance during long-term service due to the dissolution of Ni cations and the devastation of the coating *** with bit worse adhesion and more vulnerable Ni_(60)Nb_(40) layers,the multilayered Ni_(50)Nb_(50)/Ni_(60)Nb_(40) mGC possessed comparable corrosion resistance with the monolayered Ni_(50)Nb_(50) mG coating,which remained stable even after 32 days of *** performance should be ascribed to the combined eff;ect of the repassivation property for the sub-layers,the hindrance of propagation paths of micro-defects,and the obstruction of corrosive species by interfaces in the multilayered coating.

关键词： magnetron sputtering NiNb metallic glasses multilayer Corrosion protection

Semi-exact Solutions of konwent Potential

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Communications in Theoretical Physics 2019年第2期71卷 231-236页

作者： Qian dong Shi-Shan dong Eduardo Hernández-márquez Ramón Silva-Ortigoza Guo-Hua Sun Shi-Hai dong Laboratorio de Informaci′on Cu′antica CIDETECInstituto Polit′ecnico NacionalUPALMCDMX 07700Mexico Information and Engineering College Dalian UniversityDalian 116622China ′Area de mecatr′onica CIDETECInstituto Polit′ecnico NacionalUPALMCDMX 07700Mexico Catedr′atica CONACYT CICInstituto Polit′ecnico NacionalCDMX 07738Mexico

In this work we study the quantum system with the symmetric konwent potential and show how to find its exact solutions. We find that the solutions are given by the confluent Heun function. The eigenvalues have to be calculated numerically because series expansion method does not work due to the variable z ≥ 1. The properties of the wave functions depending on the potential parameter A are illustrated for given potential parameters V_0 and a. The wave functions are shrunk towards the origin with the increasing |A|. In particular, the amplitude of wave function of the second excited state moves towards the origin when the positive parameter A decreases. We notice that the energy levels ε_i increase with the increasing potential parameter |A| ≥ 1, but the variation of the energy levels becomes complicated for |A| ∈(0, 1), which possesses a double well. It is seen that the energy levels ε_i increase with |A| for the parameter interval A ∈(-1, 0), while they decrease with |A| for the parameter interval A ∈(0, 1).

关键词： exact solution konwent potential confluent Heun function double well potential