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N-月桂酰肌氨酸钠在磷灰石反浮选中的应用及机理研究

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N-月桂酰肌氨酸钠在磷灰石反浮选中的应用及机理研究

作者： Mohamed Mohamed Ahmed Abdel halim 中南大学

学位级别：硕士

磷灰石[Ca(PO)(OH,F,Cl)]是磷的主要来源。通常,采用浮选法将磷灰石和脉石矿物分离,获得可用于化工的磷精矿。磷灰石矿中的主要脉石矿物是白云石[Ca Mg(CO)]和方解石(Ca CO)。但三种含钙矿物的表面物理和化学性质相似,导致采用传统的脂... 详细信息

磷灰石[Ca(PO)(OH,F,Cl)]是磷的主要来源。通常,采用浮选法将磷灰石和脉石矿物分离,获得可用于化工的磷精矿。磷灰石矿中的主要脉石矿物是白云石[Ca Mg(CO)]和方解石(Ca CO)。但三种含钙矿物的表面物理和化学性质相似,导致采用传统的脂肪酸类捕收剂无法将其高效分离。对此,本论文开发了一种选择性好、可生物降解的氨基酸类捕收剂——N-月桂酰肌氨酸钠(SNLS)。通过单矿物、人工混合矿和实际矿浮选试验,考察了SNLS对三种含钙矿物可浮性的影响。借助Zeta电位、傅里叶变换红外光谱(FTIR)和密度泛函理论(dFT)计算研究了SNLS在白云石、方解石和磷灰石上的吸附机理。主要结论如下:(1)单矿物浮选试验结果表明,SNLS对白云石和方解石的捕收性能较好。在矿浆p H 10和SNLS用量为5×10 mol/L的最佳浮选条件下,白云石和磷灰石、方解石和磷灰石的浮选回收率差值分别为83%和86%。(2)将磷灰石与白云石或方解石按质量比1:1混合形成的人工混合矿浮选试验结果表明,SNLS可实现磷灰石与白云石和方解石的反浮选分离。采用上述最佳浮选条件,针对磷灰石与白云石混合矿,可获得PO品位和回收率分别为16.8%和85.5%的磷灰石精矿,针对磷灰石与方解石混合矿,可获得PO品位和回收率分别为29.5%和83.1%的磷灰石精矿。(3)机理研究表明,磷灰石天然疏水性弱于白云石和方解石,SNLS在白云石和方解石表面的吸附更强。相比磷灰石,SNLS羧基中的O原子与白云石表面的Ca/Mg原子以及方解石表面的Ca原子化学键合能力更强。(4)磷矿实际矿浮选试验结果表明,采用SNLS可获得高品位和高回收率的磷精矿。经过破碎、磨矿、筛分和脱泥后,针对原矿品位PO的红海磷矿,采用2×10 mol/L的SNLS和p H 10的浮选条件,可获得品位和回收率分别为30.9%和81.5%的磷精矿;针对原矿品位为21.1%的尼罗河磷矿,采用5×10 mol/L的SNLS和p H 10的条件,可获得PO品位和回收率分别为30.5%和80%的磷精矿。图X幅,表X个,参考文献X篇

关键词：浮选 SNLS捕收剂磷灰石白云石方解石选择性吸附

Effects of deep cryogenic treatment on mechanical and tribological properties of AISI d3 tool steel

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Friction 2015年第3期3卷 234-242页

作者： Nay Win KHUN Erjia LIU Adrian Wei Yee TAN d.SENTHILKUMAR Bensely ALBERT d.MOHAN LAL School of Mechanical and Aerospace Engineering Nanyang Technological University 50 Nanyang AvenueSingapore 639798Singapore department of Mechanical Engineering P.A.College of Engineering and TechnologyPollachi 642002TNIndia QuEST Global Services-NA Inc.GreenvilleSC 29615USA department of Mechanical Engineering College of EngineeringGuindyAnna University Chennai 600025India

In this study,the effects of deep cryogenic treatment(dCT)on the mechanical and tribological properties of AISI d3 tool steel were investigated together with a systematic correlation between their hardness and wear *** was found that conventionally heat treated AISI d3 tool steel samples were significantly hardened via an additional dCT,which was attributed to the more retained austenite elimination,more homogenized carbide distribution and more reduction in carbide size in the *** a result,the hardened AISI d3 samples exhibited reductions in their friction and wear during rubbing against alumina and 100Cr6 steel balls under different normal loads due to the effectively hindered removal of surface *** results clearly showed that the dCT was an effective way to improve the mechanical and tribological properties of the AISI d3 tool steel samples as the tribological performance of the tool steel samples was significantly influenced by their hardness.

关键词： AISI d3 tool steel deep cryogenic treatment hardness friction wear

3d Flow Past Transonic Turbine Cascade SE 1050-Experiment and Numerical Simulations

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Journal of Thermal Science 2013年第4期22卷 311-319页

作者： d.imurda J.Fürst M.Luxa Institute of Thermomechanics AS CR v.v.i.Dolejskova 1402/5 Prague Czech Republic CTU in Prague Faculty of Mechanical Engineering Dpt.of Technical MathematicsKarlovo Náměstí 13 Prague Czech Republic

This paper is concerned with experimental and numerical research on 3d flow past prismatic turbine cascade SE1050 （known in QNET network as open test case SE1050）. The primary goal was to assess the influence of the inlet velocity profile on the flow structures in the interblade channel and on the flow field parameters at the cascade exit and to compare these findings to results of numerical simulations. Investigations of 3d flow past the cascade with non-uniform inlet velocity profile were carried out both experimentally and numerically at subsonic （M2 = 0.8） and at transonic （M2 = 1.2） regime at design angle of incidence. Experimental data was obtained using a traversing device with a five-hole conical probe. Numerically, the 3d flow was simulated by open source code OpenFOAM and in-house code. Analyses of experimental data and CFd simulations have revealed the development of distinctive vortex structures resulting from non-uniform inlet velocity profile. Origin of these structures results in increased loss of kinetic energy and spanwise shift of kinetic energy loss coefficient distribution. differences found between the subsonic and the transonic case confirm earlier findings available in the literature. Results of CFd and experiments agree reasonably well.

关键词： blade cascade vortex structures transonic flow CFd

GRId GENERATION ANd NUMERICAL SIMULATION OF 2-d RIVER FLOW

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Journal of Hydrodynamics 2001年第2期13卷 50-54页

作者： Zhao, M.d. Li, Y.T. dept. of River Eng. Wuhan Univ. Wuhan 430072 China

This paper presents new weighting functions in grid generation and new discretizing scheme of momentum equations in numerical simulation of river flow. By using the new weighting functions, the curvilinear grid could be concentrated as desired near the assigned points or lines in physical plane. By using the new discretizing scheme, the difficulties caused by movable boundary and dry riverbed can be overcome. As an application, the flow in the Wuhan Section of Yangtze River is simulated. The computational results are in good agreement with the measured results. The new method is applicable to the numerical simulation of 2-d river flow with irregular region and moveable boundary.

关键词： Computer simulation Flow of fluids Mathematical models Poisson equation Two dimensional

Encoding and Multiplexing of 2d Images with Orbital Angular Momentum Beams and the Use for Multiview Color displays

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Research 2019年第1期2019卷 1144-1154页

作者： J.Chu d.Chu Q.Smithwick Centre for Photonics devices and Sensors University of Cambridge9 JJ Tomson AvenueCambridge CB30FAUK disney Research GlendaleCalifornia 91201-5020USA

Te orthogonal nature of diferent orbital angular momentum modes enables information transmission in optical communications with increased bandwidth through mode division *** far the related works have been focused on using orbital angular momentum modes to encode/decode and multiplex point-based on-axis signals for maximum data channel numbers and *** orbital angular momentum modes can be utilized to encode/decode of-axis signals for multiplexing in twodimensional space is of signifcant importance both fundamentally and practically for its enormous potential in increasing the channel information *** this work,a direct use of orbital angular momentum modes to encode/decode and multiplex twodimensional images is realized in a scalable multiview display architecture,which can be utilized for viewing three-dimensional images from diferent *** efect of of-axis encoding/decoding and the resultant crosstalk between multiplexed diferent twodimensional views are *** on which,a color display of good image quality with four independent views is *** resolution of the decoded images is analyzed and the limitation of this approach ***,a spatially multiplexed data communication scheme is also proposed with such a two-dimensional encoding/decoding approach to signifcantly enhance the data transmission capacity in free space for future data communication needs.

关键词： orbital momentum utilized

Bound state solutions of d-dimensional Schrdinger equation with Eckart potential plus modified deformed Hylleraas potential

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Chinese Physics B 2013年第2期22卷 80-85页

作者： Akpan N.Ikot Oladunjoye A.Awoga Akaninyene d.Antia Theoretical Physics Group Department of PhysicsUniversity of UyoUyoNigeria

We study the d-dimensional Schrdinger equation for Eckart plus modified deformed Hylleraas potentials using the generalized parametric form of Nikiforov-Uvarov *** obtain energy eigenvalues and the corresponding wave function expressed in terms of a Jacobi *** also discuss two special cases of this potential comprised of the Hulthen potential and the Rosen-Morse potential in three *** results are also computed for the energy spectrum and the potentials.

关键词： parametric Nikiforov-Uvarov method new approximation scheme Eckart plus Hylleraas potential

Advancing Wound Filling Extraction on 3d Faces:An Auto-Segmentation and Wound Face Regeneration Approach

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2197-2214页

作者： duong Q.Nguyen Thinh d.Le Phuong d.Nguyen Nga T.K.Le H.Nguyen-Xuan department of Mathematics and Statistics Quy Nhon UniversityQuy Nhon City55100Viet Nam Applied Research Institute for Science and Technology Quy Nhon UniversityQuy Nhon City55100Viet Nam CIRTECH Institute HUTECH UniversityHo Chi Minh City72308Viet Nam

Facial wound segmentation plays a crucial role in preoperative planning and optimizing patient outcomes in various medical *** this paper,we propose an efficient approach for automating 3d facial wound segmentation using a two-stream graph convolutional *** method leverages the Cir3d-FaIR dataset and addresses the challenge of data imbalance through extensive experimentation with different loss *** achieve accurate segmentation,we conducted thorough experiments and selected a high-performing model from the *** selectedmodel demonstrates exceptional segmentation performance for complex 3d facial ***,based on the segmentation model,we propose an improved approach for extracting 3d facial wound fillers and compare it to the results of the previous *** method achieved a remarkable accuracy of 0.9999993% on the test suite,surpassing the performance of the previous *** this result,we use 3d printing technology to illustrate the shape of the wound *** outcomes of this study have significant implications for physicians involved in preoperative planning and intervention *** automating facial wound segmentation and improving the accuracy ofwound-filling extraction,our approach can assist in carefully assessing and optimizing interventions,leading to enhanced patient ***,it contributes to advancing facial reconstruction techniques by utilizing machine learning and 3d bioprinting for printing skin tissue *** source code is available at https://***/SIMOGroup/WoundFilling3d.

关键词： 3d printing technology face reconstruction 3d segmentation 3d printed model

Mixed convection of alumina-water nanofluid inside a concentric annulus considering nanoparticle migration

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Particuology 2016年第1期14卷 113-122页

作者： A. Malvandi d.d. Ganji department of Mechanical Engineering Neyshabur Branch Islamic Azad University Neyshabur Iran Mechanical Engineering department Babol University of Technology Babol Iran

A theoretical investigation was conducted of laminar fully developed mixed convection of alumina-water nanofluid through a vertical annulus, to improve its heating/cooling performance. We focused on con- trolling the nanoparticle migration and studying how it affected the heat transfer rate and pressure drop. Because the nanoparticles have very small dimensions, we only considered Brownian motion and ther- mophoretic diffusivity as the main causes of nanoparticle migration. Because thermophoresis is very sensitive to temperature gradients, we imposed various temperature gradients using asymmetric heat- ing. Considering hydrodynamically and thermally fully developed flow, the governing equations were reduced to two-point ordinary boundary value differential equations and were solved numerically. The imposed thermal asymmetry changed the direction of nanoparticle migration and distorted the velocity, temperature, and nanoparticle concentration profiles. Moreover, we found optimum values for the radius ratio （ζ） and heat flux ratio （ε）; with these optimum values, the nanofluid enhanced the efficacy of the system.

关键词： Nanofluid Nanoparticle migration Mixed convection Asymmetry heating Modified Buongiorno's mode

Fullwave doppler reflectometry simulations for density turbulence spectra in ASdEX Upgrade using GENE and IPF-Fd3d

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Plasma Science and Technology 2020年第6期22卷 41-48页

作者： C LECHTE G d CONWAY TGÖRLER T HAPPEL the ASdEX Upgrade Team Institute of Interfacial Process Engineering and Plasma Technology IGVP Universität StuttgartD-70569 StuttgartGermany Max-Planck-Institute for Plasma Physics D-85748 GarchingGermany 不详

doppler reflectometry is an important microwave diagnostic for turbulent fusion plasmas.A microwave beam is scattered off density fluctuations,with wavenumbers according to incident frequency and relative *** way,a density fluctuation spectrum is ***,the correspondence between fluctuation power and scattered microwave power is strongly *** these processes numerically therefore requires fullwave simulations(IPF-Fd3 d),with density fluctuations supplied by a separate plasma turbulence code(GENE).Earlier such attempts suffered from the low number of data points in the‘interesting’part of the spectrum,where a power law had to be fitted to 4 or 5 *** has been overcome with recent simulations,which now show a much better agreement with experimental data.

关键词： plasma diagnostics doppler reflectometry simulation microwaves