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Sorption of certain lanthanides by kieselguhr loaded with Cyanex 572 from sulfate medium

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Journal of Rare Earths 2020年第3期38卷 299-305页

作者： sh.sh.Emam M.S.Gasser N.E.El-hefny W.h.Mahmoud h.F.Aly hot Laboratories Centre Atomic Energy AuthorityCairo 13759Egypt Department of Chemistry Faculty of ScienceAin Shams UniversityCairoEgypt

Kieselguhr for chromatography was loaded with Cyanex 572 extractant and characterized using X-ray diffraction(XRF),scanning electron microscopy(SEM),Fourier transform infra-red(FT-iR),and thermal *** of some heavy lanthanides together with yttrium by the prepared kieselguhr/Cy-572 sorbent was investigated by batch experiment in terms of initial metal ions concentrations,volume to solid mass ratio(V/m),sulfuric acid concentration as well as *** sorption equilibrium of Cy-572 loaded kieselguhr was satisfactorily explained by the pseudo second-order kinetic model and Langmuir isotherm ***,the values of thermodynamic parameters △G°,△h°,and △S°at25℃of the studied metal ions show that the process is spontaneous and endothermic in nature.2.0 mol/L hNO3 is promising to desorb these metal ions.

关键词： Sorption Cyanex 572 Lanthanides Kieselguhr Sulfate medium Rare earths

Effects of Silicon Content and intercritical Annealing on Manganese Partitioning in Dual Phase Steels

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Journal of iron and Steel Research international 2010年第5期17卷 44-50页

作者： A Nouri h Saghafian sh Kheirandish Department of Metallurgy and Materials Engineering Iran University of Science and Technology

Steels of constant manganese and carbon contents with silicon content of 0.34 %- 2.26% were cast. The as-cast steels were then hot rolled at 1 100 ℃ in five passes to reduce the cast ingot thickness from 80 to 4 mm, air cooled to room temperature and cold rolled to 2 mm in thickness. Dual phase microstructures with different volume fraction of martensite were obtained through the intercritical annealing of the steels at different temperatures for 15 min followed by water quenching. in addition to intercritical annealing temperature, silicon content also altered the volume fraction of martensite in dual phase steels. The partitioning of manganese in dual phase silicon steels was investigated using energy-dispersive spectrometer （EDS）. The partitioning coefficient, defined as the ratio of the amounts of alloying element in the austenite to that in the adjacent ferrite, for manganese increased with increasing intercritieal annealing temperature and silicon content of steels. it was also found that the solubility of manganese in ferrite and austenite decreased with increasing intereritical temperature. The results were discussed by the diffusivity and the solubility of manganese in ferrite and austenite existed in dual phase silicon steels.

关键词： partitioning dual phase steel intercritical annealing temperature silicon manganese

非洲Okavango裂谷及邻区三维剪切波速度与径向各向异性结构研究

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地球物理学报 2024年第10期67卷 3796-3813页

作者：王拓王旭陈凌喻志超胡少乾 Stephen S.Gao Kelly h.Liu 中国科学院地质与地球物理研究所岩石圈演化与环境演变全国重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049 中国地质大学地球物理与空间信息学院地球内部多尺度成像湖北省重点实验室武汉430074 Department of Earth Sciences and Engineering Missouri University of Science and TechnologyRollaMO 65409USA

非洲Okavango裂谷是东非裂谷系最年轻且仍处于发育初期阶段的裂谷,研究其地下结构及变形特征有助于深入了解东非裂谷系裂解初期结构构造特征,并进一步完善对裂谷系裂解动力学机制的认识.本文收集Okavango裂谷区域内41个宽频地震台站的... 详细信息

非洲Okavango裂谷是东非裂谷系最年轻且仍处于发育初期阶段的裂谷,研究其地下结构及变形特征有助于深入了解东非裂谷系裂解初期结构构造特征,并进一步完善对裂谷系裂解动力学机制的认识.本文收集Okavango裂谷区域内41个宽频地震台站的连续波形数据,采用背景噪声技术获取Rayleigh和Love波相速度频散数据,进一步通过直接成像技术获得研究区地下50 km深度范围内的三维剪切波速度和径向各向异性结构.剪切波速度和径向各向异性结果显示,Okavango裂谷的中地壳具有低速和负径向各向异性(V_(sh)sh)>V_(SV))的特征,结合前人资料,本文认为Okavango裂谷的发育可能是在先存构造薄弱带上由板内相对运动所提供的水平方向构造应力诱发的.此外,我们的结果还显示,在邻区Zimbabwe克拉通西南部,中、下地壳呈现出负径向各向异性,这一观测支持Okavango岩墙群侵入地壳导致该区域地壳增厚的认识.

关键词： Okavango裂谷裂谷发育机制背景噪声剪切波速度径向各向异性

Comparative studies on Y(Ⅲ)and Dy(Ⅲ)extraction from hydrochloric and nitric acids by Cyanex 572 as a novel extractant

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Journal of Rare Earths 2018年第12期36卷 1342-1350页

作者： N.E.El-hefny M.S.Gasser sh.sh.Emam W.h.Mahmoud h.F.Aly hot Laboratories Centre Atomic Energy Authority Faculty of Science Ain Shams University

Extraction of Y(iii) and Dy(iii) from hydrochloric and nitric acids by Cy-572 in kerosene was studied. The factors affecting the extraction were separately investigated. The stoichiometry of the extracted species was deduced on the basis of slope analysis method. Evaluation of extraction equilibrium and stripping investigation was studied as well as saponification effect of Cy-572. The composition of the extracted metal species in the organic phase was found to be [MA·(hA)] for Y(iii) or Dy(iii) in both media.1.0 mol/L hCi is the best stripping agent for each metal ion from the studied acidic media in one *** Cy-572 does not exhibit any selectivity towards the extraction of Y(iii) or Dy(iii) from both hCi and hNOsolutions. Based on the obtained results, the data were compared and the separation feasibility between lanthanides and Y(iii) in the two media was discussed.

关键词： Extraction Cyanex-572 Yttrium Lanthanides Separation factor Saponification

Monoenergetic electron parameters in a spheroid bubble model

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Chinese Physics B 2013年第2期22卷 347-351页

作者： h.Sattarian sh.Rahmatallahpur T.Tohidi Maraghe Branch Physics DepartmentIslamic Azad UniversityMaraghehIran Bonab Branch Physics DepartmentIslamic Azad UniversityBonabIran Department of Physics Azarbaijan University of Tarbiat MoallemTabrizIran

A reliable analytical expression for the potential of plasma waves with phase velocities near the speed of light is *** presented spheroid cavity model is more consistent than the previous spherical and ellipsoidal models and it explains the mono-energetic electron trajectory more accurately,especially at the relativistic *** maximum energy of electrons is calculated and it is shown that the maximum energy of the spheroid model is less than that of the spherical *** electron energy spectrum is also calculated and it is found that the energy distribution ratio of electrons △E/E for the spheroid model under the conditions reported here is half that of the spherical model and it is in good agreement with the experimental value in the same *** a result,the quasi-mono-energetic electron output beam interacting with the laser plasma can be more appropriately described with this model.

关键词： quasi-mono-energetic electron bunches intense laser plasma accelerator laser wake field bubble regime

inverse heat Transfer Problem of Thermal Contact Conductance Estimation in Periodically Contacting Surfaces

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Journal of Thermal Science 2009年第2期18卷 150-159页

作者： M.h.shojaeefard K.Goudarzi M.sh.Mazidi Dept. of Mechanical Engineering Iran University of Science and Technology

The problems involving periodic contacting surfaces have different practical applications. An inverse heat conductionproblem for estimating the periodic Thermal Contact Conductance (TCC) between one-dimensional, constantproperty contacting solids has been investigated with conjugate gradient method (CGM) of function *** method converges very rapidly and is not so sensitive to the measurement errors. The advantage of thepresent method is that no a priori information is needed on the variation of the unknown quantities, since the solutionautomatically determines the functional form over the specified domain. A simple, straight forward techniqueis utilized to solve the direct, sensitivity and adjoint problems, in order to overcome the difficulties associatedwith numerical methods. Two general classes of results, the results obtained by applying inexact simulatedmeasured data and the results obtained by using data taken from an actual experiment are presented. in addition,extrapolation method is applied to obtain actual results. Generally, the present method effectively improves theexact TCC when exact and inexact simulated measurements input to the analysis. Furthermore, the results obtainedwith CGM and the extrapolation results are in agreement and the little deviations can be negligible.

关键词： thermal contact inverse problem conjugates gradient method

Saturation Estimation with Complex Electrical Conductivity for hydrate-Bearing Clayey Sediments:An Experimental Study

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Journal of Ocean University of China 2024年第1期23卷 173-189页

作者： XiNG Lanchang ZhANG shuli ZhANG huanhuan WU Chenyutong wang Bin LAO Liyun WEi Wei hAN Weifeng WEi Zhoutuo GE Xinmin DENG shaogui College of Control Science and Engineering China University of Petroleum(East China)Qingdao 266580China School of Water Energy and EnvironmentCranfield UniversityCranfield MK430ALUnited Kingdom Department of Alternative Energy PetroChina Research Institute of Petroleum Exploration&DevelopmentLangfang 065007China School of Geosciences China University of Petroleum(East China)Qingdao 266580China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China

Clays have considerable influence on the electrical properties of hydrate-bearing *** is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S_(h))models for reservoir evaluation and *** electrical properties of tetrahydrofuran-hydrate-bearing sediments with montmorillonite are characterized by complex conductivity at frequencies from 0.01 hz to 1 *** effects of clay and sh on the complex conductivity were analyzed.A decrease and increase in electrical conductance result from the clay-swelling-induced blockage and ion migration in the electrical double layer(EDL),*** quadrature conductivity increases with the clay content up to 10%because of the increased surface site density of counterions in *** the in-phase conductivity and quadrature conductivity decrease consistently with increasing sh from 0.50 to *** sets of models for sh evaluation were *** model based on the Simandoux equation outperforms Archie’s formula,with a root-mean-square error(E_(RMS))of 1.8%and 3.9%,respectively,highlighting the clay effects on the in-phase *** fre-quency effect correlations based on in-phase and quadrature conductivities exhibit inferior performance(E_(RMS)=11.6%and 13.2%,re-spectively)due to the challenge of choosing an appropriate pair of frequencies and intrinsic uncertainties from two *** second-order Cole-Cole formula can be used to fit the complex-conductivity *** pair of inverted Cole-Cole parameters,i.e.,characteristic time and chargeability,is employed to predict S_(h) with an E_(RMS) of 5.05%and 9.05%,respectively.

关键词： gas hydrate complex electrical conductivity hydrate-bearing clayey sediment hydrate saturation Simandoux equation frequency dispersion Cole-Cole formula

SLOW PELLETiNG COAGULATiON OF POLYMER LATEX EMULSiON

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Chinese Chemical Letters 1996年第3期7卷 297-298页

作者： Li, YM Chen, MW Xu, GJ Ou, sh wang, K ZhEJiANG UNiV DEPT POLYMER SCI & ENGNHANGZHOU 310027PEOPLES R CHINA

in this paper, slow pelleting flocculation of polymer latex consisting of butadiene, styrene and methyl methacrylate(MBS) were investigated, using aqueous h2SO4 as coagulant. it is found that spherical particles with uniform particle size and high bulk density were produced in the narrow range of ph. in order to obtain good particle morphology, well-distributed concentration, temperature and shear field in the coagulating system were required. Polymer latex made from emulsion polymerization often needs to be converted into dry powders. Usually, we simply add excessive coagulant, such as inorganic acid, salt, etc., into latex emulsion to make it coagulate. The particles formed with such method always have irregular shape and high fines content. in recent years, more attention has been paid to the method of getting coagulated particles with satisfactory particle morphology(1-3)].

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Experimental and numerical study on plasma nitriding of AiSi P20 mold steel

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international Journal of Minerals,Metallurgy and Materials 2016年第9期23卷 1065-1075页

作者： N.Nayebpashaee h.Vafaeenezhad sh.Kheirandish M.Soltanieh Materials Processing Simulation Laboratory(MPS-LAB) School of Materials and Metallurgical EngineeringIran University of Science and Technology(IUST) School of Materials and Metallurgical Engineering Iran University of Science and Technology(IUST)

in this study, plasma nitriding was used to fabricate a hard protective layer on AiSi P20 steel, at three process temperatures（450℃, 500℃, and 550℃） and over a range of time periods（2.5, 5, 7.5, and 10 h）, and at a fixed gas N2：h2 ratio of 75vol%：25vol%. The morphology of samples was studied using optical microscopy and scanning electron microscopy, and the formed phase of each sample was determined by X-ray diffraction. The elemental depth profile was measured by energy dispersive X-ray spectroscopy, wavelength dispersive spectroscopy, and glow dispersive spectroscopy. The hardness profile of the samples was identified, and the microhardness profile from the surface to the sample center was recorded. The results show that ε-nitride is the dominant species after carrying out plasma nitriding in all strategies and that the plasma nitriding process improves the hardness up to more than three times. it is found that as the time and temperature of the process increase, the hardness and hardness depth of the diffusion zone considerably increase. Furthermore, artificial neural networks were used to predict the effects of operational parameters on the mechanical properties of plastic mold steel. The plasma temperature, running time of imposition, and target distance to the sample surface were all used as network inputs; Vickers hardness measurements were given as the output of the model. The model accurately reproduced the experimental outcomes under different operational conditions; therefore, it can be used in the effective simulation of the plasma nitriding process in AiSi P20 steel.

关键词： tool steel plasma nitriding sputtering neural networks