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Thermodynamics and kinetics of extracting zinc from zinc oxide ore by the ammonium sulfate roasting method

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International Journal of Minerals,Metallurgy and Materials 2015年第5期22卷 467-475页

作者： Yi Sun Xiao-yi Shen yu-chun zhai School of Materials and Metallurgy Northeastern University

Thermodynamic analyses and kinetic studies were performed on zinc oxide ore treatment by （NH4）2SO4 roasting technology. The results show that it is theoretically feasible to realize a roasting reaction between the zinc oxide ore and （NH4）2SO4 in a temperature range of 573-723 K. The effects of reaction temperature and particle size on the extraction rate of zinc were also examined. It is found that a surface chemical reaction is the rate-controlling step in roasting kinetics. The calculated activation energy of this process is about 45.57 kJ/mol, and the kinetic model can be expressed as follows： 1 - （1 - α）1/3 = 30.85 exp（-45.57/RT）·t. An extraction ratio of zinc as high as 92% could be achieved under the optimum conditions.

关键词： zinc metallurgy extraction ammonium sulfate ore roasting thermodynamics kinetics

Monte Carlo simulations of electromagnetically induced transparency in a square lattice of Rydberg atoms

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Chinese Physics B 2021年第7期30卷 283-288页

作者： Shang-yu zhai Jin-Hui Wu Center for Quantum Sciences Northeast Normal UniversityChangchun 130117China School of Physics Northeast Normal UniversityChangchun 130024China

We study the steady optical response of a square lattice in which all trapped atoms are driven by a probe and a coupling fields into the ladder configuration of electromagnetically induced transparency(EIT).It turns out to be a manybody problem in the presence of van der Waals(vd W)interaction among atoms in the upmost Rydberg state,so Monte Carlo(MC)calculation based on density matrix equations have been done after introducing a sufficiently large cut-off *** is found that the absorption and dispersion of EIT spectra depends critically on a few key parameters like lattice dimension,unitary vd W shift,probe Rabi frequency,and coupling *** modulating these parameters,it is viable to change symmetries of the absorption and dispersion spectra and control on demand depth and position of the transparency *** MC calculation is expected to be instructive in understanding many-body quantum coherence effects and in manipulating non-equilibrium quantum phenomena by utilizing vd W interactions of Rydberg atoms.

关键词： electromagnetically induced transparency Rydberg atomic lattices Monte Carlo simulations

Recovery of titania from high titanium slag by roasting method using concentrated sulfuric acid

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Rare Metals 2015年第12期34卷 895-900页

作者： Li-Li Sui yu-Chun zhai Li-Hua Miao Department of Chemistry Shenyang Medical College School of Materials and Metallurgy Northeastern University

By means of energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscope (SEM) analysis, the phase structure characteristics of high titanium slag were analyzed. Through the single factor and the orthogonal experiment methods, the effects of material particle size, mass ratio of acid to ore, roasting temperature, and roasting time on the acidolysis ratio of TiO2 during the process of roasting high titanium slag with concentrated sulfuric acid were systematically investigated. The results show that the sequence of each factor affecting the acidolysis ratio of TiO2 is: mass ratio of acid to ore, roasting time, and roasting temperature. The optimum technological conditions are obtained as mass ratio of acid to ore of 2.1, roasting temperature of 310°C, roasting time of 75min, and material particle size of 45–53μm. The acidolysis ratio of TiO2 is over 96% under the optimum conditions. The roasting process is proved to be significant in the exploitation and utilization of high titanium slag. The advantages of the proposed roasting process are of high efficiency, low power consumption, and minimum pollution.

关键词： Concentrated sulfuric acid Roasting High titanium slag Titania

Extracting B_2O_3 from calcined boron mud using molten sodium hydroxide

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Rare Metals 2015年第10期34卷 744-751页

作者： Zhi-Qiang Ning yu-Chun zhai Qiu-Shi Song School of Materials and Metallurgy Northeastern University

Extracting B2O3 from calcined boron mud(CBM) was studied. The effect of factors such as reaction temperature and NaO H-to-CBM mass ratio on B2O3 extraction efficiency was investigated. The results show that increasing reaction temperature and NaO H-to-CBM mass ratio increases B2O3 extraction efficiency. There are two stages for the B2O3 extracting process: 0–20 min is the first stage, which is rapid; 20–50 min is the second stage, which is slower than the first stage. The overall extracting process follows the shrinking core model, and the first and second stages are determined to obey the surface chemical reaction model and the diffusion through the products layer model,respectively. The activation energies of the first and second stages are calculated to be 41.74 and 15.43 kJ·mol-1,respectively. The B2O3 extracting kinetics equations of the first and second stages are also obtained.

关键词： Boron mud Sodium hydroxide Boron oxide Kinetics

Thermodynamics and kinetics of alumina extraction from fly ash using an ammonium hydrogen sulfate roasting method

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 144-149页

作者： Ruo-chao Wang yu-chun zhai Zhi-qiang Ning School of Materials and Metallurgy Northeastern University

A novel method was developed for extracting alumina （Al2O3） from fly ash using an ammonium hydrogen sulfate （NH4HSO4） roasting process, and the thermodynamics and kinetics of this method were investigated. The thermodynamic results were verified experi-mentally. Thermodynamic calculations show that mullite present in the fly ash can react with NH4HSO4 in the 298-723 K range. Process op-timization reveals that the extraction rate can reach up to 90.95% when the fly ash reacts with NH4HSO4 at a 1：8 mole ratio of Al2O3/NH4HSO4 at 673 K for 60 min. Kinetic analysis indicates that the NH4HSO4 roasting process follows the shrinking unreacted core model, and inner diffusion through the product layer is the rate-controlling step. The activation energy is calculated to be 16.627 kJ/mol;and the kinetic equation can be expressed as 1-（2/3）α-（1-α）2/3=0.0374t exp[-16627/（RT）], whereαis the extraction rate and t is the roasting temperature.

关键词： ammonium hydrogen sulfate ore roasting fly ash alumina thermodynamics kinetics

DFT Studies on Non-IPR C_(68) and Endohedral Fullerene Sc_3N@C_(68)

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Chinese Journal of Structural Chemistry 2007年第3期26卷 321-327页

作者： WANG Dong-Lai SUN Xiao-Ping zhai yu-Chun College of Materials and Metallurgy Northeastern University Shenyang 110004 China Department of Chemistry Anshan Teachers College Anshan 114005 China

Density functional theory （DFT） calculations on two isomers of C68 with the minimal number of fused pentagon pairs, its anions and Sc3N as well as Sc3N@C68 （6140） metallofullerene were carded out at the B3LYP/6-31G^＊ level. The optimized configurations and electrostatic potential distributions have been obtained. The calculated results show that the electrostatic potentials of C68 （6140） inside the sphere have three minima in the middle of the double bonds at fusion of two hexagonal rings. In contrast, potential minimum Vmin（r） of C68 （6275） inside the sphere occurs at the center of the sphere. Concerning the two isomers of C68, the largest regions with the most negative MEP outside the sphere are both localized in the neighborhood of pentagon-pentagon vertex fusions. They constitute the most probable active sites in chemical reactions. Our results present a reasonable explanation for the bonding between scandium atoms and fullerene cage.

关键词： C68 fullerene metallofullerene electrostatic potential bonding

关注学习路上的慢跑者——苏霍姆林斯基“学困生”教育思想及启示

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兵团教育学院学报 2025年第1期35卷 56-64页

作者：王福关满姗翟玉洁石河子大学师范学院/兵团教育学院新疆石河子832003 石河子大学师范学院新疆石河子832003

苏霍姆林斯基在长期的教育实践中,形成了其独特的学困生教育观。本研究基于苏霍姆林斯基关于学困生的教育思想,主要从学校教育和家庭教育两方面分析了学困生的成因,并提出了相应的转化策略。苏霍姆林斯基的教育思想对当下学困生教育有... 详细信息

苏霍姆林斯基在长期的教育实践中,形成了其独特的学困生教育观。本研究基于苏霍姆林斯基关于学困生的教育思想,主要从学校教育和家庭教育两方面分析了学困生的成因,并提出了相应的转化策略。苏霍姆林斯基的教育思想对当下学困生教育有着重要启示,应让学生养成良好的学习习惯和学习的自觉性,构建学校的全面育人系统,强化教师的主导作用,引导学困生发挥自我转化的主体作用。

关键词：学困生苏霍姆林斯基转化策略启示

Misiurewicz points on the Mandelbrot-like set concerning renormalization transformation

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Science China Mathematics 2014年第12期57卷 2539-2548页

作者： GAO JunYang QIAO JianYong zhai yu School of Science China University of Mining and Technology School of Science Beijing University of Posts and Telecommunications

We study Misiurewicz points on the parameter space about a family of rational maps Tλ concerning renormalization transformation in statistical mechanic. We determine the intersection points of the Julia set J(Tλ) an... 详细信息

关键词： Julia set Mandelbrot set Misiurewicz points Hausdorff dimension transformation

Theoretical Study of the Molecular Electrostatic Potential of C_(50)

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Chinese Journal of Structural Chemistry 2006年第6期25卷 719-723页

作者： WANG Dong-Lai SHEN Hong-Tao zhai yu-Chun College of Materials and Metallurgy Northeastern University Shenyang 110004 China

Density functional theory （DFT） calculations on three lower energy isomers of C50 were carried out at the B3LYP/6-31G＊ level. Of the three isomers, two have D5h symmetry （a singlet state and a triplet state） and the other one has D3 symmetry. The optimized configurations and electrostatic potential distributions have been obtained. The calculated results show that potential minima Vmin（r） inside the sphere occur at the center of the sphere. The most negative value of the effective Mulliken atomic charge and the largest regions with the most negative MEP outside the sphere are localized in the neighborhood of pentagon-pentagon vertex fusions. They constitute the most probable active sites in chemical reactions. Our results offer a possible explanation for protonation and alkylation of C50 fullerene.

关键词： C50 fullerene electrostatic potential protonation