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Preparation of Mn_3O_4 from low-grade rhodochrosite ore by chemical bath deposition method

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Chinese Journal Of Geochemistry 2015年第1期34卷 55-61页

作者： Jing Zhao Longjun Xu Taiping xie chao xie State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University School of Environmental Protection and Safety Engineering University of South China

Mn3O4was prepared with the chemical bath deposition(CBD) method. A Mn SO4 solution was obtained by the leaching and purifying of low-grade rhodochrosite ore(LGRO), which was used as raw material. The prepa ration procedures were studied and promoted. The result showed that the Mn3O4 with the highest purity and highes specific surface area could be obtained under the following processes. An Mn SO4 solution of 1.0 mol/L was added into a beaker under a flow rate of 30 m L/h. The p H of the reaction solution was adjusted to 10 using NH3 H2 O a80 °C. Then the solids were washed and dried at 200 °C fo2.5 h. The total Mn content(TMC) of Mn3O4 was 72.0 %The ionic distributions was formulated as [Mn2?[Mn2??0.3024Mn30.2937Mn4?h0.37860.0254]2O4. The average crys tallite size of Mn3O4 with a tetragonal hausmannite struc ture was found to be about 35 nm by X-ray diffraction(XRD) analysis. The BET specific surface area of the Mn3O4 measured was 32 m2/g.

关键词：四氧化三锰化学浴沉积法低品位矿石碳酸锰矿石制备硫酸锰溶液比表面积平均晶粒尺寸

Sign-changing Solutions to Nonlinear Elliptic Equations with Hardy Potential and Critical Parameter in R^2

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Acta Mathematicae Applicatae Sinica 2019年第3期35卷 689-694页

作者： chao-dong xie Zhi-hui CHEN School of Economics&Management Guizhou University for Ethinic MinoritiesGuizhou 550025China chool of Mathematics South China University of TechnologyGuangzhou 510640China

In this paper,a new Hilbert space is defined which is embedded into W01,q(Ω)for 1≤q<*** using sign-changing critical point theory,we prove the existence of infinitely many sign-changing solutions in this new space f... 详细信息

关键词： elliptic PDE sign-changing solution critical point

Size Effect of a Negatively Charged Exciton in a Two-Dimensional Quantum Dot

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Communications in Theoretical Physics 2009年第2期51卷 353-357页

作者： LIU chao xie Wen-Fang Department of Physics Guangzhou University Guangzhou 510006 China

In this paper we study a negatively charged exciton （NCE）, which is trapped by a two-dimensional （2D） parabolic potential. By using matrix diagonalization techniques, the correlation energies of the low-lying states with L=0, 1, and 2 are calculated as a function of confinement strength. We find that the size effects of different states are different. This phenomenon can be explained as a hidden symmetry, which is originated purely from symmetry. Based on symmetry, the features of the low-lying states are discussed in the influence of the 2D parabolic potential well. It is found that the confinement may cause accidental degeneracies between levels with different low-excited states. It is shown that the effect of quantum confinement on the binding energy of the heavy hole is stronger than that of a light hole.

关键词： quantum dot charged exciton size effect energy spectrum symmetry

Preparation of chemical manganese dioxide from low-grade rhodochrosite ore

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Chinese Journal Of Geochemistry 2013年第4期32卷 380-384页

作者： ZHAO Jing XU Longjun xie chao State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University School of Environmental Protection and Safety Engineering University of South China

The preparation of chemical manganese dioxide(CMD) from low-grade rhodochrosite ore(LGRO) in Xiushan,Chongqing,was studied and improved,including leaching with sulfuric acid,purifying,crystallizing and decomposing of MnCO3,and refining of primary *** product was characterized by X-ray *** results showed that the extraction ratio,the manganese recovery ratio of purifying,crystallization and refining reached 96.8%,93.9%,97.7%and 85.4%,*** optimum conditions of refining were described as follows:liquid(H2SO4)/solid(primary MnO2) ratio was 3 L/g,the concentrations of NaClO exceeded 20%,and reaction time was 3 *** the above conditions,the contents of MnO2and Mn in the obtained manganese dioxide were respectively 85.1%and 53.9%.The refined MnO2can be used as the super grade manganese dioxide mine powder in chemical *** XRD indicated that the structure of the product wasγ-MnO2.

关键词：化学二氧化锰菱锰矿低品位制备 X-射线衍射 H2SO4 锰回收率 MnO2

Derivative Formula and Coupling Property for Linear SDEs Driven by Lévy Processes

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Acta Mathematicae Applicatae Sinica 2019年第4期35卷 708-721页

作者： Zhao DONG Yu-lin SONG Ying-chao xie Institute of Applied Mathematics Academy of Mathematics and Systems Sciences Chinese Academy of Sci- ences Beijing 100190 China School of Mathematical Sciences Beijing Normal University Beijing 100875 China School of Mathematics and Statistics Jiangsu Normal University Jiangsu Province Xuzhou 221116 China

In this paper we investigate an integration by parts formula for Lévy processes by using lower bound conditions of the corresponding Lévy measure. As applications, derivative formula and coupling property are derive... 详细信息

关键词： Lévy processes integration by parts formula derivative formula coupling property

Recent advances in defect electrocatalysts: Preparation and characterization

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Journal of Energy Chemistry 2021年第2期30卷 208-225,I0008页

作者： Zhaohui Xiao chao xie Yanyong Wang Ru Chen Shuangyin Wang State Key Laboratory of Chem/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082HunanChina

the types and strategies used to prepare defect electrocatalysts will continue to be studied and developed as new defective materials are generated.4. Characterization of defectsThis review briefly summarizes recent progress in defect electrocatalysts, and the synthesis strategies and characterization techniques for defects are systematically discussed. Although challenges in the characterization of defect structures in the electrocatalytic reaction process remain, the dynamic evolution of defect sites is predicted to be helpful for designing and preparing high-performance electrocatalysts for commercial applications. Furthermore, due to an insufficient understanding of the defect-structureproperty relationships, future possibilities for the reasonable design of defect electrocatalysts to obtain desirable performance are suggested.

关键词： Defect Electrocatalysts Vacancies Heteroatom doping

Effect of curing humidity on performance of cemented paste backfill

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International Journal of Minerals,Metallurgy and Materials 2020年第8期27卷 1046-1053页

作者： Di Wu Run-kang Zhao chao-wu xie Shuai Liu School of Energy and Mining Engineering China University of Mining and Technology-BeijingBeijing 100083China

Cemented paste backfill(CPB),a mixture of tailings,binder,and water,is widely and extensively used for the recovery of mineral resources,the prevention of ground subsidence,and the management of mine *** installed,the CPB is subjected to complex environmental conditions such as water content,temperature,and power,which have a significant impact on its ***,this study conducts a series of laboratory programs,including investigation of moisture,temperature,stress–strain relation,and microstructure to show the effect of curing humidity on the CPB *** results obtained indicate that ambient humidity can have a dramatic effect on CPB in terms of its macro performance of internal relative humidity,temperature and strength,as well as the micro *** examples of these effects on CPB include an increase in curing humidity,which favors binder hydration,and then an increase in hydration materials,temperature and peak stress in the *** results obtained will lead to a better understanding of CPB’s responses to various environmental conditions.

关键词： cemented paste backfill curing humidity temperature microstructure

Stress-corrosion coupled damage localization induced by secondary phases in bio-degradable Mg alloys:phase-field modeling

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Journal of Magnesium and Alloys 2024年第1期12卷 361-383页

作者： chao xie Shijie Bai Xiao Liu Minghua Zhang Jianke Du The Faculty of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211P.R.China Key Laboratory of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province Hunan University of Science and TechnologyXiangtan 411201P.R.China

In this study,a phase-field scheme that rigorously obeys conservation laws and irreversible thermodynamics is developed for modeling stress-corrosion coupled damage(SCCD).The coupling constitutive relationships of the deformation,phase-field damage,mass transfer,and electrostatic field are derived from the entropy *** SCCD localization induced by secondary phases in Mg is numerically simulated using the implicit iterative algorithm of the self-defined finite *** quantitative evaluation of the SCCD of a C-ring is in good agreement with the experimental *** capture the damage localization,a micro-galvanic corrosion domain is defined,and the buffering effect on charge migration is *** cases are investigated to reveal the effect of localization on corrosion acceleration and provide guidance for the design for resistance to SCCD at the crystal scale.

关键词： Phase field Mg alloys Stress-corrosion coupled damage Damage localization Finite element method

Tuning heat transport via coherent structure manipulation:recent advances in thermal turbulence

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National Science Review 2023年第6期10卷 245-257页

作者： Ke-Qing Xia Shi-Di Huang Yi-chao xie Lu Zhang Center for Complex Flows and Soft Matter Research and Department of Mechanics and Aerospace Engineering Southern University of Science and Technology State Key Laboratory for Strength and Vibration of Mechanical Structures and School of Aerospace Xi'an Jiaotong University

Tuning transport properties through the manipulation of elementary structures has achieved great success in many areas,such as condensed matter ***,the ability to manipulate coherent structures in turbulent flows is much less *** article reviews a recently discovered mechanism of tuning turbulent heat transport via coherent structure *** first show how this me chanism can be realized by applying simple geometrical confinement to a classical thermally driven turbulence, which leads to the condensation of elementary coherent structures and significant heat-transport enhancement,despite the resultant slower *** potential applications of this new paradigm in passive heat management are also *** then explain how the heat transport behaviors in seemingly different turbulence systems can be understood by this unified framework of coherent structure *** future directions in this research area are also outlined.

关键词： coherent structure turbulent flow heat transport geometrical confinement dynamical constraint