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Electrochemistry of Hf(Ⅳ)in NaCl-KCl-Na-K_(2)HfF_(6) molten salts

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International Journal of Minerals,Metallurgy and Materials 2020年第12期27卷 1644-1649页

作者： yan-ke Wu guo-qing yan Song Chen Li-jun Wang GRINM Resources and Environment Tech.Co. LtdBeijing 101407China

The cathodic reduction mechanism of Hf(Ⅳ)ions in a fused Na Cl–KCl–Na F–K_(2) HfF_(6) salt system was studied in various Na F concentrations at 1073 K to obtain a purified dendritic Hf *** results of cyclic voltammetry and square wave voltammetry indicated that the reduction process comprised two steps of Hf(Ⅳ)→Hf(Ⅱ)and Hf(Ⅱ)→Hf at low Na F concentrations(0

关键词： electrochemical behavior cyclic voltammetry potentiostatic electrolysis dendritic hafnium molten salts

Phase Separation and Transport Behavior in La_(0.67-x)Sm_xSr_(0.33)MnO_3 System

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Chemical Research in Chinese Universities 2005年第6期21卷 707-713页

作者： LIU Ning yan guo-qing XU Su-jun Department of Physics Suzhou College Suzhou 23400 P. R. China Structure Research Laboratory Science and Technology University of China Hefei 230026 P. R. China

The magnetic behavior and the transport behavior of La0.67-x Smx Sr0.33 MnO3 （x = 0. 00, 0. 10, 0. 20, 0. 30, 0. 40, 0. 50 and 0. 60 ） systems were studied through measuring the M-T curves, electron spin resonance （ ESR ） curves and ρ-T curves. The samples exhibit a long-range ferromagnetic order when x = 0. 00, 0. 10, a cluster-spin glass state when x = 0. 20 and 0. 30, and an anti-ferromagnetic state at low temperatures when x = 0. 40, 0. 50 and 0. 60. The samples of x = 0. 30 and 0.40 show phase separation at temperatures above Te. The transport behavior of the sample of x = 0. 60 becomes abnormal when the doping is high, and an insulator-metal transition occurs near To and then a metal-insulator transition occurs, which rarely appears in an ABO3 structure. It is concluded that the magnetic and electric behavior changes of the systems depend on the extra magnetism and lattice distortion effect induced by Sm doping.

关键词： Magnetic structure Phase separation Transport behavior Colossal magnetoresistance effect

Description of N=7～9 Isotones with a Modified Single-Particle Potential

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Communications in Theoretical Physics 2008年第12期50卷 1396-1400页

作者： guo yan-qing REN Zhong-Zhou CHEN Yu-qing Department of Physics Nanjing University Nanjing 210008 China Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator Lanzhou 730000 China Joint Center for Particle Nuclear Physics and Cosmology Nanjing 210008 China Department of Physics and Electronic Engineering Hanshan Normal University Chaozhou 521041 China

We study the level structures of N = 7 - 9 isotones and their mirror nuclei in the framework of the single-particle potential model. Considering the limitation of the conventional potential-model calculation, the isospindependent 12 coupling is newly introduced in the average potential. The modified model gives a unified description for the structures of all studied nuclei. Galculations self-consistently produce the s-d level inversion in N = 9 isotones and their mirror nuclei. Meanwhile, the s-p level inversion in the mirror nuclei ^11Be and ^11N is reproduced. The study confirms the neutron halo structures in ^11Be（2s1/2）, ^11Be（1p1/2）, ^12B（2s1/2）, ^14B（2s1/2）, ^13C（2sl/2）, ^15C（2s1/2） and the proton halo structure in ^17F（2s1/2）. The agreement between theory and experiment indicates that the inclusion of the i2 coupling is a feasible way to explain the abnormal structures of exotic light nuclei.

关键词： modified single-particle potential level inversion l^2 coupling

Properties of oxide coating on the surface of ZrH_(1.8) prepared by microarc oxidation with different positive voltages

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Rare Metals 2013年第2期32卷 169-173页

作者： guo-qing yan Wei-Dong Chen Xue-Kui Zhong Shu-Fang yan School of Materials Science and Engineering Inner Mongolia University of Technology

Zirconia coatings as hydrogen permeation barriers were formed on disktype ZrHj.s substrate speci mens in phosphate solution system by microarc oxidation technique. Influence of positive voltage on hydrogen per meation barriers on the surface of zirconium hydride was investigated as the main factor. The thickness of total oxide layer increased from 42.5 to 55.0 ~tm the increase of positive voltage increasing from 325 up to 425 V. The permeation reduction factor （PRF） was observed under different voltages, which increased with the increasing positive voltages. The phase structure of oxide layer was monoclinic Zr02 and tetragonal ZrO1.88. No reduction reaction occured in the process of hydrogen escaping, and it indicates that hydrogen permeation through oxide layer is restricted.

关键词： Zirconium hydride Hydrogen permeationbarrier Oxide layers Microarc oxidation technique

A Position-Dependent Two-Atom Entanglement in Real-Time Cavity QED System

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Communications in Theoretical Physics 2007年第1期47卷 59-62页

作者： guo yan-qing CAO Hai-Jing SONG He-Shan Department of Physics Dalian Maritime University Dalian 116026 China Department of Physics Dalian University of Technology Dalian 116023 China

We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent atomic resonant dipole-dipole interaction （RDDI） for large interatomic separation limit. We show that the RDDI, even t, hat which is much smaller than the maximal atomic Rabi frequency, can induce distinct diatom entanglement. The peak entanglement reaches a maximum when RDDI strength can compare with the Rabi frequency of an atom.

关键词： two-atom entanglement cavity QED RDDI

Solid solubility extension and microstructure evolution of cast zirconium yttrium alloy

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Rare Metals 2016年第4期35卷 325-330页

作者： Jia-qing Peng yang Chen guo-qing yan Ming Wu Li-Jun Wang Jing-She Li Division of Rare Metals Metallurgy and Materials General Research Institute for Nonferrous Metals School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

Yttrium addition can improve the oxidation resistance, mitigate hydrogen embrittlement and thus enhance the mechanical properties of the zirconium alloy. To study solid solubility extension of yttrium in zirconium alloy, the lattice parameters of ：t-Zr phase in Zr-Y alloy were accurately determined by X-ray diffraction （XRD）. Yttrium exhibits solid solubility extension in the cast zirconium alloy which forms a metastable supersaturated solid solution with solubility limit of around 3 wt%. The effect of yttrium and thermal treatment on the microstructure of the alloys was investigated by optical microscopy （OM） and scanning electron microscope （SEM）. The cast Zr-Y alloy shows a normal polycrys- talline structure with dispersed α-Y particles when Y content is lower than 4 wt%, while the alloy shows a eutectic structure with dendrites formation when the Y content is higher. Yttrium exhibits a strong grain refining effect on zirconium alloy and precipitates from the metastable supersaturated Zr matrix after annealing at 700 and 900 ℃.

关键词： Zirconium alloy Yttrium addition Solidsolubility extension Microstructure

Preparation of Al-Hf master alloy by aluminothermic reduction of HfO_(2)

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Rare Metals 2021年第12期40卷 3645-3650页

作者： Hai Liu Zhao-Hui Ma Jing-Cun Huang Jian-Dong Zhang guo-qing yan Li-Jun Wang Division of Rare Metals Metallurgy and Materials GRINM Group Corp.LtdGRIMAT Engineering Institute Co.LtdBeijing 100088China

The Al-Hf alloy was prepared by open aluminothermic reduction of HfO_(2) using CaF_(2) and Na F as the flux. The influence of the slag composition, the amount of aluminum, and the heat energizer was studied detailly to establish optimum conditions for the sufficient recovery of the alloy and the complete slag-alloy separation. The Al-Hf alloy with 40 wt% Hf was obtained by this method, and the maximum recovery was 70.7%. The microstructure of the alloy was observed by scanning electron microscope(SEM). Moreover, X-ray diffraction(XRD) analysis and energy-disperse spectrometry(EDS) were applied to characterize the formation of the phases. The results show that the alloy consists of Al and Al_(3)Hf phases and the oxygen content is about 0.2 wt%.

关键词： Al-Hf master alloy Aluminothermic reduction Hafnium oxide Slag-alloy separation

Hydrogen permeation resistance and characterization of Si–Al and Si–Zr composite sol oxide coating on surface of zirconium hydride

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Rare Metals 2017年第1期36卷 55-60页

作者： Ming Wu yang Chen Jia-qing Peng guo-qing yan Yu-Pu Sun Jian-Dong Zhang Shun-Li Zhang Li-Jun Wang Division of Rare Metals Metallurgy and Materials General Research Institute for Nonferrous Metals Beijing 100088 China

The hydrogen permeation resistance of Si–Zr(SZ) and Si–Al(SA) composite sol oxide coating on zirconium hydride blocks(Zr H) was studied. SZ and SA composite sol were prepared by sol–gel method. SZ and SA composite oxide coatings were prepared on the surface of Zr H(in situ oxidized or not) in turns by dip-coating and heat treatment. Hydrogen permeation of Zr Hwith and without composite oxide coating was *** desorption experiments in thermal vacuum show that hydrogen permeation resistance of SA composite oxide coating is better than that of SZ, to a certain extent,which could decrease hydrogen thermal loss. Experimental results in the working condition show that the SA composite oxide coating can not only prevent hydrogen permeation, but also retard contact and reaction between COand Zr Hmatrix, which could mitigate excessive oxidation of in situ oxide film. Differential scanning calorimetry and thermogravimetry(DSC–TG) analysis was performed to investigate the decomposition behavior of SA and SZ liquid sol in heat treatment process. X-ray diffraction(XRD) and scanning electron microscopy(SEM) analysis were employed to characterize the phase composition,surface and cross-section morphology of the coatings.

关键词： Zirconium hydride Hydrogen permeation resistance Composite oxide coating Si–Zr Si–Al Sol–gel

Abnormal electric transport property and magnetoresistance stability of La-Sr-K-Mn-O system

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Rare Metals 2013年第3期32卷 258-263页

作者： Yong-Gang Tang Gui-Ying Wang guo-qing yan Qi-Xiang Song Ming-Yu Zhang Zhen-Sheng Peng Cultivating Base of Anhui Key Laboratory of Spintronics and Nano-materials Research School of Mechanical and Electronic Engineering Suzhou University

The perovskite samples La1-x（Sr1-yKy）xMnO3 （y = 0.0, 0.2, 04, 0.6, 0.8） were prepared by the solid-state reaction method with comparatively low sintering tem- perature and with comparatively short sintering time, and the electric transport property and temperature stability of MR of this system were studied. The p-T curves show the abnormal phenomenon that with the increase of K doping amount, resistivity increases, and the insulator-metal transition temperature decreases, which is because the influence of the occupation disorder degree of A-site ions σ2 on the electric transport property of perovskite manga- nites is larger than that of the radius of A-site ions （rA）. In the temperature range below 225 K, MR increases contin- uously with the decrease of temperature, which is the characteristic of low-field magnetoresistance; in the com- paratively wide temperature range near 250 K, the MR- T curves of all the samples are comparatively fiat, and the value of MR almost does not change with temperature, which shows the temperature stability of magnetoresis- tance, and can be explained by the competition between the low-field magnetoresistance induced by spin-dependent tunneling of surface phase and the intrinsic magnetoresis- tance of grain phase. The magnetoresistance value of the sample with y = 0.8 keeps at （7.92 ±0.36） % in the very wide temperature range of 225-275 K, and this is a goodreference for the preparation of this kind of sample with practical application value in the future.

关键词： Keywords Magnetoresistance K doping Disorder degree σ2 Electric transport property