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基于黏性蒸馏-气相分离的冶金级粗碲提纯方法

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Transactions of Nonferrous Metals Society of China 2024年第3期34卷 1037-1048页

作者：黄大鑫蒋文龙徐宝强查国正杨斌昆明理工大学真空冶金国家工程研究中心昆明650093 昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室昆明650093 昆明理工大学冶金与能源工程学院昆明650093

开发一种基于黏性蒸馏-气相分离的高纯碲材料制备方法。通过调节冷凝器结构和冷凝温度,达到黏性蒸馏、控制碲优势冷凝区的目的,使挥发性差的物质留在残留物中,而硒在气相中与碲分离,实现冶金级粗碲的提纯。研究饱和蒸气压、碲分子平均... 详细信息

开发一种基于黏性蒸馏-气相分离的高纯碲材料制备方法。通过调节冷凝器结构和冷凝温度,达到黏性蒸馏、控制碲优势冷凝区的目的,使挥发性差的物质留在残留物中,而硒在气相中与碲分离,实现冶金级粗碲的提纯。研究饱和蒸气压、碲分子平均自由程、不同冷凝位置的杂质分布特征以及冷凝物形貌。500 g级的实验结果表明,在5 Pa、773 K和90 min的最佳实验条件下,碲的直收率为83.40%,纯度高于99.9996%,碲优势冷凝区冷凝物中硒含量降低至2.76×10^(-4)%(质量分数)。

关键词：高纯碲除硒提纯平均自由程优势冷凝区

Application of vacuum distillation in refining crude indium

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Rare Metals 2013年第6期32卷 627-631页

作者： Wen-Long Jiang Yong Deng Bin Yang Da-Chun Liu Yong-Nian Dai bao-qiang xu The National Engineering Laboratory for Vacuum Metallurgy Kunming University of Science and Technology State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province Yunnan Provincial Key Laboratory of Nonferrous Vacuum Metallurgy

Vacuum distillation is a technique suitable for low boiling and melting point materials,to remove the heavy and low vapor pressure impurities at low *** indium has low melting point and high boiling point,it is suitable for refining by vacuum ***,saturation vapor pressure for major elements in crude indium was calculated by the Clausius–Clay Prang equation,which could approximately predict the temperature and pressure during vacuum distillation ***,the activity coefficients for In–Cd,In–Zn,In–Pb,In–Tl at 1373 K,and In–Sn at 1573 K were acquired by means of molecular interaction on volume ***–liquid equilibrium composition diagrams of those above systems in crude indium were drawn based on activity *** diagrams could estimate the compositions of products in each process during the refinement of crude ***,1.2–1.6 ton crude indium was used per day when vacuum distillation experiments were carried out,and experimental results are in good agreement with the predicted values of the vapor–liquid equilibrium composition diagrams.

关键词： Vacuum distillation Crude indium Vapor–liquid equilibrium

Theoretical research on vacuum separation of Au-Ag alloy

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Transactions of Nonferrous Metals Society of China 2022年第8期32卷 2719-2726页

作者： Shuang-ping WANG Jin-yang ZHAO bao-qiang xu Ling-xin KONG Wen-long JIANG Bin YANG National Engineering Research Center for Vacuum Metallurgy Kunming University of Science and TechnologyKunming 650093China Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China

To provide an accurate prediction of the product component dependence of temperature and pressure in vacuum distillation and give convenient and efficient guidance for the designing of the process parameters of industrial production, according to the molecular interaction volume model(MIVM), the separation coefficient(β) and vapor-liquid equilibrium composition of Au-Ag alloy at different temperatures are calculated. Combined with the vapor-liquid equilibrium(VLE) theory, the VLE phase diagrams, including the temperature-composition(T-x) and pressure-composition(p-x) diagrams of Au-Ag alloy in vacuum distillation are plotted. The triple points and condensation temperatures of gold and silver vapors are calculated as well. The results show that the β decreases and the contents of gold in vapor phase increase with the distillation temperature increasing. Low pressures have positive effect on the separation of Ag and Au. The difference between the condensation temperatures of gold and silver is about 450 K in the pressure range of 1-10 Pa.

关键词： Au-Ag alloy vacuum separation molecular interaction volume model(MIVM) vapor-liquid equilibrium(VLE)phase diagram condensation temperature

Improved mass relations of mirror nuclei

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Nuclear Science and Techniques 2024年第9期35卷 178-185页

作者： Cheng xu Man bao Department of Physics University of Shanghai for Science and TechnologyShanghai 200093China

In this study,we revisit the previous mass relations of mirror nuclei by considering 1/N-and 1/Z-dependent terms and the shell effect across a *** root-mean-squared deviation is 66 keV for 116 nuclei with neutron number N≥10,as com-pared with experimental data compiled in the AME2020 *** predicted mass excesses of 173 proton-rich nuclei,including 98 unknown nuclei,are tabulated in the Supplemental Material herein with competitive accuracy.

关键词： Nuclear mass Mirror nuclei Proton-rich nuclei

Production of magnesium during carbothermal reduction of magnesium oxide by differential condensation of magnesium and alkali vapours

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Journal of Magnesium and Alloys 2013年第4期1卷 323-329页

作者： Cheng-bo Yang Yang Tian Tao Qu Bin Yang bao-qiang xu Yong-nian Dai National Engineering Laboratory for Vacuum Metallurgy Kunming University of Science and TechnologyKunming 650093China Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province Kunming 650093China State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province Kunming 650093China

Most of researchers believed that the developments on the condensation of magnesium produced by carbothermic reduction just concentrated on two process routes:the“quench”route and the“solvent”*** this paper will briefly analyzes the major challenges in magnesium vapor condensation during the vacuum carbothermic reduction of calcined dolomite,on equipment upgrade,heat transfers alter,to achieve condensation control and production *** are then proposed using theoretical calculations and experiment *** analysis of the experiment results shows that the burning and even explosion of condensation products during the vacuum carbothermic reduction of calcined dolomite are mainly due to the burning of crystallized powder magnesium,which results from the self-ignition of alkali ***,this paper proposes a multistage condensation solution to improve traditional vacuum condensation *** result show that the condensation equipment can effectively mitigate the burning and loss during condensation,also the morphology of the condensation products clearly improved,the grain size increased,and the oxidation rate *** potassium/sodium vapor and the magnesium vapor were separately condensed.

关键词： Carbothermic reduction Calcined dolomite Magnesium vapor Condensation

Analysis of the behavior of magnesium and CO vapor in the carbothermic reduction of magnesia in a vacuum

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Journal of Magnesium and Alloys 2014年第1期2卷 50-58页

The aim of this paper is to experimentally investigate the behavior of magnesium and carbon monoxide vapor in the carbothermic reduction of magnesia at condensing zone temperatures ranging from 923 K to 1223 *** phase,surface morphology,and composition of the condensates obtained were examined by means of scanning electron microscopy and energy-dispersive X-ray *** main findings of this paper include:the reverse reaction products,carbon and magnesium oxide,were formed following the process of magnesium vapor condensation,preventing two metal clusters from mutually ***,the nearer the temperature of the condensation zone approached the liquid transformation temperature(810-910 K),the lower the rate of the reverse reaction between carbon monoxide and magnesium *** in the rate of the reverse reaction of magnesium was possible by controlling the condensation temperature.

关键词： Carbon monoxide Magnesium vapor Carbothermic reduction CondensationVacuum

An Online Q-Learning Method for Linear-Quadratic Nonzero-Sum Stochastic Differential Games with Completely Unknown Dynamics

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Journal of Systems Science & Complexity 2024年第5期37卷 1907-1922页

作者： ZHANG bao-qiang WANG Bing-Chang CAO Ying School of Control Science and Engineering Shandong University

In this paper, the authors design a reinforcement learning algorithm to solve the adaptive linear-quadratic stochastic n-players non-zero sum differential game with completely unknown dynamics. For each player, a critic network is used to estimate the Q-function, and an actor network is used to estimate the control input. A model-free online Q-learning algorithm is obtained for solving this kind of problems. It is proved that under some mild conditions the system state and weight estimation errors can be uniformly ultimately bounded. A simulation with five players is given to verify the effectiveness of the algorithm.

关键词： Actor-critic algorithm model-free adaptive control nonzero-sum stochastic game reinforcement learning

Theoretical analysis and experimental verification of thermal decomposition mechanism of CuSe

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Transactions of Nonferrous Metals Society of China 2022年第10期32卷 3478-3486页

作者： Huan LUO Heng XIONG Wen-long JIANG Lang LIU Guo-zheng ZHA Tian-tian ZHEN Bin YANG bao-qiang xu National Engineering Research Center of Vacuum Metallurgy Kunming University of Science and TechnologyKunming 650093China Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Yunnan Provincial Key Laboratory for Nonferrous Vacuum Metallurgy Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of Complex Non-Ferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China

Experiments on the thermal decomposition of CuSe were carried out by using a thermogravimetric analyzer(TGA)at different heating *** kinetic parameters and mechanisms were discussed based on model-free and model-based *** decomposition rate and decomposition behavior of CuSe were investigated by using a vacuum thermogravimetric *** results showed that the R3 model was identified as the most probable mechanism function under the present experimental *** average values of activation energy and the pre-exponential factor were 12.344 J/mol and 0.152 s^(−1),*** actual decomposition rate of CuSe was found to be 0.0030 g/(cm^(2)·min).

关键词： CuSe thermal decomposition non-isothermal kinetics mechanism

Magnesium production by carbothermic reduction in vacuum

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Journal of Magnesium and Alloys 2015年第2期3卷 149-154页

作者： Yang Tian bao-qiang xu Bin Yang Cheng-b Yang Tao Qu Da-chun Liu Yong-nian Dai National State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization Kunming University of Science and TechnologyKunming 650093China National Engineering Laboratory for Vacuum Metallurgy Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Non-Ferrous Metals Vacuum Metallurgy of Yunnan Province Kunming 650093China College of Metallurgy and Energy Engineering Kunming University of Science and TechnologyKunming 650093China

In present work,we investigate production of magnesium by carbothermic reduction under vacuum *** process was divided into two parts,one is reduction process,and the other one is condensation *** experimental results revealed that during reduction process,the gas-solid reaction between MgO and CO was not occurred at a temperature and pressure of 1723 K and 30-100 Pa *** the main reduction reaction was MgO(_(s))+C(_(s))=Mg(_(g))+CO(_(g))(under vacuum)and reaction type belonged to solid-solid *** Condensation Process,according to a contrast and analysis,the condensation quality of magnesium is associated with CO *** resultant product C was formed and it followed magnesium vapor condensation which prevents mutual combination of two metal droplets to forms the compact condensation ***,in order to compact morphological forms of magnesium crystal whiskers,we must control the technical conditions and find the method to separate the magnesium vapor and carbon ***'s the key factor to get better crystalline structure.

关键词： Metal magnesium Carbothermic reduction Condensation Vacuum