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Ultra fast microwave-assisted leaching for the recovery of copper and tellurium from copper anode slime

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International Journal of Minerals,Metallurgy and Materials 2015年第6期22卷 582-588页

作者： Zhi-yuan Ma Hong-ying Yang Song-tao Huang Yang lü liu Xiong School of Materials and Metallurgy Northeastern University National Engineering laboratory of Bio-hydrometallurgy General Research Institute for Nonferrous Metals

The decomposition of copper anode slime heated by microwave energy in a sulfuric acid medium was investigated. leaching experiments were carried out in a multi-mode cavity with microwave assistance. The leaching process parameters were optimized using response surface methodology（RSM）. Under the optimized conditions, the leaching efficiencies of copper and tellurium were 99.56% ± 0.16% and 98.68% ± 0.12%, respectively. Meanwhile, a conventional leaching experiment was performed in order to evaluate the influence of microwave radiation. The mechanism of microwave-assisted leaching of copper anode slime was also investigated. In the results, the microwave technology is demonstrated to have a great potential to improve the leaching efficiency and reduce the leaching time. The enhanced recoveries of copper and tellurium are believed to result from the presence of a temperature gradient due to the shallow microwave penetration depth and the superheating at the solid-liquid interface.

关键词： copper anode slime leaching microwave heating sulfuric acid response surface experiments

Hopf-flip bifurcation of high dimensional maps and application to vibro-impact systems

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Acta Mechanica Sinica 2005年第4期21卷 402-410页

作者： Jianhua Xie Wangcai Ding E.H. Dowell l. N. Virgin Department of Applied Mechanics and Engineering Southwest Jiaotong University Chengdu 610031 China School of Mechanical Engineering Lanzhou Jiaotong UniversityLanzhou 730070 China School of Engineering.Duke University. Durham NC27708-0300USA

This paper addresses the problem of Hopf-flip bifurcation of high dimensional maps. Using the center manifold theorem, we obtain a three dimensional reduced map through the projection technique. The reduced map is further transformed into its normal form whose coefficients are determined by that of the original system. The dynamics of the map near the Hopf-flip bifurcation point is approximated by a so called “time-2τ^2 map” of a planar autonomous differential equation. It is shown that high dimensional maps may result in cycles of period two, tori T^1 （Hopf invariant circles）, tori 2T^1 and tori 2T^2 depending both on how the critical eigenvalues pass the unit circle and on the signs of resonant terms＇ coefficients. A two-degree-of-freedom vibro-impact system is given as an example to show how the procedure of this paper works. It reveals that through Hopf-flip bifurcations, periodic motions may lead directly to different types of motion, such as subharmonic motions, quasi-periodic motions, motions on high dimensional tori and even to chaotic motions depending both on change in direction of the parameter vector and on the nonlinear terms of the first three orders.

关键词： Maps Vibro-impact dynamics Hopf-flip bifurcation Torus Chaos

Can Talent Policies Attract Population Inflows?—An Empirical Analysis Based on Spatial Panel Modeling

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Journal of Systems Science and Information 2023年第6期11卷 726-744页

作者： Xiaohong JIN Jian XU Cuihong YANG Qingyun lü School of Economics and Management University of Chinese Academy of SciencesBeijing 100049China Academy of Mathematics and Systems Sciences Chinese Academy of SciencesBeijing 100190China School of Economics and Management University of Chinese Academy of Sciences School of Business The University of WarwickCoventry CV48UWUnited Kingdom

To analyze the spatial influence mechanism of talent policy on population flow, this study compares the government work reports of 31 provinces between 2008 and 2020, and quantifies regional talent policies in nine aspects, including talent evaluation and incentives, utilizing a comprehensive, standardized, and continuous approach. Additionally, this paper develops a spatial econometric analysis model and expands on the conventional neighborhood, distance, and economic matrices by constructing a spatial weight matrix that reflects talent flow. The findings indicate that population movement exhibits spatial clustering patterns. The regional government's talent policy, primarily based on talent evaluation and incentives, positively influences population inflow. Moreover, during the implementation of talent policies, local governments demonstrate cooperative relationships. The inter-regional spillover effect between talent evaluation and talent incentives is significantly positive. In other words, a stronger local talent evaluation policy, along with robust talent incentives, encourages population inflow from neighboring provinces. However, this conclusion may vary in different regions and over time. Recently, the spatial spillover effect of population inflow and the impact of talent policies have not shown significant results. Additionally, the attractiveness of talent evaluation in the eastern region surpasses that of talent incentives, while the opposite holds true for the central and western regions. This study investigates the impact of local government talent policies on population inflow and its spatial spillover effect, offering theoretical support for intergovernmental cooperation.

关键词： talent policy population mobility spatial econometric modeling

Randomized controlled trials in frontotemporal dementia: cognitive and behavioral outcomes

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Translational Neurodegeneration 2014年第1期3卷 89-97页

作者： Justin B Miller Sarah J Banks Gabriel C léger Jeffrey l Cummings Cleveland Clinic Lou Ruvo Center for Brain Health888 W.Bonneville AveLas VegasNevada 89106USA

Progress has been made in understanding the genetics and molecular biology of frontotemporal dementia(FTD).Targets for intervention have been identified,therapies are being developed,and clinical trials are advancing.A major challenge for FTD research is that multiple underlying pathologies can be associated with heterogeneous *** neuropsychological profiles associated with FTD spectrum disorders often include executive dysfunction,language impairments and behavioral *** variant FTD is characterized by an initial presentation of changes in personality,behavior and/or emotion,which are often difficult to objectively capture using traditional neuropsychological *** two principal language variants of FTD are Progressive Nonfluent Aphasia(PNFA)with predominant agrammatic/non-fluent impairments and Semantic Dementia(SD)with semantic impairments and visual *** of appropriate endpoints for clinical trials is critical to ensure that the measures are adequately sensitive to detect change,yet specific enough to isolate signal from noise,and acceptable to regulatory *** the anticipated potential for small effect sizes,measures must be able to identify small incremental changes over *** is also imperative that the measures provide adequate coverage of the constructs or behaviors of *** outcome measures should be suitable for repeat administration,yet relatively robust to practice effects to ensure that observed changes reflect true signal variance and not residual effects due to repeated measurement or poor *** facilitate widespread adoption as an endpoint,measures should be readily *** provide several examples of potential global,composite,and individual cognitive measures,as well as behavioral measures promising for FTD *** and application of appropriate trial outcomes is critically important to success in advancing new treatments for FTD patients.

关键词： Frontotemporal dementia Primary endpoints Secondary endpoints Randomized controlled trial Methods

Utilization of clean energy and future trend of Antarctic research stations

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Advances in Polar Science 2021年第3期32卷 185-194页

作者： lI Zhao lÜDongxiang SUN Zilu lI Chuan The 18th Research Institute of China Electronics Technology Group Corporation Tianjin 300384China

The polar regions are rich in resources with high scientific *** scientific research is of great significance to natural environment,climate,astronomy and *** scientific research is closely related to polar energy *** research stations still use fossil fuels as the main source of power *** kind of power supply not only pollutes the environment,but also consumes a lot of manpower and material *** a kind of renewable energy such as solar energy and wind energy,renewable energy not only has the characteristics of sustainable development,but also has the characteristics of local power generation and transportation cost *** present,several countries have started the construction and application of polar renewable energy,and achieved good results in some Antarctic *** on the investigation and summary of the application of renewable energy in various countries,this paper discusses the development trend of polar energy supply in the future,and provides a clear idea and direction for the development of polar renewable energy.

关键词： Antarctic research station renewable energy wind power solar power

Unexpected creep behavior in a rejuvenated metallic glass

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Journal of Materials Science & Technology 2023年第32期163卷 140-149页

作者： J.P.Wu Y.lin F.H.Duan Q.Chen H.T.Wang N.li J.l.Wen J.Pan l.liu Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China State Key laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China laboratory of Nanomaterials&Nanomechanics Department of Mechanical EngineeringCity University of Hong KongHong KongChina Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074China Shenzhen Polytechnic Shenzhen 518055China

Rejuvenation,bringing metallic glasses(MGs)to the younger and higher energy states,provides an alternative avenue to explore the interplay between the property and microstructures of *** this study,the creep behavior of the Zr_(69.5)Cu_(12)Ni_(11)Al_(7.5)MGs was experimentally examined by controlling the energy state in terms of structural rejuvenation and thermal *** is found that compared to the as-cast counterpart,the annealed MG at a lower energy state exhibits a higher hardness,a smaller displacement,and a lower creep rate due to the decreased free volume and the inhibited activation of the shear transformation ***,the rejuvenated MG at a high energy state displays lower hardness and increased free volume content,yet it demonstrates superior creep resistance compared to its as-cast counterpart,which deviates from conventional *** unexpected phenomenon occurs as the initial high-content free volume annihilates during creep,and strain hardening takes precedence over strain softening as the prevailing process during creep deformation,leading to a superior creep performance in extremely rejuvenated MGs.

关键词： Metallic glass Energy state Rejuvenation Creep Strain-hardening

Effective Dielectric Properties of an Array of Multishell Carbon Nanotubes

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Chinese Physics letters 2001年第8期18卷 1129-1131页

作者： lÜ Wen-Gang WANG Rong-Zhou DONG Jin-Ming National laboratory of Solid State Microstructures and Department of Physics Nanjing UniversityNanjing 210093

Using a photonic band calculation method,we calculate the effective dielectric function of an array of carbon nanotubes which have a simple equivalent isotropic dielectric *** results for the equivalent dielectric function and for the local graphite-like dielectric tensor are found to be almost the *** a fixed outer diameter of the nanotubes to be 10 nm and a fixed distance between them to be 10.3 nm,we investigate the effect of the hollow core and found that the ratio of the inner to the outer radii is approximately larger than *** taking a large ratio of 0.58,the theoretical results are improved greatly and can describe the experimental data very well.

关键词： dielectric outer function

A new green process for biodiesel production from waste oils via catalytic distillation using a solid acid catalyst-Modeling, economic and environmental analysis

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Green Energy & Environment 2016年第1期1卷 62-74页

作者： Aashish Gaurav Flora T.T.Ng Garry l.Rempel Department of Chemical Engineering University of Waterloo

The challenges in the chemical processing industry today are environmental concerns, energy and capital costs. Catalytic distillation(CD) is a green reactor technology which combines a catalytic reaction and separation via distillation in the same distillation column. Utilization of CD in chemical process development could result in capital and energy savings, and the reduction of greenhouse gases. The efficacy of CD and the economic merits, in terms of energy and equipment savings, brought by CD for the production of biodiesel from waste oil such as yellow grease is quantified. Process flow sheets for industrial routes for an annual production of 10 million gallon ASTM purity biodiesel in a conventional process(reactor followed by distillation) and CD configurations are modeled in Aspen Plus. Material and energy flows, as well as sized unit operation blocks, are used to conduct an economic assessment of each process. Total capital investment, total operating and utility costs are calculated for each process. The waste oil feedstock is yellow grease containing both triglyceride and free fatty acid. Both transesterification and esterification reactions are considered in the process simulations. Results show a significant advantage of CD compared to a conventional biodiesel processes due to the reduction of distillation columns, waste streams and greenhouse gas emissions. The significant savings in capital and energy costs together with the reduction of greenhouse gases demonstrate that process intensification via CD is a feasible and new green process for the biodiesel production from waste oils.

关键词： Yellow grease Catalytic distillation Aspen plus economic analyzer Process intensification

High-Temperature Thermodynamic Investigation of Nano-Dispersed Nitrides Obtained in Thermal Plasma

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Plasma Science and Technology 2007年第2期9卷 174-176页

作者： M. GEORGIEVA G. VISSOKOV Iv. GRANCHAROV l. BRAKAlOV Department of Technology of Inorganic Substances University of Chemical Technology andMetal|urgy 8 K. Okhridski Blvd. 1756 Sofia Bulgaria

The nitrides of transient metals have a high hardness, thermal stability, remarkable wear resistance in aggressive chemical mediums, melted metals and alloys, high corrosion resistance, and low coefficient of electric resistance. Under the conditions of low-temperature argon plasma （lTP）, thermodynamic investigations were conducted in the process of obtaining of A1N, TiN and Si3N4 in a temperature range of 1000 K to 6000 K. To investigate the thermodynamic possibility of obtaining nitrides, a computer model was used which provided the equilibrium composition of gaseous and solid phases at different temperatures. The conditions for chemical equilibrium of the system were based on the minimization of Gibbs＇ energy.

关键词： plasma-chemical treatment nitrides thermodynamic analysis