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Kinetics of iron removal from metallurgical grade silicon with pressure leaching

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Rare Metals 2011年第6期30卷 688-694页

作者： yu Zhanliang XIE Keqiang MA Wenhui ZHOU Yang XIE Gang DAI Yongnian National Engineering Laboratory for Vacuum Metallurgy Kunming University of Science and Technology Kunming 650093 China Technology Center of yunnan Metallurgy Group Co. Kunming 650031 China Kunming Metallurgy Research Institute Kunming 650031 China

In this paper, the kinetics of pressure leaching for purification of metallurgical grade silicon with hydrochloric acid was investigated. The effects of particle size, temperature, total pressure, and concentration of hydrochloric acid on the kinetics and mechanism of iron removal were studied. It was found that the reaction kinetic model followed the shrinking core model, and the apparent activation energy of the leaching reaction was 46.908 kJ/mol. And the apparent reaction order of iron removal with pressure leaching was 0.899. The kinetic equation was obtained and the mathematical model of iron removal from metallurgical grade silicon （MG-Si） was given as follows：The values calculated from the equation were consistent with the experimental results.

关键词： metallurgical physics and chemistry kinetics pressure leaching metallurgical grade silicon iron removal

Approximate analytical solutions for threedimensional ascent trajectory of a solid-fuel launch vehicle with time-varying mass flow rate

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Chinese Journal of Aeronautics 2024年第10期37卷 275-293页

作者： Qi yu Wanchun CHEN Wenbin yu School of Astronautics Beihang UniversityBeijing 102206China

In the scenario that a solid-fuel launch vehicle maneuvers in outer space at high angles of attack and sideslip for energy management,Approximate Analytical Solutions(AAS)for the threedimensional(3D)ascent flight states are derived,which are the only solutions capable of considering time-varying Mass Flow Rate(MFR)at *** uneven MFR makes the thrust vary nonlinearly and thus increases the difficulty of the problem *** AAS are derived based on a 3D Generalized Ascent Dynamics Model(GADM)with a normalized mass as the independent *** simplify some highly nonlinear terms in the GADM,several approximate functions are introduced carefully,while the errors of the approximations relative to the original terms are regarded as minor ***,a finite series with positive and negative exponents,called Exponent-Symmetry Series(ESS),is proposed for function approximation to decrease the highest exponent in the AAS so as to reduce computer round-off *** calculate the ESS coefficients,a method of seeking the Optimal Interpolation Points(OIP)is proposed using the leastsquares-approximation *** to the artful design of the approximations,the GADM can be decomposed into two analytically solvable subsystems by a perturbation method,and thus the AAS are obtained ***,to help implement the AAS,two indirect methods for measuring the remaining mass and predicting the burnout time in flight are put forward using information from *** results verify the superiority of the AAS under the condition of time-varying MFR.

关键词： Approximate analytical solutions 3D ascent trajectory Solid-fuel launch vehicle Uneven thrust Energy management

Low-melting mixture solvents: extension of deep eutectic solvents and ionic liquids for broadening green solvents and green chemistry

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Green Chemical Engineering 2024年第4期5卷 409-417页

作者： yu Chen Zhiwu yu MOE Key Laboratory of bioorganic Phosphorous Chemistry and Chemical biology Department of ChemistryTsinghua University

Green solvents such as water and ionic liquids(ILs) are pillars of the great mansion of green chemistry and green processing. Initially proposed as a new family of ILs,deep eutectic solvents(DESs) have received fast development in the past two decades. In this contribution,DESs are reviewed critically and the concept is extended to lowmelting mixture solvents(Lo MMSs),which cover all kinds of materials including ionic compounds,molecular compounds,and metals. Six classes of Lo MMSs are proposed as the new classification system and examples are given. Finally,several thermodynamic issues concerning Lo MMSs are discussed. Two new concepts,robustness of Lo MMSs and high-entropy Lo MMSs,are proposed.

关键词： Green solvents Deep eutectic solvents Low transition temperature mixture solvents Phase diagram EGaIn

Noise behaviour of a THz Superconducting Hot-Electron bolometer Mixer

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Chinese Physics Letters 2007年第6期24卷 1778-1781页

作者：张文李宁蒋玲缪巍林镇辉姚骑均史生才陈健吴培亨 S.I.Svechnikov yu. b. Vachtomin S. V. Antipov b. M. voronov G. N. Gol'tsman Purple Mountain Observatory National Astronomical Observatories Chinese Academy of Sciences Nanjing 210008 Department of Electronic Science and Engineering Nanjing University Nanjing 210093 Department of Physics Moscow State Pedagogical University Moscow 119992 Russia

A quasi-optical superconducting NbN hot-electron bolometer （HEb） mixer is measured in the frequency range of 0.5-2.5 THz for understanding of the frequency dependence of noise temperature of THz coherent detectors. It has been found that noise temperature increasing with frequency is mainly due to the coupling loss between the quasioptical planar antenna and the superconducting HEb bridge when taking account of non-uniform distribution of high-frequency current. With the coupling loss corrected, the superconducting HEb mixer demonstrates a noise temperature nearly independent of frequency.

关键词： PERFORMANCE

THE REINFORCING MECHANISM OF Tib2 IN Tib2/A357 COMPOSITE

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Acta Metallurgica Sinica(English Letters) 2003年第5期16卷 375-378页

作者： b.yu Y.J.Zhang Z.X.Zhao~ F.X.Zhao: Q.K.Cai C.S.Liu ShenyangResearchInstituteofFoundry TheChineseAcademyofMachinerySciencesShenyang110022China EastChinaUniversityofScienceandTechnology Shanghai200237China SchoolofMaterials&Metallurgy NortheasternUniversityShenyang110004China

Mechanical properties were tested for in situ Tib2/A357 composite fabricated by LSM (mixed salts reaction) method. Micro structures of as cast and plastic deformed Tib2/A357 were investigated. The results show that there is a low misfit between (200) Al and (101)Tib2 with [011]//Al [101]Tib2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of Tib2/A357. Significant increases in proof stress and Young's modulus can be obtained at low Tib2 additions. There exist dislocation loops around neighboring Tib2 particles with about 0.1μm in diameter and dislocation multiplication near Tib2 particles.

关键词： Tib2/Al in situ composite reinforcing mechanism

The precipitation strengthening behavior of Cu-rich phase in Nb contained advanced Fe-Cr-Ni type austenitic heat resistant steel for USC power plant application

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Progress in Natural Science:Materials International 2012年第3期22卷 175-185页

作者： Cheng-yu Chi a, Hong-yao yu b, Jian-xin Dong b, Wen-qing Liu c, Shi-chang Cheng d, Zheng-dong Liu d, Xi-shan Xie b a School of Metallurgical and Ecological Engineering, University of Science & Technology beijing, beijing 100083, China b School of Materials Science and Engineering, University of Science & Technology beijing, beijing 100083, China c Instrumental Analysis & Research Center, Shanghai University, Shanghai 200444, China d Central Iron and Steel Research Institute, beijing 100081, China School of Metallurgical and Ecological Engineering University of Science & Technology Beijing Beijing 100083 China School of Materials Science and Engineering University of Science & Technology Beijing Beijing 100083 China Instrumental Analysis & Research Center Shanghai University Shanghai 200444 China Central Iron and Steel Research Institute Beijing 100081 China

Copper has been used as a strengthening element in newly developed Fe-Cr-Ni type austenitic heat resistant steel for inducing Cu-rich phase precipitation to meet high temperature strength requirement for 600 ℃ Ultra Super-Critical (USC) coal fired power plants for many years. However, the precipitation behavior and strengthening mechanism of Cu-rich phase in these advanced austenitic heat resistant steels is still unclear. In order to understand the precipitation strengthening behavior of Cu-rich phase and to promote high strength austenitic heat resistant steel development, 18 Cr9 NiCuNb steel which is a Cu-added Nb contained advanced Fe-Cr-Ni type austenitic heat resistant steel has been selected for this study to be aged at 650 ℃ till to 10,000 h. Micro-hardness and room temperature tensile test were conducted after long-time aging. SEM, TEM, HRTEM and three dimensional atom probe (3DAP) technology accompanying with thermodynamic calculation have been used to investigate the Cu-rich phase precipitation behavior during 650 ℃ aging. The experimental results showed that Cu atoms can quickly concentrate in clusters at very early precipitation stage to form the fine nano-size Cu-rich "segregation areas" within less than 1 h at 650 ℃. With increasing aging time at 650 ℃ Cu atoms continuously concentrate to Cu-rich segregation areas (clusters) and simultaneously other kinds of atoms such as Fe, Cr and Ni diffuse away from Cu-rich segregation areas to austenitic matrix, and finally to complete the transformation from Cu-rich segregation areas to Cu-rich phase. However, there is only Cu atoms concentration but not crystallographic transformation from early stage of Cu-rich clusters forming to the final Cu-rich phase formation. Even the Cu atom becomes the main composed element after 500 h aging at 650 ℃ the Cu-rich phase still keeps coherent relationship with austenitic matrix. According the experimental results in this study, Cu-rich phase precipitation sequence which st

关键词： USC power plant Austenitic heat resistant steel Microstructure Cu-rich phase TEM 3DAP

Topological Stability and Entropy for Certain Set-valued Maps

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Acta Mathematica Sinica,English Series 2024年第4期40卷 962-984页

作者： yu ZHANG yu Jun ZHU School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China

In this paper,the dynamics(including shadowing property,expansiveness,topological stability and entropy)of several types of upper semi-continuous set-valued maps are mainly considered from differentiable dynamical systems points of *** is shown that(1)if f is a hyperbolic endomorphism then for eachε>0 there exists a C^(1)-neighborhood U of f such that the induced set-valued map F_(f,U)has theε-shadowing property,and moreover,if f is an expanding endomorphism then there exists a C^(1)-neighborhood U of f such that the induced set-valued map F_(f,U)has the Lipschitz shadowing property;(2)when a set-valued map F is generated by finite expanding endomorphisms,it has the shadowing property,and moreover,if the collection of the generators has no coincidence point then F is expansive and hence is topologically stable;(3)if f is an expanding endomorphism then for eachε>0 there exists a C^(1)-neighborhood U of f such that h(F_(f,U,ε))=h(f);(4)when F is generated by finite expanding endomorphisms with no coincidence point,the entropy formula of F is ***,the dynamics of the set-valued maps based on discontinuous maps on the interval are also considered.

关键词： Set-valued map orbit space hyperbolic endomorphism perturbation shadowing expansiveness topological stability entropy

A new liquid membrane diffusion model for characterizing the adsorption kinetics of europium by using a continuous measurement of adsorption platform

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Nuclear Science and Techniques 2024年第1期35卷 59-72页

作者： Hao-Qi yu Tao yu Jian-Hua Ye State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China CGN Cangnan Nuclear Power Co. Ltd.Cangnan 325800China Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices East China University of TechnologyNanchang 330013China School of Nuclear Science and Engineering East China University of TechnologyNanchang 330013China

To explore the kinetic adsorption under continuous and nonequilibrium states, an integration of continuous measurement and adsorption platform kinetics method was proposed, which was initially called the ICM-AP kinetics method, and a corresponding kinetic adsorption experimental method was developed. Adsorption experiments of europium(Eu) on Ca-bentonite,Na-bentonite, and the D231 cation exchange resin were performed using the ICM-AP kinetics method and continuous measurements. because the kinetic experimental results observed in this study were different from those of traditional batch adsorption data, pseudo-first-order or pseudo-second-order kinetic models were unsuitable for fitting the experimental ***, a liquid membrane diffusion(LMD) model was developed based on the assumption of simultaneous adsorption/desorption to discuss the mechanism of kinetic adsorption. The kinetic adsorption mechanism was also studied by using *** results indicated that the proposed adsorption model can fit the experimental data more suitably, and the adsorption/desorption behaviors of Eu on bentonite and the D231 resin were simultaneously observed, suggesting that the adsorption kinetics of Eu(Ⅲ) was mainly dominated by hydrated Eu(Ⅲ) ions on the liquid membrane.

关键词： ICM-AP method LMD model Adsorption mechanism Eu(Ⅲ)

Device design principles and bioelectronic applications for flexible organic electrochemical transistors

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International Journal of Extreme Manufacturing 2024年第1期6卷 126-153页

作者： Lin Gao Mengge Wu Xinge yu Junsheng yu State Key Laboratory of Electronic Thin Films and Integrated Devices School of Optoelectronic Science and EngineeringUniversity of Electronic Science and Technology of China(UESTC)Chengdu 610054People’s Republic of China Department of biomedical Engineering City University of Hong KongHong Kong Special Administrative Region of ChinaPeople’s Republic of China

Organic electrochemical transistors(OECTs) exhibit significant potential for applications in healthcare and human-machine interfaces, due to their tunable synthesis, facile deposition, and excellent biocompatibility. Expanding OECTs to the fexible devices will significantly facilitate stable contact with the skin and enable more possible bioelectronic applications. In this work,we summarize the device physics of fexible OECTs, aiming to offer a foundational understanding and guidelines for material selection and device architecture. Particular attention is paid to the advanced manufacturing approaches, including photolithography and printing techniques, which establish a robust foundation for the commercialization and large-scale fabrication. And abundantly demonstrated examples ranging from biosensors, artificial synapses/neurons, to bioinspired nervous systems are summarized to highlight the considerable prospects of smart healthcare. In the end, the challenges and opportunities are proposed for fexible OECTs. The purpose of this review is not only to elaborate on the basic design principles of fexible OECTs, but also to act as a roadmap for further exploration of wearable OECTs in advanced bio-applications.

关键词： flexible organic electrochemical transistors wearable bioelectronics manufacturing approaches device physics neuromorphic applications