检索结果-南通市图书馆

PURIfICATION Of COBALT ANOLYTE USING THE NOVEL SOLVENT EXTRACTION SYSTEM

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2003年第2期16卷 114-121页

作者： Y.f.shen W.Y.Xue W.Y.Niu Jinchuan Non-ferrous Metals Complex Jinchuan 737100ChinaState Key Laboratory of Rolling and AutomationNortheastern UniversityShenyang 110014ChinaState Key Laboratory of Rolling and AutomationNortheastern UniversityShenyang 110014ChinaState Key Laboratory of Rolling and AutomationNortheastern UniversityShenyang 110014China

In present research, a novel extractant system (D2EHPA + naphthenic acid + pyridine- ester) was used to purify cobalt anolyte and a simulated industrial production were carried out. This novel extraction system can extract Cu and/or Ni against Co from chloride medium solutions at pH range of 2.5-4.5. About 2g/l nickel and 0.2g/l copper were removed from the cobalt chloride anolyte containing about 100g/l cobalt and 200g/l chloride ions respectively, the raffinate contains nickel and copper less than 0.03g/l and 0.0003g/l respectively and can be used to electrolyze high-purity cobalt. About 5.5t cobalt anolyte was purified in the simulation industrial experiment and kilogram quantities of cobalt of 99.98% purity and about 95% recovery have been produced.

关键词： solvent extraction nickel cobalt anolyte naphthenic acid pyridine-ester

Grain refinement mechanism of Mg-3Sn-1Mn-1La alloy during accumulative hot rolling

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第32期91卷 251-261页

作者： Z.Y.Zhao R.G.Guan Y.f.shen P.K.Bai School of Materials Science and Engineering North University of ChinaTaiyuan 030051China bEngineering Research Center of Continuous Extrusion Ministry of EducationDalian Jiaotong UniversityDalian 116028China Key Laboratory for Anisotropy and Texture of Materials Northeastern UniversityShenyang 110004China

We elucidate the effect of lanthanum(La) on the grain refinement of Mg-3 Sn-1 Mn alloy during accumulative hot rolling. The lath-shaped Mg_(2) Sn phase in the Mg-3 Sn-1 Mn alloy is firstly broken and spheroidized,and then the size increases and coarsens with the increase of rolling reduction, most of Mg_(2) Sn move from grain boundary to grain and are homogeneously distributed within the matrix. However, the plate-shaped Mg Sn La compound in Mg-3 Sn-1 Mn-1 La gradually becomes fine, spheroidized, and homogeneously distributed. The grain sizes of Mg-3 Sn-1 Mn and Mg-3 Sn-1 Mn-1 La alloys become fine through dynamic recrystallization(DRX), though the grain refinement of Mg-3 Sn-1 Mn-1 La alloy is better compared to the Mg-3 Sn-1 Mn alloy. A large number of uniformly distributed spherical Mg Sn La compounds pin the dislocations, thus increasing the dislocation density. Hence, the driving force for DRX increases and promotes the formation of deformation bands and more twins, providing the sites for DRX nucleation and growth.

关键词： Mg alloy Grain refinement Dynamic recrystallization Accumulative hot rolling

High strength-superplasticity combination of ultrafine-grained ferritic steel:The significant role of nanoscale carbides

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第24期83卷 131-144页

作者： J.W.Liang Y.f.shen R.D.K.Misra P.K.Liaw Key Laboratory for Anisotropy and Texture of Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang110004China The State Key Lab of Rolling&Automation Northeastern UniversityShenyang110819China Laboratory for Excellence in Advanced Steel Research University of Texas at El PasoTX79968USA Department of Materials Science and Engineering University of TennesseeKnoxvilleTN37996USA

There is currently a gap in our understanding of mechanisms that contribute to high strength and high plasticity in high strength UfG ferritic steel with nano-size fe3 C carbides in situations that involve combination of various strain rates and high *** this regard,we describe the mechanistic basis of obtaining high strength-high plasticity combination in an ultrafine-grained(UfG)(~500±30 nm)ferritic steel with nano-size carbides,which sustained large plastic deformation,exceeding 100%elongation at a temperature significantly below 0.5 of the absolute melting point(Tm).To address the missing gap in our knowledge,we conducted a series of experiments involving combination of strain rate and temperature effects in conjunction with electron microscopy and atom probe tomography(APT).Strain rate studies were carried out at strain rates in the range of 0.0017-0.17 s^(-1)and at different temperatures from 25℃to 600℃.Dynamic recrystallization occurred at 600℃,resulting in a significant decrease in yield and tensile ***,the UfG ferritic steels had an advantage in tensile strength(UTS)and elongation-to-failure(εf)at 600℃,especially at strain rate of 0.0017 s^(-1),with high UTSof 510 MPa and excellent low temperature(f=110%).These mechanical properties are significantly superior compared to similar type of steels at identical temperature.A mechanistic understanding of mechanical behavior of UfG ferritic steels is presented by combining the effect of strain rate,temperature,and nano-size carbides.

关键词： UfG ferritic steel Strain rate Temperature Nano-size precipitate Low temperature superplasticity

NUMERICAL SIMULATION Of MACRO-SEGREGATION IN STEEL INGOT DURING SOLIDIfICATION

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 288-294页

作者： C.W.Ma H.f.shen T.Y.Huang B.C.Liu Department of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 China

A mathematical model coupling the momentum, energy and species conservation equa-tions was proposed to calculate the macro--segregation of fe--C alloy ingot during solid-ification. The corresponding simulation software which concurrently solves the macro-scopic mass, momentum, energy and species conservation equations has been developedby applying the SIMPLE algorithm.The thermo--solutal convection in a NH_4 Cl--H_2O ingot is verified and the result showsgood agreement with that reported. Then macro--segregation in a steel ingot is simu-lated by using the developed program. The steel ingot is in a rectangular mold with ariser. The fluid flow is mainly induced by the temperature field and the solid fraction.The macro--segregation pattern is mainly affected by the thermo--induced convectionin the mushy zone. The negative segregation forms along the walls of the casting.The positive segregation forms at the top center of the casting into the riser. Thespecies concentration reaches the peak in the center of the ingot where solidificationends lastly.

关键词： macro-segregation thermo-solutal convection steel ingot numerical simulation

ACTIVATION MECHANISM Of AMORPHOUS Ni_(63)Zr_(32)La_5 ALLOY HYDROGENATION CATALYST

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1996年第4期9卷 291-297页

作者： Wang, X.K. shen, N.f. Lei, G.J. Gu, H.C.

The catalytic activity of amorphous Ni_63 Zr_32 La_5 ribbon for hydrogenation of ethyne to ethylene can be greatly enhanced when the alloy ribbon is pretreated with dilute acid solution,heated under negative atmosphere pressure and subjected to hydrogen reduction successively. The change of surface state of the ribbon during the activation has been analysed by AES and XPS. The surface of as-received ribbon is covered with a thin film of La_2 O_3. After pretreatment. the surface concentrations of both Ni and Zr increase obviously, whereas the surface concentration of La decreases ***, on the surface of activated catalyst the Ni and NiO disperse finely on the matrix consisting of oxides of both Zr and La and a small amount of fluorides of Zr and La.

关键词： amorphous Ni_(63) Zr_(32) La_5 alloy catalyst activation mechanism

ON THE MONTE CARLO SIMULATION Of NORMAL GRAIN GROWTH

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 282-288页

作者： Y.T. Liu X.J. Guan X.M. shen X.f. Ma L.J. Wang School of Materials Science and Engineering Shandong University Jinan 250061 China

The microstructures and their kinetics of normal grain growth are simulated using different Monte Carlo （MC） algorithms. Compared with the relative figures and the theoretical normal grain growth exponents of n =0.5, the effects of some factors of MC algorithm, i.e. the lattice types, the methods of selecting lattice sites, and the neighbors selection for energy calculations, on the simulation results of grain growth are studied. Two methods of regression were compared, and the three-parameter nonlinear regression is much more suitable for fitting the grain growth kinetics. A better model with appropriate factors included triangular lattice, the attempted site randomly selected, and the first and second nearest neighbors for energy calculations is obtained.

关键词： Grain growth Microstructure Monte Carlo method Computer simulation Grain growth kinetics Nonlinear regression

Effects of Processing Parameters on Weld Geometries in Electron Beam Welding Based on Partial Correlation Analysis

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2011年第S4期40卷 30-34页

作者： shen X f,Huang W R,Zhang Y Z Institute of Machinery Manufacturing Technology,China Academy of Engineering Physics,Mianyang 621900,China China Acad Engn Phys Inst Machinery Mfg Technol Mianyang 621900 Peoples R China

Accelerating voltage,electron beam current,welding speed constitutes the main electron beam welding process parameters,while the penetration depth and depth-width ratio are two of the most important characteristic parameters of the weld *** complex interactions exists between the five variables,so the analysis of a single process parameter on one of weld geometries is affected by the other process parameters,and the impact of these interference parameters should be excluded to find the real relationship between the variables where partial correlation analysis provides such a *** of the accelerating voltage,electron beam current,welding speed of electron beam welding process parameters on weld geometries is analyzed by using partial correlation *** priority order of adjustment of process parameters is obtained,namely:in order to obtain a larger depth-width ratio indicators,it should be taken firstly to increase the beam current and accelerating voltage,and then to raise the welding speed;in order to obtain greater penetration depth,it is preferred to increase the beam current,followed by increasing the accelerating voltage,and reducing the welding speed finally.

关键词： electron beam welding process parameters characteristic parameters of weld morphology partial correlation analysis

Macrophage-derived small extracellular vesicles promote biomimetic mineralized collagen-mediated endogenous bone regeneration

在线全文

学校读者我要写书评

暂无评论

International Journal of Oral Science 2020年第4期12卷 317-326页

作者： Anqi Liu Shanshan Jin Cuicui fu shengji Cui Ting Zhang Lisha Zhu Yu Wang Steve G.f.shen Nan Jiang Yan Liu Department of Oral and Maxillofacial Surgery Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai Key Laboratory of StomatologyShanghaiChina Laboratory of Biomimetic Nanomaterials Department of OrthodonticsPeking University School and Hospital of StomatologyNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital StomatologyBeijingChina Department of Oral Biochemistry Academic Centre for Dentistry Amsterdam(ACTA)University of Amsterdam(UvA)and Vrije Universiteit Amsterdam(VU)Gustav Mahlerlaan 3004AmsterdamThe Netherlands Shanghai University of Medicine and Health Sciences ShanghaiChina Central Laboratory Peking University School and Hospital of StomatologyNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital StomatologyBeijingChina

Macrophages play an important role in material-related immune responses and bone formation,but the functionality of macrophage-derived extracellular vesicles(EVs)in material-mediated bone regeneration is still ***,we evaluated intracellular communication through small extracellular vesicles(sEVs)and its effects on endogenous bone regeneration mediated by biomimetic intrafibrillarly mineralized collagen(IMC).After implantation in the bone defect area,IMC generated more neobone and recruited more mesenchymal stem cells(MSCs)than did extrafibrillarly mineralized collagen(EMC).More CD63+CD90+and CD63+CD163+cells were detected in the defect area in the IMC group than in the EMC *** determine the functional roles of sEVs,extracellular vesicles from macrophages cultured on different mineralized collagen were isolated,and they showed no morphological ***,macrophage-derived sEVs in the IMC group showed an enhanced Young’s modulus and exerted beneficial effects on the osteogenic differentiation of bone marrow MSCs by increasing the expression of the osteoblastic differentiation markers BMP2,BGLAP,COL1,and OSX and calcium nodule ***,sEVs from IMC-treated macrophages facilitated MSC osteogenesis through the BMP2/Smad5 pathway,and blocking sEV secretion with GW4869 significantly impaired MSC proliferative,immunomodulative and osteogenic *** together,these findings show that macrophage-derived sEVs may serve as an emerging functional tool in biomaterial-mediated endogenous bone regeneration.

关键词： endogenous CD63 mediated

COUPLED NUMERICAL SIMULATION ON COLD ROLLER'S TEMPERATURE fIfLD-PHASE TRANSfORMATION - STRESS fIELD DURING ITS QUENCHING PSOCESS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2000年第1期13卷 254-262页

作者： J. f. Gu J. S. Pan M. J. Hu and f. f. shen (School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China)

Complicated changns occur inside the steel parts during quenching process. The abruptly changed boundary conditions make the temperature field,micro - structure and stress field change dramatically in very short time, and these variables take a contact interactions in the whole process. In this paper, a three dimensional non - linear mathematical model for queeching process has been founded and the numerical simulation on temperature field,microstructre and stress field has been *** the fEM analysis, the incremental iteration method is used to deal with such complicated nonlinear as boundary nonlinear, physical property nonlinear,transformation nonlinear *** effect of stress on transformation kinetics has been considered in the calculation of microstructure. In the stress field anal- ysis,a thermo- elasto - plastic model has been founded, which considers such factors as transforma- tion strain,transformation plastic strain, themal strain and the effect of temperature and transforma- tion on mechanical propertier etc. The transient temperature field, microstructure distribution and stress field of the roller on any time can be displayed vividly,and the cooling curve and the changes of stress on any position can also be given.

关键词： quenching,phase transformation,temperature field stress field finite element method (fEM) numerical simulation