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OptiLam:Design of Optimised rolling Schedules

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Journal of Iron and Steel research International 2011年第S1期18卷 492-499页

作者： B Pea M Arribas A r Carrillo J I Barbero J Calvo Tecnalia Foundry and Iron & Steel Unit c/Geldo-Parque Tecnológico de Bizkaia Edificio 700C.P 48160-Derio (Bizkaia)-Espa a Department of Mining Metals and Materials EngineeringMcGill University3610 University StreetMontrealQuebecCanadaH3A 2B2

Nowadays it is known that the thermomechanical schedules applied during hot rolling of flat products provide the steel with improved mechanical *** this work an optimisation tool,OptiLam (OptiLam v.1),based on a predictive software and capable of generating optimised rolling schedules to obtain the desired mechanical properties in the final product is *** includes some well-known metallurgical models which predict microstructural evolution during hot rolling and the transformation austenite/ferrite during the ***,an optimisation algorithm,which is based on the gradient method,has been added,in order to design thermomechanical sequences when a specific final grain size is *** has been used to optimise rolling parameters,such as strain and ***,some of the results of the software validation performed by means of hot torsion tests are presented,showing also the functionality of the ***,the application of classical optimisation models,based on the gradient method,to hot rolling operations,is also discussed.

关键词： rolling schedules optimisation models mechanical properties grain size

A. S. Convergence of Two-Parameter Banach Space Valued Martingales and the radon-Nikodym Property of Banach Spaces

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Acta Mathematica Sinica,English Series 1999年第2期15卷 187-196页

作者： Shixin Gan, Department of Mathematics, Wuhan University, Wuhan 430072, P. r. China Department of Mathematics Wuhan University Wuhan P. R. China

In this paper, we prove that under the F4 condition, any L log+ L bounded two-parameter Banach space valued martingale converges almost surely to an integrable Banach space valued random variable if and only if the Banach space has the radon-Nikodym property. We further prove that the above conclusion remains true if the F4 condition is replaced by the weaker local F4 condition.

关键词： Two-parameter Banach space valued martingale A. S. convergence radon-Nikodym property F4 condition Local F4 condition

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

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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

Challenges and prospects of plastic waste management in Nigeria

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Waste Disposal and Sustainable Energy 2019年第2期1卷 117-126页

作者： r.U.Duru E.E.Ikpeama J.A.Ibekwe Department of Pure and Industrial Chemistry University of Port HarcourtPort HarcourtNigeria 15791 Pebblebrook Drive BellevilleMI 48111USA Department of Oil and Gas Chemistry University of AberdeenAberdeenScotlandUK

The combined properties of low cost,lightweight,and resistance to chemicals and corrosion has increased the use of plastic materials for packaging and storage purposes in preference to other ***,there is a continued increase in their proportion in domestic solid wastes worldwide as well as the concern of their impacts on the *** developed and developing countries have put in place and continue to improve their plastic waste disposal,collection,and recycling methods to reduce these *** Nigeria with a population of about 186 million,there are little or no available data on the use of plastic materials in relation to city populations,their disposal,collection,and recycling *** are a few numbers of plastic waste recycling companies in a fewer number of cities and disposal practices for the greater percentage of the plastic wastes that are not captured for recycling possess immediate and future danger for the *** work reviews the consumption of plastics,its waste generation,collection,and treatment in Nigeria and a few selected *** problems associated with inadequate management of the wastes were emphasized and recommendations were proffered to not only highlight research and investment opportunities that are inherent in plastic waste management in Nigeria,but also provide a background for the formulation of sustainable regulatory policies by the government to address the problems.

关键词： Plastic waste Disposal recycling Environment Investment Waste management

Assessment of accuracy of modal parameters of a rotor dynamic system using different types of finite elements

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International Journal of Modeling, Simulation, and Scientific Computing 2018年第1期9卷 46-56页

作者： E.S.ramasubramaniam P.r.Thyla N.Mahendrakumar Department of Mechanical Engineering PSG College of Technology Coimbatore 641004 Tamil NaduIndia

The main objective of this work is to check the compatibility of Finite element method(FEM)to determine the modal parameters of the rotor system and to compare the results with analytical *** work is an attempt to implement different finite element(FE)models for the estimation of modal *** different order elements from Beam,Axisymmetric and Solid FE models are *** analysis is carried out on the rotor system and the accuracy of the results and the computation time of the FE models are *** FE results are compared with the analytical *** is observed that FE model can be used to simulate even at higher order frequencies,which is a limitation of analytical *** analysis shows that the FE results closely match with analytical method and also the study summarizes that proper choosing of FE helps in developing rotor models in both a desirable accuracy and ***,a Campbell diagram is generated using the analytical method and *** critical speeds are also calculated from the Campbell *** closeness of the results between the two methods is checked.

关键词： Natural frequency meshing convergence test finite element method Campbell diagram

Two new diterpenoids from Isodon eriocalyx

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Chinese Chemical Letters 1999年第1期10卷 31-32页

作者： Chen, NY Tian, MQ Wu, r Sun, HD Li, CM Lin, ZW Lanzhou Univ Natl Lab Appl Organ Chem Lanzhou 730000 Peoples R China Acad Sinica Kunming Inst Bot Lab Phytochem Kunming 650204 Peoples R China

Two new diterpenoids, maoecrystal U and epi-maoecrystal P were isolated from the leaves of Isodon eriocalyx. Their structures were determined as 6 beta-acetoxy-15 beta-hydroxy-3 alpha, 20epoxy-ent-kaur-16-ene-1,7-dione 1 and 16 (s)-methoxymethyl-6 beta,7 beta-dihydroxy-7 alpha,20-epoxy-ent-kaur-2,3-ethenylene-1, 15-dione 2 respectively, by spectroscopic methods.

关键词： Isodon eriocalyx ent-kaurenoids maoecrystal U epi-maoecrystal P

Effects of vertical position on trematode parasitism in larval anurans

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Current Zoology 2019年第6期65卷 657-664页

作者： Jacob r.JONES Camille L.STEENrOD John A.MArINO Jr. Biology Department Bradley UniversityPeoriaILUSA Department of Geography University of MarylandCollege ParkMDUSA

Spatial distributions of animals can affect interactions with their natural enemies,such as parasites,and thus have important implications for host-parasite *** spatial variation in infection risk has been explored in many systems at the landscape scale,less attention has been paid to spatial structure at smaller ***,we explore a hypothesized relationship between a common spatial variable,vertical position,and risk of parasite infection in a model aquatic system,larval frogs(rana)and trematode(Digenea)*** position is relevant to this system given evidence that the densities of snail first intermediate hosts,tadpole second intermediate hosts,and trematode infective stages can vary with *** test the effects of depth on infection risk of larval frogs by trematodes,we performed two enclosure experiments,one in the laboratory and one in the field,in which larval frogs in cages just below the water surface or near the bottom of the water column were exposed to *** with near-surface cages,mean infection load(number of cysts)in tadpoles in near-bottom cages was 83%higher after 48-h exposures in the laboratory and 730%higher after 10-day exposures in the *** findings thus indicate that infection risk depends on depth,which may have adaptive significance,as tadpoles have previously been shown to change vertical position in response to parasite *** results motivate future work examining vertical variation in infection risk and may have broader implications for host-parasite dynamics and evolution of host and parasite behavior.

关键词： avoidance behavior cercariae Echinostomatidae host-parasite interactions rana spatial structure

DYNAMICS IN NEWTONIAN-rIEMANNIAN SPACETIME (Ⅰ)

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Applied Mathematics and Mechanics(English Edition) 2000年第7期21卷 825-835页

作者： Zhang rongye (Institute of Mathematics, Academia Sinica, Beijing 100080, P r China) Institute of Mathematics Academia Sinica Beijing P R China

By the theory of Modern Geometry, the mechanical principle and advanced calculus, the dynamics in Newtonian_Galilean spacetime is generalized to Newtonian_riemannian Spacetime, and the dynamics in N_r spacetime is est... 详细信息

关键词： riemannian manifold connection absolute differential Lie derivative exterior differential co_moving time derivative fiber bundle duality pairing

Series solution of unsteady peristaltic flow of a Carreau fluid in small intestines

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International Journal of Biomathematics 2014年第5期7卷 41-49页

作者： Arshad ria S. Nadeem r. Ellahi Noreen Sher Akbar Department of Mathematics and Statistics FBAS HU Islamabad 44000 Pakistan Department of Mathematics University of Sargodha Canal Campus Lahore Pakistan Department of MathematicsQuaid-i-Azam University 45320 Islamabad 44000 Pakistan DBSSJH CEMENational University of Sciences and Technology Islamabad Pakistan

The study of peristaltic flow of a Carreau fluid in a non-uniform tube under the con- sideration of long wavelength is presented. The flow is investigated in a wave frame of reference moving with velocity of the wave e. Numerical integration has been used to obtain the graphical results for pressure rise and frictional forces. The effects of various emerging parameters are investigated through graphs.

关键词： Peristaltic flow Carreau fluid diverging tube perturbation solution.