Separation of hematite from banded hematite jasper (BHJ) by magnetic coating

The separation of iron oxide from banded hematite jasper(BHJ) assaying 47.8% Fe, 25.6% Si O2 and 2.30%Al2O3 using selective magnetic coating was studied. Characterization studies of the low grade ore indicate that besides hematite and goethite,jasper, a microcrystalline form of quartzite, is the major impurity associated with this ore. Beneficiation by conventional magnetic separation technique could yield a magnetic concentrate containing 60.8% Fe with 51% Fe recovery. In order to enhance the recovery of the iron oxide minerals, fine magnetite, colloidal magnetite and oleate colloidal magnetite were used as the coating material. When subjected to magnetic separation, the coated ore produces an iron concentrate containing 60.2% Fe with an enhanced recovery of56%. The AFM studies indicate that the coagulation of hematite particles with the oleate colloidal magnetite facilitates the higher recovery of iron particles from the low grade BHJ iron ore under appropriate conditions.     

Optical Properties of One-dimensional Three-component Photonic Band Gap Structure

1　IntroductionMaterialswithPhotonicBandGaps (PBG’s)havebeenwidelystudiedboththeoreticallyandex perimentallyinthepastfew years[1～ 4] .Theexis tenceofgaps,which prohibitthepropagationofelectromagnetic (EM )wavesinacertainrangeoffrequencies,canhavesignificantimpactsbothinsci enceandtechnology .Manypracticalapplicationsofthesestructureshavebeensuggestedanddemon strated ,suchasPhotonicCrystal (PC)microcavi ties[5] ,infraredPC[6] ,PClens[7] ,suppressingspontaneousemission ,manipulatinglight…     

High Power Fiber Bundle Array Coupled LDA Module

1 Introduction High power laser diode arrays (LDA) have many advan- tages such as small volume, long working life, high slope efficiency and high optical density, so they have many applications in medical treatment, material pro- cessing, and for the pumping source of solid laser and etc. But unfortunately, the LDA can not be easy to use directly in these fields because of their poor beam quality and extremely asymmetric divergent beams (!x≈ 5°～10°and !y≈20°～35°, for example), so it …     

The Algorithm and Its Application of a Multi-Channel Adaptive Decision-Feedback Equalizer

1　IntroductionOneofthekeyproblemsinhigh speeddigitalradiocommunicationistheInter Symbol Interfer ence (ISI)causedbythemulti pathbetweenthetransmitterandthereceiver.Becauseoftherelativemovementbetweenthereceiverandthetransmitterandthecontinuouschangeoftransmissionmedia,ISIisusuallytime variant.Inthepasttwotothreedecades,abroadstudyofthetype ,structureandadaptivealgorithmofadaptiveequalizershasbeencarriedouttomitigateISI[1～ 7] .Withtheintroductionofadaptiveantennasanddiversityreceptiontec…     

An Improved Immune Genetic Algorithm for Solving the Optimization Problems of Computer Communication Networks

1　IntroductionIndesigningacomputercommunicationnet work ,thenetworkaveragedelayisanimportantpa rameterinthenetworkperformance .Inthispaper,weonlyconsiderM /M/1networks,whichmeansthatthemessageprocessingtimeisaprobabilisticdensityfunctionwithnegativepower,thegroupar rivalandsendingisofPoissiondistributionwithasinglequeue .Supposethatthenetworktopologicalstructureandtheestimatesoftheexternaltrafficrequirementsaregiven ,howtoselecttheoptimalroutestobeusedbythecommunicatingnodesinthenetworksoast…     

停运44年后混流式水轮机复活了

最初于二十世纪二十年代投入运行的澳大利亚艾尔登(Eildon)水电站两台7．5MW混流式水轮机已经重新投入运行了。对机组恢复使用并在原来两倍的水头下运行的可行性进行了调查，发现这两台机组能够重新投运，并且可在更高压力下运行。本文介绍了这个非常规项目的机械试验、有限元分析和其它试验，这个项目后来在澳大利亚和新西兰获得了三项优秀工程奖。     

BaxSr（1—x）TiO3多层膜椭偏光谱研究

用溶胶－凝胶技术在Bi(100）衬底上制备了单层和渐变型多层的BaxSr(1-X)TiO3薄膜，其膜层组分分别为：Ba0.7Sr0.3TiO3,Ba0.8Sr0.2TiO,Ba0.9Sr0.1TiO3,BaTiO3，对生长制备出的多层BaxSr(1-X)TiO3薄膜进行了变角度椭偏光谱测量，通过椭偏光谱解谱分析研究，首次得到了BaxSr(1-X)TiO3多层膜结构不同膜层的膜厚和光学常数，其结果显示：椭偏光谱分析得到的不同膜层的膜厚与卢瑟福背向散射测量得到的结果基本相符；渐变型多层膜中BaTiO3薄膜的折射率比单层BaTiO3薄膜折射率大许多，与体BaTiO3的折射率相接近，这说明渐变型多层膜中BaTiO3薄膜的光学性质与体材料的光学性质接近。     

Study of the Improvement on Network Management Performance with Mobile Agent

1　IntroductionWiththerapiddevelopmentofInternet,thenetworkisbecominglargerandmorecomplex ,whichcallsformoresophisticatednetworkmanage mentstrategiestobeadoptedinordertoguaranteeadequatelevelsofperformance .Confrontedwiththepresentstatusofnetworkmanagement,manyschol arsmakegreateffortstoinventnewapproachesforthepurposeofimprovingtheperformanceofnet workmanagement.MobileAgenttechnologiesandtheirapplicationtonetworkmanagementaread vancedunderthisbackground .Althoughalotofworkhasstilltobedone ,t…     

Noise-Assisted Signal Reception in Threshold Neuron

1IntroductionSometi mes,noise can i mprove signal transmission orsignal processing in a nonlinear system.This phe-nomenonis the so-called Stochastic Resonance(SR)[1].Most studies of SRinvolve asubthresholdsignal througha single nonlinear systemand the non…     

The Application of the Theory of the Price Elasticity of Demand to the EMS Management

1　Introduction　ExpressMailService (EMS )wasopenedupbyChinaPostintheearly 80stomeettheneedsofeco nomicdevelopment.It sthemostcompetitiveoneofthepostservices.There recivilaviation ,Chinarail wayandotherprivateexpressdeliverycompaniesdomesticallyandUPS ,TNT ,DHLandTEDEXcompetingwithEMSintheinternationalmarket.OneofthemostpowerfulcompeteweaponofthesecompaniesisthelowerpricethanEMS[1 ] .BecauseofthefiercecompetitionEMSdeclinedfromthemo nopolistindomesticandinternationalmarketoftheear…