简介:进入2015年1季度,国际黄金价格先扬后抑维持震荡下行态势;1季度伦敦金银协会(LBMA)黄金现货均价(下午定盘价)为1219.22美元/盎司,环比下跌5.78%。2015年1季度国际黄金行情,主要受到美国经济形势和美国货币政策主导,随着美国经济持续复苏经济数据走强,美元强势反弹美元指数在3月中旬一度突破百点大关(创12年来新高),金价不断受到打压;而美联储3月关于加息是否推迟言论再次推动金价反复震荡;相对于美国经济复苏开始走上加息通道,欧洲央行1月22日宣布启动欧版量化宽松政策,各国央行相机抉择纷纷降息降准应对欧洲央行QE,这加剧了国际金价的下行:1月希腊债务危机、3月中东也门局势升级也一度推动国际黄金行情短暂反弹,但黄金价格整体走势颓势依旧。
简介:GaxIn1-xAs1-ySbyalloyshavebeengrownbyatmosphericpressureMOCVDonn-GaSb(Te-doped)substrate.Thesohdcompositionwasdeterminedbyusingelectronmicroprobe.ThealloysofGalnAsSbwithcompositioninmiscibilitygapweresuccessfullygrown.TheopticalpropertiesofGaxIn1-xAs1-ySbylaverswerecharacterizedbythephotoluminescenceandtheinfraredabsorption.Thespectralresponsesofp+-GaInAsSb/p-GaxIn1-xAs1-ySby/n-GaSbdetectorsshowedwavelengthcutoffat2.4μmanddetectivity-D*=5×108cmHz1/2/Watroomtemperature.
简介:LayeredcathodematerialLiCo1/3Ni1/3Mn1/3O2wassynthesizedbyPechiniprocess,andinvestigatedusingX-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andgalvanostaticcharge/dischargecycling.Thesampleiswell-crystallizedandhasaphase-purea-NaFeO2structure.Theparticlesizesareuniform,anddistributedintherangeof20-200nm.TheinitialdischargecapacityoftheLi/LiCo1/3Ni1/3Mn1/3O2cellwasabout149mAh·g-1whenitwascycledatavoltagerangeof4.5-2.3Vwithaspecificcurrentof0.25mA.Theresultisbetterincomparisonwithsolid-statesolutionmethod.Thesyntheticprocedurewasdiscussed.Threemajorreactions:chelation,esterification,andpolymerizationsuccessivelyoccurred.
简介:"非典"期间,我给一位老朋友也是客户打电话祝贺五一节,顺便多聊了几句.这位朋友说:我做企业十几年了,做了四、五个产业,最后只有最早做的生意还赚钱,其他生意全不赚钱,为啥我总做不好新业务?首先,第一个误区是思维模式的习惯性阻碍了新业务的发展.由于10多年前起家的业务通常是自己最熟悉的,很多人原来在高校、国企或研究所工作几年、十几年后才下海自己开公司,对这摊子业务的熟悉,对行业、客户、技术、关键成功因素等的知识从下海开公司之前几年就已经开始积累,达到了深谙的程度,所以,开办公司后业务很快就起来了.但"成也萧何、败也萧何",由于对第一个业务的成功模式熟悉得刻骨铭心,所以,有意无意中形成了习惯性思维模式,对新开始的第二、第三个业务也有意无意地从习惯性思维模式出发,而不是从新业务本身的特点出发.所以都做不大,都不赚钱.
简介:EmployingLi2CO3,NiO,Co3O4,andMnCO3powdersasstartingmaterials,Li[Ni1/3Co1/3Mn1/3]O2wassynthesizedbysolid-statereactionmethod.Variousgrindingaidswereappliedduringmillinginordertooptimizethesynthesisprocess.Aftersuccessiveheattreatmentsat650and950℃,thepreparedpowderswerecharacterizedbyX-raydiffraction(XRD)analysis,scanningelectronmicroscopy,andtransmissionelectronmicroscopy.Thepowderspreparedbyaddingsalt(NaCl)asgrindingaidexhibitaclearR3mlayerstructure.ThepowdersbyothergrindingaidslikeheptaneshowsomeimpuritypeaksintheXRDpattern.Theformerpowdersshowauniformparticlesizedistributionoflessthan1μmaveragesizewhilethelattershowsawidedistributionrangingfrom1to10μm.EnergydispersiveX-ray(EDX)analysissshowthattheratioofNi,Co,andMncontentinthepowderisapproximately1/3,1/3,and1/3,respecively.TheEDXdataindicatenoincorporationofsodiumorchlorineintothepowders.Charge-dischargetestsgaveaninitialdischargecapacityof160mAh·g-1forthepowderswithNaCladditionwhile70mAh·g-1forthepowderswithheptane.
简介:PolycrystallinesamplesofLa12x(Sr12yAgy)xMnO3(y=0.0,0.2,0.4,0.6,1.0)werepreparedbythesolid-statereactionmethod.ThetemperaturestabilityofmagnetoresistanceandmagnetoresistanceenhancementinLa1-x(Sr1-yAgy)xMnO3systemwithbothunivalentandbivalentelementsdopedatAsiteandwithunchangedvalueofMn3+/Mn4+ratiowereexploredthroughthemeasurementsofX-raydiffractionpatterns,magnetiza-tion-temperature(M-T)curves,resistivity-temperature(q-T)curvesandmagnetoresistance-temperature(MR-T)curves.Theresultsareasfollows:therearetwopeaksintheq-TcurvesofthesampleswithAgdoping,oneiscausedbyresistancechangeduringtheparamagnetism-ferromagnetismtransition,andtheotherisfromboundary-dependentscatteringofconductionelectronsontheboundariesofgrains.ThepeakvalueofMRincreaseswithincreasingAgdopingcontent,anditincreasesfrom8.2%fory=0.2to29.6%fory=1.0underthemagneticfieldofB=0.8T;MRremainsaconstantof12%inthetemperaturerangeof218-168Kforthesamplewithy=1.0,andthetemperaturestabilityofMRisinfavorofthepracticalapplicationofMR.
简介:采用标准的剥落腐蚀浸蚀实验、剥落腐蚀后样品的强度损火测量以及电化学阻抗谱等技术,对固溶后经不同淬火转移时间处理的7050-T6态样品的剥落腐蚀行为进行研究。结果表明,7050-T6铝合金的抗剥落腐蚀性能随着淬火转移时间的延长而减小。背散射电子扫描连同透射电镜观察揭示,影响合金腐蚀性能的最主要因素是晶界的析出相覆盖率和析出相的微观组织,而晶界附近的贫溶质区对其不产生影响或影响较小。通过对合金进行静电势扫描发现,合金的剥落腐蚀敏感性与瞬态电势之间有很好的对应关系,即可以测试瞬态电势变化的数量来表征材料的剥蚀性能。