简介：采用国内首创的交流电弧直读光谱仪,以交流电弧为激发光源、凹面光栅分光、光电倍增管接收、智能测控系统快速数据采集及处理,可取代传统1米或2米光栅摄谱仪的相板记录方式及洗相、译谱等繁琐的操作程序。在优化的实验条件下,对粉末状地球化学样品中的银、锡、硼、钼、铅,进行交流电弧直读光谱法测定,检出限分别为0.012,0.24,1.65,0.20,1.30μg/g,精密度和准确度均可满足行业规范的要求,其测定值与ICP-MS和ICP-AES的分析结果相符。

简介：在Hilbert空间中定义了K-g-框架,研究了Hilbert空间中K-g-框架扰动的稳定性,利用分析与框架理论上的方法和技巧,得到了K-g-框架满足扰动稳定性的一些充分条件,所得的结论推广了g-框架扰动稳定性的相关结果.

简介：Inthisarticle,westudytheproblemsofBorel'sdirectionsofmeromorphicfunc-tionsconcerningsharedvaluesandprovethatiftwomeromorphicfunctionsofinfiniteordersharethreedistinctvalues,theirBorel'sdirectionsaresame.

简介：Letl1,l2,…,lgbeevenintegersandxbeasufficientlylargenumber.Inthispaper,theauthorsprovethatthenumberofpositiveoddintegersk≤xsuchthat（k+l1）2,（k+l2）2,…,（k+lg）2cannotbeexpressedas2n+pαisatleastc（g）x,wherepisanoddprimeandtheconstantc（g）dependsonlyong.

简介：

简介：Inthisarticle,westudytheexplicitexpressionsoftheconstantsintheerrorestimateofthenonconformingfiniteelementmethod.WeexplicitlyobtaintheapproximationerrorestimateandtheconsistencyerrorestimatefortheWilson'selementwithouttheregularassumption,respectively,whichimpliesthefinalfiniteelementerrorestimate.Suchexplicitapriorierrorestimatescanbeusedascomputableerrorbounds.

简介：K-phillipsite用一个热水的方法被准备。可溶的玻璃和钠铝酸盐当一个器官的模板不在时被用作原料。关于K+离子的调查在房间温度被进行在海水样品和混合K+Na+答案的选择系数决定离子交换能力。样品被X光检查衍射(XRD)描绘，扫描电子显微镜学(SEM)，和精力分散光谱学(版本)。K+离子交换能力是在海水的51mg/g，选择系数在混合K+Na+答案是75.1。样品为K+有选择偏爱，并且能因此被用来有选择地从海水提取钾。由Si，艾尔，K，Na，和O组成的样品展出跨like形状并且是典型K-phillipsite结构。

简介：

简介：Theoptimizationdesignofthepowersystemisessentialforstratosphericairshipswithparadoxicalrequirementsofhighreliabilityandlowweight.Themethodologyoforthogonalexperimentispresentedtodealwiththeproblemoftheoptimizationdesignoftheairship’spowersystem.Mathematicalmodelsofthesolararray,regenerativefuelcell,andpowermanagementsubsystem(PMS)arepresented.Thebasictheoryofthemethodoforthogonalexperimentisdiscussed,andtheselectionoffactorsandlevelsoftheexperimentandthechoiceoftheevaluationfunctionarealsorevealed.TheproposedmethodologyisvalidatedintheoptimizationdesignofthepowersystemoftheZhiYuan-2stratosphericairship.Resultsshowthattheoptimalconfigurationiseasilyobtainedthroughthismethodology.Furthermore,theoptimalconfigurationandthreesub-optimalconfigurationsareintheParetofrontierofthedesignspace.Sensitivityanalysesfortheweightandreliabilityoftheairship’spowersystemarepresented.

简介：TheauthorsconsiderthescatteringphenomenaofthedefocusingH~s-criticalNLS.ItisshownthatifasolutionofthedefocusingNLSremainsboundedinthecriticalhomogeneousSobolevnormonitsmaximalintervalofexistence,thenthesolutionisglobalandscatters.

简介：Lithiumsulfurbattery(LSB)offersseveraladvantagessuchasveryhighenergydensity,low-cost,andenvironmental-friendliness.However,itsuffersfromseriousdegradationofitsreversiblecapacitybecauseofthedissolutionofreactionintermediates,lithiumpolysulfides,intotheelectrolyte.Tosolvethislimitation,therearemanystudiesusinggraphene-basedmaterialsduetotheirexcellentmechanicalstrengthandhighconductivity.Comparedwithgraphene,grapheneoxide(GO)containsvariousoxygenfunctionalgroups,whichenhancethereactionwithlithiumpolysulfides.Here,weinvestigatedthepositiveeffectofusingGOmixedwithcarbonblackontheperformanceofcathodeinLSB.WehaveobservedasmallerdropofcapacityinGOmixedsulfurcathode.Wefurtherdemonstratethatthemechanisticoriginofreversibilityimprovement,asconfirmedthroughCVandRamanspectra,canbeexplainedbythestabilizationofsulfurinlithiumpolysulfideintermediatesbyoxygenfunctionalgroupsofGOtopreventdissolution.Ourfindingssuggestthattheuseofgrapheneoxide-basedcathodeisapromisingroutetosignificantlyimprovethereversibilityofcurrentLSB.

简介：

简介：AmethodtoidentifycomplexYoung’smodulusofviscoelasticmaterialsusingforcedlongitudinalvibrationofslenderrodsisproposed.Themethoddiffersfromthebeamone.Experimentaltestswerecarriedoutatroomtemperaturewithdifferentlengthsin108mm,100mm,90mm,83.5mm,80mm.74.5mm,70mmforthepolycarbonatebars,andthecurvesofratiosA2/A1betweentwoendsofaviscoelasticbarversusfrequenciesareobtained,furthermore,thecorresponding3dBbandwidthandthestorageandlossmoduluscanbecalculated.SufficientnumberofobtainedcomplexYoung’smodulusatdifferentfrequencyallowsustocalculateotheronesusingtheleastsquaremethod.Ifthestepofthetestedfrequencyis5Hz,themaximumerrorofresultscanbelessthan6%.Bycomparisonwiththemeasurementmethodswhichthepreviousliteraturementioned,thisnewmethodsimplifiesthecalculation,andthephysicalmeaningappearsapparentlyandclearly.

简介：

简介：Westudyboundaryvalueproblemsforfractionalintegro-differentialequationsinvolvingCaputoderivativeoforderα∈(n-1,n)inBanachspaces.ExistenceanduniquenessresultsofsolutionsareestablishedbyvirtueoftheHolder'sinequality,asuitablesingularGronwall'sinequalityandfixedpointtheoremviaaprioriestimatemethod.Atlast,examplesaregiventoillustratetheresults.

简介：

简介：DrivenbycuriosityaboutpossibleflightoptionsfortheChang’e-2spacecraftafteritremainsattheSun-EarthL2point,effectiveapproachesweredevelopedfordesigningpreliminaryfuel-optimalnear-Earthasteroidflybytrajectories.Theapproachesincludetheuseofmodifiedunstablemanifolds,gridsearchofthemanifolds’parameters,andatwo-impulsemaneuverfororbitalphasematchingandz-axisbiaschange,andaredemonstratedtobeeffectiveinasteroidtargetscreeningandtrajectoryoptimization.Asteroidflybysareexpectedtobewithinadistanceof2×107kmfromtheEarthowingtotheconstrainedEarth-spacecraftcommunicationrange.Inthiscase,thespacecraft’sorbitalmotionissignificantlyaffectedbythegravitiesofboththeSunandtheEarth,andtherefore,theconceptofthe"heliocentricoscillating-Keplerorbit"isproposed,becausetheclassicalorbitalelementsoftheflybytrajectoriesreferencedintheheliocentricinertialframeoscillatesignificantlywithrespecttotime.Theanalysisandresultspresentedinthisstudyshowthat,amongtheasteroidswhoseorbitsarethemostaccuratelypredicted,"Toutatis","2005NZ6",or"2010CL19"mightbeencounteredbyChang’e-2inlate2012or2013withtotalimpulseslessthan100m/s.

简介：随着有色金属选冶技术的发展，有色金属物料越来越复杂，对分析检测要求越来越高，为了加强各相关企业间的交流与合作，促进有色金属行业分析技术的推广与规范，进一步提升新技术、新仪器、新方法在有色金属分析中的应用，由中国分析测试协会、中国有色金属学会、中国矿业联合会、北京材料测试服务联盟主办，北京矿冶研究总院、国家重有色金属质量监督检验中心、《中国无机分析化学》编辑部承办，拟于2013年8月在北京举办“第一届全国有色金属分析检测与标准化技术交流研讨会”。会议将围绕有色金属分析中的热点、难点问题，探讨复杂原料与中间物料中主要计价元素及有害元素、高纯金属中痕量杂质元素分析方法，交流科研成果和实践经验。会议拟邀请有关领导以及国内分析测试领域知名专家学者作专题报告。热诚欢迎大家踊跃投稿和参加会议。

简介：金秋送爽,丹桂飘香,在收获的季节,2013年10月20-24日,＂第一届全国有色金属分析检测与标准化技术交流研讨会＂在北京展览馆宾馆隆重召开。会议由中国分析测试协会、中国有色金属学会、中国矿业联合会选矿委员会、北京材料分析测试服务联盟主办,北京矿冶研究总院、国家重有色金属质量监督检验中心、《中国无机分析化学》编辑部承办,得到仪器信息网、分析测试百科网、有色金属在线、安捷伦科技（中国）有限公司、岛津（中国）有限公司、德国耶拿分析仪器股份公司和北京海光仪器公司的热情参与和赞助。参加会议的代表150多人，包括国内多名在分析检测和标准化方面影响深远的知名专家学者和业内权威人士。