简介：OnJune2011,theBeijingResearchInstituteofUraniumGeology,anInstitutewithintheChinaNationalNuclearCorporation(CNNC),andtheDepartmentofGeology&MiningCNNCcarriedoutaprojectScientificDrillingforDeepMetallogenicResearchintheXiangshanLargeUraniumOreField.AyearlateronJune21,theproject,representingthefirstscientificdrillingofChina’suranium,wasofficiallylaunched,andsuccessfullycompletedonJune17,2013.A2818.88mofdrillingdepthhasbrokenthepreviousrecord1200mofexplorationdepth.TheXD-35DBdrillingmachinedevelopedbyChinaGeo-EquipmentCorporationistheChina’sfirstAC-VFDDirectDriveTopDriveCoreDrill.Ithasgreatlyimproved

简介：SeismicPvelocitystructureisdeterminedfortheupper500kmoftheinnercoreandlowermost200kmoftheoutercorefromdifferentialtraveltimesandamplituderatios.ResultsconfirmtheexistenceofagloballyuniformFregionofreducedPvelocitygradientinthelowermostoutercore,consistentwithironenrichmentneartheboundaryofasolidifyinginnercore.Pvelocityoftheinnercorebetweenthelongitudes45oEand180oE(quasi-EasternHemisphere)isgreaterthanorequaltothatofanAK135-Freferencemodelwhereasthatbetween180oWand45oE(quasi-WesternHemisphere)islessthanthatofthereferencemodel.Observationofthisheterogeneitytoadepthof550kmbelowtheinnercoreandtheexistenceoftransitionsratherthansharpboundariesbetweenquasi-hemispheresfavoreithernoorveryslowinnercoresuperrotationoroscillationswithrespecttothemantle.DegreeoneseismicheterogeneitymaybebestexplainedbyactiveinnercorefreezingbeneaththeequatorialIndianOceandominatingstructureinthequasi-EasternHemisphereandinnercoremeltingbeneathequatorialPacificdominatingstructureinthequasi-WesternHemisphere.Variationsinwaveformsalsosuggesttheexistenceofsmaller-scale(1to100km)heterogeneity.

简介：Separationtechnologyofrareearthelements(REEs),asthecriticalstepintheseparationprocess,hadlongbeenfraughtwithtechnicaldifficulty.AresearchprojectconductedbyBaotouShiboRareEarthExtraction&EquipmentCo.Ltd.,BaotouREEResearchInstitute,andBaotouSteel&REEGroupHi-TechCo.Ltd(InnerMongolia),hassuccessfullysolvedtheproblemusingacentrifugalextractorandadvancedtechniquestoachieveakeybreakthrough.ThekeydeviceofthewholeproductionlinecontainsCTL-500FBcentrifugalextractorsanddigitalflowsystemequipment.Employmentofanautomaticcontrollingsystemanditsfullyfunctionaloperationsystem,alongwithvarioussupportivefacilities,fulfilstheseparationprocessesforvariousrareearthmaterials.Comparedwithconventionalbox-typeseparationtechnology,thisnewapproachsignificantlyimprovesthestirringintensity,thusimprovingproduction

简介：同位素技术是研究区域地下水循环规律的主要手段之一。本文对平原区地下水进行了取样分析，运用同位素技术并结合水文地质条件，研究了北京市平原区地下水循环演化规律。运用^3H和^14C的测年技术确定了地下水年龄；利用D和18^O关系曲线探讨了地下水的起源；按照是否积极参加了现代水循环的原则将第四系地下水划分为浅层水和深层水；对浅层水和深层水的更新状况进行了研究。研究表明，浅层水广泛分布于北京平原区，径流条件好，更新快；深层水主要分布于永定河、潮白河冲洪积扇下部及冲洪积平原的深部地区，补给条件相对差，与现代大气降水联系弱，径流条件差，更新慢。