简介：应用于矿产勘查的地下纳米物质刘应汉任天祥汪明启（地质矿产部物化探所，河北廊坊０６５０００））关键词纳米物质地球化学测量矿产勘查收稿日期：１９９６－１２－２４修改稿：１９９７－３－１７第一作者简介：刘应汉男１９６５年生工程师勘查地球化学诞生于９０年代的...

简介：Icecoreδ18OrecordefromtheNo.aglacierattheheadoftheUrumqiRiverwereusedocharacterizetherelationshipbetweenδ18Oandcontemporaneoussurfaceairtemperature(Ta)nearbytheDaxigouMeteorologicalStation(3539mabovesealevel,-2kmawayfromtheicecoredrillingsite),Althoughtheicecorerecordsofannuallyaveragedδ18Oarepositivelycorrelatedwithconemporaneoussurfaceairtemperature,especiallysummerairtemperature,thecorrelationislesssignificantthanthatfortheprecipitationsamplesduetodepositionalandpost-depositionalmodificationprocesses,However,theClimatologicalsignificanceoftheicecorδ18Orecordscanbestillpreservedtoacertaindegree,whichmoghtextendtheapplicationofhighaltitudeandsub-tropicalicecoreδ18Orecordstopaleoclimatereconstruction.

简介：ExperimentshavebeenperformedonthesystemMgO-SiO2-Cr-Oat0-2.88GPaand1100-1450℃,focusingonthestabilityofCr^2+inolivine(O1),orthopyroxene(Opx)andspinel(Sp)anditspartitioningbetweenthesephases.Analyticalreagentgradechemicals,MgO,SiO2,Cr2O3.andCrwereusedtomakestartingmixtures.ExcessCr(50%)wasthenaddedinthesemixturestoensurethattheresultantphaseswereinequilibriumwiththemetalCr.FluxofBaO+B2O3(%)wasaddedforfacilitatingexperimentalequilibriumandcrystalgrowth.Crwasusedascapsulematerial.AllphasesintheproductwereidentifiedbyX-rayandanalyzedbyelectronmicroprobe,ThecontentsofCrOinthedifferentphases(O1,OpxandSp)werecalculatedaccordingtostoichiometry.TheobtainedresultsofcalculationindicatethatCr^3+inOlandOpxisnegligible.Theexperimentalresultsshow;(a)withincreasingtemperatureanddecreasingpressure,Cr^2+solubilityinOl,OpxandSpincreases;(b)withincreasingtemperature,thepartitioningcoefficientofMgandCr^2+betweenOlandOpxdecreases,thatbetweenOpxandSpincreases,andthatbetweenOlandSpremainsalmostunchanged;(c)theeffectofpressureonallpartitioningcoefficientsisnegligible.

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简介：神农架滑雪场位于国家级自然保护区的边缘地带.运用景观生态学原理和方法,采用3S技术,对滑雪场景观生态体系的结构和功能状况进行评价,通过景观多样性指数、景观聚集度指数等指标量化计算及比较分析,预测了项目建成后对所在区域生态完整性的影响程度及将造成的敏感生态问题.结果表明,评价区自然系统的生物量将减少430.26t,平均净生产力降低为881.55g/m^2·a,项目建设不会改变林地的模地地位,其对生态环境质量仍有较强的调控能力.3S技术结合景观生态学方法将生态环境影响评价由定性评价转向定量预测,为建设项目生态影响评价研究作了有益的探索.