学科分类
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105 个结果
  • 简介:我国企业规模普遍较小,2002年中国企业500强平均资产规模只有2002年世界500强的6.46%,平均营业收入只有世界企业500强的5.26%;劳动生产率水平。中国企业500强的平均人均营业收入,人均利润、人均资产分别只有世界企业500强的12.95%、29.62和1.57%。

  • 标签: 中国 企业规模 营业收入 人均利润 技术开发
  • 简介:本文从F-的物质来源及影响F-活性的各个化学指标入手,对全省7个水文地球化学观测井进行分析并作出总体评价,指出ZⅢ-6钻孔、华安汰内井、安溪魁斗井的F-在理论上可作为前兆特征离子

  • 标签: 水化前兆 条件分析 特征离子
  • 简介:Theresultsof118REEanalysesofLi-FgranitesfromSouthChinaandothercountriesindicatethattherearethreevariationtypesofREEpatterncurveswithdifferentevolutiontrendsfromearlytolatestagesofLi-FgranitecomplexoffromlowertoupperpetrofaciesoftheLi-Fgranitebody;(1)thedecreasing,(2)theincreasing,and(3)thesaltatoryvariationtypes.Thefirstvariationtypeiscalledthepositiveevolutiontype,attributedtocrystallizationdifferentiation.Thesecondiscalledthereversionevolutiontype.whichrepresentsliquidsegreationdominatedbyvapor-liquiddistillation.Thethirdiscalledthesaltatoryvariationtype,whichisformedfromliquidsegregationdominatedbyimmiscibilty,Therefore,theindicaticesofliquidsegregationdominatedbyimmiscibilityarethesaltatoryvariationtypeofREEpatternevolutionandtheseparationofthemainevolutiontrendlineseitherfromthesub-evolutiontrendlinesorfromthecompositionpointsofLi-FgranitesinthediagramsofREE-(La-Yb)NandLa/Sm-La,Theindicatricesofliquidsegregationdominatedbyvapor-liquidfractionaldistillationarethereverstionevolutiontypeofREEpatterncurvesandthemainevolutiontrendlinesofLi-Fgranitesdirectingtotheupperright-handontheREE-La/Yb)NandLa/Sm-Ladiagrams.

  • 标签: 稀土元素 地球化学 花岗岩 岩浆
  • 简介:WintertemperatureinChinaduringthelast500yearswasconstructedbasedonhistoricaldataaboutthefreeze-upevents,theheavysnowandtheagriculturaldamagesbroughtaboutbycoldweathersinEastChina(25°N--35°N,115°E--120°E).Fisrt,thedataaboutthefreezingofriversandlakesandthoseaboutsnowfallinthisregionwerecompiledandevaluatedonthebasisofanordinalscale.Thentheseriesoffreeze-upeventsandheavysnowwereproducedseparatelyandthecombinationoftheseserieswasmadetogenerateaconsistentseriesthatreflectsthechangesinthedegreeofcoldnessinwinterduringthelast500years.Finally,areconstructionofwintertemperaturewascarriedoutataresolutionof10yearsbasedonacalibrationofaregressionbetweenrecenttemperatureobservationsandthecoldwinterseriesconstructed.

  • 标签: WINTER HISTORICAL DAMAGES extreme RIVERS SEASONAL