简介:TheBaimazhainickeldeposit,YunnanProvince,China,islocatedinthesouthernpartoftheSanjiang(Tri-river)alkali-richintrusiverockbelt(SanjiangARIR).Inthispaperwasconducted40Ar-39Ardatingoftwophlogopitesinlamprophyreswhichare,asdikes,widelydistributedintheorefield,andtwoplateauageswereac-quired,i.e.,32.46±0.62Maand32.01±0.60Ma,respectively(averaging32.23±0.60Ma).Theagesareobviouslyyoungerthanthoseoftheore-hostedcomplexandmineralizationoftheBaimazhainickeldeposit.Incombinationwiththecharacteristics,itisindicatedthatlamprophyresintheorefieldandthoseintheSanjiangARIRaresimilarintectonicsetting,mineralassemblageandgeochemistry.Itisconsideredthatlamprophyresintheorefieldaretheim-portantcomponentoftheSanjiangARIR,andthelamprophyresandore-hostedcomplexintheorefieldrepresenttheproductsoftwotimesofdifferentmagmaticactivityfromdifferentmantlesources.Ontheotherhand,theageoflamprophyresintheorefieldisolderthanthatofthestrike-slipshearingoftheAilaoshan-Honghefaultbelt,sug-gestingthatthestrike-slipshearingoftheAilaoshan-Honghefaultbeltisnotthefactorleadingtomagmaticactivityoflamprophyresintheorefield,whileitismorepossiblethatmagmaticactivityoftheSanjiangARIRpromotedstrike-slipshearingofthefaultbelt.
简介:“ThetravelsoftheCaesarsbringinmostaspectsofimperialhistory”.SuchwastheassertionofSymeinhissurveyoftheperipateticreignofHadrian(1988,159).AfterHadrian,thenextjourneyofrealsignificanceundertaknbyanemperorwasthatofLuciusVerus,whospentfiveyearsawayfromRomeascommanderofmilitarycampaignsintheeast.Thesetravels,likethoseofHadrian,
简介:活动特定的网络(MANET)是有能是的无线移动式节点的一种很复杂的分布式的通信系统自由地并且动态地self-organizedinto任意、暂时的网络拓扑。MANET继承无线网络的几限制,同时使从MANET的特性产生的新挑战例如线路失败,隐藏终端和暴露的终端。当TCP在MANET环境被使用时,问题不得不被处理的流氓的棕土。在这篇论文,这块动态地上的全面调查被给。明确地,第一次,损害TCP性能的所有因素基于网络协议分级被识别,即,在物理层的有损耗的无线隧道;在MAC层的过多的竞争和不公平的存取;在网络层,MAC层和网络层的脆弱的路由选择协议联系了移动式节点;在传送层和传送层的不适宜的拥挤窗口大小联系了不对称的路径。这些因素怎么降级TCPperformance清楚地被解释。基于怎么减轻每上面列出的这些因素的影响,然后,存在答案尽可能包括地被收集并且分类进很多个范畴,和他们的优点和限制被讨论。这些答案的基于的在限制,为设计更柔韧的答案的一套开的问题被建议。
简介:Inmobileadhocnetworks(MANET),nodesmovefreelyandthedistributionofaccessrequestschangesdynamically.Replicaallocationinsuchadynamicenvironmentisasignificantchallenge.Inthispaoer,adynamicadaptivereplicaallocationalgorithmthatcanadapttothenodesmotionisproposedtominimizethecommunicationcostofobjectaccess.Whenchangesoccurintheaccessrequestsoftheobjectorthenetworktopology,eachreplicanodecollectsaccessrequestsfromitsneighborsandmakesdecisionslocallytoexpandreplicatoneighborsortorelinquishthereplica.Thealgorithmdynamicallyadaptsthereplicaallocationschemetoalocaloptimalone.SimulationresultsshowthatouralgorithmsefficientlyreducethecommunicationcostofobjectaccessinMANETenvironment.