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简介：SeveralearthquakeswithMs≥5.0occurredintheDatongseismicregionin1989,1991and1999,TheprecisefocuslocationoftheearthquakesequencewasmadebytherecordsoftheremotesensingseismicstationnetworkinDatong.Usingthatdatatogetherwithmacro-intensitydistributionandfocalmechanismsolutions,weanalyzethedifferenceamongthreesubsequences.Theresultsshowthatthefocalfaultofthe1999Ms5.6earthquakewasaNWW-trendingleft-lateralstrike-slipfault.Itis16kmlongand12kmwide.Itdevelopedatthedepthof5kmandisnearlyverticalindip.Thetwopreviousearthquakesubsequences,however,weregeneratedbyactivityalongNNE-trendingright-lateralstrike-slipfault.Itcanbefoundthattherupturedirectioinofthe1999earthquakehaschanged.Itisgenerallyfoundthatarupturezonehasmorethantwodirectionsandhasdifferentstrengthalongthesetwodirections.Thecomplicatedegreeoffocalcircumstanceisrelatedtothetypeofearthquakesequences.ThereistheNE-trendingDawangcunfaultandtheNW-trendingTuanbufaultintheseismicregion,butnoproofindicatesaconnectionbetweenfocalfaultsandthesetwotectonicfaults.Thefeaturethatfocalfaultsofthreesubsequencesarestrike-slipisdifferentfromthatofthetwotectonicfaults.Itissuggestedthatthe1999earthquakesubsequencewaspossiblygeneratedbyanewrupture.

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简介：Usingthe78focalmechanismsolutionsoftheforeshocks,mainshockandaftershocksoftheearthquakesequencefortheYao'anearthquake,thecharacteristicsofthefocalfaultsandstressfieldfortheearthquakesequenceareanalyzed.TheresultsshowthatthemainruptureplaneoftheYao'anearthquakesequenceisatectonicfaultwithN50°Wstrikeandsteepdipandallthemainshock,theforeshocksandthevastmajorityofaftershocksoccurredonthemainruptureplane.AtectonicfracturewithNNE-NEstrikealsoparticipatedindevelopmentprocessofthesequencedominatedbyprincipalcompressionalstresswithnearlyhorizontalorientationSSEisconsistentwiththeregionaltectonicstressfield.Inthesequencedevelopment,thestressfieldinthefocalregionwascomplexwithmultiaximuthsandmulti-actionmodelsandthefocalruptureshowedcomplexfeatureswithmulti-directionsandmulti-patterns.

简介：目的：探讨局灶性脑缺血再灌注大鼠病理学改变以及针刺的干预作用。方法：采用线栓法建立缺血再灌注模型，应用“醒脑开窍”针法并通过电镜与光镜来观察缺血侧大脑皮层形态结构的变化。结果：脑缺血再灌注可引发大鼠脑神经元、胶质细胞、毛细血管等结构损伤，针剌可改善脑缺血周围区超微结构损伤。并且发现在3h时间点给予针刺干预较其他时间点理想。结论：针刺对局灶性脑缺血再灌注大鼠脑神经细胞超微结构损伤具有保护作用。在3h内给予针刺干预可以收到满意的效果。

简介：TheRedRiverFaultZoneisagiganticslide-slipfaultzoneextendingupto1000kmfromTibettoSouthChinaSea.Ithasbeendividedintothenorth,centralandsouthsegmentsaccordingtothedifferenceofthegeometry,kinetics,andseismicityontheland,butaccordingtothecontactedrelationshipbetweentheoldpre-CenozoicblockinIndochinaPeninsulaandtheSouthChinablock,theRedRiverFaultZonewasdividedintotwopartsextendingfromlandtoocean,thenorthandsouthsegments.SincetheTertiary,theRedRiverFaultZonesufferedfirstthesinistralmovementandthenthedextralmovement.Theactivitiesofthenorthandthesouthsegmentsweredifferent.Basedontheanalysisofearthquakesandfocalmechanismsolutions,earthquakeswiththefocusdepthsof0-33kmaredistributedoverthewholeregionandmoredeepearthquakesaredistributedonthenortheasternsidesoftheRedRiverfault.Typesoffaultingactivitiesarethethrustinthenorthwest,thenormalinthenorthandthestrike-slipinthesouth,withtheoddtype,viz.thetransitiontype,intheotherregion.TheseshowtheRedRiverFaultZoneanditsadjacentregionsufferedtheextrudingforceinNNWdirectionandthenormalstressinNEEdirectionanditmakesthefaultintheregionextrude-thrust,horizontalstrike-slipandextensionalnormalmovement.

简介：Ｃｏｍｐｌｅｘ　ｔｉｍｅ－ｓｐａｃｅ　ｓｐｒｅａｄｉｎｇ　ａｎｄ　ｆｏｃａｌ　ｍｅｃｈａｎｉｓｍ　ｏｆ　ｔｈｅ　１９８９　Ｂａｔａｎｇ　ｅａｒｔｈｑｕａｋｅ　ｓｗａｒｍ　（Ｍ＿ｓ＝６．７）（程万正）（陈天长）Ｃｏｍｐｌｅｘｔｉｍｅ－ｓｐａｃｅｓｐｒｅ...

简介：Basedonwaveformdata,severalmethodstodeterminefocalmechanismsofsmallearthquakesweredevelopedsince1980.Kisslinger(1980)andJulian,Foulger(1996)proposedanapproachtodeterminesolutionbyusingamplituderatioofPandSwave.Schwartz(1995)devisedamethodtodeterminesolutionsbytheuseofpolaritydataandamplitudesofseismogramenvelopes.Amplitudesofshortperiodseismicwavespropagatinginaninhomogene-ousmediumaresensitivetothevariationinvelocityandQstructure.Nakamura,etal(1999)tookmediuminhomo-geneityintoaccountindeterminingfocalmechanismsofsmallearthquakesusingwaveformdata.Ifthelocationsofsmallearthquakesareconcentratedinasmallregion,wecanassumethattheraypathsfromtheeventstoagivenstationarealmostthesame.SoPandSwaveattenuationsareindependentofeventlocations.Inthiscaseitiscon-venienttodeterminefocalmechanismsoftheseeventsbyusingshortperiodPandSwavedataj.Focalmechanismsolutionsofsmallearthquakesin5regions,i.e.,Rongchang,Mabian-Muchuan,Ya￠an,BaoxingandMianzhu,whicharecoveredbytheChengduTelemeteredNetwork,areobtainedbyanalyzingthePpolarityandshortbodywaveamplitudedatarecordedinthenetworksince1992.AccordingtothemethodproposedbyGephartandForsyth(1984),basedonwelldeterminedfocalmechanismsolutionsin15sub-zonesofSichuanandYunnanarea,threeprincipalstresstensorss1,s2,ands3,insteadofaveragesofP,B,andTaxisofthesolutions,aredeterminedtorepresenttheregionalstressfielddistribution.

简介：AIMProstaglandinA1(PGA1)isacyclopentenoneprostaglandin.Recently,wereportedthatPGA1caninhibitexcitotoxin-inducedapoptosisofstriatalneuronsinvivoandrotenone-inducedapoptosisofculturedSH-SY5Ycells,suggestingthatPGA1mayhaveneuroprotectiveefficacy,possiblymediatedbyinhibitionofNF-kBactivation.ThepresentstudyevaluatedtheneuroprotectivepotentialofPGA1anditseffectonIKK/I(B/NF-kB/c-mycsignalingpathwayinratmodelsofpermanentfocalcerebralischemia.METHODSPermanentmiddlecerebralarteryocclusion(pMCAO)modelwasconstructedbyintraluminalsuturecannulationthroughtheinternalcarotidarteryinWistarrats.