简介：本文提出了一种新的反演方法:通过采用纵、横波走时数据对(从相同的震源产生的P和S波被同一台站记录)来联合反演纵波速度(Vp)和纵、横波速度比(Vp/Vs),然后单独反演横波速度Vs,在反演过程中同时对地震参数进行定位。该方法不需要假设P和S波的射线路径一致,它是沿着P和S波射线路径计算相对慢度扰动值。该方法直接把Vp/Vs作为一个模型参数,由此能获得比采用从独立反演获得的Vp和Vs计算出Vp/Vs的方法更精确的速度比值。该新方法被应用到反演日本东北地区的壳幔速度及波速比结构的研究中,获得了较好的效果。反演结果表明,在日本东北地区,太平洋俯冲板块为一高Vp,高Vs和低Vp/Vs异常区,而在活火山下方的浅部地幔楔以及背弧深部地区为低Vp,低VS和高Vp/VS异常。虽然这些特征在前人的研究中已经报道过,但与前人的研究结果相比,本次研究所获得的Vp/Vs的空间分布具有较小的分散性,同时,它的分布特征能较好的与地震波速度结构相吻合。

简介：ShanxiGrabenisinthemiddlepartoftheNorthChinaCraton,fromsouthtonorth.WiththeteleseismicdatarecordedbyRegionalSeismographNetworksandthetemporaryZBnet-WSeismicArrayaroundeastpartofShanxiGraben,wemeasuredthecrustalthicknessandvP/vSratiobeneatheachstationusingtheH-jstackofreceiverfunctions.Theobservedcrustalthicknessshowsobviouslateralvariation,increasinggraduallyfromeasttowestintheShanxiGraben.BeneaththeShanxiGrabenthecrustisrelativelythickerthanbothsidesofthesouthandthenorth.Inaddition,thevP/vSratiointhenorthofstudyzoneishigherthanthatinthesouth.ThehighestvP/vSratioexistsinthecrustoftheXindingbasinandtheDatongbasin.Ourstudyalsosuggeststhathighvelocityratiomightresultfromthestrongactivitiesofthemagmationandvolcanism.

简介：ThegeologicalstructureiscomplexintheHohhot-Baotouarea.SeveralearthquakeswithMS≥6.0haveoccurredintheareainhistory.ThisarticleselectedtheHohhot-Baotouareaasthestudyregionanddivideditinto2sub-regions,eachwithaspatialscopeof3°×2°,accordingtothespatialdistributionofML≥1.0earthquakesoccurringbetweenJanuary2001andApril2010,andthelayoutoftheseismicnetworkinthestudyregion.Averagevelocityratiosofrespectivesub-regionswerecalculated,andcomparativeanalysiswasmadeontheirtemporalandspatialvariations.Resultsshowthatthereareslightdifferencesbetweensub-regionsinthevariationamplitudeofaveragevelocityratiocurvesovertime,whichmostlyremainsbetween2.5%to2.584%.IntheHohhotarea,theaveragevelocityratiois1.722,significantlylowerthantheaveragevelocityratioof1.733intheBaotouarea.WepreliminarilyconcludedthatthiswasrelatedtothedistributionoffaultstructuresandpropertiesofundergroundmediaintheHohhotarea.

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简介：Whitespotsyndromevirus(WSSV)isoneofthemajorshrimppathogenscausinglargeeconomiclossestoshrimpfarming.Inanattempttoidentifytheenvelopeproteinsinvolvedinthevirusinfection,purifiedWSSVvirionsweremixedwiththreeantiseraagainstWSSVenvelopeproteins(VP39,VP124andVP187),individually.Andthentheywereinjectedintramuscularlyintocrayfish(Procambarusclarkii)toconductinvivoneutralizationassays.TheresultsshowedthatforgroupsinjectedwithvirionsonlyandgroupsinjectedwiththemixtureofvirionsandantiserumagainstVP124,thecrayfishmortalitieswere100%and60%onthe8thdaypostinfection,individually.ThevirusinfectioncouldbedelayedorneutralizedbyantibodyagainsttheenvelopeproteinVP124.QuantitativePCRwasusedtofurtherinvestigatetheinfluenceofthreeantiseradescribedaboveonthevirusinfection.TheresultsshowedthattheantiserumagainstVP124couldrestrainthepropagationofWSSVincrayfish.AlloftheresultssuggestedthattheviralenvelopeproteinVP124playedaroleinWSSVinfection.

简介：BasedonarrivaltimedataofseismicphasesofML≥2.0earthquakesmeasuredatShanxiDigitalSeismicNetworkfortheperiodfromJanuary2001toOctober2014,V_P/V_SintheShanxiregioniscalculatedusingtheWadatisinglestationandmulti-earthquakemethod,andaninvestigationisconductedintothevariationbehaviorofV_P/V_SintheShanxiregionbeforeandafterthethreeearthquakesofMS≥4.5in2010.OurstudyfindsthatabnormalV_P/V_Sappearedearlieratdistantstationsbeforeallofthethreeearthquakes,whichisatthetimerangefrom6monthsto1yearbeforetheearthquakes,andlateratnearstations,atthetimerange10daysto2monthsbeforeearthquakes.Therefore,itspossibletonarrowdownthescopeofthelocationinearthquakepredictionfromthedistantandnearstationdata.ThecalculationsofDongshanseismicstationindicatethatthesizeoftheresidualoftheorigintimehasimpactonthedetailofV_P/V_Svariation,thus,appropriatethresholdsshouldfirstlybesetfortheresidualsoforigintimeateachseismicstationinpracticalapplication,toensurescientificandsteadyV_P/V_Scalculations.