简介:摘要:根据高速公路采用 ( 70+70 ) mV 型刚构转体桥跨运营客运专线的成功案例,对此种桥型的设计特点作了介绍, 为同类桥梁的设计研究提供参考和借鉴。
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.
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,itspossibletonarrowdownthescopeofthelocationinearthquakepredictionfromthedistantandnearstationdata.ThecalculationsofDongshanseismicstationindicatethatthesizeoftheresidualoftheorigintimehasimpactonthedetailofV_P/V_Svariation,thus,appropriatethresholdsshouldfirstlybesetfortheresidualsoforigintimeateachseismicstationinpracticalapplication,toensurescientificandsteadyV_P/V_Scalculations.
简介:下扬子地区二叠纪缺氧环境沉积物V/(V+Ni)特征李双应,金福全(合肥工业大学资源与环境科学系,合肥230009)关键词V/(V+Ni)比值,缺氧环境,二叠纪,下扬子地区下扬子地区二叠纪的缺氧沉积,近年来引起了许多研究者的关注[1~3]。这一方面是因...
简介:<正>所谓3S技术即GPS、GIS、RS技术。GPS(全球定位系统)是英文缩写词NAVSTAR/GPS(NAVigationSystemTimeAndRanging/GlobalPositioningSystem)的简称。全称应为“测时测距导航系统/全球定位系统”。GPS是由美国研制,并投入实际应用的最新卫星定位系统。其主要目的是为飞机和船舶导航定位。也可以用于其它多种目的。GPS技术已在航空、航天、航海、军事、地质、石油、勘探、交通、测绘等领域得到广泛的应用。美国于1993年6月26日已将GPS21颗卫星和3颗备用卫星全部发射入轨。