简介:分别地,发生在北京和天津的二下得很大的冰雹被调查,主要基于系统dAlerteFondre同等InterferometricRadioelecctrique(SAFIR3000)观察的全部的闪电数据,一个CG闪电地点系统的cloud-to-ground(CG)闪电数据,并且一架Doppler雷达的回响数据。两下得很大的冰雹展出了二座闪电频率山峰:第一在hailfall前,第二在hailfall以后,与比第一大的第二座山峰。CG闪电的主导的极性在在第一座频率山峰附近的阶段是积极的,但是改变了到在在第二座频率山峰附近的阶段否定。雷达回响的进化和闪电放射来源的高度分发被探索,表明下得很大的冰雹有更强壮的传送对流,主要正电荷发生在在在第一座频率山峰附近的阶段期间的中间的层次。然而,虽然北京下得很大的冰雹经历了传送对流的改进,与在在第二座频率山峰附近的上面的层次的主要正电荷,当传送对流不停地变弱,主要正电荷落下到中间降低层次时,天津下得很大的冰雹在时期期间产生了它的第二座频率山峰。通过雷达参数的评估,我们调查为活跃闪电分泌物的第二个阶段负责的机制。而且,闪电活动与雷达回响参数和hailfall展出了一种靠近的关系。闪电跳信号在hailfall前被发现并且与1.87ogic网孔在15tions上面与40-dBZ回响卷的变化比率被联系如果反对?????
简介:读下面的歌谣,根据歌谣内容给图中两个风筝涂上颜色。AMykiteisredandgreen,It'syellow,blackandblue,It'sorangeandit'sbrown,It'swhiteandpurple(紫色的)too.
简介:Weidentifytwointerrelatedbutindependentspeciesofmicrocrackswithdifferentoriginsanddifferentdistributions.Onespeciesistheclassichigh-stressmicrocracksidentifiedinlaboratorystress-cellsassociatedwithacousticemissionsasmicrocracksopenwithincreasingstress.Theotherspeciesisthelow-stressdistributionsofclosely-spacedstress-alignedfluid-saturatedmicrocracksthatobservationsofshear-wavesplitting(SWS)demonstratepervadealmostallinsiturocksintheuppercrust,thelowercrust,andtheuppermost400kmofthemantle.Onsomeoccasionsthesetwosetsofmicrocracksmaybeinterrelatedandsimilar(hence'species')buttheytypicallyhavefundamentally-differentproperties,differentdistributions,anddifferentimplications.TheimportanceforhydrocarbonexplorationandrecoveryisthatSWSinhydrocarbonreservoirsmonitorscrackalignmentsandpreferreddirectionsoffluid-flow.TheimportanceforearthquakeseismologyisthatSWSabovesmallearthquakesmonitorstheeffectsofincreasingstressonthepervasivelow-stressmicrocrackdistributionssothatstress-accumulationbefore,possiblydistant,earthquakescanberecognisedandimpendin~earthquakesstress-forecast.