简介:CH4emissionrateshavebeenmeasuredcontinuouslyfortheearlyriceof1988andlatericesof1987and1988duringentiregrowingseasonsinaricepaddyfieldinHangzhou,ZhejiangProvince,China,byusinganautomaticsamplingandanalyzingsystem.DuringmostpartsoftheseasonsCH4emissionratesshowedstrongdiurnalvariations.Bi-modepatternswiththehighestvalueintheafternoonandasecondpeakatmid-nightweregenerallyfoundfortheearlyrice,whilethehighestvalueswerealmostalwaysfoundinthenightforthelaterice.Bi-modepatternswithasecondpeakintheafternoonwerealsofoundduringthereproductivephaseofthelatericeplants.Thesediurnalvariationsmaybeexplainedbythediurnalvariationsofthesoiltemperatureandtheactivityofriceplants.Strongseasonalvariationswithonepeakinthetilleringstageandtwoduringthereproductivephaseofriceplantswereobservedforallthethreegrowingseasons.Theseasonalvariationsmaybeexplainedbytheactivityofriceplants,availabilityoforganicsubstratesinthesoil,andtheactivityofsoilbacteriarelatedtosoiltemperatures,FertilizationdidnotshowsignificanteffectsonthetotalseasonalCH4emissionsbutslightlychangedthepatternoftheseasonalvariationsoftheCH4emissionrates.Averagedoverthemeasuringperiodsand8spots,CH4emissionratesof7.8mgm-2h-1fortheearlyriceand28.6mgm-2h-1forthelatericewereobtained.Basedonthesemeasureddata,thetotalglobalemissionofCH4fromricepaddiesisestimatedtobeabout90Tg/yrrangingfrom70to110,accountingfor20%ofthetotalsourceofCH4.
简介:Acomprehensivestrengthmonitoringsystemusedonafixedjacketplatformispresentedinthispaper.Thelong-termmonitoringofW-11-4Aplatformachieved.Structuralresponses(strainandacceleration)atselectedlocations,aswellasassociatedenvironmentalparameters,havebeenobtained.Theemphasisofthepaperisplacedonthesystemdesign,andtheinstrumentationandoperationmethodologyemployedinthemonitoringofthestructuralresponses.Theperformanceofthesystemandthecharacteristicresultsobtainedduringits13-monthoperationarealsosummarized.
简介:
简介:在在M_W9.0地震前的不同时间空间的领域的地震活动的特征被学习。结果如下:①T他在澳大利亚的板的北方边界地区的深地震的活动是显然加强的since1994,显示出增加的频率,大小和深度,特别关于地震深度的异构的分发(也就是在500km和689km之间)。同时thes使神圣7.0显然在苏门答腊岛和它的附近是的M≥的地震也加强了,并且与一段大约1000km和宽度300km②T形成了一个加强的区域他有7.0显示出的M≥的全球强震的时间分发异常地震静止活动的特性在M_W9.0地震前并且在它的活跃句号期间的年,强震形成了在NWW方向罢工的一条地震的带。同时,有地震差距,M≥的地震形成5.0在震中和它的附近的区域。③TwoM≥的深地震7.0半年以前发生在西方并且在澳大利亚的板的北方边界地区的东方。他们之一在在哪儿的苏门答腊岛发生了,是著名的有M≥的没有深地震6.0发生在过去的三十年里。三天以前发生的中等震动的④Thespace分发展出了NWW罢工沿着澳大利亚的板的北方边界地区的地震的带。⑤T他在澳大利亚的板的北方边界地区散布的火山的活动在过去的4年里被加强了,特别在M_W9.0地震的出现前的几个月。
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:BasedonthewaveformdataobservedbytheregionalseismicnetworkofGansuProvince,wecalculatedtheapparentstressof422earthquakeswithM_L≥2.0occurringinthesurroundingareaoftheMinxianearthquakefromJanuary2010toJuly2014andobtainedthetemporalandspatialvariationofapparentstressbeforeandaftertheMinxianearthquake.Resultsshowthat(1)thehighvalueofapparentstressofearthquakeswithM_L≥4.0wasconcentratedintheepicenterareabeforetheMinxianearthquakewhilethatofearthquakeswithM_L<4.0wasnot;(2)ApparentstressaroundtheepicenterareashowedanobviousincreasingprocessbeforetheMinxianearthquakeandtheincreasingprocesshascontinuedafterthemainshock,whichmeansthatthisstudyareaisstillinthedangerofstrongearthquakes.
简介:介绍了用于上海天文台佘山25m射电望远镜VLBI观测站S2-PT终端的S2FS(S2FieldSystem)控制软件。该软件在甚长基线干涉测量(VLBI)实验中,能实现S2终端系统记录观测数据自动化。
简介:摘要:我公司设计研发的 TPZ80/2500型节段拼装造桥机可同时架设铁路 64m简支箱梁及 80m跨连续箱梁,并成功应用于京唐铁路潮白河特大桥 2联( 48+80+48) m连续梁胶接拼装施工。本文主要阐述了造桥机总体构造设计理念及优势,采用 MIDAS/Civil软件进行造桥机整体结构计算,对关键部位进行手算,保证造桥机各项设计均满足规范要求并达到安全使用的目的。该造桥机适应能力强,自动化程度高,操作简便,工效高,安全可靠。该造桥机的设计理念及计算过程,对同类设计具有借鉴意义。
简介:Significantpostseismicdeformationofthe2008MW7.9WenchuanearthquakehasbeenobservedfromGPSdataofthefirst14daysaftertheearthquake.Thepossiblemechanismsfortherapidpostseismicdeformationareassumedtobeafterslipontheearthquakeruptureplaneandviscoelasticrelaxationofcoseismicllystresschangeinthelowercrustoruppermantle.WefirstlyusetheconstrainedleastsquaresmethodtofindanafterslipmodelwhichcanfittheGPSdatabest.Theafterslipmodelcanexplainnear-fielddataverywellbutshowsconsiderablediscrepanciesinfittingfar-fielddata.Toestimatetheeffectduetotheviscoelasticrelaxationinthelowercrust,wethenignorethecontributionfromtheafterslipandattempttoinverttheviscositystructurebeneaththeLongmenshanfaultwheretheWenchuanearthquakeoccurredfromthepostseismicdeformationdata.Forthispurpose,weuseaviscoelasticmodelwitha2DgeometrybasedonthegeologicalandseismologicalobservationsandthecoseismicslipdistributionderivedfromthecoseismicGPSandInSARdata.Bymeansofagridsearchwefindthattheoptimumviscosityis9×1018Pa·sforthemiddle-lowercrustintheChengduBasin,4×1017Pa·sforthemiddle-lowercrustintheChuanxiPlateauand7×1017Pa·sforthelowvelocityzoneintheChuanxiplateau.Theviscoelasticmodelexplainsthepostseismicdeformationobservedinthefar-fieldsatisfactorily,butitisconsiderablyworsethantheafterslipmodelinfittingthenear-faultdata.Itsuggeststhereforeahybridmodelincludingbothafterslipandrelaxationeffects.Sincetheviscoelasticmodelproducesmainlythefar-fieldsurfacedeformationandhasfewerdegreeoffreedoms(threeviscosityparameters)thantheafterslipmodelwithahugenumberofsourceparameters,wefixtheviscositiystructureasobtainedbeforebutredeterminetheafterslipdistributionusingtheresidualdatafromtheviscoelasticmodeling.Theredeterminedafterslipdistributionbecomesphysicallymorereas
简介:AnM=6.0earthquakeoccurredonFebruary23,2001inthewesternSichuanProvince,China.Themacroseismicepicentersituatedinthehighmountain-narrowvalleyregionbetweenYajiangandKangdingcounties.Accordingtofieldinvestigationintheregion,theintensityofepicentralareareachedVIIIandtheareaswithintensityVIII,VIIandVIare180km2,1472km2and3998km2,respectively.TheisoseismalsaregenerallyinellipticshapewithmajoraxistrendingnearN-Sdirection.TheearthquakedestroyedmanybuildingsandproducedsomephenomenaofgroundfailureandmountainousdisastersintheareawithintensityVIII.Thiseventmayberesultedfromlong-termactivitiesoftheLitangfaultandYunongxifault,twomainfaultsinthewesternSichuan.Themovementsbetweenthemainfaultsmadethecruststressadjustedandconcentrated,andfinallytheearthquakeonasecondaryfaultintheblockreleasedaquitelargeenergy.
简介:本文收集了733个四川地区的实测钻孔数据,从中筛选出深度大于30m的268个钻孔剖面资料.分别获得了10m、15m、20m、25m和28m不同深度处的平均剪切波速(Vs)(d)与(Vs)(30)的对数线性相关关系.同时还与Boore(2004)的结果做了对比分析,比较了采用常数外推法和对数线性外推法得到的不同深度处剪切波速的残差分布.结果表明,不同深度处剪切波速(Vs)(d)与(Vs)(30)的对数相关关系可能具有一定的区域性特征,本文得到的对数关系更适合四川地区.对数线性外推法与常数外推法相比,前者的系统偏差更小;随着深度的增加,两种方法的外推误差均逐渐减小,但常数外推法普遍低估了(Vs)(30)值;当深度较浅时,低估的情况更为明显.本文的研究结果为利用大量的不足30m的钻孔资料估计(Vs)(30)值提供了参考.
简介:摘要:介绍了韶钢炼铁厂降低固体燃料消耗的多种措施,通过采用新技术、改善原燃料条件、优化工艺参数和管理方式,使360m2烧结机固体燃料消耗降低至47.52 kgce/t。