简介:TheseismicwaveformoftheYutianMS7.3earthquake,XinjiangonFebruary12,2014wasrecordedclearlyandcompletelybytheDigitalSeismicNetworksofXinjiang,Qinghai,Tibet,andXinjiangHotanarray,sothemethodofjointlocationbyregionalseismicnetworkandseismicarraycanbeusedtoaccuratelydeterminetheearthquakesourcelocation.Thefollowingtechnologieswereusedintheprocessoflocation:(1)WeselectedseismicstationsequallylocatedaroundtheepicenteroftheMS7.3earthquakewithanaverageintervalofabout15degreesintheinitiallocation.(2)TherecordingwaveformsofYutianseismicstationwererotatedtotheradialandtangentialdirectionstopreciselyobtainthearrivaltimeofS-wavestodeterminetheepicentraldistance.(3)Thevelocitymodelwasusedinthedeterminationoflocationoftheepicenter,basedonthehistoricalrecordsofearthquakesintheareawithinaradiusof1.0°fromthesourceasthecenter,andthevelocitymodelisobtainedafterre-fittingandcalibration.(4)BasedonthewaveformrecordsoftheHotanseismicarray,themethodofwaveformbeamingwasusedtodeterminetheazimuthsandperformthecorrectionoftheepicenterlocationwiththeseazimuths.(5)Thedeterministicmethodwasusedtomeasurethesourcedepth.Finally,itisconcludedthattheYutianMS7.3mainshockhypocenterlocationis36.197°N,82.467°E,focaldepth12kmandoriginaltime17:19:48.2p.m.February12,2014.
简介:AnM_S7.3earthquakeoccurredonFebruary12,2014inYutianCounty,XinjiangUygurAutonomousRegion,whichwasfollowedbyaseriesofaftershocks.ThispapercalculatesthedepthoftheM_S7.3earthquakesequencebyusingthedeterministicapproachwiththeseismicphasedatafromthecatalogdatabaseoftheChinaEarthquakeNetworksCenter,combinedwithoriginalseismicwaverecordsfromtheDigitalSeismicNetworkCenteroftheEarthquakeAdministrationofXinjiangUygurAutonomousRegion.
简介:Theearth-resistivitychangerecordedbeforetheJingtaiearthquake(EQ).withMs=6.2at11geoelectricstationswithin400kmoftheEQwasdiscussedinthispaper,andthefollowingconclusionsaremade:1)imminentvariationsofearth-resistivitypriortotheEQwererecordedattheWuwei,DingxiandShandanstationsimmediatelybeforetheEQ;2)therecordabilityoftheimminentvariationsatastationwasrelatedtotheactivedeepfaultsandthestronglyactivefaultsinsideandoutsidethefocalzone,andtothecausativestressfieldaswell;3)thetemporalandspatialcharacteristicsoftheearth-resistivitychangeimmediatelybeforetheEQshowedthattheEQwasprobablyinducedbytheNNWdirectionstressfield(orbyanotheroneofsimilardirection)whichwasgreatlyincreasedduringashortperiodimmediatelybeforetheEQandthatthenorthernwallofthefocalfaultplayedamajorroleintheprocessoftheEQpreparationandoccurrenceoftheEQ.
简介:【摘要】目的 用气相色谱-质谱联用仪对柴银退热凝胶及其中所含柴胡、金银花、薄荷、葛根挥发油的有效成分进行分析,为质量评定和凝胶产业化生产提供支持。方法 采用水蒸气蒸馏法提取柴银退热凝胶及四味药物的挥发油,经甲醇稀释定容,再用无水硫酸钠脱水。运用GC-MS进行成分分析、结合光谱库检索,对药材中的色谱峰进行归属,并采用色谱峰面积归一法计算每个成分的相对百分比。结果 从中药柴银退热凝胶及其组成药味的挥发性成分中共鉴别出118种成分,其中DL-薄荷醇(57.57%)相对量最高。通过色谱峰的药材归属,已将113个色谱峰归属到对应药物,占鉴别总峰的95.76%。结论 使用GC-MS法对柴银退热凝胶挥发油进行分析,为其退热成分的研究和质量把控提供参考。
简介:摘要:随着我国科技的飞速发展,GC-MS在环境检测中的应用备受关注。为探究笔尖单瓣茉莉花和对照种双瓣茉莉花开放阶段香气的动态变化以及二者间差异,采用顶空固相微萃取-气相色谱-质谱(headspacesolid-phasemicroextraction-gaschromatography-massspectrometry,HS-SPME-GC-MS)联用仪,对笔尖单瓣茉莉花和双瓣茉莉花不同开放阶段的香气成分进行分析。结果表明,苯乙醛、邻氨基苯甲酸甲酯、苯甲酸甲酯、α-法尼烯、乙酸苄酯等香气成分是茉莉花的主要香气组分。笔尖单瓣茉莉花开放过程中β-苯乙酸乙酯、邻氨基苯甲酸甲酯、α-石竹烯、α-法尼烯等香气成分含量显著增加,双瓣茉莉花开放过程中乙酸苄酯、顺-3-己烯基苯甲酸酯、苯甲酸苄酯等香气成分含量显著增加,上述香气成分含量呈现先上升后下降的趋势。此外,本研究结果发现,苯甲醛、苯乙醛和β-苯乙酸乙酯等香气成分为笔尖单瓣茉莉花香气较为鲜灵清香的关键物质,而苯甲酸己酯、顺-3-己烯基苯甲酸酯和α-法尼烯等香气成分是赋予双瓣茉莉花浓郁花香的关键物质。本研究为笔尖单瓣茉莉在茉莉花茶生产中应用提供了依据。
简介:目的:比较HPLC-MS/MS法与MEIA法在监测器官移植患者他克莫司全血浓度中的应用。方法:建立和确讧可行的HPLC-MS/MS法,并与ME—M法分别测定他克莫司相同样本的浓度,对测试结果进行统计分析,评价两种方法。结果:HPLC-MS肌S法测定他克莫司平均浓度为(4.86±0.46)ng/mL,MEIA法测定浓度平均为(5.52±0.43)ng/mL,两种方法测定结果相关系数r平均为0.8771,两种方法相关性较强。LC-MS/MS法测定浓度值/MEn法测定浓度值平均值为(90.34-5.3)%。结论:HPLC—MS/MS法测定浓度为他物在体内的准确浓度,更适用于日常治疗药物监测(TDM)工作。
简介:摘要目的建立中成药、保健食品中非法添加的13种抗风湿化学成分的快速测定方法。方法采用高效液相色谱四极杆飞行时间串联质谱法(HPLC–QTOF-MS法),使用AgilentZORBAXExtend-C18RRHT色谱柱(2.1mm×50mm,1.8μm),以甲醇(A)-20mmol-1醋酸铵溶液为流动相,梯度洗脱。结果上述13种化学成分在一定范围内具有较好的线性关系,r值均大于0.9821,精密度RSD均小于10%,加样回收率均在97.2%~103.8%之间。结论该方法灵敏度高,专属性强,适用于对抗风湿类中成药、保健品中非法添加成分的高通量筛选。
简介:摘要:目的:建立一个用 HPLC-MS测定川楝子中川楝素含量的方法,以十八烷基硅烷键合硅胶为填充剂 ;以乙腈 -0.01% 甲酸溶液( 31:69 )为流动相,采用三重四极杆质谱检测器,电喷雾离子化( ESI )负离子模式下选择质荷比( m/z)573 离子进行检测。 结果:该方法中川楝素的仪器检测限为 0.01μg/ml,仪器定量限为 0.03μg/ml,线性回归方程: y=115758x-24.398( r2=0.999),相关系数满足要求。结论:该方法简便、准确、可靠,可用于川楝子中川楝素含量的质量控制。
简介:ThispapercalculatesthestaticCoulombstresschangesgeneratedbyfourearthquakesintheYutianareaduring2008~2014separately,thendiscussesthetriggeringinfluence,theiraccumulatedCoulombstresschangesandtheirinfluenceonnearbyfaults.TheresultsindicatethattheMS5.5earthquakein2011andtheM_S7.3earthquakein2014arebothintheregionswheretheCoulombstresschangeispositive,thestresschangesare0.004MPaand0.021MPa,respectively,meaningtheyaretriggeredbypriorearthquakes.TheMS6.2earthquakein2012occurredintheplacewhereCoulombstresschangewasnegative,soitispostponedbythepriorearthquakes.TheimageofCoulombstresschangesoftheMS7.3earthquakein2014isinaccordwithaftershocks(ML≥3.0)distribution,butsomeregionsonthefaultwheretheCoulombstresschangeispositivehavefewaftershocks,andstrongaftershocksmayoccuratthesedistrictsinfuture.Inaddition,thispapercalculatestheCoulombstresschangeonnearbyfaults,andfindsthattheCoulombstresschangesofdifferentelementsintheGGCfaultareverydifferent,andmustreceivestrongtriggered-influence,thoughtheresultmaybeinfluencedbytheinputfinitefaultmodel,sothereisstillalargeearthquake-risk.TheGGN,PLC,PLWandLBWfaultswerealsotriggeredbythefourearthquakesoccurringbetween2008~2014.TheirmaximumCoulombstresschangesallexceed0.002MPa,sotheyalsohaveastrongearthquakehazard.
简介:Asthekeypointinsexhormoneanalysis,samplepre-treatmenttechnologyhasattractedscientists’attentionallovertheworld,andthedevelopmenttrendofsamplepreparationforwardedtofasterandmoreefficienttechnologies.Takingeconomicandenvironmentalconcernsintoaccount,subcriticalfluidextractionasafasterandmoreefficientmethodhasstoodoutasasamplepre-treatmenttechnology.Thisnewextractiontechnologycanovercometheshortcomingsofsupercriticalfluidandachievehigherextractionefficiencyatrelativelylowpressuresandtemperatures.Inthisexperiment,asimple,sensitiveandefficientmethodhasbeendevelopedforthedeterminationofdiethylstilbestrol(DES)infishtissueusingsubcritical1,1,1,2-tetrafluoroethane(R134a)extractionincombinationwithgaschromatography-massspectrometry(GC-MS).Afterextraction,freezing-lipidfiltrationwasutilizedtoremovefattyco-extract.FurtherpurificationstepswereperformedwithC18andNH2solidphaseextraction(SPE).Finally,theanalytewasderivedbyheptafluorobutyricanhydride(HFBA),followedbyGC-MSanalysis.Responsesurfacemethodology(RSM)wasemployedtooptimizingtheextractioncondition,andtheoptimizedwasasfollows:extractionpressure,4.3MPa;extractiontemperature,26℃;amountofco-solventvolume,4.7mL.Underthiscondition,ataspikedlevelof1,5,10μgkg-1,themeanrecoveryofDESwasmorethan90%withrelativestandarddeviations(RSDs)lessthan10%.Finally,thedevelopedmethodhasbeensuccessfullyusedtoanalyzingtherealsamples.
简介:在这份报纸,我们分析外壳的运动,紧张领域变化和大规模在Wenchuan地震前的水平变丑的动态特征(女士=8.0)用从
简介:TheFebruary12,2014,MS7.3,earthquakeinYutian,Xinjiang,China,occurredasaresultofshallowstrike-slipfaultinginthetectonicallycomplexregionofthenorthernTibetanPlateau,withadepthof17km.ThisearthquakeoccurredseveralhundredkilometersnorthoftheconvergentIndia-Eurasiaplateboundary.TheepicenterlocationoftheYutianearthquake,36.1°N,82.5°E,is110kmnorthofYutianCounty,HotanPrefecture.AlargenumberofaftershocksfromML2.0toML3.0occurreduntil12:00oclock,February23,2014andthelargestaftershock,MS5.7,occurredat17:24p.m.,February12,2014.ThebandhvalueofYutiansequenceare0.70and1.29,respectively.ThewaitingtimemethodrevealsthatthestrongaftershocksaboveML4.5complywithalinearrelationship,whichisconsistentwiththecharacteristicsofamainshock-aftershocksequence.Furthermore,wecalculatethesourceparametersandanalyzetheruptureprocessbasedontheempiricalrelationshipsfortheYutianearthquake,andtheresultsindicateafrictionalundershootbehaviorinthedynamicsourceprocessoftheYutianearthquake,whichisalsoinagreementwiththelowerandsimilarbvaluescomparedwiththe2008MS7.3Yutianearthquakeandthe2012MS6.2Yutianearthquake.