简介:在这个工作,试验性的调查被追求了分析影响向下在在在冲积隧道的圆形的桥码头附近的旋涡结构的流动和相应变化的狂暴的特征上的渗出物。实验为没有渗出物,10%渗出物和20%渗出物盒子与不同尺寸的圆形的墩在沙床隧道被进行。象速度和雷纳兹压力那样的狂暴的流动统计的测量被发现在scour洞在以内否定墩在上游而申请向下,渗出物延迟在速度和雷纳兹引起减少的流动的颠倒强调。更高级的雷纳兹砍因为生产,应力在下游的方面占优势弄醒旋涡。到彻底的雷纳兹的所有爆炸事件的贡献砍压力生产被观察了增加与向下渗出物。不可分的规模的分析建议旋涡的那种尺寸与渗出物增加,它为粒子活动性的增加负责。开始搜索评价是消退逐渐地象与一样与膨胀预定的更多增加了向下渗出物。存在向下,渗出物向墩的下游的方面减少旋涡和移动的深度和长度。
简介:Soilsalinityisoneofthemostimportantproblemsofcropproductioninestuarineandcoastalzones.Improvementinsalttoleranceofmajorfoodcropsisanimportantwayfortheeconomicutilizationofcoastalzones.Thisstudyprovedthattheapplicationofsalicylicacid(SA)improvedthegrowthandyieldundersaltstressconditionsandinvestigateditsphysiologicalmechanismsforsalttolerance.TheinvestigationontheeffectofSAforsalttoleranceduringgerminationshowedthatthedecreasedratesofgerminationandgrowth(intermsofshootandrootlengths)bythesaltstressweresignificantlyincreasedbytheSAapplication(SA+NaCl).ThetreatmentofSAtothehighandlowsalinesoilsenhancedthegrowth,yieldandnutrientvaluesofrice.TheeffectsofSAonNa+,K+andCl–ionicaccumulationweretracedundersaltstressconditionbyinductivelycoupledplasmaopticalemissionspectrometryandionchromatography.ItwasrevealedthattheincreasedaccumulationofNa+andClˉionsbythesaltstresswerereducedbySAapplication.AnincreasedconcentrationofendogenousSAlevelwasdetectedfromtheSA-treatedricevarieties(ASD16andBR26)byliquidchromatographyelectrosprayIonization-tandemmassspectrometry.Theactivitiesofantioxidantenzymessuchassuperoxidedismutase,catalaseandperoxidasewereincreasedbysaltstresswhereasdecreasedbytheSAapplication.ThestudyprovedthattheapplicationofSAcouldalleviatetheadverseeffectsofsaltstressbytheregulationofphysiologicalmechanisminriceplants.Inspiteofsaltstress,itcanbeappliedtothecoastalandestuarineregionstoincreasethericeproduction.
简介:Hydrocarbonmicro-seepagecancauseoxidationreductionreactionsandproducealteredmineralsinsurfacesedimentsandsoil.Thetypicalalteredmineralsmappingbytheirdiagnosticspectralfeaturesonhyper-spectralimagesisanimportanttoolforthepetroleumexplorationindustry.Inthisstudy,theairbornehyper-spectraldatawereusedtoinvestigatethealteredmineralsinducedbyhydrocarbonmicro-seepagesbyspectralfeaturefitting(SFF)intheloesscoverageareaofXifengOilfield.Theresultsrevealthatthedistributionregionofthealteredmineralsinducedbyhydrocarbonmicro-seepageislargerthantheknownoilfieldexplorationarea.Thepotentialhydrocarbonmicro-seepageregionwasalsorevealedbythedistributionofalteredmineralsbesidestheknownhydrocarbonarea.Afastindexwasproposedbytheabsorptiondepthsofclayandcarbonatemineralsforassessmentofhydrocarbonmicroseepage.Anditgavemuchclearerboundariesforthehydrocarbonmicro-seepageintheloesscoverageareathanthosebythealteredmineralmapping.Inaddition,somefieldsampleswereanalyzedbyX-raydiffraction(XRD)andatomicabsorptionspectrophotometertovalidatetheresults.Withintheextentsofhydrocarbonmicro-seepage,therearelowercontentsofferricironandhighercontentsofcarbonatemineralsinthesesamples.Therefore,itissatisfactorytohavetheairbornehyper-spectraldatatooutlinetheextentsofhydrocarbonmicro-seepageforfurtherhydrocarbonexplorationintheloesscoveragearea.
简介:Droughtisthemajorabioticstressfactorthatlimitsriceproductionworldwide.Toevaluatetheosmoticstressresponsesinricevarietiesunderdroughtcondition,atotalof42high-yieldingricevarietieswerecollectedfromvariousresearchstationsofKeralaAgriculturalUniversityinIndia.Theexperimentalsetupcomprisesofinitialhydroponictreatmentsatdifferentosmoticpotentials,artificiallyinducedbydesiredstrengthsofpolyethyleneglycol(PEG6000),andfollowedbythepotplantedexperimentsintherain-out-zone.Theactivitiesofantioxidantenzymes,relativewatercontent,cellmembranestability,photosyntheticpigments,prolinecontent,alongwithplantgrowthparametersofthevarietiesunderdroughtconditionwereevaluated.Moreover,thestandardscoresofthesericevarietieswereassessedunderstressandrecoveryconditionsbasedonthescoringscaleoftheStandardEvaluationSystemforrice.Amongthe42ricevarieties,weidentified2ricevarieties,SwarnaprabhaandKattamodan,withlessleafrolling,betterdroughtrecoveryabilityaswellasrelativewatercontent,increasedmembranestabilityindex,osmolyteaccumulation,andantioxidantenzymeactivitiespointedtowardstheirdegreeoftolerancetodroughtstress.Thepositiveadaptiveresponsesofthesericevarietiestowardsdroughtstresscanbeusedinthegeneticimprovementofricedroughtresistancebreedingprogram.
简介:Thestress-inducedmagneticdomainswitchinginFeGathinfilmsisstudiedusingphase-fieldmethod.Inparticular,themagneticfieldisappliedalongthe[110]directionandbiaxialstressesareappliedalong[100]and[010].Acompressivepre-stresscorrespondstoasmallercoercivemagneticfieldwhileatensilepre-stresscorrespondedtoalargercoercivefield.Atthesametime,itisalsofoundthatthetransitionbetweenbutterflyandsquare-likemagnetostrictionloopsoccursatthecriticaloppositebiaxialstressstate.Thetwodifferentevolutionscorrespondtotwodifferentmechanisms:oneisthatthesingledomainswingsacrossafanareabackandforth;theotheristhatthesingledomainturnsaclockwisecircle.Theresultscanbeexplainedbythestresstunedanisotropyenergywell.
简介:有在紧张和压缩的不同moduli的材料被称为双性人模量材料。Graphene是有最高的力量和最薄的厚度的如此的一种材料。在这份报纸,受到温度效果并且放了在Winkler地基上的双性人模量横梁的机械反应被学习。关于中立的轴位置和双性人模量基础横梁的正常紧张的未经决定的参数的微分方程被建立。然后,地基横梁的正常压力,弯曲时刻,和排水量的分析表情被导出。同时,一个计算过程基于有限元素方法(女性)被开发获得双性人模量结构的温度压力。获得的双性人模量解决方案能恢复古典模量解决方案,这被显示出,并且结果由分析表达式,现在的女性的过程,和传统的女性的软件获得是一致的,它验证现在的分析模型和过程的精确性和可靠性。最后,双性人模量结果之间的差别和古典一样的模量结果被讨论,并且为在实际工程计算并且优化某些双性人模量成员的几个合理建议被介绍。
简介:Ascientifichypothesisisproposedandpreliminarilyverifiedinthispaper:underthedrivingofseepageflows,theremightbeaverticalmigrationoffine-grainedsoilparticlesfrominteriortosurfaceofseabed,whichisdefinedas‘sub-bottomsedimentpumpaction’inthispaper.FieldexperimentswereperformedtwiceontheintertidalflatoftheYellowRiverdeltatostudythisprocessviabothtrappingthepumpedmaterialsandrecordingtheporepressuresinthesubstrate.Experimentalresultsarequiteinterestingaswedidobserveyellowslurrywhichismainlycomposedoffine-grainedsoilparticlesappearingontheseabedsurface;seepagegradientswerealsodetectedintheintertidalflat,undertheactionoftidesandsmallwindwaves.Preliminaryconclusionsarethat‘sedimentpump’occurswhenseepageforceexceedsacertainthreshold:firstly,itisbigenoughtodisconnectthesoilparticlesfromthesoilskeleton;secondly,thedegreeofseabedfluidizationorbioturbationisbigenoughtoprovidepreferredpathsforthedetachedmaterialstomigrateupwards.Thentheywouldbefirstlypumpedfrominteriortothesurfaceofseabedandtheneasilyre-suspendedintooverlyingwatercolumn.Influentialfactorsof‘sedimentpump’aredeterminedashydrodynamics(waveenergy),degreeofconsolidation,indexofbioturbation(permeability)andcontentoffine-grainedmaterials(sedimentaryage).Thisnewperspectiveof‘sedimentpump’mayprovidesomeimplicationsforthemechanisminterpretationofseveraluncleargeologicalphenomenaintheYellowRiverdeltaarea.
简介:Thestressintensityfactor(SIF)isacriticalparameterassociatedwiththefracturebehaviourofmaterials.Inthispaper,weselectthedisplacementfunctionaroundacracktipastheshapefunctionofthedigitalimagecorrelation(DIC),whichmakesitpossibletodirectlycalculatetheSIFbythecorrelationscheme.Moreover,weuseanon-rectangularsubset,whichcanreducetheinfluenceofplasticdeformationandcrackwidthontheDICmeasurementaccuracy.WemeasuredtheSIFofamodeIcrackinasuper-hardaluminiumalloyspecimentoverifytheperformanceoftheproposedmethod.OurexperimentalresultsshowthataDICwithaspecificshapefunctioncanbeusedtoaccuratelyandefficientlycalculatetheSIF.Furthermore,wealsopresentapracticalapplicationofourproposedmethodfordeterminingtheSIF,crackpropagationangleandcracktipdisplacement.
简介:BasedonthedigitalwaveformdatarecordedbyXinjiangDigitalSeismicNetworkfortheXinyuan-HejingM_L6.8earthquakesequencesofJune30,2012,thispaperanalyzesthestressdropsofearthquakesequencesandthecorrelationcoefficientsoffocalmechanismssignificantforstrongaftershocks.Firstly,thesourceparametersoftheXinyuan-HejingM_L6.8earthquakesequencesareobtainedbyapplyingthespectrumanalysisandtheBrunessourcemodel.Then,thecorrelationcoefficientsofspectralamplitudesarecalculatedusingthelow-frequencyspectralamplituderecordedbythesamestationforthedifferentevents.Finally,basedontheresultsofthecorrelationcoefficientsofspectralamplitudes,theeventswithsimilarfocalmechanismsaregroupedusingtheclusteringmethod.Theresultsshowthat:(1)Thestressdropvaluesshowasteadytrendintheaftershocksequencecalmperiodandthestressdropvaluesshowarise-fallinstrongaftershocks.(2)Themovingaveragecorrelationcoefficientofamplitudespectrumbeginstospreadafterthemainshock.Itshowsthatthecorrelationdecreasesbetweenthemainshockandtheaftershocksinmechanisms.(3)Theresultsoffocalmechanismgroupsshowthattheearthquakesequencesaremainlystrikeslips.ThestressdistributionofthemainpressureaxisisnearlyNS,whichisthesameasthestructuralstressfield.(4)Themagnitudeandmechanismshowthatthereisanagreementbeforethestrongaftershock,whichshowsthattheregionalstressfieldisenhanced.
简介:ThenonlinearvibrationsofviscoelasticEuler–BernoullinanobeamsarestudiedusingthefractionalcalculusandtheGurtin–Murdochtheory.EmployingHamilton'sprinciple,thegoverningequationconsideringsurfaceeffectsisderived.Thefractionalintegro-partialdifferentialgoverningequationisfirstconvertedintoafractional–ordinarydifferentialequationinthetimedomainusingtheGalerkinscheme.Thereafter,thesetofnonlinearfractionaltime-dependentequationsexpressedinastate-spaceformissolvedusingthepredictor–correctormethod.Finally,theeffectsofinitialdisplacement,fractionalderivativeorder,viscoelasticitycoefficient,surfaceparametersandthickness-to-lengthratioonthenonlineartimeresponseofsimply-supportedandclamped-freesiliconviscoelasticnanobeamsareinvestigated.
简介:Themajorityofrice(OryzasativaL.)producedinthesouthernUSAisdrill-seededandgrownunderupland-likeconditionsbecausepermanentfloodingisestablishedafterthefour-leafstage.Therefore,riceduringtheseedlinggrowthstagewillbesubjectedtovariablesoilmoisturecontent.Agreenhouseexperimentwasconductedtoevaluatetheperformanceof15ricecultivarscommonlygrowninMississippiofUSAunderearly-seasonsoilmoisturestress.Twentymorpho-physiologicalparametersofriceseedlingssubjectedtothreedifferentlevels(100%,66%and33%fieldcapacity)ofsoilmoisture,from10to30daftersowing,weremeasured.Significantmoisturestress×treatmentinteraction(P<0.001)wasobservedformostoftheparameters.Further,thetotaldroughtresponseindex(TDRI)wasdevelopedtoscorethecultivarsfordroughttolerancewiththevariationfrom26.88to36.21.Accordingly,thecultivarswereclassifiedintodifferentgroupsoftolerance.ThecultivarsCL152andCL142-ARwereclassifiedastheleastandthemosttoleranttodroughtbasedonTDRIandstandarddeviation,respectively.Eventhoughbothtotalroot(R2=0.98)orshoot(R2=0.76)droughtresponsesindiceswerepositivelycorrelatedwithTDRI,roottraitswereimportantinderivingtheindices.Therefore,TDRIcouldbeusedtoselectcultivarsfordroughttoleranceinagivenenvironmentanddevelopricevarietieswithearly-seasondroughttolerance.However,furtherresearchisneededtoidentifyandcharacterizetoleranceatotherstagestoassistbreedingprogramsinrice.
简介:Inflammationafterstrokeisthemaincauseofcerebralischemia/reperfusioninjury.Cascadingeventsafterinjurycanleadtocelldeath.Heatshockprotein70andotherendogenousinjury-signalingmoleculesarereleasedbydamagedcells,whichcanleadtosystemicstressreactions.Protectingthebrainthroughrepairbeginswiththestress-injury-repairsignalingchain.Thisstudyaimedtoverifywhetheracupunctureactsthroughthischaintofacilitateeffectivetreatmentofischemicstroke.Ratmodelsofcerebralischemia/reperfusioninjurywereestablishedbyZeaLonga'smethod,andinjurysiteswereidentifiedbyassessingneurologicalfunction,2,3,5-triphenyltetrazoliumchloridestaining,andhematoxylin-eosinstaining.ElectroacupunctureatacupointsBaihui(DU20)andZusanli(ST36)wasperformedinthemodelratswithdilatationalwaves,deliveredfor20minutesadayat2–100Hzandanamplitudeof2mA.Weanalyzedthebloodserumfromtheratsandfoundthatinflammatorycytokinesaffectedthelevelsofadrenotrophinandheatshockprotein70,eachofwhichfollowedasimilarbimodalcurve.Specifically,electroacupunctureloweredthepeaklevelsofadrenocorticotrophichormoneandheatshockprotein70.Thus,electroacupuncturewasabletoinhibitexcessivestress,reduceinflammation,andpromotetherepairofneurons,whichfacilitatedhealingofischemicstroke.
简介:ActivinA,amemberofthetransforminggrowthfactor-betasuperfamily,playsaneuroprotectiveroleinmultipleneurologicaldiseases.Endoplasmicreticulum(ER)stress-mediatedapoptoticandautophagiccelldeathisimplicatedinawiderangeofdiseases,includingcerebralischemiaandneurodegenerativediseases.ThapsigarginwasusedtoinducePC12celldeath,andActivinAwasusedforintervention.OurresultsshowedthatActivinAsignificantlyinhibitedmorphologicalchangesinthapsigargin-inducedapoptoticcells,andtheexpressionofapoptosis-associatedproteins[cleaved-caspase-12,C/EBPhomologousprotein(CHOP)andcleaved-caspase-3]andbiomarkersofautophagy(Beclin-1andlightchain3),anddownregulatedtheexpressionofthapsigargin-inducedERstress-associatedproteins[inositolrequiringenzyme-1(IRE1),tumornecrosisfactorreceptor-associatedfactor2(TRAF2),apoptosissignal-regulatingkinase1(ASK1),c-JunN-terminalkinase(JNK)andp38].Theinhibitionofthapsigargin-inducedcelldeathwasconcentration-dependent.ThesefindingssuggestthatadministrationofActivinAprotectsPC12cellsagainstERstress-mediatedapoptoticandautophagiccelldeathbyinhibitingtheactivationoftheIRE1-TRAF2-ASK1-JNK/p38cascade.
简介:被动导致电影的压力和危险性在在各种各样的pH价值的3.5%钠氯化物答案的7050铝合金的SCC被慢紧张率测试调查(SSRT)并且流动应力微分方法。结果证明到SCC的被动导致电影的压力和危险性与增加pH减少了价值什么时候pH7,当他们与增加pH增加了时价值什么时候pH>7。然而,当,腐蚀类型被解释脱落腐蚀什么时候pH=1并且14,并且没有电影,在标本的表面上形成。整个变化与pH导致电影的应力和SCC危险性阴谋当,价值两个都被介绍山谷形状。导致电影的压力的标志和数量与被动电影的作文有关,它用X光检查光电子被分析光谱学(XPS)。
简介:Purpose:Thepurposeofthisstudywastoinvestigatetheeffectsofobesityandhigh-intensityacuteexerciseonoxidant-antioxidantstatus,neurotrophicfactorexpression,andblood-brainbarrier(BBB)disruption.Methods:Twenty-fourhealthy,untrainedmen(12non-obese(mean14.9%bodyfat)and12obesesubjects(mean29.8%bodyfat))performed20minofcontinuoussubmaximalaerobicexerciseat85%maximaloxygenconsumption.Bloodsamplingwasperformedtoexaminetheoxidant-antioxidantstatus(reactiveoxygenspecies(ROS)andsuperoxidedismutase(SOD)),neurotrophicfactors(brain-derivedneurotrophicfactor(BDNF)andnervegrowthfactor(NGF)),andBBBdisruption(S100βandneuron-specificenolase)beforeandafteracuteexercise.Results:Theobesegroupshowedsignificantlyhigherpre-exerciseserumROSlevelsandsignificantlylowerpre-exerciseserumSODlevelsthanthenon-obesegroup(p<0.05).SerumROS,SOD,BDNF,NGF,andS100βlevelsweresignificantlyincreasedpost-exercisecomparedwithpre-exerciselevelsinboththenon-obeseandtheobesegroups(p<0.05).TheobesegroupshowedsignificantlyhigherserumROS,BDNF,NGF,andS100βlevelspost-exercisecomparedtothenon-obesegroup(p<0.05).Conclusion:OurstudysuggeststhatepisodicvigorousexercisecanincreaseoxidativestressandbloodneurotrophicfactorlevelsandinducedisruptionoftheBBB.Moreover,highlevelsofneurotrophicfactorinthebloodafterexerciseintheobesegroupmaybeduetoBBBdisruption,anditisassumedthatoxidativestresswasthemaincauseofthisBBBdisruption.