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355 个结果
  • 简介:Haloaceticacids(HAAs)areformedduringthechlorinationofdrinkingwater,whichareharmfultopeople′shealthduetotheircarcinogenicandmutageniceffects.Inthepresentstudy,adetectionmethodcombiningmethyltert-butylether(MtBE)extractionwithacidcatalysisandgaschromatographycoupledwithanelectroncapturedetector(GC/ECD)wasdevelopedfordeterminingHAAs.Thedetectionlimitofthismethod(MDL)andrelativestandarddeviation(RSD)werebelow0.37μg/Land6.2%,respectively.Thelaboratorychlorinationexperimentswereconductedwiththepurposeofinvestigatingtheinfluencesofreactiontime,temperature,UV254,bromideandammonia-nitrogenontheformationofHAAs.TheresultsshowthattheformationamountofHAAsincreaseswithincreasingreactiontimeandtemperature,respectively;andthereexistsalinearrelationshipbetweentheformationofHAAsandUV254.TheformationamountofHAAsdecreasesfirstandthenincreasesasthebromideionconcentrationincreases,andaddingNH+4isapossiblewaytocontroltheformationofHAAs.

  • 标签: 醋酸盐 HAA 饮用水 氯化
  • 简介:CuSpinealmicrospherescongregatedfrominterleavingnanoflakeswiththicknessof40to200nmweresynthesizedbyapyridine-solvothermalprocessviathereactionbetweencupricchloride(CuCl2·2H2O)andthioacetamide(TAA,CH3CSNH2).TheproductswerecharacterizedbyX-raydiffractionandscanningelectronmicroscopy.UV-Visabsorptionspectrum,excitationandphotoluminescencespectraofCuSpinealmicrosphereswereobtainedatroomtemperaturetoinvestigatetheiropticalproperties.ApossiblegrowthmechanismontheformationofCuSpinealmicrospheresisproposed.ThefactorsinfluencingtheevolutionofmorphologiesofCuScrystalsincludingthedosageofthereactants,surfactant,andsulphur-sourcewerealsoanalyzed.

  • 标签: 溶剂热合成 CUS 松果体 吡啶 CH3CSNH2 硫代乙酰胺
  • 简介:AbstractBackground:Although osteopontin (OPN) is expressed in the liver and pigment gallstones of patients with hepatolithiasis, its role in pigment gallstone formation remains unclear. This study aimed to explore the function of OPN in pigment gallstone formation.Methods:Rats were fed a chow diet (CD) or lithogenic diet (LD) for 10 consecutive weeks; blocking tests were then performed using an OPN antibody (OPN-Ab). Incidence of gallstones and levels of several bile components, OPN, tumor necrosis factor alpha (TNF-α), and cholesterol 7 alpha-hydroxylase (CYP7A1) were analyzed. To determine TNF-α expression in hepatic macrophages and both CYP7A1 and bile acid (BA) expression in liver cells, recombinant rat OPN and recombinant rat TNF-α were used to treat rat hepatic macrophages and rat liver cells, respectively. Chi-square or Fisher exact tests were used to analyze qualitative data, Student t-test or one-way analysis of variance were used to analyze qualitative data.Results:Incidence of gallstones was higher in LD-fed rats than in CD-fed rats (80% vs. 10%, P < 0.05). BA content significantly decreased in bile (t= -36.08, P < 0.01) and liver tissue (t= -16.16, P < 0.01) of LD-fed rats. Both hepatic OPN protein expression (t= 9.78, P < 0.01) and TNF-α level (t= 8.83, P < 0.01) distinctly increased in the LD group; what’s more, CYP7A1 mRNA and protein levels (t= -12.35, P < 0.01) were markedly down-regulated in the LD group. Following OPN-Ab pretreatment, gallstone formation decreased (85% vs. 25%, χ2 = 14.55, P < 0.01), liver TNF-α expression (F = 20.36, P < 0.01) was down-regulated in the LD group, and CYP7A1 expression (F = 17.51, P < 0.01) was up-regulated. Through CD44 and integrin receptors, OPN promoted TNF-α production in macrophage (F= 1041, P < 0.01), which suppressed CYP7A1 expression (F = 48.08, P < 0.01) and reduced liver BA synthesis (F= 119.4, P < 0.01).Conclusions:We provide novel evidence of OPN involvement in pigmented gallstone pathogenesis in rats.

  • 标签: Pigment gallstone Rat model Osteopontin TNF-α CYP7A1
  • 简介:<正>ANALYSISONTECTONICSETTINGOFBASINFORMATIONANDITSSIGNIFICANCEINBASINMODELLINGChenYongsheng(AdministrativeBureauofDaqingOilField,Daqing,163003,Heilongjiang,China)LiZhi’an(ChangshaInstituteofGeotectonics,AcademiaSinica,Changsha,410013,Hunan,China)basinformation,tectonicsetting,basinmodellingFromtheviewpointsofprogressivedevelopmentoftheearth’scrust,thispa-perexpoundsthecomplexityofformingprocessesofoil-gaspoolsinbasins,andanalysestheweaknessanddefectsofcurrentresearchesonbasinmodelling.Theauthorsemphasizethesig-nificanceofanalysisontectonicsettingofbasinsformationonbasinmodelling,andputforwardsomebasicprinciplesandmethodsforestablishingmodelsoffivehistoriesofbasins.

  • 标签: BASIN formation TECTONIC SETTING BASIN MODELLING
  • 简介:Inthispaper,aheavyseafogeventoccurringovertheYellowSeaon11April2004wasinvestigatedbaseduponobservationalandmodelinganalyses.Fromtheobservationalanalyses,thisseafogeventisatypicaladvectioncoolingcase.Seasurfacetemperature(SST)andspecifichumidity(SH)showstronggradientsfromsouthtonorth,inwhichwarmwaterislocatedinthesouthandconsequently,moistureislargerinthesouththaninthenorthduetoevaporationprocesses.Afterfogformation,evaporationprocessprovidesmoremoistureintotheairandfurthercontributestofogevolution.TheseafogeventwasreproducedbytheRegionalAtmosphericModelingSystem(RAMS)reasonably.Therolesofimportantphysicalprocessessuchasradiation,turbulenceaswellasatmosphericstratificationinseafog’sstructureanditsformationmechanismswereanalyzedusingthemodelresults.Therolesoflongwaveradiationcooling,turbulenceaswellasatmosphericstratificationwereanalyzedbasedonthemodelingresults.Itisfoundthatthelongwaveradiativecoolingatthefogtopplaysanimportantroleincoolingdownthefoglayerthroughturbulencemixing.Thefogtopcoolingcanoverpowerwarmingfromthesurface.Seafogdevelopsupwardwiththeaidofturbulence.Thebuoyancyterm,i.e.,theunstablelayer,contributestothegenerationofTKEinthefogregion.However,thetemperatureinversionlayerpreventsfogfromgrowingupward.

  • 标签: 海雾 事件 机制 结构 黄海 辐射冷却
  • 简介:暴露于波浪的跨岸的沉积运输率为沿海的形态学,象防波堤那样的海洋的结构的设计,突堤,防波提等等,和由于onoff岸沉积交通的沿海的侵蚀和生长的预防是很重要的。在现在的学习,跨岸的沉积运输的实验与1/8,1/10和1/15的起始的沙滩斜坡在一条实验室波浪隧道被执行。由使用常规波浪,不同深海的波浪险峻由一个踏脚板类型波浪生成器产生了,沙滩的几何特征在影响开关岸沉积运输的暴风雨条件和参数下面介绍与d50=0.25的中等直径为沙滩材料被调查,0.32,0.45,0.62和0.80公里。近海酒吧几何特征是从海岸线的水平距离到酒吧开始(Xb),冠(Xt),并且(Xs)结束指,从酒吧冠的深度到静止的水水平(ht),并且酒吧体积(V酒吧)。当时,试验性的结果显示了那深海的险峻(H0/L0)增加,到海滨的网运动增加了。与增加的波浪险峻,移动附此从静止的水拓宽垂直距离的酒吧铺平到酒吧开始(Xb),冠(Xt)并且结束(Xs)从海岸的点和水平距离排队到酒吧开始,冠和结束的点增加了。它也从试验性的结果被显示出来自开始并且结束点到海岸线的酒吧的水平距离与沙滩斜坡的减少增加了。从这研究获得的试验性的结果与以前的试验性的工作相比并且发现具有象试验性的大小的一样的大小并且跟随期望的基本趋势。

  • 标签: 沿海 沙质岸 淹没 水平距离 实验室 海洋结构物
  • 简介:Boilingandfoulingaretakenastypicalexamplesofnewphaseformationprocesstobeanalyzedanddiscussedinthispaper.Theprocessdynamicsofnucleateboilingisanalyzedanditsmechanismisdiscussedfromtheviewpointofself-organization.Fouling,whichisamorecomplicatedphenomenonofnewphaseformation,involvesseriesofunderlyingprocesses.Themorphologyandfractalanalysisoffoulingonlow-energysurfaceandthatwithfoulinginhibitorsarestudiedanddiscussed.Itissuggestedthatconsideringtheprocessdynamics,fractalanalysisandself-organization,anewavenueofresearchshouldbefound.

  • 标签: 相变 新相形成过程 热过程
  • 简介:Basedontheanalysisofsideritedistribution,occurrence,chemicalcompositionk,structurealcharacteristics,carbon-oxygenisotopiccharacteristicsandrelationshipbetweensideriteandhematite,thispaperpresentsasystematicstudyofsideriteintheregionstudied.suggestingthatthesideriteintheXuanlongareageneticallyresultedfromorganicallyreducedprimaryhematiteduringthediagenesis.Theferricandferrousrelationsdirectlydependonorganiccontents.Inthepresenceoforganicmatterferrousironcanbeconvertedtoferricironthroughorganicreduction.Theaboveconclusionhasalsobeenprovedbyorganicgeochemistry.data.

  • 标签: 河北 菱铁矿 碳同位素 氧同位素 有机地球化学 铁矿床
  • 简介:Theformationofatropicalcycloneistheresultofaprocessinwhichaninitialdisturbanceevolvesintoawarm-corelow-pressuresystem;however,theoriginoftheinitialdisturbanceandthefeaturesoftheinitialfieldsareoverlookedinmostexistingtheories.Inthisstudy,basedonFY-2CbrightnesstemperaturedataandtheJapanreanalysisdataset,theoriginandevolutionofthetropicaldisturbancethatbecameTyphoonFung-Wong(2008)wereexamined.Theresultsdemonstratedthattheinitialdisturbanceemergedwithinasaddle-typefieldwithlargeverticaltroposphericwindshear.Theverticalwindsheardecreasedwiththeadjustmentoftheuppercirculation;moreover,accompaniedbyconvectionoverthewarmsectionaroundtheuppercoldvortex,itprovidedfavorablethermalanddynamicconditionsforthedevelopmentofatropicalvortex.Duringitsdevelopment,thezoneofassociatedpositiverelativevorticitystrengthenedanddescendedfromthemid-tropospheretolowerlevels.Thisrapidstrengtheningoflower-levelvorticitywasduetoincreasingconvergencerelatedtotheintensificationofthepressuregradientsouthwestofthesubtropicalhigh.ThisindicatedthattheuppercoldvortexandWestPacificsubtropicalhighplayedveryimportantrolesinthiscase.

  • 标签: structural evolution diagnostic analysis tropical cyclone Fung-Wong vertical wind shear subtropical high
  • 简介:TheChangjiangRiverDeltaisadeltaoftremendousscalewhichisformedunderthecontroloftideandtidalcurrents.ThestudyontheroleoftideandtidalcurrentsintheprocessofformationanddevelopmentoftheChangjiangRiverDeltacanprovideatypicalexamplefortheocean-continentinteractionprocessintheeastareaofourcountry.ThetideandtidalcurrentsintheBohaiSea,YellowSeaandEastChinaSeaatthepost-glacialtransgressionmaximumaresimulated,thesedimenttransportfieldinthePaleo-ChangjiangRiverEstuary(PCRE)anditsperipheralareaatthattimeiscalculated,andtheseabederosion/accretionpatternisobtainedaccordingtothedivergenceofsedimenttransportrate.Theresultsshowthatadistinctivewavebellyofstandingtidalwaveexistedatthepost-glacialtransgressionmaximumandthewavebellylinesprotrudedseawardsfromthewavebellypointinthemouthofthePCRE.Underthewavebellycontroltidalcurrentsconvergetoordivergefromthewavebell

  • 标签: the CHANGJIANG River Delta TIDE TIDAL
  • 简介:Objective:Totesttheeffectsofsalidrosideonformationandgrowthofgliomatogetherwithtumormicroenvironment.Methods:SalidrosideextractedfromRhodiolaroseawaspurifiedandtreatedonhumangliomacellsU251attheconcentrationof20μg/mL.3-(4,5-dimethylthiazol-2-yl)-2,5-dephenyltetrazoliumbromide(MTT)assayforcytotoxicityandflowcytometry(FCM)forcellcycleanalysiswereperformed.Thenforinvivostudy,xenotransplantationtumormodelinnudemicewasgeneratedandtreatedwithsalidrosideattheconcentrationof50mg/kg.dfortotally20d.Bodyweightandtumorsizeweredetectedevery2dafterthetreatment.Thelevelsof8-isoprostane,superoxidedismutase(SOD)andmalondialdehyde(MDA),specialmarkersforoxidativestress,weredetectedwhileimmunofluoresencestainingwasperformedforastrocytedetection.Results:Forinvitrostudy,salidrosidecoulddecreasetheviabilityofhumangliomacellsU251andthegrowthofU251cellsatG0/G1checkpointduringthecellcycle.Forinvivostudy,salidrosidecouldalsoinhibitthegrowthofhumangliomatissueinnudemice.Thebodyweightofthesenudemicetreatedwithsalidrosidedidnotdecreaseasquicklyascontrolgroup.Inthetumorxenotransplantationnudemicemodel,micewerefoundofinhibitionofoxidativestressbydetectionofbiomarkers.Furthermore,overgrowthofastrocytesduetothestimulationofoxidativestressinthecortexofbrainwasinhibitedafterthetreatmentofsalidroside.Conclusions:Salidrosidecouldinhibittheformationandgrowthofgliomabothinvivoandinvitroandimprovethetumormicroenvironmentviainhibitionofoxidativestressandastrocytes.

  • 标签: 红景天苷 肿瘤模型 生长抑制 脑胶质瘤 微环境 星形胶质细胞
  • 简介:Thenumericalsimulationcanovercomethehardshipofmathematicalanalysisandexperimentalresearch,explicatethemechanismofmicrostructureshaping,predictmechanicalpropertiesandoperatinglifeofcastingsandthenoptimizetechnologyandcontrolmicrostructureformationtoobtainthequalifiedcastings.Thefinitedifferencemethod(FDM)isappliedtothesimulationoftemperaturefieldbasedonallkindsofnucleationandgrowthmodelsonallstagesofsolidificationofspheroidalgraphitecastiron.VisualC++isusedtoprogramthenumericalsimulationsoftware,QTstructure-1tosimulatethesolidificationprocessofspheroidalgraphitecastironandtheformationofallphasesinsolidificationprocess.Finally,theresultofsimulationiswellagreedwiththeexperimentalresult.

  • 标签: SPHEROIDAL GRAPHITE iron NUMERICAL simulation Finite
  • 简介:<正>MostofU-depositsofChina,speciallythelargeU-deposits,aresimilartotheU-depositsofmanycountries.Therearecloserelationsbetweentheirformation,distributionsoftimeandspaceandthetectono-magmaticactivationofcrust.Thetectono-magmaticactivationdiscussinginthispaper(thefollowingcalledactivationforshort)isonlyconfinedtotheactivationaftergeosynclinestageortheconsolida-tionofplatform.Asaresult,thepalingeneticgeosynclineandmedianmassifalsobelongtothediscussingscope.Thetectono-magmatismofgeosynclinestageitselfanditsrelevantU-depositsdonotbelongtothe

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