简介：Theobjectivesofthisresearchweretocharacterisetheclaymineralscompositionofsoil-deriveddustinNorthernChinaandtosetupamineralogicalsignaturetotracetheirorigin.MineralcompositionofaerosolparticleswasinvestigatedatAksu,Dunhuang,Yulin,TongliaoandChangwuduringanintensivefieldcampaignperiodofACE-Asia.Theresultsshowthatthekaolinite(K)tochlorite(C)ratioissensitivetotheregionaloriginofAsiandust.Westernsourceareas(representedbyAksu)displayedthelowestK/Cratioof0.3(average),whileitwasfoundtoincreaseupto0.70(average)uponmovingtowardsnorthernsourceareas(representedbyYulin).BystudyingtransporteddustinadepositionarearepresentativeoftheChineseLoessPlateau,theusefulnessoftheK/Cratio,whenassociatedwithbackair-masstrajectories,wasfoundtolieinrevealingtheoriginofthedust.ComparisonofthemineralogicaldatabetweenAsiandustandSaharadust,showsthattheK/Cratioisalsoaneffectivesignaturetoidentifythesourceareasonahemispherescale.

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简介：Objective:ToelucidategeneralcharacteristicsofHIV/AIDSpatientsseekingcareatDitanHospitalinanattempttoguideearlydiagnosisinroutinemedicalcare.Materialsandmethods:Aretrospectiveanalysisof185HIV/AIDScasesfromJanuary1990toJune2002wascompletedusingSPSSstatisticalanalysis.Results:Maletofemaleratiowas1.8:1.Subjectsrangedinagefrom1yearoldto64yearsold.16caseswereyoungerthan20yearsoldwiththemedianageamongtheyoungersubsetat7.7years.169caseswereolderthan20yearsoldwithamedianageof36yearsold.29%ofthesubjectswerepeasants.Theremaining71%,wereofotherunspecifiedoccupations.90.8%ofindividualswereofHandescentwhile3.7%ofindividualswereofaminorityheritage.50.3%ofsubjectsweremarried;23.8%havenevermarried;8.1%weredivorced;andtheremaining17.8%wereofunknownmaritalstatus.Ofthoserepresentedinthisstudy,36.8%camefromtheHenanprovince;17.8%werefromBeijing;8.6%werefromShanxi;31.4%fromtheother20provincesofChina;and5.4%fromoutsideofChina.Modeoftransmission:40.0%(74/185)contractedHIVthroughunprotectedsexualcontact;29.2%(54/185)throughreceivingbloodorplasmatransfusions;21.1%(39/185)throughdonatingplasma;7caseswereintravenousdrugusers;7caseswereverticallytransmitted.Modeoftransmissionwasunknownin4cases.Clinicalcategories:Anincluded45cases;Bincluded85cases:Cconsistedof76cases.12casesweredeceased.Initialpresentation:39casespresentedwith_fever,coughanddiarrhea.37caseshadfeverandcoughonly-38casespresentedwithchronicdiarrhea.16caseswerediscoveredincidentallyattimeofoperation.8casespresentedwithfungalinfectionoftheoralcavityorinesophagus.ThecommonHIVassociatedsymptomsandopportunisticinfectionswere:weightlossanddiarrhea,respiratorydiseases,dermatologicdiseases,anemia,neutropenia.Diseasesofotherorgansystemswerelesscommon.Commonmisdiagnosesincluded

简介：ThediagnosticmodelofthecumulusconvectionproposedbyYanaietal.(1973)wasappliedtotheatmosphereovertheTibetanPlateau,andusedtoestimatetheverticalmassflux,entrainmentanddetrainment,excesstemperatureandmoisture,liquidwatercontent,andcondensationandprecipitationratesofhighlandcloudclusters.TheresultsillustratedthatincloudsovertheTibetanPlateau,thewatervaporcondensationrate,liquidwatercontent,andefficiencyoftheraingenerationprocessarelessthanthoseinthetropics(representedbytheMarshallIslandsregion).Therefore,thecondensationallatentheatreleasedovertheTibetanPlateau,overall,ismuchsmallerthanthatinthetropics.Thewatervaporandliquidwaterdetrainmentfromshallownonprecipitatingcumulusclouds,andtheirentrainmentintodeepcumulusclouds,serveasagrowingmechanismforthedeepprecipitatingcumulustowersovertheTibetanPlateau.Itshouldbenotedthatthereisastrongerdetrainmentofliquidwater

简介：OnthebasisofthedataofoceanographicsurveyintheEastChinaSeainfourseasonsduring1997～2000(23°30′～33°00′N,118°30′～128°E),thevariationoftotalbiomassanddietbiomassofzooplanktonandtheirspatial-temporaldistributionandrelationshipwiththefishinggroundofEngraulisjaponicusareapproachedandanalyzed.Theresultsshowthattheaveragebiomassis65.32mg/m3infourseasons,autumn(86.18mg/m3)beinggreaterthansummer(69.18mg/m3)greaterthanspring(55.67mg/m3)greaterthanwinter(50.33mg/m3).Theaveragevalueofdietzooplanktonbiomassis40.9mg/m3.Thetrendsofhorizontaldistributionbothinthetotalbiomassandthedietbiomassofzooplanktonaresimilar.Thehighbiomassregion(250～500mg/m3)isverylimited,onlyaccountingfor1%oftheinvestigationarea.SeasonalvariationofthebiomassisveryremarkableinthewestandnorthpartsofEastChinaSeacoastalwaters(29°30′N,125°E).Thehorizontaldistributionofdietzooplanktondependsontheabundancedistributionofcrustacean.ThedistributionofdietzooplanktonisrelatedtothefishinggroundofEngraulisjaponicusandthehigh-densityareaofyoungfishandlarval.Inspring,thecentralfishinggroundofEngraulisjaponicus(＞100kg/h)andthehigh-densityareaofyoungfishandlarval(＞100individualspernet)arelocatedatthesameplaceofhigh-density(100～250mg/m3)areaofdietzooplanktoninthemiddle-southernpartofEastChinaSeaortheedgeofitswaters.

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简介：１ＴｈｅｕｓｅｄｄａｔａＴｗｏｃｏｐｉｅｓｏｆＣｈｉｎａＥａｒｔｈｑｕａｋｅＣａｔａｌｏｇｕｅｓｅｄｉｔｅｄｂｙＰｒｏｆｅｓｏｒＧＯＮＧＸＵＧＵｗｅｒｅｕｓｅｄｆｏｒｔｈｅｄａｔａｂｅｆｏｒｅ１９７９；ＣｈｉｎａＥａｒｔｈｑｕａｋｅＣａｔａｌｏｇｕ...

简介：Naturalandventilatedcavitationsgeneratedonasmooth-nosedaxisymmetricbodywerestudiedexperimental-ly.Thecharacteristicsofsmallscaleandlocalizedfluctuationsof'steadycavities'weremeasuredbypressuretransducers.Comparisonsbetweennaturalandventilatedcavitiesatdiffer-entmeasuredpointsforseveralcavitationnumbersweredone.Itwasobservedthatthedominantfluctuationswereconcen-tratedinthefrequencyrangeofOHz-50Hzforallthecavitati-oncases,Similarshapesandmagnitudesofthefrequencyspectraweredetectedforbothnaturalandventilatedcavities.Muchlargerspectralamplitudeinthecavityclosureregionsuggestedasfluctuationssource.Frompartialcavitatingflowtosupercavitatingflow,thedominatfrequencyandthecorre-spondingamplitudedecreasedwithdecrasingcavitationnum-ber,whichmeantthatcavitybecamemoresteadywhiledevel-oping.

简介：ThereflectivecharacteristicsofSAWbyslantingmetalstripsonthesurfaceofYZ-LiNbO3havebeenstudied.ByusingbothSimpleModelandMulti-ReflectionModel,thereflectivecharacteristicsofSAWbyaperiodicmetalstriparrayandtheSAWdistributioninthearrayhavebeencalculated.Furthermore,Byusinganimprovedlaserprobe,thereflectiveSAWfieldbythearrayhasalsobeenmeasured.Bycomparingthetheoreticalresultswiththeexperiments,itisshownthattheresultsofMul-ti-ReflectionModel,beingmoreexactthantheSimpleone,areinbetteragreementwiththeexperiment

简介：半的答案性质参量的模型被分析，特别，最不惩罚了那为半摆平参量的模型当矩阵B~TPB是ill-posedor时，将无效单个。根据为线性参量的模型的山脉估计的原则，为半概括了惩罚最少的广场参量的模型被提出，并且一些公式和估计的统计性质被导出。最后，根据模拟例子，一些有用结论被得出。

简介：Sodiumnitroprussideismainlyusedtoreducebloodpressureandcontrolcardio-vasculardiseases.Thisstudyistoinvestigatetheeffectofsodiumnitroprussideonthecardiovas-cularmechanics.Eightmalemongreldogswereused.Anesthetizedwithsodiumpen-tobarbital,thedogswerecatheterizedontheleftfemoralarterytorecordbloodpres-sure.Electromagneticcuff-typeflowtransducerwasfixedonascendingaortatomea-

简介：ByanalyzingturbulencedatameasuredattwositesincoastalregionsofHangzhoubay,itisdiscoveredthat:(1)TheturbulentintensityI_kisinverselyproportionaltothewindspeedatlowerspeed.Whileathigherwindspeed,itkeepsbasicallytobeconstant.(2)Undertheunstableconditionsinthevicinityofseashore,thedimensionlessstandarddeviationsofwindspeedσ_k/U(?)areconstantsbasically,whileintheinland,theycanbedescribedbytheexpressionssimilartoPanofsky(1977)modelsbutwithdifferentconstants.Underthestableconditions,theyareconstantswhenZ/L<0.2andproportionalto1/3powerofZ/LforlargerZ/L.(3)Nearthecoast,thevariationofU(?)/UwithZ/LfollowsBusinger(1971)modelU(?)/U=k/(?)(Z/L)verywellnotonlyunderstablebutalsounderunstablecondition.Inland,itiscoincidentverywellmerelyunderthecondition-1.0≤Z/L≤0.3.Outthisrange,thedeviationislarge.(4)ThedispersionparameterscanbedescribedintheformrecommendedbyDraxler(1976)butwithdifferentconstants.Undertheunstablecondition,theycanalsobeexpressedasBriggs(1985)modelwithdifferentconstants.

简介：Objective:Toevaluatetheepidemiologiccharacteristicsofexpresswaytraffictraumain2040casesinZhejiangProvince.Methods:Thedataof2040casesofexpresswaytraffictraumatakenfromZhejiangProvincialExpresswayTrafficBureauwereanalyzedwithcomputertechniques.Results:Atotalof2040personswereinjuredin7963expresswaytrafficaccidentsinZhejiangProvincefromJanuary1999toDecember2001.Amongthem,435personsdied(mortality,21.3%)and1605wereinjured.Theeconomiclosseswereover170millionyuanRMB.Theaccidentscausedbyhumanfactorsaccountedfor84.9%(vehicledriversaccountingfor79.2%),whichmainlyincludedimpropermeasures(20.4%),steeringfailure(17.7%),insufficientlongitudinalspace(15.9%),overspeeddrive(12.5%),fatiguedrive(6.4%),loadingviolation(5.9%)andcarelessdrive(6.3%).Mechanicaltroublesandotherfactorstookup15.1%.Thereexistedobviousunevendistributionamongvariousregions.JiaxingandShaoxingwerethesectionswithhighincidenceofaccidents.Theaccidentsmostlyhappenedat12:00-18:00,butthecausing-deadonesmostconcentratedat0:00-6:00.Themainvictimswereyoungandmiddle-agedpeople(accountingfor72.3%),butaccident-strickenchildrenandelderlypersons(over70yearsold)tookuphighermortalities(30.2%and40.7%,respectively).Conclusions:Thenumberofexpresswaytrafficaccidentsandtheeconomiclossesareincreasingyearbyyear,withobviousunevendistributionatdifferentplaces,differenttimeandunderdifferentweatherconditions.Toreducetheaccidentfrequency,itisimportanttostrengthentheenforcementoftrafficregulation,tobalancethesystemof'person-vehicle-road',andtoimprovethesafetyconsciousnessofpeople.

简介：ＴＨＥＳＴＵＤＹＯＦＴＨＥＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＢＯＵＮＤＡＲＹＬＡＹＥＲＯＶＥＲＨＩＬＬＴＥＲＲＡＩＮＨａｏＷｅｉｆｅｎｇ（郝为锋），ＬｉｕＫａｉ（刘凯）（ＭｅｔｅｏｒｏｌｏｇｉｃａｌＣｏｌｌｅｇｅｏｆＡｉｒＦｏｒｃｅ，Ｎａｎｊｉｎｇ２...

简介：为了为光电子满足当前的高效光电子，有双同轴的包裹(剧降)的二种包裹类型和球格子数组(BGA)的电、热的表演要求，被建模并且热地模仿了，他们的热描述被在免费的空中使用温度轮廓和模仿的加热描述曲线比较并且讨论并且强迫了空气周围。结果证明那BGA有上级在内并且在全部的表演外面，并且在高度综合的光电子有有希望的未来。

简介：Dynamiccharacisticsoflargestructures,suchastallbuildings,long_spansuspension,cable_stayedbridgesandtallchimneys,includingrelativedisplacementsandvibratingfrequencies,arekeytoassesstheirdriftandstressconditions,Thesestr_ucturesaredifficulttomeasuredirectly,especiallyundertheconditionofearthquakesorstrongwind/typhoon.Ingeneral,accelerometersarethemostcommoninstrumentsusedtomonitortheresponseofstructuralsystems,butdisplacementmeasuringrequiresprocessingbydoubleintegration.Theintegrationprocesscannotbeautomatedbecauseofthefollowingrequirementsofsignalprocessing:(a)choiceoffiltersandbaselinecorrection(theconstantsofintegration),and(b)substantialjudgmentswhenanomaliesexistintherecords.Consequently,thisprocesscanleadtoerrorsinthecalculationofvelocitiesanddisplacements,someasurementswithaccelerometercannotbeusedtodiscoverdisplacementsatthecentimeterlevelinreal_timeornearreal_time.Othertraditionalmethods,likelasercollimatorandtotalstation,canbealsoappliedtomeasuredisplacementsatveryhighprecision,butcannotworkproperlyduringearthquakesorstrongwinds/typhoons,andinmostcasesdonotworkinreal_timeornearreal_time.Untilrecently,therearenoefficientorfeasiblemethodstomeasuredisplacementsduringanearthquakeorseverewind.Therefore,thereisagreatneedfordevelopinganewmethodortechniquetomonitorthedynamiccharacteristicsoflargestructurespreciselyinreal_timeornearreal_timeunderbadconditions.　　Fortunately,recentadvancesinGlobalPositioningSystem(GPS)technologyenableabove_mentionedlong_periodchangesofstructurestobereliablymonitored.GPSreceiverswithacapabilityofresolvingmotionatthecentimeterorsub_centimeterlevelandsamplingfrequency10Hzoreven20Hzarenowavailablefromseveralmanufacturers.Thatprovidesagreatopportunitytomonitorlong_periodchangesofstructuresreliably,andwillbeveryusefulfors

简介：Whenflowpassesoverafreeoverfallspillway,formsajet.Thisjetofflowwithahighvelocitymaycausescouratthedownstreamofspillway.Thescourholecharacteristicsisaffectedbyparameterslikedischargeintensity,dropheight,tailwaterdepth,sizeofbedmaterialandstandarddeviationofbedmaterial.Inthispaper,resultsofexperimentsonscourbelowfreeoverfallspillwayforuniformandnonuniformbedmaterialsarepresented.Itwasfoundthatscourholecharacteristics(i.e.maximumdepthofscour,distanceofmaximumscourpointfromspillway,widthofscourhole,distanceofendofscourholefromspillwayandheightofridgeformedatthedownstreamofscourhole)isafunctionofdensimetricFroudenumberandratioofdropheighttotailwaterdepth.Analysisofexperimentaldatawithuniformbedmaterialresultedinequationsforestimationofscourholecharacteristics.Furthercorrectionfactorswereintroducedinordertoconsidertheeffectofnon-uniformityofbedmaterial.

简介：Theeffectoftheimprovementofcommercialactivatedcarbon(AC)onitsspecificcapacitanceandhighratecapabilityofdoublelayer(dl)charging/dischargingprocesshasbeenstudied.TheimprovementofACwascarriedoutviaasecondaryactivationundersteaminthepresenceofcatalystNiCl2,andthesuitableconditionwasfoundtobeaheattreatmentatabout875℃for1h.Underthoseconditions,thedischargespecificcapacitanceoftheimprovedACincreasesupto53.67F/g,showinganincreaseofabout25%ascomparedwiththatofas-receivedAC.Thegoodrectangular-shapedvoltammogramsandA.C.impedancespectraprovethatthehighratecapabilityofthecapacitormadeoftheimprovedACisenhancedsignificantly.Thecapacitanceresistance(RC)timeconstantofthecapacitorcontainingtheimprovedACis1.74s,whichismuchlowerthanthatoftheonecontainingas-receivedAC(anRCvalueof4.73s).ItisnotedthatbothkindsofACsamplesshowasimilarspecificsurfaceareaandporesizedistribution,butsomechangeshavetakenplaceinthecarbonsurfacegroups,especiallyadecreaseintheconcentrationofsurfacecarbonylgroupsaftertheimprovement,whichhavebeenverifiedbymeansofX-photoelectronspectroscopy.Accordingly,itissuggestedthatthedecreaseintheconcentrationofsurfacecarbonylgroupsfortheimprovedACisbeneficialtotheorganicelectrolyteionpenetratingintothepores,thusleadingtotheincreaseinboththespecificcapacitanceandhighratecapabilityofthesupercapacitor.

简介：BasedontheanalysisofDCcharacteristicsofsiliconbipolartransistorsatlowtemperature,DCanalyticmodelsofECLcircuitatlowtemperaturearederived,thencomparedwiththeexperimentaldataandcomputersimulationresults.ThemodificationofSPICEBJTmodelabouttemperatureanddesignoflowtemperatureECLcircuitarediscussed.