学科分类
/ 1
14 个结果
  • 简介:AGeometricRepresentationSchemeSuitableforShapeOptimizationWangXuelinandZhouJiCADCenter,HuazhongUniversityofScienceandTechnolo...

  • 标签: SHAPE optimization NURBS CURVE FINITE ELEMENT
  • 简介:AbstractSeptoplasty is widely used in the treatment of structural nasal obstructions, and it also has a good effect and a high degree of postoperative satisfaction. However, there a large number of structures demonstrate abnormalities related to structural nasal obstruction, including the external nose, maxilla, nasal cavity and paranasal sinus. Nasal septum deviation is only one signs of structural nasal obstruction and does not represent all possible structural abnormalities of the nasal cavity and its surrounding structure. Septoplasty is only performed to correct deviations of the nasal septum, which in many cases is obviously insufficient in restoring the symmetry of the nasal structure. Therefore, septoplasty alone is not suitable for the treatment of most structural nasal obstructions. Nasal ventilation expansion surgery, which typically covers more abnormal structural correction procedures than septoplasty, should be used when describing the treatment of structural nasal obstruction.

  • 标签: Septoplasty Nasal septum deviation Structural nasal obstruction Nasal ventilation expansion surgery Nasal cavity
  • 简介:根据各种各样的算法的分析,称为刷子方法的一个抗混叠算法被介绍,它是合适的印射出版标志。在详细介绍刷子方法的基本原则和实现以后,结果和效率通过实验被评估。

  • 标签: 地图编制 图像失真 电刷法 图像处理
  • 简介:Amethodofenhancingpowersystemstabilityforasinglemachinetoinfinitebuspowersystemispresented.ThetechniqueusedcompromisestheeffectivenessofProportional-Integral-Derivativecontroller(PID).Inordertosatisfythedampingcharacteristicsfortheproposedpowersystemoverawiderangeofoperatinginterval,rotationalspeed,torqueangleandterminalvoltagesignalsofthesynchronousmachineareutilizedascontrolsignalsofthesystem.Itiswellknownthatthesevariableshavesignificanteffectsondampingthegeneratorsshaftmechanicaloscillations,it'llbesoeasytovalidatethemostsuitablecontrollerasseenfromthesimulationresults.

  • 标签: 电力系统稳定器 动态稳定性 比例积分微分控制器 电力系统稳定性 PID控制器 控制信号系统
  • 简介:Athree-dimensionalcloud-scalemodelhasbeendesigned.Thegoverningequationsofthemodelarecomposedoftwogroupsofequations:onegroupincludescompressiblemotionequations,continuityequation,pressureequationandthermodynamicequation,whichareofEuleriantype,andtheotherconsistsofcloud-precipitationmicrophysicsequationswhichareofLagrangiantype.Sincethedegreeofinfluenceofsoundwaveontheairmotionisquitedifferentfromthatonthetemperatureorhydrometeors,thetimesplittingprocedureisusedinsolvinggoverningequations.Bothunstaggeredandstaggeredmesheshavebeenutilized.Integra-tionschemesadoptedaretheEulerianbackwarddifferencemethodfortheunstaggeredmeshandsemi-implicitmethodforstaggeredmesh.Severalexperimentsofmodellinghavebeenconductedandareasonablethree-dimensionalimageofdeepconvectionisobtained.Withthismodelthehorizontalandverticalvortexcircula-tionsaresimulated.Furthermore,theeffectsofhorizontalvortexontheformationanddevelopmentofdowndraftwithincloudhavealsobeenstudied.

  • 标签: CLOUD CONTINUITY utilized MESHES EULERIAN BACKWARD
  • 简介:OnAug.8,2017,anMS7.0earthquakestruckJiuzhaigou,acountyofSichuanprovince,China.Anumberofinvestigationsandstudieshavebeenconducted,someofwhichinvolvedlocalvelocitymodels.However,thesuitabilityofthesemodelshasnotbeenproperlyaddressed.Herewecollect11already-existingmodels,includingthoseusedinstudiesofthe2017MS7.0Jiuzhaigouearthquake,choose10localstationssurroundingtheearthquake,andemploythesametechnique(TRIT)torelocatethehypocenter.Andfurthermore,wechooseamoresuitablemodelfromthe11already-existedmodelsbyanalyzingtherelocationprocessandtherelocatedresultsforreasonability.Finally,ourconclusionisthatthemodelFang2018ismoresuitableandthehypocenterparameters,103.801°E,33.192°Nand15.8kmforlongitude,latitudeanddepth,respectively,and2017-08-0813:19:46.66foritsorigintime,basedonthismodelshouldberecommendedforthe2017MS7.0Jiuzhaigouearthquake.

  • 标签: the 2017 MS7.0 Jiuzhaigou EARTHQUAKE the
  • 简介:Thequantitativeinterpretationofgravityanomaliesduetoshallowstructuresneedsseparationbetweenlongwavelengthanomalies(regionalanomalies)andshortwavelengthanomalies(residualanomalies).Theregional-residualfieldseparationcanbecarriedoutusingthepolynomialmethod.Inthiscase,theso-calledregionalfieldofordernistreatedasapolynomialofdegreen.Thepresentstudyshowsthatthedegreenmustvarybetweenasmallestvaluenminandamaximumvaluenmax.Thisarticlepresentsamethodtoprocessgravitydatathatallowsdeterminationofnminandnmaxforagivenstudyarea.WeapplythemethodtogravitydataoftheSouth-WestCameroonzone.Inthischosenstudyarea,wefindthatregionalanomalymapsofordersrangingfrom1to9andresidualanomalymapsofordersrangingfrom1to8canbeusedforsuitableinterpretation.Theanalysesshowthatonemayneedresidualanomalymapsofseveralorderstoperformsatisfactoryquantitativeinterpretationofthedifferentintrusivebodiesfoundinagivenarea.

  • 标签: gravity REGIONAL ANOMALY RESIDUAL ANOMALY upward
  • 简介:Theclassicalpowerlawnon-Newtonianfluidsenergyboundarylayerequationisprovedimpropertodescribetheself-similarheattransfer.Atheoreticalanalysisformomentumandenergyboundarylayertransferbehaviorismadeandthefullsimilarityheatboundarylayerequationisdeveloped,whichmaybecharacterizedbyapowerlawrelationshipbetweenshearstressandvelocitygradientwiththeFalkner-Skanequationasaspecialcase.Bothanalyticalandnumericalsolutionsarepresentedformomentumandenergyboundarylayerequationsbyusingthesimilaritytransformationandshootingtechniqueandtheassociatedtransfercharacteristicsarediscussed.

  • 标签: Power LAW fluid BOUNDARY LAYER heat
  • 简介:Fordealingwithhigh-salinitywastewaterintherefinery,thehighcostofdrivingheatsourceisthedisadvantageofmulti-effectdistillation(MED)soitisofgreatimportancetoevaluatetheperformanceoflow-temperatureheatsourceforconductingMEDandselecttheoptimaltemperatureforit.BoththeMEDandthelow-temperatureheatsourcesstudiedinthispaperwerefromatypicalrefinerylocatedinnorthwesternChina.Besides,anewmethodologytoevaluateheatsourcesastheoptimalcandidatewasproposedforMEDbasedonthegreysystemtheory.Fiveprocessunits,whichincluded18fluidsoftherefinery,werenamedastheevaluationprojects.Threefactors,whichincludedsafetyeffects,totalcostsandcharacteristicsoflow-temperatureheatsourcesweredeterminedastheevaluationindexes,thevaluesofwhichwereestablishedthroughtheanalyses.Theresultsobtainedthroughthegreycorrelationanalyseshaverevealedthatthegreycorrelationdegreesoftheseunitswere0.661(AVDU),0.732(#1FCCU),0.618(#2FCCU),0.535(#1DCU),and0.572(#2DCU),respectively.Thus,theoptimalheatsourcewasprovidedfrom#1FCCU.Throughfurtheranalysesofthefluidsfrom#1FCCU,thegreycorrelationdegreesofthefluidswere0.597(oilandgasattopoftower),0.714(recycleoilandgas),and0.512(diesel),respectively.Thus,theoptimalheatsourcewastheoilandgasrecyclestream.

  • 标签: 灰色系统理论 驱动热源 多效蒸馏 炼油厂 低温热源 评估项目
  • 简介:ImpactsongrowthofyoungtreesofPinusKoraiensisof6environmentalfactorsofintensityofsunlight,directsunlight,thicknessofsoilhumus,neighboringtrees,uppercanopyspecies,herbsandshrubswereinvestigatedonyoungtreeofPinusKoraiensisand4neighboringtreeswhichareconsideredthestructuralunitofthemicroenvironment.Resultsindicatedthatthe6environmentalfactorsunderinvestigationhadeffects,tovariousextents,ongrowthoftheyoungtrees.Basedonthefindings,suitablegrowingconditionsforregeneratedyoungtreeofPinusKoraiensisunderforestwereidentifiedandcorrespondingsilviculturalmeasureswereproposedforoperationalpractice.

  • 标签: 松阔混交林 次生林 天然更新 生长微环境 幼林松树
  • 简介:Inaviewofnaturalconditionsofestablishingnaturereserve,anindexsystemwaspreparedforquantitativeassessmentonstatusofendangeredspecies,andthusdegreeofendangeredspeciesinTibetwasevaluated.Takingasub-ecozoneasbasicunit,top5animalsand1plantwithhighEaswellasthenumberofspeciesineachunitwereenumerated;andthedegreeoflandutilizationwasfiguredout.Afterward,weselected6coefficients,assignedweight,andframedformulatoreckonproportionofnaturereserve,thusanareaofnaturereserveineachsub-ecozonewasobtained.In5schemesofweightassignment,aschemewithmediumareaofnaturereservewasselected.Allsub-ecozoneswereclassifiedinto4gradespriorconservation,1wasingradeA,2ingradeB,2ingradeC,and11ingradeD.Totalplannedareawasapproximately365135km2,about48834km2smallerthantheactualareaof413969km2,ratioofnaturereserveinTibetdiminishesfrom34.4%to30.38%.Basedon3factorsofhumandisturbance,ratioofbuffer-experimentalzoneinproposednaturereservewascalculated.Itwasdemonstratedthatexistingsizeofnaturereservesisexcessiveonthewhole,andtheirdistributionisnotreasonableentirely.Thesizeofnaturereservesin3sub-ecozonesofnorthernChangtangshoulddecrease,anddecrementofareaisapportionedamongother13sub-ecozoneswhichshouldincreasenaturereserve.HeterogeneityofregionaldistributionofrarespeciesinTibetisquiteobvious,soproposedareadistributionofnaturereservesismorescatteredthantheexisting.

  • 标签: endangerment DEGREE sub-ecozone land UTILIZATION nature
  • 简介:Aratmodelofextra-vertebralforamencervicalnerveentrapmentwasestablishedaccordingtothefollowingparameters:stimulationintensity20V;frequency50Hz;pulsewidth200μs;duration333ms/sforatotalof8hours.Aftertheelectricalstimulation,ratsexhibitedmildmusclefiberatrophy,mildinflammatoryexudates,connectivetissuelocalfibrosisandchondrocytemetaplasia.Meanmusclefibercross-sectionalareawasreduced.Thenervemyelinsheathcontinuitywaspartiallydemyelinated.Themicrostructureofnervecellswasdisruptedandthesesymptomsworsenedwithprolongationofthestimulation.Theshoulder,neckandupperextremitymusclesonthetestedsidedemonstratedpositivesharpwavesandfibrillations.Theseverityincreasedwithcontinuationofthestimulation.Highamplitudeandpolyphasicmotorunitpotentialsgraduallyappeared.Similarfindingswereseeninthecontralateralside,butatalessseverelevel.

  • 标签: 神经细胞 电刺激 动物模型 大鼠模型 脉冲宽度 持续时间