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258 个结果
  • 简介:Tosolvetheflightsafetyproblemcausedbynonlinearinstabilities(categoryIIpilotinducedoscillations,PIOs)oftheclosed-looppilot-vehiclesystemwithrate-limitingactuator,theantiwindup(AW)compensationmethodtoavoidcategoryIIPIOsisinvestigated.Firstly,theAWcompensationmethodoriginallyusedforcontrollinginputmagnitudelimitedsystemisintroduced,thenthismethodisextendedforcontrollinginputrate-limitingsystemthroughacirclecriteriontheorem.Secondly,theestablishmentoftheAWcompensatoristransformedintothesolvingoflinearmatrixinequalities.Finally,anAWcompensatorestablishmentalgorithmfortheclosed-looppilot-vehiclesystemwiththerate-limitingactuatorisobtained.TheeffectivenessoftheAWcompensationmethodtoavoidcategoryIIPIOsisvalidatedbytime-domainsimulations,andcomparedwithrate-limitedfeedback(RLF)commandratecompensationmethod.TheresultsshowthattheAWcompensationmethodcaneffectivelysuppresscategoryIIPIOsandmaintainthenominalperformancewhentheclosed-looppilot-vehiclesystemisnormal.Unlikethecommandratecompensatorwhichworksuponsystemuninterruptedly,theAWcompensationmethodaffectstheclosed-looppilot-vehiclesystemonlywhentherate-limitingofactuatorisactivated,soitisanovelPIOavoidancemethod.

  • 标签: 非线性不稳定性 人机系统 闭环 饱和补偿 速度 执行器
  • 简介:Notopterygiumincisum(QH)hasbeenusedforthetreatmentofrheumatoidarthritis(RA),andvolatileoilsmaybeitsmainlybioactiveconstituents.ThepresentstudywasdesignedtoanalyzethevolatilecompoundsinQHandtodeterminetheanti-arthriticcapacityofNotopterygiumvolatileoilsandthepotentialmechanismofaction.ThevolatilecompoundsanalysiswasconductedbyGC-MS.Theanti-arthriticcapacitytestofthevolatileoilswasconductedonadjuvant-inducedarthritis(AIA)rats.Theanti-inflammatorypropertywastestedinNOreleasemodelinRAW264.7cells.Endothelialcellswereusedtoevaluatetheanti-proliferativeandanti-tubeformativeeffects.70compoundswereanalyzedbyGC-MSinthevolatileoils.NotopterygiumvolatileoilsweakenedtheratAIAinadose-dependentmanner(2,4,and8gcrudedrug/kg).TheNOproductionbyRAW264.7wasdecreasedbymorethan50%inNotopterygiumvolatileoils(5,15,and45μg·mL-1)pretreatedgroups.NotopterygiumvolatileoilsalsoinhibitedEAhy926cellproliferationandfurtherdelayedEAhy926cellcapillarytubeformationinaconcentration-dependentmanner.Theanti-NOproductive,anti-proliferative,andanti-tubeformativeeffectsofNotopterygiumvolatileoilsstronglysuggestedthatthetherapeuticeffectofQHinAIAmightberelatedtothepotentanti-inflammatoryandanti-angiogeniccapacitiesofthevolatileoils.

  • 标签: NOTOPTERYGIUM incisum Volatile oil Adjuvant-induced ARTHRITIS
  • 简介:Carbon-containingrefiactoriesareeasilyoxidizedathightenperature,thusmakingserviceliferapidlydrop.Theanti-oxidationmethods,suchasimpregnationandaddinganti-oxidatonagents,can'tmeettherequire-mentsofindustry'sdevelopmentandsomespecialcases,Byanalyzingthecharcteristicsofseveraloxidesandnon-oxidesrawmaerials,theoxidationresistantmechanismoftherefractoryanti-oxidationcoatings(RAOC),whichpossessthecharacteristcofself-healingathighttemperature,isdiscussed.

  • 标签: 耐火材料 抗氧化机理 制备 碳化物 原料 氧化硅
  • 简介:ByusingthegeneralizedPoincaréindextheoremitisprovedthatifthen^2criticalpointsofann-polynomialsystemformaconfigurationoftype(2n-1)-(2n-3)+(2n-5)-…+(-1)^n-1,andthe2n-1outmostanti-saddlesformtheverticesofaconvex(2n-1)-polygon,thenamongthese2n-1anti-saddlesatleastonemustbeanode.

  • 标签: 立方多项式微分 反鞍 指数定理 赤道 临界点 半球
  • 简介:目的:分析耳郭刺激抗衰老的疗效,寻求一种简便、安全的抗衰老的保健方法。方法:综合分析耳郭刺激与抗衰老的文献报道,从衰老与耳的关系,耳郭抗衰老的刺激方法、临床应用及机理研究等方面进行探讨。结果与结论:耳郭刺激通常选用与五脏相对应的耳穴心、肝、脾、肺、肾及内分泌、皮质下。耳郭刺激,尤其是耳穴贴压和耳郭按摩法,是简便有效的无创伤性保健、治疗方法,应当在抗衰老中起更大作用。

  • 标签: 针刺 耳穴贴压 衰老 综述
  • 简介:Thepresentstudywasdesignedtoexaminetheanti-hyperuricemicandanti-inflammatoryeffectsandpossiblemechanismsofvaticaffinol,aresveratroltetramerisolatedfromethanolextractsofDipterocarpusalatus,inoxonate-inducedhyperuricemicmice.At1hafter250mg·kg~(-1)potassiumoxonatewasgiven,vaticaffinolat20,40,and60mg·kg~(-1)wasintragastricallyadministeredtohyperuricemicmiceoncedailyforsevenconsecutivedays.Vaticaffinolsignificantlydecreasedserumuricacidlevelsandimprovedkidneyfunctioninhyperuricemicmice.Itinhibitedhepaticactivityofxanthinedehydrogenase(XDH)andxanthineoxidase(XOD),regulatedrenalmRNAandproteinlevelsofuratetransporter1(URAT1),glucosetransporter9(GLUT9),organicaniontransporter1(OAT1),organiccationtransporter1(OCT1),OCT2,organiccation/carnitinetransporter1(OCTN1),andOCTN2inhyperuricemicmice.Moreover,vaticaffinolmarkedlydown-regulatedrenalproteinlevelsofNOD-likereceptor3(NLRP3),apoptosis-associatedspeck-like(ASC),andCaspase-1,resultinginthereductionofinterleukin(IL)-1β,IL-18,IL-6andtumornecrosisfactor-α(TNF-α)levelsinthisanimalmodel.Additionally,HPLCandLC-MSanalysesclearlytestifiedthepresenceofvaticaffinolinthecrudeextract.Theseresultssuggestthatvaticaffinolmaybeusefulforthepreventionandtreatmentofhyperuricemiawithkidneyinflammation.

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  • 简介:China'sAnti-JapaneseWarWORLDWARⅡ,whichendedhalfacenturyagoinacrushingdefeatforthefascistpowers,wasalife-and-deathstrugglebetw...

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  • 简介:Anti-globalizationtrendsareinplayintheUSandWesternEuropewhereelectoratesarerecalcitranttoallowimmigrantsintotheirsocieties,nationalsovereigntyissoughtincertaingeographicareas,andthenationalmoodseekstosuppressnewlyrisingcountries'tradeanddevelopment.ThecontinuationofeconomicdownturninWesterncountriesisreinforcedbytheirinternalwealthgapandexternalcompetition.Ascapitalism'sdemandforprofitisnowbeingcritiquedalongwiththeemergentprofitprospectstobedeliveredbypendingtechnologicalprogress,thetemperofthetimescouldtemporarilyslowdownbutnotreverseglobalization.Timelydiscussionsaboutreformofinternationaleconomicorderandaboutaneffectivenationaldevelopmentmodelshouldseeksustainablesolutionsforhealthy,stableglobalizationanddevelopmentoftheworldeconomy.

  • 标签: 西方国家 化探 全球化 地理区域 国家主权 经济衰退
  • 简介:Therearefewstudiesontheneuroprotectiveeffectsofsyringaldehydeinaratmodelofcerebralischemia.Thestudyaimedtoelucidatethemechanismsunderlyingtheneuroprotectiveeffectsofsyringaldehydeonischemicbraincells.Ratmodelsofcerebralischemiawereintraperitoneallyadministeredsyringaldehyde.At6and24hoursaftersyringaldehydeadministration,celldamageinthebrainofcerebralischemiaratswasobviouslyreduced,superoxidedismutaseactivityandnuclearrespiratoryfactor1expressioninthebraintissueweremarkedlyincreased,malondiadehydelevelwasobviouslydecreased,apoptosis-relatedcysteinepeptidasecaspase-3and-9immunoreactivitywasobviouslydecreased,andneurologicalfunctionwasmarkedlyimproved.Thesefindingssuggestthatsyringaldehydeexertsneuroprotectiveeffectsoncerebralischemiainjurythroughanti-oxidationandanti-apoptosis.

  • 标签: 神经保护作用 细胞损伤 脑缺血 抗凋亡 抗氧化 丁香
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  • 简介:ChinesetoplegislatorWuBangguoonDec.29,2004promisedthatthe10thNationalPeople'sCongress(NPC)woulddoitsbesttofullyreflectthecommonwillofallChinesepeopleinmakingtheanti-secessionlaw.

  • 标签: 大学英语 注释 阅读练习 时事新闻