首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
INTRODUCTIONTime delays,duetotransportationlags,fi nitecalculationtimes,measurementstimes,etc.,appearinnumerousindustrialandnaturalprocesses,oftenleadingtooscillationsandsome timesinstability.Thestabilityandstabilizationproblemsoftime delaysystemswithorwit…  相似文献   

2.
Stars     
Doyouliketowatchstarsintheevenings ?Howmanystarsarethereinthesky ?NowIwouldliketotellyousomethingaboutthestars .About 5 ,0 0 0starscanbeseenwithourhumaneyes.Withasmalltelescope,youwillseemanymorestarsandwiththelargesttelescope ,billions①ofstarswillberevealed②…  相似文献   

3.
SamuelL .Clemens,betterknownasMarkTwain ,remainsoneoftheworld’swidelyreadau thors.Toagreatextent,hispopularityhasrestedonhishumor,butitwouldbeamistaketothinkofhimsimplyasahumorist.Todosoistooverlookmanyofhisothersuperiorqualitiesofwriting ,includinghisclar…  相似文献   

4.
Zirconiumalloyspossessingverylowabsorptionforthermalneutrons,goodcorrosionresistanceinhightemperaturewater ,andreasonablemechanicalprop ertiesareimportantmaterialsfornuclearindustry ,andhavebeenemployedasnuclearfuelcladdingandasstructurematerialsinlight…  相似文献   

5.
MissGreenhadbeentakingdrivinglessonsandtryingtopassherdrivingtestforseveralyears,butshehadfailedmanytimes ,becauseshealwaysbecametoo  1 todrivewell.Nowshewastakinganothertestbutagainshe  2 manymistakes.Shewas  3 shehadnochanceofpassing .Toher  4  ,theex amine…  相似文献   

6.
Oneofthesignificantproblemsarisingfromthemanagementandoperationofmutualfundishowtopre serveappropriatecash position ,whichconsistsofthecashpositionheldbymutualfundandthecashinflowre sultingfrominvestors′purchasingmutualfundshares ,tomeetinvestors′redemp…  相似文献   

7.
1 Introduction Inquantumoptics ,somenon classicalstatesoflighthavebeenstudiedrecently .Inparticular ,thoseopticalsuperpositionstates ,whicharebasedontheprincipleofquantumsuperposition ,giverisetovariousnon classicalproperties.Numbersuperpositionstates[1] arep…  相似文献   

8.
ThecoreofcollegeEnglishteachingistodevelopstudents’languageusingcompetence ,whichshowstheabilityofone’sreading ,lis tening ,writing ,speakingandtranslation .Inlistening ,teachersusuallytrainstudents’lan guageusingcompetencebymeansofvariouslanguageskills .Upo…  相似文献   

9.
MaryTyroneisO’Neill’smostfullyrealizedfemalecharacter,afigurewhosesufferingexposesthelimitationsandparadoxesimposedonwomeninaworldshapedaroundmaledesires.InhisportraitofMaryTyrone ,awomanwhochafesattheoverwhelmingdemandsplaceduponher,whoimaginesaworldi…  相似文献   

10.
Colourwordsarewordsusedtodescribethecoloursofdifferentthings.Besidesindicatingtheirspecificcolours,suchasred ,yellow ,blackandwhite ,theyalsoreflectthedifferentculturalconnota tionsindifferentlanguages.Forexample,Chinesegirlslikewearingreddressesontheirwe…  相似文献   

11.
1 Introduction Longrangeorderedintermetallicspossessanumberofadvantages ,suchaslowdensity ,goodhigh tem peraturestrength ,excellentoxidationresistance ,whichmakeitpossibleforthemtobeusedasstruc turalmaterialsforhightemperatureapplications .However ,mostofthe…  相似文献   

12.
1 Introduction Singularlyperturbeddifferentialequationswithturningpointsareveryimportantformathematiciansandphysicistssincetheseproblemsexistwidelyinmanyproblemsofphysics.TheproblemswithturningpointswerestudiedbyWentzal,Kramers,Bullounin[1],Langer,A…  相似文献   

13.
Tolstoy,inhisgreatestnovel WarandPeace,vividlyreproduceseveryaspectofsociallifeinoldRussiabetween1805-1820.Hesuccessfullycreatesavastnumberofcharacters,agroupofprogressivearistocraticyouths,suchas,Pierre,Andrey,Natasha,etc..Theseyouthsabsorbedpowerdirectlyfrom…  相似文献   

14.
I.IntroductionTeachingmaterialsrefertoanythingthatisusedbyteachersorlearnerstofacilitatethele arningofalanguage.Materialscouldobviouslybecassettes,videos,CD Roms,dictionaries,grammarbooks,readers,workbooks,newspap ers,foodpackagesor photographs.Inotherwords,…  相似文献   

15.
1 Introduction Thesolutionsoftemperatureanddisplacementfieldsofdamsareofinteresttomanyresearchersinhydropowerindustryandothersforyears,becauseoftheirimportanceinthesafetyofdams.Generallyspeaking,numericalsolutionsweredevelopedtounderstandthedisplace…  相似文献   

16.
THEORETICALCONSIDERATIONSInthepast 2 0 years,withpsycho linguisticsprobingdeeperintolearningstrategies,researchonlisteningcomprehensionstrategies,donebywesternscholars,hasalsoreachedaclimax .Theirresearchmainlycoverstwoaspects :researchonlisteningcomprehens…  相似文献   

17.
SOFTWAREEVOLUTIONSoftwareevolutionhasbeenaddressedfrommanyviewpoints .Theseincludemanagementis suessuchaswhichpartsofasystemshouldberebuilt,configurationissuessuchaskeepingtrackofmanyversionsofthesamesystem ,test ingissuessuchasdeterminingwhichtestcases…  相似文献   

18.
AAsinglemother,LiRuizhiranintoseriousfinancialproblemshalfayearago .Herformerhusband ,whoshedi vorcedin 1 990refusedtopaythemoneyhepromisedfortheirson .Asanordinaryworker,shecouldnotearnenoughtosupporthersonwhoisnowacollegestudent.Whatwasshetodo ?Afterprivate…  相似文献   

19.
INTRODUCTIONCr4 :YAGcrystalshadbeenwidelyusedassaturableabsorbersforflashlamppumpedoscil latorandMOPAsystems (Shimonyetal.,1 995,1 996,Eichler,1 994 ,1 995,Yankov,1 994 )aswellasindiodepumpedlasers(Zayhowskietal.,1 994 ) .Theypresentedaneasywaytogen eratepassivelyQ switchedlase…  相似文献   

20.
INTRODUCTIONTheproblemofmentaloverloadbecamein creasinglyseriouswithdevelopmentofindustrialautomation .Inmanyindustrialstations,itwasbelieved ,operatorswerefrequentlyunderthepressureofhighmonitoringmentalworkloadbe causemanypanelsandotherinstrumentsmust…  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号