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1.
1 Introduction Fe3Albasedalloysexhibithighoxidationresistance ,excellentsulphidationresistanceandlowcostofalloyconstituents.However ,thesealloyshavenot yetfoundwidespreadapplicationfortheirenvironmentalembrittlement[1~ 3] .Thetensilepropertiesandenvi ronment…  相似文献   

2.
1 Introduction Squashmosaicvirus (SqMV)isoneofthemostim portantcucurbitviruses[1~ 3] ,anditcausesgreatlossesinmuskmelonproduction[4 ] .Oneofthemainwaystocontrolplantvirusdiseasesistheinducementofresis tancetoviruses[5] bysomebiologicalandnon biologicalfactors[6~ 9…  相似文献   

3.
OurWebsiteforinternationalexchangehasnowcameintoexistence .Currently ,therearesixcolumnsonoursite ,namely :Presidents’mssage ,OurMission ,AboutUs ,ContactUs ,UpdatedEventsandCourses .ThesitehasbeenlinkedtothehomepageofShanghaiDistanceEducationGroup .Theset upo…  相似文献   

4.
TheNecessityandCertaintyofDevelopingDistanceEducationbyZhangDeming  OnJanuary 2 4thof2 0 0 0 ,ShanghaiDistanceEducationBlocwasfounded,asaneces sityofthefurtheringofShanghaieducationalreformandthedevelopmentofeducationindus tryforthepurposeofservingeconomicco…  相似文献   

5.
INTRODUCTIONPositronEmissionTomography (PET)isapowerfulbiologicalimagingtoolcapableofpro vidinghighqualityfunctionalimages.Aradioac tivelylabelledsubstance,designedtoshowthephysiologicalfunctionofaparticulartissue,isinjectedintoapatient.Thechosensubstanc…  相似文献   

6.
INTRODUCTIONThemicrostructureofthinfilmsplaysacru cialroleinawidevarietyofphysicalprocesses.Thereareclearevidencesthatmanyphysicalpropertiesofathinfilmvarydramaticallyasitsmicrostructurechanges (Hausetal.,1 987) .Forinstance,roughsubstratescanbeusedtofabric…  相似文献   

7.
1 .Theindependenttheoryandcooperativeteaching&learningmodeofdistanceeducation .Differentfromtraditionaleducation ,distanceeducationisbasedonstudent’spersonalizedstudy .Therefore,oneimportantpartofdistanceeducationisindependent -studytheory .Thetheoryfocuses…  相似文献   

8.
1 Introduction IronaluminidesbasedonFe3 Alhavemanyadvantagesforstructuralusesatelevatedtemperaturebecauseoftheirexcellentcorrosionresistanceandrelativelylowmaterialcost.However,thesealloyshavenotyetfoundwidespreadusebecausetheyexhibitpoorductilityandbr…  相似文献   

9.
I.IntroductiontostudyDistanceeducation ,alsoknownasopenandflexiblelearning ,createsneweducationaloppor tunitiesforthosepreviouslyexcludedbygeogr aphicaldistance ,disability ,strictselectiveentrysystem ,financialandtimeconstraints.TheInn erMongoliaAutonomous…  相似文献   

10.
1 Introduction Longrangeorderedintermetallicspossessanumberofadvantages ,suchaslowdensity ,goodhigh tem peraturestrength ,excellentoxidationresistance ,whichmakeitpossibleforthemtobeusedasstruc turalmaterialsforhightemperatureapplications .However ,mostofthe…  相似文献   

11.
StudyonLong-DistanceDistributedMachineConditionMonitoringandFaultDiagnosisSystemJiaMinping(贾民平)ZhongBinglin(钟秉林)(Departmento...  相似文献   

12.
Zirconiumalloyspossessingverylowabsorptionforthermalneutrons,goodcorrosionresistanceinhightemperaturewater ,andreasonablemechanicalprop ertiesareimportantmaterialsfornuclearindustry ,andhavebeenemployedasnuclearfuelcladdingandasstructurematerialsinlight…  相似文献   

13.
数学问答     
58 .问 :已知secα -tanα =5,求sinα. (河南西平县高中一 ( 6 )班 颜 寅 )答 :secα-tanα=5=5·1=5(sec2 α -tan2 α) =5(secα +tanα) (secα -tanα) .故secα +tanα =15.与已知式联立 ,则secα=135,tanα=- 125.sinα =tanαcosα =- 1213.(解答 赵振华 )59.问 :若a、b、c均是不等于 0的常数 ,求函数y =(x +a) 2 +(x +b) 2 +(x +c) 2 的最值 . (浙江天台县平桥中学高三九班 许海燕 )答 :将原函数化为 y =3x2 +2 (a +b +c)x +(a2 +b2 +c2 ) .因 3>0 …  相似文献   

14.
INTRODUCTIONThemagneticandtransportpropertiesofthinmagneticmultilayershaveattractedconsiderableattentionduringthepastyears.Sincediscoveryofnegativegiantmagnetoresistance (GMR)byBaibichetal.inFe/Crmultilayers (Baibich ,1 998) ,extensiveresearchhasbeendonecon c…  相似文献   

15.
《河北自学考试》2000,(9):33-37
Ⅰ .VocabularyandStucture (1 0 points,1 pointforeach)1 .Almosteverythingamanagerdoes  deci sions;indeed ,somesuggestthatthemanagementpro cessisdecisionmaking .[A]imposes[B]improvises[C]involves[D]indi cates2 .Astronomersandscientiststhinkthatablackholeisaregionofspace…  相似文献   

16.
亚太地区开发人力资源的远距离教育研讨会会综述朱雪雯1995年10月24—27日,在上海召开了题为“开发人力资源的远距离教育”(DistanceEducationasanAsPectofHumanResourceDevelopment)地区研讨会。会议...  相似文献   

17.
1 Introductiion In 1994 ,O’LearyandYeremin[1] extendedthequasi Newtonalgorithmtotheblockcase ,inwhichtheyminimizedacollectionofthefollowingfunctions :fi(x) =f~(x) +bTix +ci  (i=1,… ,p) (1.1)withx∈Rn.Herefordistinctvaluesofthevectorsbi,eachofthesefunctionshasadifferentmin…  相似文献   

18.
1 Introduction ThestudyofB啨ziersurfaces’convexityisusefulinCAGD (computeraidedgeometricdesign)andtherehavebeenmanydiscussionsandresultsforthecon vexityoftheB啨ziersurfaceoveratriangle[1~ 6] .ButfortheconvexityoftheB啨ziersurfaceoverarectan gle ,whatweknewisli…  相似文献   

19.
由国际知名远程教育专家德斯蒙德·基更(Desmond Keegan)主编,丁新等编译的《远距离教育理论原理》(TheoreticalPrinciplesOfDistanceEduca-tion)将于1999年7月由中央广播电视大学出版社正式出版。现代...  相似文献   

20.
现代通讯技术、计算机网络技术和多媒体技术的迅猛发展,使现代远程教育成为80年代以来国际教育发展的共同趋势。世界上各发达国家的政府都以积极的态度,采取有效措施,支持本国的现代远程教育,为21世纪科学技术的快速发展作好高素质人才的准备。一、现代远程教育的概念和特点远程教育(DistanceEducation)是指教师和学生处于分离状态,而必须利用各种通讯媒体进行教学的教育形式。它具有远程教学(DistanceTeaching)和远程学习(DistanceLearning)两方面的含义。现代远程教育是…  相似文献   

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