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1.
1 Introduction Inecology ,apredator preyinteractionofbothpopu lationsinonedimensionisdescribedbythefollowingsystem[1] :ut(x ,t) =uxx uM (u ,v) ,vt(x ,t) =βvxx vN(u ,v) ,(1)whereβisapositiveconstant,uandvarethepreyandpredatordensitiesrespectively ,andthefunctionsMandNare…  相似文献   

2.
Aim :TheJournalofZhejiangUniversity(Science)iseditedbyaninternationalboardofdistinguishedChineseandforeignscientists,andisaimedtopresentthelatestdevel opmentsandachievementsinscientificresearchinChinaandoverseastotheworld sscientificcircles,speciallytost…  相似文献   

3.
Aim :TheJournalofZhejiangUniversity(Science)iseditedbyaninternationalboardofdistinguishedChineseandforeignscientists,andisaimedtopresentthelatestdevel opmentsandachievementsinscientificresearchinChinaandoverseastotheworld sscientificcircles,speciallytost…  相似文献   

4.
THEORETICALCONSIDERATIONSInthepast 2 0 years,withpsycho linguisticsprobingdeeperintolearningstrategies,researchonlisteningcomprehensionstrategies,donebywesternscholars,hasalsoreachedaclimax .Theirresearchmainlycoverstwoaspects :researchonlisteningcomprehens…  相似文献   

5.
Aim:TheJournalofZhejiangUniversity(Science)iseditedbyaninternationalboardofdistinguishedChineseandforeignscientists,andisaimedtopresentthelatestdevelopmentsandachievementsinscientificresearchinChinaandoverseastotheworldsscientificcircles,speciallytosti…  相似文献   

6.
INTRODUCTIONATMhasgreatsuperiorityincertainaspects,suchasresourceallocationflexibility ,qualityofserviceguaranteeing ,integratedtrafficsupport ing ,etc .ATMhasbeenadoptedbyInternation alTelecommunicationUnion (ITU)astheex changeandmultiplexingtechniquesofth…  相似文献   

7.
每个人每天夜里都做梦 ,而且还不止做一个梦。不信?请看下文。AspeciallabattheUniversityofChicagoisbusyonly1.Itisadreamlab2researchersare3onstudying 4.Theirfindingsshowedthatev eryonedreams5three6seven7anight,8inordinarylifeaperson9remember10oronlyoneofhisdreams.Whilethesubjects—usua…  相似文献   

8.
INTRODUCTIONThispaperconsidersthemixed effectcoeffi cientsemiparametricregressionmodelZ =X′α Y′β g(T) e,(1 )whereX ,YandTarerandomvectorsonRp,Rqand [0 ,1 ]respectively ,αisap dimensionalfixed effectparameter,βisaq dimensionalran dom effectparameter (Eβ =b ,Cov(β) =∑) ,g(.)i…  相似文献   

9.
1 Introduction Breastcancerisoneofthemostmalignantdiseases,especiallyforwomen.Anearlydetectioncansavelives,achievedbyearlydetectionwithmammograms.Itisanintensivetaskfortheradiologistbecausemultiplereadingsofasinglemammogramarenecessaryinordertoincre…  相似文献   

10.
Motivatedbyredesigningafuselageinengineeringapplication,thenumericalandexperimentalinvestigationoftheseparatedflowfieldaroundaspecialbluntbodyisdescribedinthisthesis.Theaerodynamicresponseofthebluntbodyissuccessivelystudied.Thethesisconsistsoffour…  相似文献   

11.
长期以来 ,传统语言学家认为“体”(ASPECT)与“时”(TENSE)都属于语法范畴 ,但若就表达效用而言 ,英语动词的“体”与“时”和语用学有着千丝万缕的联系 ,这是因为语用学与语法本来就互相补充 ,相互重叠。所谓“体”,其实就是表示某一动作或过程在某一时间内处于何种状态的形式。在英语中 ,动词有两个“体”:进行体 (progressiveaspect)和完成体 (perfectaspect)。本文着重讨论进行体的语用功能与英语动词词汇意义的关系。一、进行体的分类及语用功能进行体可分为现在进行体 (presentpr…  相似文献   

12.
INTRODUCTIONSoftsoiliswidelydistributedovercoastalandriversideregions ,wherebecauseoftheirspeciallocations,oil tanksareoftenconstruct ed .Largeoil tankswithheavyloadaresensitivetodifferentialsettlement.Engineersareusuallymoreconcernedwiththedifferentials…  相似文献   

13.
听力部分1 听对话 ,并圈出对话中出现的词汇 (斜体为磁带录音内容 ) (1 )A :Whereismykite,mummy?B :Idon’tknowexactly.a .bike   b .kite   c .ride(2 )A :Now ,let’shaveatest.B :It’sagoodidea .a .test   b .rest   c.west(3)A :Wheredoesyourgrandfatherlivenow ?B :Oh,helivesinShanghainow .a .leaves   b .loves   c.lives2…  相似文献   

14.
1 Introduction Computerintegratedmanufacturing (CIM)asaphi losophyhasreceivedworldwideattentionsincethe1980sandhasbeenappliedtodirectenterprisespro ductionsuccessfullyinmanyindustrializedcoun tries[1] .TheUSgovernmenthasconsideredtheman ufacturingindustrytob…  相似文献   

15.
李士芗 《当代电大》2002,(11):46-49
听力部分1 听对话 ,并圈出对话中出现的词汇 (斜体为磁带录音内容 ) (1 )A :Whereismykite,mummy?B :Idon’tknowexactly.a .bike   b .kite   c .ride(2 )A :Now ,let’shaveatest.B :It’sagoodidea .a .test   b .rest   c.west(3)A :Wheredoesyourgrandfatherlivenow ?B :Oh,helivesinShanghainow .a .leaves   b .loves   c.lives2…  相似文献   

16.
INTRODUCTIONProteindeficiencyisoneofthemostseriousproblemsintheworld ,especiallyindevelopingcountries.Ithasbeenestimatedthatabouttwo thirdsofthepopulationintheworldaresufferingfromlackofprotein ,especiallyhigh qualityani malprotein (Liu ,1 992 ) .Itistherefore…  相似文献   

17.
FOREWORD     
The 10 2 yearoldZhejiangUniversitynowputsouthernewjournal″JournalofZhejiangUniversity (SCIENCE)″,aimedatdevelopingacademicresearch ,pro motingacademicexchange ,andnurturingcreativityinthespiritofseekingthetruth .Creativityishighlyvalued .Therehavelongbeentwok…  相似文献   

18.
1 Introduction Sincethe 90’s ,thefemtosecondlasertechniqueshavebeenusedtostudyvariousultra processwithinmaterials,becauseofitshightime resolution .Inchemicalreactions ,chemicalbondbreakingorbondformationisonthescaleoffemtosecond (10 - 15sec ond) [1] .Withfemtosecon…  相似文献   

19.
INTRODUCTIONOn lineseparationandpreconcentrationhavereceivedconsiderableattentioninflowinjectionanalysiscoupledwithatomicabsorptionspec trometryduringrecentyearsandiswidelyap pliedforselectivityandsensitivityenhancement(Fang ,1 995 ) .Automationofthesamplep…  相似文献   

20.
INTRODUCTIONAntisenseoligodeoxynucleotides (ASODN )caninhibittranscriptionandinterferewithspe cialgeneexpression .AfixedpointontheK rasgenewithhighmutationrateinpancreaticcarci nomaoffersanintracellulartargetforpancreaticcarcinomagenetherapywithASODN (Cai…  相似文献   

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