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1.
6o.IntroductionThemainresultsofthispaperwerepresentedin[4l.Letusconsiderthetransversalvibrationsu(x,t)(o5x5L,t2o)ofahomogeneousbeam.Inthefollowing,thelettersp,E,G(resp.S,I,k)withdenotetheusualphysical(resp.geometrical)paJrametersofthebeam.Moreprecisely,p:=volumedensity,E:=Youngmodulusofelasticity,G:=shearmodulus,S:=areaofthecrosssection,I:=momentofinertiaofthecrosssection,R2:=IS-',kisapositivenumber51whichdependsupon'thegeometryofthecrosssection(see[62,2o]),e.g.forrectangularcrosssection…  相似文献   

2.
二元一次方程组{(1)当a:、b:、a一x b.夕=cla:x bZ少=cZc:和a:、b:、(!忿;会;},。)c:分别成等差数列时,方程组的解是{(2)当a:、b:、劣=一1y二2c;和a:、bZ、。2分别成等比数列且公比分别为q:、q,时,方程组的解是{y=证明:(l)一q一qZq一 q:将方程组改写成a:‘ (a: d:)夕=a: Zd;aZ二 (a: dZ)夕=a: Zd:(I)(I)(a:b:一匕:d:斗。)(I)xa:一(I)xa:,得(a;d:一a,dZ)夕=2(a Zd:一a,dZ)(2) 夕=2代入(I)〔或(I)〕得x=一1.将方程组改写成.’.广“一1 、夕=2。X q lyx q:y=好=q量(I)(F)(g:一Q:车。)(l(一(F),得(g:一g;)少=g荃.’.y=q: qZ,代入(l)一…  相似文献   

3.
1.IntroductionWeconsiderthefollowingsecondorderellipticboundaryvalueproblem:Lu=f,infl,(1)u=o,onOfl,(2)whereLisaselfadjointpositiveoperatorandflCnd(15dS3)isapolyhedraldomain.Aweaksolutionhasthefollowingform:FinduEHf(fl)suchthat:LetVh:=M=Span{rki},where{ghi}couldbenodalbasisconsistingofpiece-wiselinearfunctionsorothersplinefunctions-Substitutingthefollowingsolutionuh=Zui4iintotheaboveweakformleadstoadiscreteequationAu=f,(3)whereA=(crij),oij=A(ofi,rkj).(4)Itiswellknownthatthec0efficientmat…  相似文献   

4.
1.IntroductionConsidertheequationdependingontheparametersA,pER,wheref'R-Rands:R-RaresmoothoddfunctionandLetS'u(x)-u(T--x),r={S,I}.Then(l.l)isr-equivalent.Theequality(l.Za)isjustanormalizationoffatx=0.WeintroduceaSobolevspaceX:=Ha(0,7),anddefineamappingT'gEL'(0,T)u'=TaEXimplicitly'Aweakformof(1.1)inXxRZisDuetof(0)~0,theproblem(1.3)(resp.(1))hasatrivialsolutioncurveIfwerestrictp=0,then(l.3)reducestoaproblemwithsingleparameteranditsbifurcationsonthetrivialsolutioncurveCOarewellknown,…  相似文献   

5.
1 IntroductionConsider the parameter dependent equationu"+ (λ+ s(μ) ) f( u) -μsinx =0  in ( 0 ,π)u( 0 ) =u(π) =0 ( 1 .1 )whereλ,μ∈R are parameters and f:R→R and S:R→R are smooth odd functions anda) f′( 0 ) =1 ,   b) f ( 0 )≠ 0 ,   c) s( 0 ) =0 ,   d) s′( 0 ) =1 . ( 1 .2 )Let S:u( x)→ u(π-x) ,Γ ={ S,I} ,then ( 1 .1 ) isΓ -equivariant.The equality ( 1 .2 a) isjust a normalization of f at x=0 .Otherwise,one may reseek the parameter x to ensure( 1 .2 a) .To simplify an…  相似文献   

6.
1IntroductionConsidertl1eparameterdependentequationwhereA,ltERarepara1ueterandf:R-RandS:R-RaresinoothoddfunctionwithLetS1:u(x)-u(T-x),r={S1,I}then(l.1)isr-equivariant.Tl1eequality(1.2a)isjustanormalizatiolloffatx=o.Otherwise,onelllayreseektl1eparameterxtoensure(1.2a).To8implifyanalysisweintroduceaSobolevspaceX:=Hl(o,1)anddefilleamappingT:gEL'(o,T)-lL:=TgEXimp1icitly:for(Tg)'V'dx=-jorgl)dx,VvEX,aweakformof(1.1)inXxR2isDuetof(o)=O,theproblem(1.3)(resp.(1))hasatrivialsolutioncurvesC…  相似文献   

7.
1.IntroductionInthispaper,weinvestigatetheperiodicboundaryvalueproblem(PBVP)forfirstordernonlinearimpulsiveintegro-differentialeauationsofmixedtypeinaBanachspaceE:wherefEC[JxExExE,E],J=[0,2r]ticECIE,E](k=1,2,',m:KECID,R ],D={(t,s)EJxJ:t2s},HEC[JxJ,R ],R denotesthesetofallnonnegativenumbers,and0相似文献   

8.
王卫东 《数学季刊》1997,12(2):5-10
5l.TheMedianFormulaAseveryoneknows:in6ABC,letal=BC,a2=CA,a3=AB,;)11,)n2,n13aremedian1inesseparatelyonthethreeedgesBC,CA,AB,tI1entheequalityistrueasfollowsTheequality(l)iscalledmedianformulaofQABC,andwecanobtainfrom(l)Inthispaper,wesha1lextendtheequality(l)and(2)to,l-simplexin)l-EuclideanspaceH.Itisobtainedthemedianformulaof)I-simplex,andusingthisformula.wegetsomein-equalities.Themedianformulaofn-simp1exisobtainedasfollows:TheoremlFork=1,2,--',It 1andl相似文献   

9.
例题(全国Ⅰ卷20题)如图1,四棱锥S-AB-CD中.SD⊥底面ABCD,AB//DC.AD⊥LDC,AB=AD=1,DC=SD=2,E为棱SB上的一点,平面EDC⊥平面SBC. (Ⅰ)证明:SE=2EB; (Ⅱ)求二面角A-DE-C的大小. 教师:请将条件中的数量、位置关系在图中标出.  相似文献   

10.
在函数y =f(x)中隐含着秘密 ,发现并利用y =f(x) 的秘密 ,是顺利解题的关键 .那么 ,秘密到底藏在哪儿呢藏在函数的关系式之中例 1 :(0 1年全国高考题 )设 f(x)是定义在R上的偶函数 ,对于任意x1 ,x2 ∈ 0 ,12 ,都有f(x1 +x2 ) =f(x1 )·f(x2 ) ,且 f(1 ) =2 .求 f 12 ,f 14 .分析 :怎样由 f(1 ) =2去求f 12 呢 ?从题设给出的函数关系式 :f(x1 +x2 ) =f(x1 )·f(x2 )启发我们 ,只要把 1分成两个 12 之和 ,即可解决问题 .解析 :首先 ,由x1 ,x2 ∈ 0 ,12 都有f(x1 +x2 ) =f(x1 )·f(x2 )的条件 ,可推出x∈ [0 ,1 ]时都成立的一般式子 :f(x) =f …  相似文献   

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