简介:根据Rumyantsev提出的Poincaré—Chetaev变量下的广义Routh方程.用无限小变换的方法研究它的对称性与守恒量,得到守恒量存在的条件和形式.该结果比以往的Poincaré—Chetaev方程的相关结论更一般.最后.举例说明结果的应用。
简介:InthepresentpapertheLiesymmetricalnon-NoetherconservedquantityofthePoincaré-ChetaevequationsunderthegeneralinfinitesimaltransformationsofLiegroupsisdiscussed.First,weestablishthedeterminingequationsofLiesymmetryoftheequations.Second,theLiesymmetricalnon-Noetherconservedquantityoftheequationsisdeduced.
简介:让f在局部性的非各向同性的Sobolev空间W_(loc)~(1,p)(H~n)在n维的海森堡组H~n=C~nxR,在此1≤p<2是的Q和Q=2n+H~n的同类的尺寸。假定椭圆形的坡度是的潜水艇gloabllyL~pintegrable,即,f_(H~n)|▽_(H~n)f|~pdu是有限的。我们在全部spaceH~n上为f证明Poincare是不平等。用我们证明的这不平等,减去某个常数的功能f在thenonisotropicSobolev空间,这在标准下面由C_0~∞(H~n)的结束形成了(∫_(H~n)|f|~((Q_p)/(Q-p)))~((Q-P)/(Q_p))(∫_(H~n)|▽_(H~n)f|~p)~(1/p)。我们将也证明为H~n上的如此的Poincare不平等的最好的常数和extremals与为H~n上的Sobolevinequalities的那些一样。用到L~(2Q)/(Q-2)的锋利的常数和extremalsforL~2上的Jerison和李的结果海森堡组上的Sobolev不平等,我们因此在H~n上为上述的Poincare不平等到达明确的最好的常数什么时候p=2。我们也在HeisenberggroupH~n上在公制的球上为本地Poincare不平等导出最好的常数的更低的界限。
简介:ForareasonableclassofweakPoincaréinequalities,thedecayofthecorrespondingMarkovsemigroupsobtainedearlierbyRcknerandthefirstnamedauthorisimprovedbyremovinganextraL~2-norm.Next,aconcentrationestimateofthereferencemeasureispresentedfortheweakPoincaréinequality,whichissharpasillustratedbysomeexamplesofone-dimensionaldiffusionprocesses.
简介:Weproposetheoreticallyandverifyexperimentallyamethodofcombiningaq-plateandaspiralphaseplatetogeneratearbitraryvectorvortexbeamsonahybrid-orderPoincarésphere.Wedemonstratethatavectorvortexbeamcanbedecomposedintoavectorbeamandavortex,wherebythegenerationcanberealizedbysequentiallyusingaq-plateandaspiralphaseplate.Thegeneratedvectorbeam,vortex,andvectorvortexbeamareverifiedandshowgoodagreementwiththeprediction.Anotheradvantagethatshouldbepointedoutisthatthespiralphaseplateandq-platearebothfabricatedonsilicasubstrates,suggestingthepotentialpossibilitytointegratethetwostructuresonasingleplate.Basedonacompactmethodoftransmissive-typetransformation,ourschememayhavepotentialapplicationsinfutureintegratedopticaldevices.
简介:1.复合函数的定义域例1已知f(x)的定义域为(0,2),求厂(log2x)的定义域.分析许多学生认为在函数f(log2x)中log2x是自变量,因此,由f(x)的定义域(0,2)求出log2x的范围是(-∞,1),从而得f(log2x)的定义域为(-∞,1).
简介:以二阶的情形讨论了Poincaré差分方程y(n+m)+(a1+p1(m))y(n+m-1)+…+(an+pn(m)y(m)=0当其常系数部分x(n+m)+a1x(n+m-1)+…+anx(m)=0的特征方程有相同的根时,解的渐近性质,通过不动点方法给出了Poincaré差分方程的解渐近于其常系数方程解的条件,并给出了渐近式高阶项的估计。