简介:集中和为在一个维的设定的一个不可思议地使不安的模型问题的不连续的Galerkin(DG)方法的超级集中性质被学习。由与DG答案的适当地选择的数字踪迹,存在和唯一使用DG方法,最佳的顺序L2错误界限,和2p+i顺序数字踪迹斧子的超级集中建立了。数字结果显示DG方法不甚至在一致网孔下面生产任何摆动。数字实验证明在一致网孔下面,获得数字踪迹的一致超级集中似乎不可能。不过,对所谓的Shishkin类型的实现的感谢协调,一致2p+1顺序超级集中数字地被观察。
简介:Aclassofnormal-likederivativesforfunctionswithlowregularitydefinedonLipschitzdomainsareintroducedandstudied.Itisshownthatthenewnormal-likederivatives,whicharecalledthegeneralizednormalderivatives,preservethemajorprop-ertiesoftheexistingstandardnormalderivatives.Thegeneralizednormalderivativesarethenappliedtoanalyzetheconvergenceofdomaindecompositionmethods(DDMs)withnonmatchinggridsanddiscontinuousGalerkin(DG)methodsforsecond-orderel-lipticproblems.Theapproximatesolutionsgeneratedbythesemethodsstillpossesstheoptimalenergy-normerrorestimates,eveniftheexactsolutionstotheunderlyingellipticproblemsadmitverylowregularities.
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简介:Electronscatteringfromsphericalpolyatomicmoleculesintheintermediateandhighenergyrangeisstudiedbyemployingthedevelopedsemi-empiricalformulaforelectronscatteringfromsimplediatomicmolecules.ThetotalcrosssectionsofelectronscatteringfromCF4andCC14areobtainedovertheincidentenergyrange30-5000eV.Thequantitativetotalcrosssectionsarecomparedwiththemeasurementsandwiththeothercalculationswhereveravailableincludingtheresultsderivedfromtheadditivityrulemodelandthecorrelatedopticalpotential[Chin.Phys.Left.21(2004)474],andgoodagreementisobtainedovertheincidentenergyrange30-5000eV.Itisshownthatthecalculationsderivedfromthesemi-empiricalformulaaremuchclosertothemeasurementsthanothercalculations.Finally,somequantitativeinformationofthesingleYukawapotentialisalsoobtained.