简介:Three-dimensional(3D)flowerlikehierarchicalZn2GeO4andMn2+-dopedZn2GeO4microstructureshavebeenpreparedbyafacilehydrothermalapproach.X-Raydiffraction(XRD),fieldemissionscanningelectronmicro-scopy(FESEM),transmissionelectronmicroscopy(TEM)andphotoluminescence(PL)spectrometrywereemployedtocharacterizethesamples.SuchflowerlikehierarchicalZn2GeO4microstructureswithanaveragediameterof3―4μmwerefoundtobeconstructedbyabundantsinglecrystallinenanorodsofabout90nmindiameter.TheluminescentpropertiesofZn2GeO4:xMnphosphorswithdifferentcontentsofMn2+asanactivatorwereinvestigated.TheMn2+-dopedsamplesshowedgreenluminescencecorrespondingtothed-dtransitionofMn2+undertheirradiationofUVlight.Theredshift(from531nmto538nm)inλemwithincreasingMn2+contentwasobservedintheluminescentspectra,whichshouldbeattributedtoaweakcrystalfieldbecauseofthesubstitutionofZn2+byMn2+atadistortedtetrahedrallatticesite.
简介:构式语法研究表明,构式可以压制或者影响词义、述谓成分意义。然而某些语言现象,例如副词+形容词(+感叹词)的反讽结构,在句法上显得尤为简单,其反义往往不能借助构式本身推导得出。反义结构通常伴有较为特殊的语音语调,与交际情景、语境相应;在未明语境下,通过语音语调操控亦可以凸显或者弱化反义。表达反讽意义的话语通常在语音特征上具有"讽刺"意味,这种语音特征也带有"固化"性,如同抽象性图式一般,成为反讽结构不可剥离的组成部分。