简介:ACe3+tion-dopedα-NaYF4singlecrystalofhighqualityisgrownsuccessfullybyanimprovedfluxBridgmanmethodundertheconditionsoftakingthechemicalrawcompositionofNaF:KF:YF3:CeF3inthemolarratioof30∶18∶48∶4,wheretheKFisshowntobeaneffectiveassistantflux.Thexraydiffraction,absorptionspectra,excitationspectra,andemissionspectraoftheCe3+t-dopedα-NaYF4singlecrystalaremeasuredtoinvestigatethephaseandopticalpropertiesofthesinglecrystals.TheabsorptionspectrumoftheCe3+t:α-NaYF4showsastrongbandthatpeaksatthewavelengthof300nm.TheemissionspectrumoftheCe3+t:α-NaYF4emitsanintenseultraviolet(UV)bandatthewavelengthof332nmundertheexcitationof300nmlight.Twoseparatedluminousbandsof330and350nm,whichcorrespondtothetransitions5d→2F25∕2and5d→F7∕2,canbeobtainedbyGaussfitting.ThestrongemissionintensityattheUVbandandtheexcellentopticaltransmissionintherangeofUVwavelengthsindicatethatCe3+t:α-NaYF4singlecrystalscanbeconsideredasapromisingmaterialforUVlasers.
简介:菰黑粉菌与寄主互作形成膨大肉质茎——茭白,已成为我国第二大水生蔬菜.作为一种二态性真菌,菰黑粉菌的二型态转换与其致病力密切相关,对茭白孕茭至关重要.研究发现,尿素水解酶可能作用于真菌二型态转换.本文克隆了菰黑粉菌的尿素水解酶编码基因UeUal,发现该基因全长2598bp且无内含子,与宾地瘤黑粉菌的尿素水解酶基因近源.该蛋白的功能区域包含尿素水解酶γ亚基、尿素水解酶α亚基、尿素水解酶β亚基以及酰胺氢区域.利用qRT-PCR检测菰黑粉菌二型态转换过程中UeUal的表达变化,发现该基因在融合菌丝形成后表达量显著性升高,推测该基因与菰黑粉菌二型态转换后期的菌丝生长有密切联系.以上结果为进一步研究菰黑粉菌二型态转换机制及菰黑粉菌与茭白互作机制提供了基础材料.