简介:Cesiumcontentintheseawateris3.0910-4mg·L-1,andammonium-typemordenitewasusedtoexchangecesiumfromcesiumsource.K-typemordenitewasobtainedbyhydrothermalsynthesismethod.Afterammonium-modified,ionexchangepropertiessuchassaturatedionexchangecapacitiesandselectivitycoefficientsforalkalimetalionsweredetermined.Atthesametime,ionexchangeisothermalcurvesofammonium-typemordeniteforCs+andNH4+weredeterminedat25°C.Pitzerelectrolytesolutiontheorywasusedtoworkoutactivitycoefficientsofthesystem,andtheKiellanddiagramoftheionexchangesystemwasobtained.Thecalculatedequilibriumconstant(Ka)andionfreeenthalpy(DG0)ofmordeniteforCs+andNH4+are1.455and-930.3J·mol-1,respectively,indicatingthationexchangeprocessofammonium-typemordeniteforcesiumisaspontaneousprocess.
简介:A459nmFaradayanomalousdispersionopticalfilter(FADOF)workingatthesidewingsofthecesium6S1∕2→7P1∕2transitionwithweakoscillatorstrengthisachieved.Thetransmittanceofthehighersidewingreaches98%atatemperatureof179°Candmagneticfieldabove323G.Theexperimentalresultscoincidewiththetheoreticalpredictionsin1982and1995,whichwerenotrealizedinexperimentsforoverthreedecades.Duetoitshightransmittance,highaccuracy,andnarrowlinewidth,the459nmFADOFcanbeappliedinunderwateropticalcommunications,thebuildingofactiveopticalclocks,andlaserfrequencystabilizationinactiveopticalclocks.
简介:中国师范教育正经历着深刻的变革,顺应国际教师教育改革的潮流以及我国社会和经济发展的必然趋势,小学教师教育开始纳入高等教育体系。小学教育专业(本科)的设置宣告了培养本科层次小学教师的改革已正式向前迈开了从传统走向现代的坚定步伐,同时也宣告了师范教育由“三级结构”向“二级结构”最终向一级师范转型的实现。培养本科层次小学教师是我国基础教育获得更大发展的必然要求,关系到整个国民教育质量的重大飞跃。这种进步不仅仅是对于小学教师学历规格和学术层次提升的要求,对国家未来的建设者获得更良好教育的重视,也是对于教师本身的个人发展以及教师专业化和终身教育的呼应,更是我国积极投身于建设教育强国的必经之路。这一变革不仅促进了教师教育事业的新发展,也促成教师教育理论研究开辟新的领域。小学教师培养模式已经发生重大转变。随着本科层次小学教育专业的设置,如何构建全新的小学教育本科专业培养模式,促成小学教师的培养从传统走向现代的飞跃的问题已经摆在我们面前。