Discussions pertaining to enhancement in the luminous efficiency of cesium iodide(CsI)detectors doped with sodium(Na)abound.In this study,the defect structure of one Cs atom replaced by one Na atom is calculated using...Discussions pertaining to enhancement in the luminous efficiency of cesium iodide(CsI)detectors doped with sodium(Na)abound.In this study,the defect structure of one Cs atom replaced by one Na atom is calculated using the ab initio method.Subsequently,the electronic band structures,densities of states,optical absorption spectra,phonons,and transport properties of CsI in perfect and defective structures are investigated.The absorption spectra of CsI with and without Na impurities are compared.It is discovered that the impurity levels in the forbidden band are generated from the shell electron distributions of the impurity atoms,not from lattice distortions.Furthermore,it is discovered that the optical absorption can be enhanced by doping CsI with Na.展开更多
A sort of lightwerght porous ceramic foam ball that can float on the water was recently made from the nat- ural zeolite. The diameters of porous hall and its macroscopic pores are around 5 and 1 mm, respectively. Such...A sort of lightwerght porous ceramic foam ball that can float on the water was recently made from the nat- ural zeolite. The diameters of porous hall and its macroscopic pores are around 5 and 1 mm, respectively. Such ball surface could be modified to activate in different ways, i. e. loading the active alumina or desili- cating the ball. Both of modified products have been investigated to adsorb the toxic ion of arsenic （As） in water effectively. This kind of porous ceramic hall was prepared by powder sintering, using natural clinop- tilolite powder as the primary raw material. An active-alumina loaded porous ceramic product was genera- ted by sol-gel method with pseudoboehmite （A1OOH） as the main composition. The active AI atom on the porous ball surface could also be achieved by desilicating the ceramic ball in the NaOH solution. Such a desilicated product exhibited a good activity to adsorb the arsenic ion although carrying no ac- tive alumina. With this effective porous structure, the present products can be expected to become practically advantageous.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 12135004, 11635003, 11961141004, and 11875088)
文摘Discussions pertaining to enhancement in the luminous efficiency of cesium iodide(CsI)detectors doped with sodium(Na)abound.In this study,the defect structure of one Cs atom replaced by one Na atom is calculated using the ab initio method.Subsequently,the electronic band structures,densities of states,optical absorption spectra,phonons,and transport properties of CsI in perfect and defective structures are investigated.The absorption spectra of CsI with and without Na impurities are compared.It is discovered that the impurity levels in the forbidden band are generated from the shell electron distributions of the impurity atoms,not from lattice distortions.Furthermore,it is discovered that the optical absorption can be enhanced by doping CsI with Na.
基金supported by the Testing Foundation of Beijing Normal University(No.C16)
文摘A sort of lightwerght porous ceramic foam ball that can float on the water was recently made from the nat- ural zeolite. The diameters of porous hall and its macroscopic pores are around 5 and 1 mm, respectively. Such ball surface could be modified to activate in different ways, i. e. loading the active alumina or desili- cating the ball. Both of modified products have been investigated to adsorb the toxic ion of arsenic （As） in water effectively. This kind of porous ceramic hall was prepared by powder sintering, using natural clinop- tilolite powder as the primary raw material. An active-alumina loaded porous ceramic product was genera- ted by sol-gel method with pseudoboehmite （A1OOH） as the main composition. The active AI atom on the porous ball surface could also be achieved by desilicating the ceramic ball in the NaOH solution. Such a desilicated product exhibited a good activity to adsorb the arsenic ion although carrying no ac- tive alumina. With this effective porous structure, the present products can be expected to become practically advantageous.
