90 resultados para Sr^2
Resumo:
Ce3+Eu3+Tb3+LiMAlF6(M=Ca,Sr)LiCaAlF6LiSrAlF6Ce3+330nmCe3+.
Resumo:
KMF3(M = Mg, Ca, Sr, Ba) compounds were synthesized by solid state reaction under argon atmosphere. Their structures were determined by X-ray diffraction. It belongs to cubic system with perovskite structure. The excitation and emission spectra of KMF3:Ce3+ were measured. According to the characteristics of spectral structures, the occupation site of Ce3+ is discussed.
Resumo:
The theoretical model[17] of an ultramicroelectrode modified with a redox species film is used as the diagnostic tool to characterize the catalytic oxidation of ascorbic acid at carbon fiber ultramicrodisk electrodes coated with an Eastman-AQ-Os(bpy)(3)(2+) film. The electrocatalytic behavior of ascorbic acid at the ultramicroelectrode modified by an Eastman-AQ polymer containing tris(2,2'-bipyridine) osmium(III/II) as mediators is described. In order to determine the five characteristic currents quantitatively, the radius of the ultramicroelectrode and the concentration of ascorbic acid are varied systematically. The kinetic zone diagram has been used to study the electrocatalytic system. This system with 0.5-2.75 mM ascorbic acid belongs to SR + E case, and the concentration profiles of the catalyst in the film are given in detail. Finally, optimizing the design of catalytic system is discussed.
Resumo:
,MMgF_4:xEU,yTb.Eu~(3+)Eu~(2+).TbEu.ESR,Tb,Eu~(2+).Eu,XPSTb_3d(5/2).Eu~(3+)Tb~(3+).Eu~(3+)+Tb~(3+)(?)Eu~(2+)+Tb~(4+).SrMgF_4.
Resumo:
CO2-TPD was used to study the surface basicity of La-Me-O mixed oxides and O-2-TPD, CH4-TPD were employed to study the surface active oxygen species. Comparing the CO2-TPD with O-2-TPD, we can see that the basicity of catalyst is in parallel with the catalystic activity. The stronger basicity is more profitable for the catalyst to adsorb oxygen to form active oxygen species and to activate CH4 by breaking a C-H bond, By comparing the catalytic activity, the results showed that La-Ba-O(La/Ba=7/3) catalyst had the strongest basicity, and it gave the highest CH4 conversion and C-2 selectivity, The results from the pulse reaction showed that the lattice oxygen participated in the OCM reaction without gas oxygen, and it was the selective oxygen species.
Resumo:
Eu-TbCe-Yb.Ce~(3+)Eu~(3+),.1 1.1 CaF_2,SrF_2,BaF_2,NH_4HF_2,EuF_3CeF_3Eu_2O_3(99.95%)CeO_2(99.99%).1.2 MF_2:Eu,Ce(MF_2:X%CeF_2,y%EuF_3;X=1,y=0,0.1,0.3,0.5,1;X=0,0.05,0.1,0.3,0.5,y=1),,(
Resumo:
Resumo:
MF_2-MgF_2,,.
Resumo:
La_(2-x)Ca_xNiO_4(0x1.4)La_(2-x)Sr_xNiO_4K_2NiF_4,xLa_(2-x)Ca_xNiO_4x,La_(2-x)Sr_xNiO_4x,SrCaNiNi~(3+)
Resumo:
MeBeF_4.SrBeF_4BaBeF_4Sm~(2+).
Resumo:
Bi_2Sr_2Ca_2Cu_3O_y-Ag_xBi_(1.7)Pb_(0.3)Sr_2Ca_2Cu_3O_y-Ag_xBi_(1.7)Pb_(0.3)Sr_2Ca_2Cu_(3.2)O_y-Ag_xAgNO_3PbOBi_2O_3CaCO_3SrCO~3CuO,80012h,,850200h,,AgNO_380012h,,850200h,
Resumo:
Eu~(2+)xMF_2-yYF_3(x=1,2,3;y=0,1,2,3,4,5;M=Ca,Sr,Ba),Eu~(2+),Eu~(2+)
Resumo:
Ce~(3+)xMF_2-yYF_3(M=CaSrBa;x=012y=012) YF_3, Eu~(2+)
