169 resultados para Ce^3
Resumo:
Rheum tanguticumAnisodus tanguticusGentiana straminea3CO2UVBIsatis indigotica3AQYAQYCERpPnUVBUV-BRpPnPn3AQYCE34PnCO2GCO2PiCO2Pn
Resumo:
(MoNiPGEVAuAg (1)TommotianAtdabanianBotonianToyonian (2)()Tommotian (3)- (4)SiO2MgOCaOCO2SiO2Al2O3Fe2O3/(MoNiVU)(V/(V+Ni)V/CrNi/CoU/ThU)- (5)(REE)6.67ppm481ppm123ppmPAASCe-0.10Ce-0.100-0.10Ce-3Eu0.002-1.16Eu (6)25-GCnC14-nC31nC18nC19nC20 (7)0.05-12.314.97%(13Corg)-29.49-34.41PDB4.313carb-4.6-10.66.018Ocarb-13.7-2.3(PDB)13Corg13carbTommotian13Tommotian Tommotian-
Resumo:
80%-- 1.- 2.AbAnOrSr LREEEuCe 3.10.214.518O1.96.9 4.14030018%NaCl0.600.99g/cm3 5.
Resumo:
,(Ce,Cu)LiNbO3(Ce,Cu)LiNbO3,,CeCu(Ce,Cu)LiNbO3(Ce,Cu)LiNbO3Cu,,Cu
Resumo:
IV REIIIIV REIII REIIIIV REIIIIV REIII N1923IVREIIIIV REIIIN1923 REIII1 IV 10%N1923+4%+ 12mol/L 1%N19231IVIII N192323IV REIII REIII456
Resumo:
Polycrystalline powder sample of KSr4(BO3)(3) was synthesized by high-temperature solid-state reaction. The influence of different rare earth dopants, i.e. Tb3+, TM3+ and Ce3+, on thermoluminescence (TL) of KSr4(BO3)(3) Phosphor was discussed. The TL, photoluminescence (PL) and some dosimetric properties of Ce3+-activated KSr4(BO3)(3) phosphor were studied. The effect of the concentration of Ce3+ on TL intensity was investigated and the result showed that the optimum Ce3+ concentration was 0.2 mol%. The TL kinetic parameters of KSr4(BO3)(3):0.002 Ce3+ phosphor were calculated by computer glow curve deconvolution (CGCD) method. Characteristic emission peaking at about 407 and 383 nm due to the 4f(0)5d(1) -> F-2((5/2),(7/2)) transitions of Ce3+ ion were observed both in PL and three-dimensional (3D) TL spectra. The dose-response of KSr4(BO3)(3):0.002 Ce3+ to gamma-ray was linear in the range from 1 to 1000 mGy. In addition, the decay of the TL intensity of KSr4(BO3)(3):0.002 Ce3+ was also investigated.
Resumo:
Microstructure and some dynamic performances of Ti0.17Zr0.08V0.34RE0.01Cr0.1Ni0.3 (RE=Ce, Dy) hydrogen storage electrode alloys have been investigated using XRD, FESEM-EDS, ICP-MS and EIS measurements. The alloy is composed of V-based solid solution phase with a dendritic shape and a continuous C14 Laves phase with a network shape surrounding the dendrite. Pressure-composition isotherm curves indicate that the alloy with Dy addition has a lower equilibrium hydrogen pressure and a wider plateau region. The alloy electrode with Dy addition has higher discharge capacity, while the alloy electrode with Ce addition has better activation and higher cycle stability. The alloy electrode with Ce addition has better electrochemical activity with higher exchange current density (127.5 mA g(-1)), lower charge transfer resistance (1.37 Omega) and lower apparent activation energy (30.5 kJ mol(-1)). The capacity degradation behavior for the alloy electrode is attributed to two main factors: one is the dissolutions of V and Zr element to KOH solution, and another is the larger charge transfer resistance which increases with increasing cycle number.
Resumo:
Pr3+,Sm3+YAGCePr3+,609nmPr3+,Sm3+,616nmSm3+Pr3+Sm3+YAGCe(Y0.95Sm0.01Ce0.04)3Al5O12(Y0.95Pr0.01Ce0.04)3Al5O12(Y0.96Ce0.04)3Al5O12(),YAGCePr3+Sm3+Ce3+,Pr3+Sm3+
Resumo:
A series of cerium dioxide (CeO2,)/polyimide (PI) nanocomposites were successfully prepared from Ce(Phen)(3) and polyamic acid (PAA) via the solution direct-dispersing method, followed by a step thermal imidization process. TGA and XPS studies showed that the cerium complex decomposed to form CeO2, during the thermal imidization process at 300 degrees C. SEM observation showed that the formed CeO2, as nalloparticles was well dispersed in polyimide matrix with a size of about 50-100 nm for samples with different contents of CeO2. Thermal analysis indicated that the introduction of CeO2, decreased the thermal stability of nanocomposite films due to the decomposition of Ce(Phen)(3) in the imidization process, while the glass transition temperature (T-g) increased obviously. especially nanocomposite films with high loading of CeO2 exhibited a trend of disappearance off, DMTA and static tensile measurements showed that the storage modulus of nanocomposite films increased, while the elongation at break decreased with increasing CeO2 content.
Resumo:
Calcium lanthanide oxyborate doped with rare-earth ions LnCa(4)O(BO3)(3):RE3+ (LnCOB:RE, Ln = Y, La, Gd, RE = Eu, Tb, Dy, Cc) was synthesized by the method of solid-state reaction at high temperature. Their fluorescent spectra were measured from vacuum ultraviolet (VUV) to visible region at room temperature. Their excitation spectra all have a broadband center at about 188 nm, which is ascribed to host absorption. Using Dorenbos' and J phi rgensen's work [P. Dorenbos, J. Lumin. 91 (2000) 91, R. Resfeld, C.K. J phi rgensen. Lasers and Excite States of Rare Earth [M], Springer, Berlin, 1977, p. 45], the position of the lowest 5d levels E(Ln,A) and charge transfer band E-ct were calculated and compared with their excitation spectra.Eu3+ and Tb3+ ions doped into LnCOB show efficient luminescence under VUV and UV irradiation. In this system, Ce3+ ions do not show efficient luminescence and quench the luminescence of Tb3+ ions when Tb3+ and Ce3+ ions are co-doped into LnCOB. GdCOB doped with Dy3+ shows yellowish white light under irradiation of 254 nm light for the reason that Gd ions transfer the energy from itself to Dy.
Resumo:
High resolution magic angle spinning (MAS)-H-1 nuclear magnetic resonance (NMR) spectroscopic-based metabonomic approach was applied to the investigation on the acute biochemical effects of Ce(No-3)(3). Male Wistar rats were administrated with various doses of Ce (NO3)(3)(2, 10, and 50 mg(.)kg(-1) body weight), and MAS H-1 NMR spectra of intact liver and kidney tissues were analyzed using principal component analysis to extract toxicity information. The biochemical effects of Ce (NO3)(3) were characterized by the increase of triglycerides and lactate and the decrease of glycogen in rat liver tissue, together with an elevation of the triglyceride level and a depletion of glycerophosphocholine and betaine in kidney tissues. The target lesions of Ce (NO3)(3) on liver and kidney were found by MAS NMR-based metabonomic method. This study demonstrates that the combination of MAS H-1 NMR and pattern recognition analysis can be an effective method for studies of biochemical effects of rare earths.
Resumo:
Sr4Al14O25RE3+(RE=Eu,Ce,Tb),Eu3+,Ce3+Tb3+,Ce3+Tb3+;Eu3+,Ce3+Tb3+,Eu2+;Tb3+5D35D4,;Ce3+Tb3+
Resumo:
By solid state reaction, LiMgAlF6 and LiMgAlF6:Ln(3+) are synthetized with the ratio 120/100/110 of LiF/MgF2/AlF3, at 1008 K, in high-purity Ar stream. Their crystal structure which belongs to hexagonal system are determined by X-Ray-Diffraction (XRD). Luminescence characteristics of Ce3+, Eu3+, Tb3+ and sensitization of Ce3+ to Tb3+ in LiMgAlF6 are studied. It is shown that the sensitization of Ce3+ to Tb3+ is efficient and a bright green emission is observed.
Resumo:
LaF_3,RE_(1-x)B_xF_(3-y),,150 () RE_(1-x)B_xF_(3-y) ,CaBaRE,La_(0.95)Ba_(0.05)F_(3-y)Ce_(0.95)Ca_(0.05)F_(3-y)XLaF_3CeF_3,CaRE,Y_(0.71)Ca_(0.29)F_(3-y)Gd_(0.85)Ca_(0.15)F_(3-)XYF_3GdF_3
