964 resultados para Nd^3
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SiO297wt%Nd^31100800nmNd^362%-42%1064nm
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(Cr^4+Nd^3+GGG)QCrCr^4+GGGNd^3+GGG(Cr^4+Nd^3+)GGG(Cr^4+Nd^3+)GGGNd^3+GGG33s250s(Cr^4+Nd^3+)GGGQ
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Nd^3 ,.Judd-OfeltNd^3 1 .5at %.,2=6 .5710^-20cm^2,4=2 .0410^-20cm^2,6=4 .3810^-20cm^2.,,,,.
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2010-11-23
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Nd3+LiFe1-xNdxPO4/C(x=0,0.01,0.02,0.04,0.06,0.08)TG-DSCSQUID()Fe3+,;XRDFE-SEMEDS:LiFe1-xNdxPO4/C;Nd3+6%()70016 h,0.2C(1C=170.0 mA.g-1)165.2 mAh.g-1,10092.8%,1C2C5C146.8125.7114.8 mAh.g-1,168.7 mAh.g-1
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ABO4Nd3+E.
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V-A(CV)Nd~(3+)Ga,Nd~(3+)Ga,Nd~(3+)+e?Nd~(2+);,,Nd~(3+)+e?Nd~(2+)+mClNdCl_m~(2-m),NdGa,Nd~(2+)+2eNd(Ga)7.010~(-3)cm/s
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Neodymium based fluorescence presents several advantages in comparison to conventional rare earth or enzyme-substrate based fluorescence emitting sources (e.g.Tb, HRP). Based on this fact we have herein explored a Nd-based fluoroimmunoassay. We efficiently detected the presence of an oxidized low-density lipoprotein (oxLDL) in human plasma a well-known marker for cardiovascular diseases, which causes around 30% of deaths worldwide. Conventional fluoroimmunoassay uses time-resolved luminescence techniques, with detection in the visible range, to eliminate the fluorescence background from the biological specimens. By using an immunoassay based on functionalized Y(2)O(3):Nd(3+) nanoparticles, where the excitation and emission processes in the Nd(3+) ion occur in the near-infrared (NIR) region, we have succeeded in eliminating the interferences from the biological fluorescence background, avoiding the use of time-resolved techniques. This yields higher emission intensity from the Nd(3+)-nanolabels and efficient detection of anti-oxidized low-density lipoproteins (anti-oxLDL) by Y(2)O(3):Nd(3+)-antibody-antigen conjugation, leading to a novel biolabeling method. (C) 2010 Elsevier B.V. All rights reserved.
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The effect of the sintering method on the microstructural and electrical properties of (Pb(0.89)Nd(0.02)La(0.09))(Zr(0.65)Ti(0.35))O(3) (PNLZT) ceramics was studied by impedance spectroscopy. Structural and microstructural analyses were performed using x-ray and scanning electron microscopy techniques. Two different sintering routes were employed: the conventional and the hot-pressing sintering methods. The impedance analysis provided a convincing evidence for the existence of both grain (g) and grain boundary (gb) contributions to the conduction process. An equivalent circuit for the impedance behaviour has been proposed and discussed. The variation in the sintering method produces significant changes in the grain and grain boundary conductivities. For the grain effect, the main conduction mechanism has been associated with oxygen vacancy migration. Otherwise, for grain boundary conductivity the impedance behaviour has been discussed in terms of the brick-layer and the constriction resistance models (BLM and CRM, respectively).
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In rare earth ion doped solids, a resonant non-linear refractive index, n2, appears when the laser pumps one of the ion excited states and the refractive index change is proportional to the excited state population. In these solids there are usually thermal and non-thermal lensing effects, where the non-thermal one is due to the polarizability difference, , between excited and ground states of the ions. We have used the time resolved Z-scan and a mode-mismatched thermal lens technique with an Ar+ ion laser in Er+3 (20ZnF2-20SrF2-2NaF-16BaF2-6GaF3-(36 - x)InF3-xErF3, with x= 1, 2, 3 and 4 mol%) and Nd+3 (20SrF2-16BaF2-20ZnF2-2GdF3-2NaF-(40 - x)InF3-xNdF3, with x = 0.1, 0.25, 0.5-1 mol%) doped fluoroindate glasses. In both samples we found that the non-linear refraction is due to the thermal effect, while the non-thermal effect is negligible. This result indicates that in fluoride glasses is very small (less than 10-26 cm3). We also measured the imaginary part of the non-linear refractive index (n2) due to absorption saturation.
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We investigated near-infrared-to-blue upconversion from thulium (Tm 3+) doped in tellurite glasses upon continuous wave excitation near 800 nm. We observed an enhancement of over two orders of magnitude of the upconverted emission at 480nm when neodymium (Nd 3+) ions were codoped with Tm 3+ ions. For comparison, using a Tm 3+:Nd 3+ codoped fluorozirconate glass as a reference material we observed a 40-fold enhancement of the blue emission. Analysis of the blue emission for samples with different doping levels of Nd 3+ ions showed that energy transfer between Nd 3+ and Tm 3+ is the mechanism responsible for the enhancement in upconversion. 2002 American Institute of Physics. 2002 American Institute of Physics.
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An upconversion random laser (RL) operating in the ultraviolet is reported for Nd 3+ doped fluoroindate glass powder pumped at 575 nm. The RL is obtained by the resonant excitation of the Nd 3+ state 2G 7/2 followed by energy transfer among two excited ions such that one ion in the pair decays to a lower energy state and the other is promoted to state 4D 7/2 from where it decays emitting light at 381 nm. The RL threshold of 30 kW/cm 2 was determined by monitoring the photoluminescence intensity as a function of the pump laser intensity. The RL pulses have time duration of 29 ns that is 50 times smaller than the decay time of the upconversion signal when the sample is pumped with intensities below the RL laser threshold. 2011 Optical Society of America.
