941 resultados para anomalous Eu3 5D0->F-7(0) transition
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<p>Observations of the Galactic center region black hole candidate 1E 1740.7-2942 have been carried out using the Caltech Gamma-Ray Imaging Payload (GRIP), the Rntgensatellit (ROSAT) and the Very Large Array (VLA). These multiwavelength observations have helped to establish the association between a bright emitter of hard X-rays and soft -rays, the compact core of a double radio jet source, and the X-ray source, 1E 1740.7-2942. They have also provided information on the X-ray and hard X-ray spectrum.</p> <p>The Galactic center region was observed by GRIP during balloon flights from Alice Springs, NT, Australia on 1988 April 12 and 1989 April 3. These observations revealed that 1E 1740.7-2942 was the strongest source of hard X-rays within ~10 of the Galactic center. The source spectrum from each flight is well fit by a single power law in the energy range 35-200 keV. The best-fit photon indices and 100 keV normalizations are: = (2.05 0.15) and K_(100) = (8.5 0.5) x 10^(-5) cm^(-2) s^(-1) keV^(-1) and = (2.2 0.3) and K_(100) = (7.0 0.7) x 10^(-5) cm^(-2) s^(-1) keV^(-1) for the 1988 and 1989 observations respectively. No flux above 200 keV was detected during either observation. These values are consistent with a constant spectrum and indicate that 1E 1740.7-2942 was in its normal hard X-ray emission state. A search on one hour time scales showed no evidence for variability.</p> <p>The ROSAT HRI observed 1E 1740.7-2942 during the period 1991 March 20-24. An improved source location has been derived from this observation. The best fit coordinates (J2000) are: Right Ascension = 17^h43^m54^s.9, Declination = -2944'45".3, with a 90% confidence error circle of radius 8".5. The PSPC observation was split between periods from 1992 September 28- October 4 and 1993 March 23-28. A thermal bremsstrahlung model fit to the data yields a column density of N_H = 1.12^(+1.51)_(0.18) x cm^(-2) , consistent with earlier X- ray measurements.</p> <p>We observed the region of the Einstein IPC error circle for 1E 1740.7-2942 with the VLA at 1.5 and 4.9 GHz on 1989 March 2. The 4.9 GHz observation revealed two sources. Source 'A', which is the core of a double aligned radio jet source (Mirabel et al. 1992), lies within our ROSAT error circle, further strengthening its identification with 1E 1740.7-2942.</p>
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O estudo epidemiolgico transversal randomizado objetivou avaliar condies de sade bucal nos competidores dos XV Jogos Pan-Americanos (JPA) e III Jogos Parapan-Americanos (JPPA), 2007. Foram enviados convites para 5.662 atletas (JPA) e 1.300 (JPPA). Radiografias panormicas digitais (RPD) foram utilizadas para o exame de triagem nos 2 eventos, e nos JPPA, os atletas tambm foram submetidos avaliao do sangramento gengival interdental (SI) atravs de uma verso modificada do ndice de Sangramento Interdental de Eastman (EIBI). Foram obtidas RPDs de 410 atletas dos JPA, mdia de idade 24,38 (dp5,35), 55% homens; e de 118 dos atletas dos JPPA, mdia de idade de 32,3 (dp9,53), 77,97% homens. 121 competidores (JPPA) foram avaliados para SI: 78,51% homens, mdia de idade 32,6(dp9,6), e foram separados em grupos (G), conforme sua deficincia fsica: GI c/ deficincia visual (DV), com 2 subgrupos: GI-a: DV tardia e GI-c-: DV congnita/precoce; GII- deficincia de membro superior; com 1 subgrupo: GII-t: deficincia/ausncia bilateral; GIII- deficincia de membro inferior (grupo controle). As RPDs foram examinadas por 1 examinador com o Kodak Dental Imaging(v6.7). A frequncia e a distribuio do SI foram calculadas, e os grupos foram comparados. Resultados da triagem com RPDs, representados por nmero de observaes(mdia por atleta) JPA//nmero de observaes(mdia por atleta JPPA: Dentes erupcionados/ hgidos: 9097(22,19)//2451(20,77); Ausentes: 803(1,96 //405(3,43); No erupcionados ou impactados: 330(0,80)//52(0,44); Parcialmente erupcionados e/ou hgidos: 109(0,27)//20(0,17); Crie extensa: 261(0,64)//62(0,53); Crie extensa e leso periapical: 96(0,23)//50(0,42); Tratamento endodntico e leso periapical: 24(0,06)//13(0,11); Restaurados: 2298(5,60)//670(5,68); Imagens radiolcidas patolgicas circunscritas: 23(0,06)//0; Razes-residuais: 27(0,07)//22(0,19); Implantes:6(0,01)//5(0,04); Dentes anteriores fraturados: 13 (0,03)//3(0,03); Molares bandados: 26(0,06)//11(0,09); Dentes anmalos: 7(0,02)//12(0,10). Resultados para SI: G-I>G-III (p=0.0002);GI-c>GI-a (p=0,042). Homens exibiram > freqncia de SI (3,6%+1,7) que mulheres (0,8%+0,5), p<0,01. Concluses: Os dados das 2 populaes de atletas mostraram que h uma grande variao na sade bucal entre os indivduos avaliados. Diversas condies com potencial de influenciar o desempenho esportivo dos atletas foram detectadas atravs de radiografias panormicas digitais, sugerindo que um programa de sade bucal deve ser includo como parte da preparao destes indivduos.A avaliao da frequncia e distribuio de sangramento gengival interdental em uma populao de atletas que competiu nos III Jogos Parapan-Americanos, revelou que o tipo de deficincia ou limitao fsica dos competidores um fator que influencia na sade gengival desses indivduos. O planejamento de um programa de sade bucal para esta populao deve ser adaptado s diferentes limitaes de cada atleta.
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70TeO2-(20-x)ZnO-xPbO-5La2O3-2.5K2O-25Na2O(x=05101520)Yb2O31Yb^3+((Tx-Tg)>195TZN(118))X=15(125pm^2)(
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We report near infrared broadband emission of bismuth-doped barium-aluminum-borate glasses. The broadband emission covers 1.3 mum window in optical telecommunication systems. And it possesses wide full width at half maximum (FWHM) of similar to 200nm and long lifetime as long as 350 mus. The luminescent properties are quite sensitive to glass compositions and excitation wavelengths. Based on energy matching conditions, we suggest that the infrared emission may be ascribed to P-3(1) --> P-3(0) transition of Bi+. The broad infrared emission characteristics of this material indicate that it might be a promising candidate for broadband optical fiber amplifiers and tunable lasers. (C) 2005 Optical Society of America.
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p53PCRsso 36311416p537A |53 706 5(231)21 4(314)188(316)83251 4248I236(5)(2)(J) I251(ATCATr) 0537
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The temperature dependence of photoluminescence (PL) from a-C:H film deposited by CH3+ ion beam has been performed and an anomalous behavior has been reported. A transition temperature at which the PL intensity, peak position and full width at the half maximum change sharply was observed. It is proposed that different structure units. at least three, are responsible for such behavior. Above the transition point. increasing temperature will lead to the dominance of non-radiative recombination process, which quenches the PL overall and preferentially the red part, Possible emission mechanisms have been discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.
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CePO4:TbCePO4:Tb/LaPO4(/)CePO4CePO4:Tb10-30 nm200 nmCePO4:Tb/LaPO4(/)LaPO42-10 nmCePO4:TbCePO4:Tb/LaPO4(/)Ce3+ (5d - 4f)Tb3+ 5D4-7FJ(J = 6-3)CePO4:TbCePO4:Tb/LaPO4(/)/ (KBF4NaFNH4F)CeF3CeF3UV-VisEuF30.9 m-1.0 m0.14 mEuF3EuF3 CeVO4YVO4:Eu3+ CeVO45 nm150 nmCeVO4(122 m2•g-1)YVO4:Eu3+ 90-150 nm250-300 nmYVO4:EuEu3+ 5D0-7FJ(J = 1- 4)5D0-7F2(614nm)
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-Ca2RSSiO46O2RYGdYVO4LaPO41Eu3+Tb3+Dy3+Sm3+Er3+Pb2SEMAFMCa2R8SiO46O2RYGdEu3+Tb3+Ca2Y8SiO46O26hCs4fC35Do-7F25D4-7F5Eu3+Tb3+Y3+10mol6molCa2Y851O46O2:Eu3Ca2Y8SiO46O2:Tb3+800Pb2Ca2Gd8SiO4 6O2Gd3+Pb2Gd3Gd3nA3YVO4PechiniYvO4:AAEu3 Dy3Sm3Er3YVO4VO43-Dy3Sm3Er3Y3+2molLaPO4Etl3+591nm5Do-7FlTb3543nm5D4-7F5Ce35d-4fTb3Eu3+Tb3+Eu3+Tb3LaPO4:CeTbCe3+Tb3+95XRDx0x1 YVxP1-xO4:Eu3+YVxP1-xO4:Eu3+0x1xEu3+x0Eu3+1Eu3+5Do7F2Etlsx0Y0.98Eu0.l2PO4Eu3+D2d5D07FISD07F2xY0.98Eu0.02VxP1-xO40xl0x0.5Eu3+5 D0-7F2x0.6Eu3+5D0-7F2YVxP1-xO4:A30x1AErSmVO43-A3+VO43-VO43-n-A3+n1VO43-0.1x1xx1VO43-A3+xRVO4:A3+RYLaGdAEuSmErRA3+YVO4GdVO4D2dYVO4GdVO4A3+LaVO4A3+LaVO4C1C1D2dA3+Gd3+A3+GdVO4
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1Hbrid bilayerer membraneHBMFeCN63-HBMSTM2.RubPy32+sBLMDODABdimethyldioctadecylammonium0.1M0.1M0.1M1200M3FeCN63/4FeCN634-E12Eu3+Th3La34DDAB5M5250 mV1.8710-5cm2s0.5-10 mmolL147mV6E0pH 3.5-7.0pH-46.4 mV/pHH2O2H2O27DDABDET-169mVvs Ag/AgCl86.42nm8HBMHBMHBMATR-FTIRATR-FTIRS0.73HBMHBM
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Eu~3Sm~3Mn~2Fe~3Co~2Ni~2ZnOcccc10Onm15357-366nmEu3+Sm3Mn2+Fe3Co2Ni2Zn2+O2- Eu3+ZnO363nm368nmEg=3.423.40evEu3Zn1-xEux0.005x0.15Zn1-xTMxO356nm-369nm3.34-3.46eVCo2d-dZn1-xCoxO60Zn1-xEuxO90Zn1-xEuxO613nmEu37F5D378nmZnO394nmEu3+5D07FJJ1234zno378nmEu3+5D07F2znoE4-400KZn0.9Eu0.1OznogCooIO23oK200KM-HBr021emgHc327OeZn0.9Mn0.1OZn0.9Ni0.1OZn0.9Co0.1O80KZn0.9Eu0.1OZT110K14.53Zn1-xTMxOCoFeNiMnZn1-xTMxO80Co2DMSsol-gelZnoTMMCM-41AAOZnO:TMMCM-41MCM-41AAoloonmMCM-41Zn0.9Co0.1O80K-30OKMnFeNiZnoAAOZnO:TM(TM=MnFeCoNiSOK-30OKZnO:AABuSmcoZnlxCoxOPH5ZnORERE=EuSmZn0.98Co0.02O80KZnOREREEuSm80K
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The transition process to film pool boiling in microgravity is studied experimentally aboard the Chinese recoverable satellite SJ-8. A quasi-steady heating method is adopted, in which the heating voltage is controlled to increase exponentially with time. Small, primary bubbles are formed and slid on the surface, which coalesce with each other to form a large coalesced bubble. Two ways are observed for the transition from nucleate to film boiling at different subcoolings. At high subcooling, the coalesced bubble with a smooth surface grows slowly. It is then difficult for the coalesced bubble to cover the whole heater surface, resulting in a special region of transition boiling in which nucleate boiling and local dry areas can coexist. In contrast, strong oscillation of the coalesced bubble surface at low subcooling may cause rewetting of local dry areas and activation of more nucleate sites, resulting in an abrupt transition to film boiling.
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By introducing the Y3+ into Sr2P2O7:Eu2+, we successfully prepared a kind of new phosphor with blue long-lasting phosphorescence by the high-temperature solid-state reaction method. In this paper, the properties of Sr2P2O7:Eu2+, Y3+ were investigated utilizing XRD, photoluminescence, luminescence decay, long-lasting phosphorescence and thermoluminescence (TL) spectra. The phosphor emitted blue light that was related to the 4f(6)5d(1)-S-8(7/2) transition of Eu2+. The bright blue phosphorescence could be observed by naked eyes even 8 h after the excitation source was removed. Two TL peaks at 317 and 378 K related to two types of defects appeared in the TL spectrum. By analyzing the TL curve the depths of traps were calculated to be 0.61 and 0.66 eV. Also, the mechanism of LLP was discussed in this report.
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Single-walled carbon nanotubes (SWNTs) can selectively induce human telomeric i-motif DNA formation at pH 7.0. Based on this property, we design a DNA nanomachine induced by SWNTs on gold surface. The motor DNA is human telomeric G-quadruplex DNA. The reversible hybridization between the motor DNA and its complementary human telomeric i-motif DNA can be modulated by SWNTs without changing solution pH. Up to now, to our knowledge, there is no report to show that a DNA nanomachine is induced by SWNTs or a DNA nanomachine can detect i-motif formation at pH 7.0. Our work may provide a new concept for designing an SWNT-induced DNA nanomachine and for the detection of i-motif DNA structure at pH 7.0. DNA hybridization, conformational transition and i-motif formation have been characterized on surface or in solution by fluorescence confocal microscopy, circular dichroism, DNA melting and gel electrophoresis. The folding and unfolding kinetics of the DNA nanomachine on gold surface were studied by Fourier transform-surface plasmon resonance (FT-SPR). All these results indicate that SWNTs can induce the DNA nanomachine to work efficiently and reversibly.
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Luminescent hybrid Langmuir-Blodgett (LB) films of polyoxometaloeuropate (Na9EuW10O36) were successfully prepared. Low-angle X-ray diffraction data demonstrate that the LB films have a well-defined lamellar structure. The hybrid LB films can exhibit strong luminescence under UV irradiation, which can be observed by the human eye. The effect of the lipid ocradecylamine, on the luminescence of polyoxometaloeuropate was discussed and compared with that of the lipid dimethyldioctadecylammonium bromide. It is found that the intensity ratio for the D-5(0) --> F-7(2) transition to the D-5(0) --> F-7(1) transition of europium in two kinds of LB films is quite different. The X-ray photoelectron spectra data verify that there exist different interactions between two lipids and the inorganic polyanions. The different interactions between two lipids and the polyanions may result in the distortion of the site symmetry for europium to a different extent, which may account for the difference in luminescent behavior between the two kinds of LB films.
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Luminescent thin films of heteropolytungstate complexes containing lanthanide (europium or samarium) were successfully fabricated by the Langmuir-Blodgett (LB) technique. The pressure-area isotherm of the monolayer of dimethyldioctadecylammonium. bromide (DODA) is modified rather markedly when the subphase contains the complex of Na9EuW10O36 or Na9SmW10O36. The above results indicate that the monolayer of DODA has a strong interaction with the polyanions of EuW10O369-. (or SmW10O369-). X-ray photoelectron spectra and fluorescent spectra verify that europium and tungsten atoms are 36 36 incorporated into the LB films. Ultraviolet (UV), fluorescent spectra and low-angle X-ray diffraction experiments demonstrate that these LB films have a well-defined lamellar structure. The LB film containing EuW10O369- can give off strong fluorescence 16 on UV irradiation. The characteristic emission behaviors of europium ions in LB films and in the powder of Na9EuW10O369- are discussed. It is found that the intensity ratio of the D-5(0)-F-7(2) transition to the D-5(0)-->F-7(1) transition in LB film is quite different from that in the powder of Na9EuW10O36. The difference of the ratio indicates that the site symmetry of europiurn is distorted in LB film, which is probably due to the strong electrostatic interactions between DODA and polyanions.
