We investigate the Luminosity Function （LF） of the cluster of galaxies Abell 566. The photometric data of 15 intermediate-bands are obtained from the Beijing-Arizona- Taiwan-Connecticut （BATC） photometric sky surv...We investigate the Luminosity Function （LF） of the cluster of galaxies Abell 566. The photometric data of 15 intermediate-bands are obtained from the Beijing-Arizona- Taiwan-Connecticut （BATC） photometric sky survey. For each of the 15 wavebands, the LF of cluster galaxies is well modelled by the Schechter function, with characteristic luminosities from -18.0 to -21.9 magnitude, from the α- to the p-band. Morphological dependence of the LF is investigated by separating the cluster members into ＇red＇ and ＇blue＇ subsamples. It is clear that late type galaxies have a steeper shape of LF than the early type galaxies. We also divided the sample galaxies by their local environment. It was found that galaxies in the sparser region have steeper shape of LF than galaxies in the denser region. Combining the results of morphological and environmental dependence of LFs, we show that Abell 566 is a well relaxed cluster with positive evidence of galaxy interaction and merger, and excess number of bright early type galaxies located in its denser region.展开更多
yb3＋/Dy3＋ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results...yb3＋/Dy3＋ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results show that there are comparatively abundant spectra of up-conversion emissions centered at 378, 408, 527 and 543, and 663 nm, corresponding to 4C9/2→ 6H13/2, 4C9/2→ 6Hll/2, 4115/2 → 6H13/2, and 4F9/2 →6Hll/2 transitions of Dy3＋, respectively. Two-photon and three-photon processes are involved in ultraviolet, violet, green, and red up-conversion emissions. The energy transition between Yb3＋ and Dy3＋ is discussed.展开更多
The relationship between infrared light （IR） and vacuum ultraviolet （VUV） emission in shadow mask plasma display panels （SMPDP） at high xenon content and high voltage is investigated. The respective ratios of VI...The relationship between infrared light （IR） and vacuum ultraviolet （VUV） emission in shadow mask plasma display panels （SMPDP） at high xenon content and high voltage is investigated. The respective ratios of VIS/IR-823 am, VIS/IR-828 nm and of efficacy/VIS/IR-823 nm, efficacy/VIS/IR-823 nm are calculated to determine the behavior of the xenon excitation efficiency and the electron excitation efficiency as a function of the driving voltage and xenon content. It is found that the xenon excitation efficiency is almost independent of the driving voltage, and increases approximately linearly with the xenon content. The values for efficacy/VIS/IR-828 nm increase rapidly with the xenon content, but saturate at a xenon ratio of about 30% while, on the other hand, the efficacy/VIS/IR-823 nm values decrease continuously with the xenon content.展开更多
The mechanism of variable color luminescence in ionized gases is pre-sented from the view point of luminescence kinetics. On the basis of the simplifiedmodels for excitation radiation, it is studied that the selectiv...The mechanism of variable color luminescence in ionized gases is pre-sented from the view point of luminescence kinetics. On the basis of the simplifiedmodels for excitation radiation, it is studied that the selective excitation preduedby controlling the展开更多
Silicon dominates the electronic industry, but its poor optical properties mean that it is not preferred for photonic applications. Visible photoluminescence （PL） was observed from porous Si at room temperature in 1...Silicon dominates the electronic industry, but its poor optical properties mean that it is not preferred for photonic applications. Visible photoluminescence （PL） was observed from porous Si at room temperature in 1990, but the origin of these light emissions is still not fully understood. This paper reports that an Si nanocrystal, silicon nanoporous pillar array （Si-NPA） with strong visible PL has been prepared on a Si wafer substrate by the hydrothermal etching method. After annealing in 02 atmosphere, the hydride coverage of the Si pillar internal surface is replaced by an oxide layer, which comprises of a great quantity of Si nanocrystal （nc-Si） particles and each of them axe encapsulated by an Si oxide layer. Meanwhile a transition from efficient triple-peak PL bands from blue to red before annealing to strong double-peak blue PL bands after annealing is observed. Comparison of the structural, absorption and luminescence characteristics of the as-prepared and oxidized samples provides evidence for two competitive transition processes, the band-to-band recombination of the quantum confinement effect of nc-Si and the radiative recombination of excitons from the luminescent centres located at the surface of nc-Si units or in the Si oxide layers that cover the nc-Si units because of the different oxidation degrees. The sizes of nc-Si and the quality of the Si oxide surface are two major factors affecting two competitive processes. The smaller the size of nc-Si is and the stronger the oxidation degree of Si oxide layer is, the more beneficial for the luminescent centre recombination process to surpass the quantum confinement process is. The clarification on the origin of the photons may be important for the Si nanoporous pillar array to control both the PL band positions and the relative intensities according to future device requirements and further fabrication of optoelectronic nanodevices.展开更多
基金Supported by the National Natural Science Foundation of China.
文摘We investigate the Luminosity Function （LF） of the cluster of galaxies Abell 566. The photometric data of 15 intermediate-bands are obtained from the Beijing-Arizona- Taiwan-Connecticut （BATC） photometric sky survey. For each of the 15 wavebands, the LF of cluster galaxies is well modelled by the Schechter function, with characteristic luminosities from -18.0 to -21.9 magnitude, from the α- to the p-band. Morphological dependence of the LF is investigated by separating the cluster members into ＇red＇ and ＇blue＇ subsamples. It is clear that late type galaxies have a steeper shape of LF than the early type galaxies. We also divided the sample galaxies by their local environment. It was found that galaxies in the sparser region have steeper shape of LF than galaxies in the denser region. Combining the results of morphological and environmental dependence of LFs, we show that Abell 566 is a well relaxed cluster with positive evidence of galaxy interaction and merger, and excess number of bright early type galaxies located in its denser region.
基金Project supported by the National Natural Science Foundation of China （Grant No. 11004092） and the Scientific Research Fund of Education Department of Liaoning Province, China （Grant No. 2009A417）.
文摘yb3＋/Dy3＋ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results show that there are comparatively abundant spectra of up-conversion emissions centered at 378, 408, 527 and 543, and 663 nm, corresponding to 4C9/2→ 6H13/2, 4C9/2→ 6Hll/2, 4115/2 → 6H13/2, and 4F9/2 →6Hll/2 transitions of Dy3＋, respectively. Two-photon and three-photon processes are involved in ultraviolet, violet, green, and red up-conversion emissions. The energy transition between Yb3＋ and Dy3＋ is discussed.
基金supported by National Natural Science Foundation of China (No. 60571033)the National Hi'Tech projects of China (No. 2008AA03A308)Programme of Introducing Talents of Discipline to Universities of China (B07027)
文摘The relationship between infrared light （IR） and vacuum ultraviolet （VUV） emission in shadow mask plasma display panels （SMPDP） at high xenon content and high voltage is investigated. The respective ratios of VIS/IR-823 am, VIS/IR-828 nm and of efficacy/VIS/IR-823 nm, efficacy/VIS/IR-823 nm are calculated to determine the behavior of the xenon excitation efficiency and the electron excitation efficiency as a function of the driving voltage and xenon content. It is found that the xenon excitation efficiency is almost independent of the driving voltage, and increases approximately linearly with the xenon content. The values for efficacy/VIS/IR-828 nm increase rapidly with the xenon content, but saturate at a xenon ratio of about 30% while, on the other hand, the efficacy/VIS/IR-823 nm values decrease continuously with the xenon content.
文摘The mechanism of variable color luminescence in ionized gases is pre-sented from the view point of luminescence kinetics. On the basis of the simplifiedmodels for excitation radiation, it is studied that the selective excitation preduedby controlling the
基金supported by the Doctoral Fund of the Ministry of Education of China (Grant No. 20090010120014)the Beijing Natural Science Foundation (Grant No. 1103033)the Fundamental Research Funds for the Central Universities
文摘Silicon dominates the electronic industry, but its poor optical properties mean that it is not preferred for photonic applications. Visible photoluminescence （PL） was observed from porous Si at room temperature in 1990, but the origin of these light emissions is still not fully understood. This paper reports that an Si nanocrystal, silicon nanoporous pillar array （Si-NPA） with strong visible PL has been prepared on a Si wafer substrate by the hydrothermal etching method. After annealing in 02 atmosphere, the hydride coverage of the Si pillar internal surface is replaced by an oxide layer, which comprises of a great quantity of Si nanocrystal （nc-Si） particles and each of them axe encapsulated by an Si oxide layer. Meanwhile a transition from efficient triple-peak PL bands from blue to red before annealing to strong double-peak blue PL bands after annealing is observed. Comparison of the structural, absorption and luminescence characteristics of the as-prepared and oxidized samples provides evidence for two competitive transition processes, the band-to-band recombination of the quantum confinement effect of nc-Si and the radiative recombination of excitons from the luminescent centres located at the surface of nc-Si units or in the Si oxide layers that cover the nc-Si units because of the different oxidation degrees. The sizes of nc-Si and the quality of the Si oxide surface are two major factors affecting two competitive processes. The smaller the size of nc-Si is and the stronger the oxidation degree of Si oxide layer is, the more beneficial for the luminescent centre recombination process to surpass the quantum confinement process is. The clarification on the origin of the photons may be important for the Si nanoporous pillar array to control both the PL band positions and the relative intensities according to future device requirements and further fabrication of optoelectronic nanodevices.
