The absorption cross section of the Einstein-Maxwell Dilaton Axion (EMDA) black hole for Dirac particlesis investigated.It is shown that the absorption cross section decreases as both the v and the absolute value of t...The absorption cross section of the Einstein-Maxwell Dilaton Axion (EMDA) black hole for Dirac particlesis investigated.It is shown that the absorption cross section decreases as both the v and the absolute value of the dilatonincrease,but it increases as the mass of the particle increases.It is also shown that the absorption cross section for themassless Dirac particles is 1/8 of the area of the horizon,which may be an universal property for minimally coupledmassless Dirac particles.展开更多
A series of novel organic compounds named as CSPI, DPASPI, PSPI DEASPI and HEASPI respectively, with large two-photon absorption has been synthesized and their structures have been determined by 1HNMR and elemental an...A series of novel organic compounds named as CSPI, DPASPI, PSPI DEASPI and HEASPI respectively, with large two-photon absorption has been synthesized and their structures have been determined by 1HNMR and elemental analysis. The highest two-photon pumped (TPP) output /input efficiency is as high as 13.4% for PSPI in DMF with d0 = 0.03 mol/L and the effective two-photon absorption cross section is 8.8(10-48 cm4(s/photon for DPASPI in DMF with d0= 0.05mol/L.展开更多
Optical absorption and emission intensities of Nd3+ ion in KLu(WO4)2 crystal were investigated. Based on the Judd-Offelt theory, we calculated the following spectral parameters: phenomenological intensity parameters ...Optical absorption and emission intensities of Nd3+ ion in KLu(WO4)2 crystal were investigated. Based on the Judd-Offelt theory, we calculated the following spectral parameters: phenomenological intensity parameters Ω2=5.567×10–20, Ω4=3.597×10–20, and Ω6= 3.800×10–20 cm2. The radiative lifetime of levels 4F3/2 was 182.58 μs. The fluorescence branching ratio for the transition 4F3/2→4I11/2 was 46.98%. In addition, the radiative transition probabilities AJ,J’, oscillator strengths PJ,J’ and the values of integrated emission cross sections were also calculated. In comparison with those of other laser crystals, these results indicated that Nd: KLuW is a promising efficient laser material.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No.10675045the FANEDD under Grant No.200317,and the SRFDP under Grant No.20040542003
文摘The absorption cross section of the Einstein-Maxwell Dilaton Axion (EMDA) black hole for Dirac particlesis investigated.It is shown that the absorption cross section decreases as both the v and the absolute value of the dilatonincrease,but it increases as the mass of the particle increases.It is also shown that the absorption cross section for themassless Dirac particles is 1/8 of the area of the horizon,which may be an universal property for minimally coupledmassless Dirac particles.
文摘A series of novel organic compounds named as CSPI, DPASPI, PSPI DEASPI and HEASPI respectively, with large two-photon absorption has been synthesized and their structures have been determined by 1HNMR and elemental analysis. The highest two-photon pumped (TPP) output /input efficiency is as high as 13.4% for PSPI in DMF with d0 = 0.03 mol/L and the effective two-photon absorption cross section is 8.8(10-48 cm4(s/photon for DPASPI in DMF with d0= 0.05mol/L.
基金Project supported by Program for New Century Excellent Talents in University (NCET-08-0722)
文摘Optical absorption and emission intensities of Nd3+ ion in KLu(WO4)2 crystal were investigated. Based on the Judd-Offelt theory, we calculated the following spectral parameters: phenomenological intensity parameters Ω2=5.567×10–20, Ω4=3.597×10–20, and Ω6= 3.800×10–20 cm2. The radiative lifetime of levels 4F3/2 was 182.58 μs. The fluorescence branching ratio for the transition 4F3/2→4I11/2 was 46.98%. In addition, the radiative transition probabilities AJ,J’, oscillator strengths PJ,J’ and the values of integrated emission cross sections were also calculated. In comparison with those of other laser crystals, these results indicated that Nd: KLuW is a promising efficient laser material.
