蓝光LD抽运Pr~(3+):LiYF_4 604nm橙光激光器和红橙多波长激射

使用蓝光激光二极管抽运掺镨氟化钇锂(Pr:YLF)块状晶体,获得最大输出功率为166.6mW的σ偏振607.4nm连续橙光输出。通过在谐振腔中插入厚度为0.1mm的玻璃薄片,并适当调节角度,获得了π偏振604.6nm连续橙光输出,最大功率为60.6mW,斜效率达到13.6%。通过进一步调节玻璃薄片的插入角度,进而获得了607、604、640nm的多波长同时激射。     

5-羧基-3-氨基-1,2,4-三氮唑芳香醛席夫碱的合成与表征

利用氨基胍碳酸氢盐与草酸反应合成5-羧基-3-氨基-1,2,4-三氮唑,然后用5-羧基-3-氨基-1,2,4-三氮唑与芳香醛反应,合成了2种5-羧基-3-氨基-1,2,4-三氮唑芳香醛席夫碱,通过元素分析,红外光谱和紫外光谱对产物的结构进行了表征.     

Effects of High Pressure on BC3

High-pressure phases of BC3 are studied within the local density approximation under the density functional theory framework. When the pressure reaches 20 GPa, the layered BC3 that is a semiconductor at ambient pressure, becomes metallic. As the pressure increases, the material changes into a network structure at about 35 GPa. To understand the mechanism of phase transitions, band structure and density of states are discussed. With the increase of pressure, the width of bands broadens and the dispersion of bands enlarges. Additionally, the density of states of the network bears great resemblance to that of diamond. Formation of the sp3 bonding in the network is the main reason for the structural transformation at 35 GPa.     

New 3-mode bosonic operator realization of SU（2） Lie algebra： From the point of view of squeezing

We consider the quantum mechanical SU(2) transformation e2λ JzJ± e-2λJz= e±2λJ± as if the meaning of squeezing with e±2λbeing squeezing parameter. By studying SU(2) operators(J±,Jz) from the point of view of squeezing we find that(J±,Jz) can also be realized in terms of 3-mode bosonic operators. Employing this realization, we find the natural representation(the eigenvectors of J+ or J-) of the 3-mode squeezing operator e2λ Jz. The idea of considering quantum SU(2) transformation as if squeezing is liable for us to obtain the new bosonic operator realization of SU(2) and new squeezing operators.     

Nonlinear polarization rotation-induced pulse shaping in a stretched-pulse ytterbium-doped fiber laser

We report on controllable pulse shaping in a Yb-doped stretched-pulse fiber laser followed by a high-power chirped pulse amplifier. We demonstrate that the pulses after an extra-cavity grating pair change their intensity profile from Lorentz to Gaussian and then to sech2 shapes by adjusting the intra-cavity polarization through a quarter-wave plate inside the fiber laser cavity. The laser pulses with different pulse shapes exhibit pulse-to-pulse amplitude fluctuation of -- 1.02%, while the sech2-shaped pulse train is provided with a more stable free-running repetition rate as a result of the stronger self-phase modulation in the fiber laser cavity than Lorentz- and Gaussian-shaped pulse trains.     

荧光光谱法辨别丙二醇和二甘醇

以齐药二厂的假药事件为背景,对1,2-丙二醇、1,3-丙二醇和二甘醇的吸收光谱和荧光光谱进行了测量,实验结果证明光谱法不失为一种快捷有效的区分手段.在紫外吸收光谱中,可以通过最大吸光度的差异区分二甘醇和丙二醇;在一定紫外波长激励下,三种醇的荧光光谱特性均存在差异,以此可以对三种醇作出有效区分;在230nm激发下,将二甘醇和两种丙二醇分别混合,混合溶液的相对荧光强度均与两种丙二醇体积比呈线性反比关系,这在一定程度上证明了二甘醇的荧光量子效率大于两种丙二醇.     

Eu3+摩尔浓度对Y2O2S:Eu3+,Mg2+,Ti4+红色长余辉材料光谱的影响

用高温固相法制备了Y2O2S：Eu^3 ,Mg^2 ,Ti^4 红色长余辉材料。测量了该材料的余辉曲线,余辉时间为1h以上;由X射线衍射得到晶体结构为Y2O2S.测量了不同Eu^3 摩尔浓度下的激发光谱和发射光谱,得到从^5DJ(J=0,1,2,3)^-7FJ(J=0,1,2,3,4,5)的发射谱线,并得到位于260,345,468和540nm激发峰。由于激活剂饱和效应,Y2O2S：Eu^3 ,Mg^2 ,Ti^4 发射光谱中513．6,540．1,556．4,587．3和589．3nm属于从^5D2,^5D1到^7FJ(J=0,1,2,3,4)跃迁的发射峰随Eu^3 摩尔浓度的增加相对削弱;激发谱包括位于350nm左右属于电荷转移态吸收(Eu^3 -O^2-,Eu^3 -S^2 )的激发主峰和在可见光区位于468,520和540nm属于Eu^3 离子4f-4厂吸收的激发峰。随着Eu^3 摩尔浓度的增加,位于468,520和540nm的激发峰相对增强。     

Proton Spectroscopic Factors Deduced from Helium-3 Global Phenomenological and Microscopic Optical Model Potentials

Global phenomenological GDP08 and microscopic hefium-3 optical model potentials have been recently derived. We evaluate these two potential sets by comparing the elastic scattering data of 25 MeV 3He on 160, 180, 19F, 23Na, 24Mg, 25Mg, 26Mg, 27A1, 28Si, 30Si, 31p, 32S, 34S, 35Cl, 3761, and 39K isotopes. Using the deuteron angular distributions calculated with the distorted wave Born approximation model, we extract the ground-state proton spectroscopic factors from （3He, d） reactions on the same set of nuclei. The extracted proton spectroscopic factors are compared with the large-basis shell-model calculations.