Yb原子高激发能级的跃迁特性

采用“类氢”模型,用数值积分方法计算了Yb原子部分高激发Rydberg态和Stark态的自发跃迁概率,及环境黑体辐射引起的受激跃迁概率,并与采用延迟脉冲场电离方法对相应态的测量结果做了比较.选取典型的初始态,测量了环境黑体辐射引起的受激跃迁对周围能级的再布居特性,并给出了理论解释.对“类氢”模型应用于复杂原子的适用性进行了分析. 关键词：     

动态泡沫浮选法分离富集人参提取液中的二醇型人参皂苷

采用动态泡沫浮选法分离富集人参提取液中的二醇型人参皂苷, 用高效液相色谱法测定6种人参皂苷Rg₁, Re, Rb₁, Rc, Rb₂和Rd的含量. 考察了浮选液pH值、电解质NaCl浓度、载气流量、料液浓度及料液流速对人参皂苷浮选率的影响, 确定了动态泡沫浮选的最佳条件, 并与溶剂提取法、溶剂浮选法以及静态泡沫浮选法进行了比较. 结果表明, 动态泡沫浮选法对二醇型人参皂苷Rb₁, Rc, Rb₂和Rd具有高富集效率, 回收率分别为93.3%, 98.6%, 96.9%和98.3%, 而对三醇型人参皂苷Rg1和Re的富集效率却很低, 回收率分别为4.8%和4.2%. 该法是分离纯化二醇型人参皂苷的一种简便有效的方法.     

光谱稳定的互补色双发光层高效混合白光OLED

利用两种颜色的发光层制备了光谱稳定的高效混合WOLED。其中蓝光发光层用14%质量分数的BNE掺杂在BePP₂中,橙光发光层用1%质量分数的Ir（bt）₂（acac）掺杂在49.5%质量分数的NPB和49.5%质量分数的BePP₂组成的混合主体中。在不利用任何光耦合技术的条件下,器件在亮度为100 cd/m²时,功率效率可以达到39 lm/W;当亮度提高到1 000 cd/m²时,效率仅发生轻微滚降至27.5 lm/W。器件的光谱稳定,亮度在1 000 cd/m²和10 000 cd/m²时,CIE坐标分别为（0.37,0.48）和（0.37,0.47）。良好的光谱稳定性归结于设计的双极性中间层平衡了其两侧激子的产生。     

由雁阵引出的一些话题

编者按:欢迎就"雁陈现象"作进一步的分析、讨论."蜃楼百尺横苍海,雁字一行书绛霄","九秋惊雁序,万里狎渔翁","雁阵惊寒,声断衡阳之浦","碧云天,黄花地,西风紧,北雁南翔"……秋霄雁阵,总能给人以或壮丽、或凄婉、或温馨……不尽的     

Blue upconversion luminescence in Tm~(3+)/Yb~(3+) co-doped new oxyfluoride tellurite glass

Solid-state blue and green light sources are desirablefor high-density optical storage, color displays, optoelec-tronics, and medical diagnostics[1-4]. Tm3+ is the moststudied in rare-earth ions for blue laser operation basedupon upconversion[5,6]. One approach to improving theluminescence efficiency of Tm3+ is to co-dope it withother rare-earth ions[7]. The choice of host materials is avery important factor to obtain high efficient upconver-sion emission. In this case, the main goal of the c…     

Na原子斯塔克态寿命的实验测定

在１２５０￣２０００Ｖ／ｃｍ的静电场变化范围内，用可调谐激发实现Ｎａ原子在ｎ＝１７，ｍ＝０斯塔克族各能态布局，采用延迟脉冲场电离方法测量了各斯塔克能态在不同外电场下的寿命，讨论了外电场强度和环境黑体辐射对斯塔克态寿命的影响。     

Study on forward stimulated Brillouin scattering in a backward pumped fiber Raman amplifier

Strong multi-order forward stimulated Brillouin scattering (SBS) has been observed in the backward pumped S-band distributed fiber Raman amplifier (FRA) with tunable narrow signal source (less than 100 MHz) when the pump power of FRA reached the SBS threshold. This does not obey the theory that only weak backward SBS lines exist according to the conservation of energy and momentum and the wave vector selected rule. This is because the sound waveguide characteristic weakens the wave vector rule, and the forward transmitted sound waveguide Brillouin scattering lines are generated and amplified in FRA.When the pump power is further increased, 11 orders of SBS lines and comb-like profile are observed. For the excited line, the frequency is 197.2296 THz and the power is 0 dBm. The even order SBS lines are stronger than odd order SBS lines, the power of the 2nd and 4th order SBS lines is 1.75 dBm, which is 16 dB higher than that of the 1st and 3rd order SBS lines. The odd order SBS lines are named BrillouinRayleigh scattering lines.     

Differential System＇s Nonlinear Behaviour of Real Nonlinear Dynamical Systems

Chaos attractor behaviour is usually preserved if the four basic arithmetic operations, i.e. addition, subtraction, multiplication, division, or their compound, are applied. First-order differential systems of one-dimensional real discrete dynamical systems and nonautonomous real continuous-time dynamical systems are also dynamical systems and their Lyapunov exponents are kept, if they are twice differentiable. These two conclusions are shown here by the definitions of dynamical system and Lyapunov exponent. Numerical simulations support our analytical results. The conclusions can apply to higher order differential systems if their corresponding order differentials exist.     

基于非凸加权核范数的目标视频帧选取

主要研究的是基于监控视频的显著前景目标帧选取问题.首先利用非凸加权核范数进行低秩背景估计.然后使用Markov随机场对稀疏前景目标位置矩阵进行估计,并提取出前景目标.最后定义显著前景目标区域,根据连通域面积大小,采用阈值法判断当前帧是否为显著目标帧,并采用F值来验证该模型的准确率.结果显示,模型在Campus、Curtain、Escalator、Fountain、Hall、Lobby和Office这7个数据集上的F值均超过90%,说明该模型普遍具有较高的鲁棒性和准确性.