Tunable Nd,La:SrF_2 laser and passively Q-switched operation based on gold nanobipyramids saturable absorber

A novel Nd, La:SrF_2 disordered crystal is prepared, and its continuous-wave wavelength tuning operation is performed for the first time. Employing a surface plasmon resonance(SPR) based gold nanobipyramids(G-NBPs) saturable absorber,we obtain a compact diode-pumped passively Q-switched Nd, La:SrF_2 laser. The stable Q-switched pulse operates with the shortest pulse duration of 1.15 μs and the maximum repetition rate of 41 k Hz. The corresponding single pulse energy is 2.24 μJ. The results indicate that G-NBPs could be a promising saturable absorber applied to the diode-pumped solid state lasers(DPSSLs).     

交通灯数学模型

主要讨论在假定车流均匀的前提下如何安排路口的交通灯时间才能使路口的交通达到最大限度的畅通.这里交通最大限度通畅的定义是一个交通周期内积存车辆的最大可能长度达到最小.文章首先以最大限度通畅为目标,道路条件、行人通过马路等条件为约束,建立优化模型解决孤立丁字路口的交通灯安排问题,这个模型也适用于孤立十字路口的分析.随后文章建立了多个路口相连时路口交通灯的安排模型.最后,文章讨论了上述几个模型的稳定性以及改进方向.     

毛细管液相色谱柱的柱上筛板的原位热聚合制备

利用有机聚合物的原位聚合反应,在0.32 mm内径的弹性石英毛细管内制备了3 mm长的柱上筛板,该筛板可以耐受至少40 MPa的压力.将5 μm C18填料填充到带有筛板的毛细管内,制备了毛细管液相色谱柱,色谱分离结果令人满意.用该筛板制备的色谱柱结构最大程度地避免了柱后死体积的产生.