Optical parameters and energy levels splitting of Ho^3＋ in Ho^3＋： GdVO4

Ho^3＋ ： GdVO4 is a new laser material suitable for high-power laser systems. In this paper we measure the absorption spectra of Ho^3＋ in the sample Ho^3＋： GdVO4. The intensity parameters are calculated by using the Judd-Ofelt theory. Some predicted spectroscopic parameters, such as the spontaneous radiative transition rate, branching ratio and integrated emission cross section are dealt with. And we also compare the optical parameters with those of other materials. From these results, it is found that there are many transitions which have large oscillator strengths and large integrated emission cross sections. Especially the transitions such as ^5 F4 → ^5 I 8, ^5 S2→^5 I8, ^5 F5 → ^5 I8 and ^5 I7 →^ 5 I8 are useful in solid-state lasers and other fields. Finally, we discuss the splitting of the energy levels of Ho^3＋ in the crystal GdVO4 based on the group theory.     

AB—8树脂对罗汉果皂甙的吸附

本文初步研究了大孔吸附树脂ＡＢ－８对罗汉果皂甙的吸附性能，比较了１５℃和６５℃下的吸附速度，获得了在ＳＶ２、ＳＶ５、ＳＶ８三种空速下的穿漏吸附量。     

Er3+:GdVO4中Er3+离子的光谱参数计算和晶场中能级分裂的讨论

对Er3+:GdVO4样品的光谱参数以及Er3+在晶场中能级的分裂情况进行了研究.首先对样品进行了吸收光谱的测量,接着用Judd-Ofelt理论拟合出了Er3+在GdVO4晶体中的强度参量Ωt,并由此计算了跃迁的振子强度、自发辐射跃迁速率、荧光分支比和积分发射截面.通过计算结果可以发现有较多能级之间的跃迁都有大于10-6的振子强度和大于10-18 cm的积分发射截面,并且具有较高的荧光分支比,特别是2H11/2→4I15/2,4S3/2→4I15/2,4F9/2→4I15/2和4I13/2→4I15/2等几个强发光能级除了具有较大的振子强度和积分发射截面外还有很好的应用前景,因此也更加值得关注.最后还利用群论讨论了Er3+离子在GdVO4晶场中各能级的分裂情况并对各Stark子能级的Jz混杂情况进行了分析.     

Improved anti-Stokes energy transfer between rare earth ions in Er（0.5）Yb（9.5）：FOV oxyfluoride vitroceramics explains the strong color reversal

The widely used energy transfer theory is a foundation of luminescence,in which the rates of Stokes and antiStokes processes have the same calculation formula.An improvement on the anti-Stokes energy transfer to explain the fluorescence intensity reversal between the red and green fluorescence of Er(0.5)Yb(9.5):FOV is reported in the present article.The range of the intensity reversal Σ was measured to be 877.Dynamic processes for 16 levels were simulated.A coefficient,the improvement factor of the intensity ratio of Stokes to anti-Stokes processes in quantum Raman theory compared to classical Raman theory,is introduced to successfully describe the anti-Stokes energy transfer.A new method to calculate the distance between the rare earth ions,which is critical for the energy transfer calculation,is proposed.The validity of these important improvements is also proved by experiment.     

改进的假高稀技术合成聚苯胺三聚体和四聚体及其紫外光谱的研究

提出了一条合成还原态的苯基封端聚苯胺齐聚物的新方法:即苯胺二聚体的Schiff碱或苯胺三聚体的Schiff碱在酸性溶液中缓慢水解,形成聚苯胺二聚体和三聚体的盐酸盐,这些盐酸盐与二苯胺或N-苯基-对苯二胺反应,经苯肼还原,生成还原态的苯基封端的聚苯胺三聚体和四聚体.用红外、核磁、元素分析和基底辅助激光解吸质谱对其进行了表征,并用紫外光谱对还原态的三聚体和四聚体的化学氧化过程进行了跟踪研究.     

苯胺低聚物-二氧化硅复合纳米粒子作为高密度信息存储材料的初步探讨

近年来,在有机半导体中,聚苯胺低聚物已成为最为广泛的关注热点之一[1]．这不仅是因为它们与母体聚苯胺相比,有着良好的溶解性和确定的化学结构以及较低的杂质含量[2]．而且,通过改变共轭链长度或进行不同程度的化学修饰,如改变分子链上末端基团等,来调节它们的电子特性[3,4],使其能带值能够调制到所要求的范围内,以满足电子器件的诸多要求［’j．苯胺低聚物的这些优点及其3种相对稳定的氧化态形式使其作为高密度信息存储材料有巨大的潜力．将其以纳米粒子形式进行二维有序组装,使每一个粒子成为一个信息纪录点是我们目前所面临的…