The Degradation of Beam Quality in Large-Core Optical Fiber

The degradation of beam quality in large-core fiber is investigated experimentally. It is found that the output beam quality factor M2 is a compound tanh function ofthe fiber lengths and misalignment launch results that the beam quality degraded faster.     

RIBLL1终端实验装置

描述了一套HIRFL的放射性核次级束流引起反应测量的实验装置,它由RIB鉴别、测量系统、次级靶控制系统和次级反应产物鉴别、测量系统组成.高增益分组延迟线读出、重心定位PPAC,横向场IC,椭球面镜聚焦、PMT读出、闪烁薄膜时间拾取器,双叠层纵向场阳极分条读出IC,PMT矩阵读出x—y位置灵敏Phoswich闪烁探测器,康普顿抑制HpGeγ探测器等单元是这套装置的基本部件.目前,该装置已安装在兰州重离子加速器RIBLL1终端.性能测试和实验研究正在进行.     

基于等效衰减矢方法的非均匀光波导色散方程

利用转换矩阵理论和等效衰减矢的概念，以此为根据分析了任意折射率分布平板波导的模式传输特性，导出了意义明确的非均匀平板波导的色散方程的严格的解析解，并指出了ＷＫＢ法的局限性，数值计算的结果表明本文所得公式的结果和严格的数值解非常接近，表明本文所得的公式是严格的。     

矩阵酉扩张的刻划

本文用奇异值刻划了具有指定阶酉扩张的矩阵类，同时讨论了矩阵的正规扩张问题     

Multi-Electron Processes in 4.15-11.08 keV/u^13C^6＋ on Argon Collisions

The relative partial cross sections for ^13C^6＋ -Ar collisions at 4.15-11.08 ke V/u incident energy are measured. The cross-section ratios σ^2E/σ^SC, σ^3E/σ^SC, σ^4E/σ^SC and σ^SE/σ^SC are approximately the constants of 0.514-0.05, 0.204-0.03, 0.064-0.03 and 0.024-0.01 in this region. The significance of the multi-electron process in highly charged ions （HCIs） with argon collisions is demonstrated （σ^ME/σ^SC as high as 0.794-0.06）. In multi-electron processes, it is shown that transfer ionization is dominant while pure electron capture is weak and negligible. For all reaction channels, the cross-sections are independent of the incident energy in the present energy region, which is in agreement with the static characteristic of classic models, i.e. the molecular Coulomb over-the-barrier model （MCBM）, the extended classical over-the-barrier model （ECBM） and the semiempirical scaling laws （SL）. The result is compared with these classical models and with our previous work of ^13C^6＋ -Ne collisions [Chin. Phys. Lett. 23 （2006） 95].     

In situ fabrication of polyacrylate/nanozirconia hybrid material via frontal photopolymerization

Frontal photopolymerization was applied to fabricate polymer/nanozirconia hybrid material by using acrylates as polymerizable components and tetrabutyl zirconate (TBZ) as the precursor of nanozirconia, respectively. The nanozirconia particles were in-situ generated with the polymerization front traveling and gradiently dispersed in the simultaneously formed polymer rod. The iodonium salt was utilized as photoacid generator to produce protonic acid and drive TBZ into nanozirconia particles. With the frontal polymerization traveling downward, the particle size and concentration of zirconia increased, but layer-resolved conversion of TBZ decreased. The particle size of zirconia could be reduced remarkably by the protection of monoalkyl titanate bearing six long chains. The refractive index of the hybrid rod was found to increase from top to down. The top–down layer-resolved storage modulus of the hybrid rod increased due to nanoparticle filling effect but decreased beyond the depth of 4 cm from the top, which may be ascribed to particle aggregation. This project is supported by the National Natural Science Foundation of China (grant no. 20304019, 60378029).     

波纹圆孔光栏的衍射及其设计

详细研究了波纹光珠菲涅耳衍射特征，提出并论证了调幅正弦波纹光栏级在较大的菲涅耳数范围内有效地抑制光束中央部分的衍射调制，并给出这类波纹光栏用于高功率光系统的设计程序。     

Adaptive autoregressive modeling of non-stationary vibration signals under distinct gear states. Part 2: experimental analysis

Parametric time-frequency representation based on parametric models is more desirable for presenting highly precise time-frequency domain information due to its high-resolution property. However, the sensitivity and robustness of parametric models, in particular the parametric models on the basis of advanced adaptive filtering algorithms, has never been investigated for on-line condition monitoring of rotating machinery. Part 1 of this study proposed three adaptive parametric models based on three advanced adaptive filtering algorithms. Part 2 of this study is concerned with the effectiveness of the proposed models under distinct gear states, especially the highly non-stationary conditions accrued from advanced gear faults. Four gear states are considered: healthy state, adjacent gear tooth failure, non-adjacent gear tooth failure and distributed gear tooth failure. The vibration signals used in this study include the time-domain synchronous averaging signal and gear motion residual signal for each considered gear state. The test results demonstrate that the optimum filter behavior can readily be attained and the white Gaussian assumption of innovations can relatively be easily guaranteed for the NAKF-based model under distinct gear states and a wide variety of model initializations. On the other hand, the EKF- and MEKF-based models are capable of generating more accurate time-frequency representations than the NAKF-based model, but in general the optimality condition for white Gaussian assumption cannot be guaranteed for these two advanced models. Therefore, the NAKF-based model is preferred for automatic condition monitoring due to its appealing robustness to distinct gear states and arbitrary model initializations, whereas the EKF- and MEKF-based models are desirable when accurate time-frequency representation is concerned.