An All-Solid-State Tunable Dual-Wavelength Ti：Sapphire Laser with Quasi-Continuous-Wave Outputs

A high power dual-wavelength Ti：sapphire laser system with wide turning range and high efficiency is described, which consists of two prism-dispersed resonators pumped by an a11-solid-state frequency-doubled Nd：YAG laser. Tunable dual-wavelength outputs, with one wavelength range from 750nm to 795nm and the other from 80Ohm to 850nm, have been demonstrated. With a pump power of 23 W at 532nm, a repetition rate of 6.5kHz and a pulse width of 67.6ns, the maximum dual-wavelength output power of 5.6 W at 785.3nm and 812.1 run, with a pulse width of 17.2ns and a line width of 2nm, has been achieved, leading to an optical-to-optical conversion efficiency of 24.4%.     

一种具有时间约束的基于角色的授权管理模型

针对大型系统中角色权限管理的复杂性，提出了一种具有时间约束的基于角色的授权管理模型．考虑到用户权限通常包括私有权限、部门权限及公有权限，并存在权限频繁变动等问题，该模型扩展了权限定义，在权限定义中增加了权限的传播深度参数，即增加了可被继承的次数，使该参数与现实世界中的各级岗位数及权限类型相对应．另外，该模型在权限的继承中也加入了时间约束，使得只有满足时间条件要求的角色的权限才可以被继承．结果表明，该模型不仅有利于权限的频繁更新，也对应了现实世界中的岗位数，易于理解与操作．     

Pd/PAMAM(聚酰胺-胺)/SBA-15催化剂的制备及催化性能

利用聚酰胺-胺型(PAMAM)树形分子为模板制备出粒径可控的Pd纳米颗粒(Pd DEN),然后通过超声波法制备了SBA-15分子筛负载的Pd/PAMAM复合材料(Pd SDEN)。XRD和TEM测试表明,负载后Pd纳米颗粒的粒径没有变化,且均匀分布在分子筛的孔道中,SBA-15分子筛的结构也没有变化。以对硝基苯酚还原为例,测试了Pd SDEN的催化性能,与Pd DEN相比,其具有更高的催化效率,重复使用5次后仍具有较好的催化活性,反应速率仅下降4%,且Pd/PAMAM复合材料仍能稳定存在于分子筛的孔道中。     

面向移动通信的3DTV交织编码错误隐藏方法

针对移动通信Mobile 3DTV和传统3DTV视频表示格式与编码结构的差异以及Mobile 3DTV低计算复杂度的特点, 提出一种面向Mobile 3DTV交织编码的立体视频错误隐藏方法. 新方法在编码之前先将左右视点进行交织处理, 然后按照Stereo SEI的编码结构编码传输, 在解码端根据像素的不同错误类型有针对地选择相应低计算复杂度的错误隐藏方法恢复丢失信息. 实验表明, 该方法在解码端得到的恢复效果较好, 并且计算复杂度较低.     

Continuous-wave mid-infrared intracavity singly resonant optical parametric oscillator based on periodically poled lithium niobate

This paper reports a continuous-wave （CW） mid-infrared intracavity singly resonant optical parametric oscillator based on periodically poled lithium niobate （PPLN） pumped by a diode-end-pumped CW Nd：YVO4 laser. Considering the thermal lens effects, it adopted an optical ballast lens and the near-concentric cavity for better operation. At the PPLN＇s grating period of 28.5 μm and the temperature of 140℃, the maximum idler output power of 155 mW at 3.86 μm has been achieved when the 808 nm pump power is 8.5 W, leading to an optical-to-optical conversion efficiency of 1.82%.