Microstructure and properties of plastic deformed martensite induced by laser shock processing

Firstly, 45# steel was quenched by the NEL-2500A rapidly axial flow CO2 laser. The experimental parameters were the laser power of 750 W, the laser beam diameter of 4 mm, the scanning velocity of 7 mm/s. The thickness of coating layer was 0.1 mm and the width was 8 mm. Secondly, the martensite induced by laser quench was shocked by Nd:YAG laser. The parameters of laser shock processing were the wavelength of 1.06 μm, the pulse duration of 23 ns, and the output energy of 16-20 J. The laser was focused on a spot of φ7 mm. K9 optical glass was used as confinement. The sample was coated with black paint 86-1 (the thickness is about 0.025 mm). By testing and analysis of samples which were treated by laser quench and laser quench+shock with transmission electron microscope (TEM), it was discovered that the surface layer of martensite was deformed plastically by laser shock processing. In the secondary hardened zones, there were a lot of slender secondary twin crystal martensites, dislocation tangles, and cel     

纳米金淀积的多孔硅靶增强样品的激光解吸/电离质谱信号

硅片类型和多孔硅结构的多样性影响了多孔硅表面的激光解吸/离子化质谱(DIOS)(无辅助基质的激光解吸/电离飞行时间质谱(LDI-TOF-MS))数据的重复性和靶的耐储时间。本工作通过在多孔硅的表面淀积金纳米颗粒并将其作为目标靶来增强软物质分子如聚乙二醇和多肽的激光解吸/电离质谱信号。纳米金的淀积钝化了多孔硅表面的Si-H活性基团,增加了靶的耐储时间。用场发射扫描电镜表征了多孔硅淀积金纳米颗粒前后的形貌,用X射线能量色散光谱法分析金的百分含量,结果表明其含量随沉积时间的延长而增加。激光解吸/电离质谱信号的增强可能是由多孔硅及其支持的金纳米颗粒的光学和物理性质引起的,该类型的样品靶在激光解吸/电离飞行时间质谱的应用上结合了多孔硅和金纳米颗粒的双重优势。     

WDM光网络中一种基于SRLG限制的动态共享保护算法研究

WDM光网络中引入了共享风险链路组(SRLG)的概念 ,要求工作通路与保护通路不能处于同一个 SRLG之中.提出了一种基于SRLG限制的动态共享通道保护算法 ,即满足K对业务的动态链路权重配置(K-Dynamic Link Weight Configuration , K-DLWC)算法 ,该算法的关键在于为链路定义了2个动态权重.在计算工作通路和保护通路时 ,它能综合解决SRLG限制、局部最优等关键问题.     

激光焊接A3厚钢板的试验研究

采用5kW高功率横流CO2激光器加工系统对A3低碳厚钢板进行焊接试验,研究了工艺参数对激光深熔焊的焊缝的影响,并进一步进行了优化试验,对试样进行了拉伸试验、金相分析和显微硬度分析。     

3G网络测试仪STM-1 IMA数据采集卡的设计与实现

Iub接口是第三代移动通信系统(3G)无线接入网中最重要的网络接口之一.文章针对Iub口的传输及现有Iub接口数据采集卡的不足,设计了一种模块化的信道化数据采集卡;提出了一种基于空分交换和时分交换的STM-1/El复用解复用方法,一种基于扫描单元和扫描索引的自动获取反向复用的异步传输模式(IMA)组捆绑的算法.测试应用表明,该数据采集卡具有较好的灵活性和兼容性.