水热法KTP倍频转换效率性能的研究

首次报道了水热法KTP倍频转换效率性能的研究,通过研究水热法KTP的电子显微镜照片,分析了水热法KTP内部的缺陷;通过理论和实验,研究了水热法KTP晶体的倍频转换效率,两者的高转换效率时的温度相同;通过选择合适的控制温度,在抽运功率为6.11W时,绿光输出为0.7W,继续加大抽运功率,输出绿光的增加幅度都在加大,此时的光-光转化效率是11.5%.     

正弦相位调制下多波长掺铒光纤激光器的研究

通过理论分析并实验验证了一种能在室温下实现稳定的掺铒光纤激光器(EDF)多波长输出的方法。通过在线形谐振腔中引入正弦相位调制器。抑制了由于掺铒光纤的均匀展宽效应引起的模式竞争，从而避免了在室温情况下不稳定的单波长激射。与此同时，线形谐振腔引起的空间烧孔效应也有利于抑制均匀展宽效应。通过取样光纤光栅(SBG)的选频作用，实验中观察到稳定的5个波长的同时激射，相邻波长间隔为0．8nm，符合ITU标准。     

Analysis for surface coke deposition in used Mo-Co/γ-Al2O3 catalyst for diesel hydrodesulfurization

The coked Mo-Co/γ-Al₂O₃ catalysts were Soxhlet extracted with the solvent of tetrahydrofuran. Experimental techniques like FT-IR, GC-MS, XPS, H₂-TPR, BET, etc. were applied for the characterization of coke and catalysts to make a comparison of their physical properties. The results showed that the active components of the catalyst were slightly less after the reaction. The specific surface area and the pore volume had recovered to some degree. These results indicated that the main cause of deactivation of Mo-Co/γ-Al₂O₃ catalysts is carbon deposit. The principal components of the soluble carbon deposit on Mo-Co/γ-Al₂O₃ catalysts were alkyl aromatics with 1–4 rings and C₁₉–C₂₉ long-chain alkane compounds.     

特殊形状饮料瓶专用树脂的开发与应用

确定了特殊形状饮料瓶专用树脂高密度聚乙烯5500 B的物性指标和生产工艺条件,并进行了工业化生产及标定。结果表明,5500 B的熔体流动速率为0.60~0.80 g/10 min,密度为0.952~0.958 g/cm~3,耐环境应力开裂时间大于20 h;正已烷提取物≤2.0%、干燥失重≤0.15%、灼烧残渣≤0.2%,符合国家标准要求,产品力学性能和卫生性能均达到设计指标,所制饮料瓶制品满足用户的需求。     

单纵模激光的再生放大

调Ｑ激光器的输出单纵模脉冲经衰减和削波后，被注入到一Ｎｄ∶ＹＬＦ调Ｑ副腔里，注入脉冲能量１．２ｎＪ，放大以后的脉冲能量１．５ｍＪ，增益达１０６；脉宽由６ｎｓ压缩到４．５ｎｓ。实验和理论分析均表明，当注入信号脉宽短于放大器腔来回一周的时间时，副腔对单纵模激光的放大是一种再生放大行为，单纵模激光的再生放大消除了注入锁定中苛刻的腔长匹配要求。     

振动测量法评定磨损自修复添加剂的效果

针对现有测量自修复效果方法所存在的不足,提出了评定磨损表面自修复效果的振动测量新方法.研究表明,振动测量法评定磨损表面自修复添加剂的效果是可行的.     

一种具有不可预测性的随机延时引信延迟时间的总体分布

构造了一种变组合分布作为随机延时引信延迟时间的总体分布 ,并利用 BP网络对其与其它总体分布产生的随机延迟时间序列进行预测性分析比较 ,证明按该法产生的随机时间序列具有不可预测性     

Asymptotically stable end-point regulation of a flexibleSCARA/Cartesian robot

Presents a class of asymptotically stable end-point regulators for a flexible SCARA/Cartesian robot. Firstly, the closed-loop stability is proven for the original distributed parameter system; then, through explicitly solving the partial differential equations of the system, asymptotic stability is obtained for the undamped truncated system, in which the distributed flexibility of the robot link is represented by an arbitrary finite number of flexible modes. The controllers possess some attractive advantages for practical applications. Computer simulations are provided to illustrate the effectiveness of the approach     

Accurate localization of cortical convolutions in MR brain images

Analysis of brain images often requires accurate localization of cortical convolutions. Although magnetic resonance (MR) brain images offer sufficient resolution for identifying convolutions in theory, the nature of tomographic imaging prevents clear definition of convolutions in individual slices. Existing methods for solving this problem rely on heuristic adaptation of brain atlases created from a small number of individuals. These methods do not usually provide high accuracy because of large biological variations among individuals. The authors propose to localize convolutions by linking realistic visualizations of the cortical surface with the original image volume. They have developed a system so that a user can quickly localize key convolutions in several visualizations of an entire brain surface. Because of the links between the visualizations and the original volume, these convolutions are simultaneously localized in the original image slices. In the process of the authors' development, they have implemented a fast and easy method for visualizing cortical surfaces in MR images, thereby making their scheme usable in practical applications.     

100t复吹转炉底枪位置的设计与应用

基于水模拟实验优化后的6种底枪布置方案(对称布置A1,A2,A3和A4,以及非对称布置B1和B2),利用FLUENT软件对转炉熔池流场进行了三相流模拟,对底枪位置进一步优化,以确定最佳底吹方案。模拟结果表明,方案A2和B2的转炉熔池搅拌效果明显优于其他底枪布置方案;但由于前者的侵蚀面积小于后者,且熔池平均速度大于后者,确定采用A2底枪布置方式。工业试验表明,平均冶炼时间为14.8 min,终点含碳量满足钢种需求,脱磷率达96%以上,设计方案为转炉冶炼提供了良好的动力学条件。