Cr^4＋：YAG,Cr^4＋：Mg2SiO4近红外荧光辐射温度特性研究

测量了Ｃｒ＾４＋，ＹＡＧ、Ｃｒ＾４＋，Ｍｇ２ＳｉＯ４晶体在室温和液氮温度下的荧光光谱，吸收光谱和激发态寿命，讨论了温度变化时，两种晶体中Ｃｒ＾４＋近红外辐射积分强度变化与激光发态寿命变化的关系，得出结论：在７７Ｋ￣３００Ｋ范围内，Ｃｒ＾４＋的＾３Ｔ２能级荧光辐射截面本身受温度影响不大，Ｃｒ＾４＋辐射荧光的变化，主要是由无辐射弛豫速率随温度变化而引起的。     

微裂纹扩展中的分形现象及其计算机仿真

本文探讨了采用仿真技术研究微裂纹连接过程和生成分形断口表面的可行性，发展了用于仿真微裂纹随机生长行为的ＧＯ模型的基本构相，并进行了计算机仿真实验，由此得出了一此有的结论。     

短脉冲载荷下金属材料的层裂破坏

 本文用点炮加载聚酯薄膜飞片撞击金属靶材料，飞片速度0.714~2.24 km/s，脉冲宽度40~80 ns，击靶压力为2.280~11.952 GPa。在回收的铝、铜和钢靶样品上观察到层裂现象。通过金相分析发现它们的破坏方式与在一般较长脉冲加载下的破坏方式相似，铝和铜以延性方式破坏；钢则以脆性方式破坏。一维和二维数值模拟结果表明通常的几种层裂判据在这个应力、应变和应变率范围内也基本上适用。     

“J—646”新型光学光敏胶胶合工艺简介

“J—646”光敏胶具有透光率好,收缩率小,粘接强度适中,耐老化,毒性小和成本低廉等特点。本文简要介绍了该胶的胶合工艺。     

Emission and sputtering characteristics of Ne-Ar mixed gas glow discharge plasmas.

The emission characteristics of several Cu lines emitted from a Ne-Ar mixed gas glow discharge plasma were investigated. The addition of small amounts of Ar to a Ne plasma increases the sputtering rate of a Cu sample because Ar ions, which work as the impinging ions for cathode sputtering, are predominantly produced through Penning ionization collisions between Ne metastables and Ar atoms. Ar addition also elevates the number density of electrons in the plasma. These changes occurring in the Ne-Ar mixed gas plasma result in enhanced emission intensities of the Cu lines. The Cu II 270.10-nm and the Cu II 224.70-nm lines yield different intensity dependence on the Ar partial pressure added. This phenomenon is because these Cu II lines are excited principally through different charge transfer processes: collisions with Ne ions for the Cu II 270.10-nm line and collisions with Ar ions for the Cu II 224.70-nm line. The shape of sputtered craters in the Ne-Ar glow discharge plasma was measured. The depth resolution was improved when Ar was added to a Ne plasma because the crater bottoms were flatter with larger Ar partial pressures.     

作业车间调度问题的改进混合遗传算法

作业车间调度是一类求解困难的组合优化问题,本文在考虑遗传算法早熟收敛问题和禁忌搜索法自适应优点的基础上,将遗传算法和禁忌搜索法相结合,提出了一种基于遗传和禁忌搜索的混合算法,并用实例对该算法进行了仿真研究.结果表明,该算法有很好的收敛精度,是可行的,与传统的算法相比较,有明显的优越性.     

CCD狭缝摄象

在过去的几十年中,各靶场已广泛应用狭缝摄影对种种飞行弹丸的多项重要技术参数进行测试,它在许多测试项目中应用的有效性、广泛性和经济性已被人们所肯定。据报道,在国外的一些靶场所进行的发射试验中,狭缝摄影机曾占全部测试设备中所使用的摄影仪器的百分之九十,这是因为狭缝摄影有其独特的、其它方法不可比拟的优点。     

Positive Schatten(-Herz) Class Toeplitz Operators on the Half-space

On the harmonic Bergman space of the half-space, we give characterizations for an arbitrary positive Toeplitz operator to be a Schatten (or Schatten-Herz) class operator in terms of averaging functions and Berezin transforms. Examples are provided to show that various results are sharp. This research was supported by KOSEF(R01-2003-000-10243-0).