选用6 mm厚低碳贝氏体钢板进行激光-MAG复合焊接(MAG焊，熔化极活性气体保护电弧焊)，以激光功率、焊接速度、送丝速度为试验参数，以焊缝成形系数(ψ)、激光区面积比(R)为响应指标，建立响应面分析数学模型。送丝速度对ψ和R的影响显著，激光功率与焊接速度的交互作用对ψ的影响显著，送丝速度与焊接速度的交互作用对R的影响显著。对焊缝成形进行评定，筛选出最优工艺参数：激光功率4120～4300 W，焊接速度15.3～16.3 mm/s，送丝速度12.3～13.6 m/min。经试验验证，ψ和R的模型准确度分别为95.0%和92.3%。

本研究为了提高截齿的性能, 延长截齿的使用寿命。本实验使用大功率宽带半导体激光设备, 在42CrMo基材上制备了超硬复合材料, 获得了与基材紧密结合的高硬度, 高耐磨性熔覆层。研究结果表明: 熔覆层的硬度可达到855.6 HV0.3, 将基体硬度提高了3.45倍; 在基体的热影响区, 部分基体硬度可达到550 HV0.3; 熔覆层的摩擦系数与失重量均比基体的摩擦系数与失重量小, 提高了截齿的抗磨损性能; 熔覆层厚度可以达到1 351 μm; 当功率为3 500 W时, WC开始大量的熔解, 并与其他的元素相结合, 形成树枝状、块状的共晶物, 其成分主要是由Fe、Co、Cr、W等元素组成; 熔覆层中不同梯度元素含量的变化导致熔覆层各个梯度的性能出现差异, Fe、Cr、Si、W元素的改变是影响熔覆层中硬度变化的内在因素; WC颗粒周围存在微小的树枝状晶体, 有利于防止WC颗粒的脱落, 提高熔覆层耐磨性及硬度; 铁基碳化物涂层能够增强截齿性能, 减少截齿在应用过程中损伤, 延长截齿的使用寿命。

双能X射线光栅相衬成像系统具有成像效率高、辐射小、无须步进装置、成像平台简单等优点。研究了不同X射线能量下,CsI厚度与荧光透射率、金属铋的厚度与光强透射率的关系。基于以上研究,设计了一种双能分析光栅,阐述了光栅结构及栅条的制作材料,分析了栅条厚度的计算方法。对双能分析光栅成像进行了仿真,结果表明,设计的双能分析光栅可以获得清晰的条纹图像,并具有良好的条纹对比度。将设计的双能分析光栅应用于双能X射线光栅相衬成像系统,对成像系统进行了仿真,成像系统可以获得被测物体的相位一阶导数图像,表明设计的双能分析光栅是有效的。

根据菲涅耳衍射积分理论, 提出了X射线光栅相衬成像系统的仿真模型。以聚甲基丙烯酸甲酯(PMMA)小球作为成像物体模型, 选取30 keV的X射线做模拟计算。通过仿真, 得到了穿过球体和相位光栅的X射线波前的变化。采用多步位移法从模拟条纹图中恢复出了PMMA小球的相位信息, 并分析了莫尔条纹对比度对成像质量的影响, 为实际的实验提供可靠的参数选择。经过仿真得到的相移信息与通过实验得到一致, 验证了仿真算法的正确性。

为了便于在红外成像仿真中对目标表面温度场进行计算，提出了一种基于可达辐射能的目标表面辐射传递系数计算方法。分别用公式法、蒙特卡洛法和可达辐射能计算法计算了两两垂直表面和两两平行表面模型间的辐射传递系数，并进行了仿真验证。结果表明，该可达辐射能计算方法在确保计算精度满足要求的同时，在计算效率上相对于公式法和蒙特卡洛法都有较大提高。

In this paper we study the influence of the relative phase between the probe and driving fields on propagation effect in an open Doppler broadening V-type three-level atomic system with spontaneously generated coherence (SGC) by using the calculation result of the density matrix motion equations and the propagation equations of the driving and probe fields. It is shown that the relative phase (Φ) has remarkable periodical influence on the propagation effect, and the period is 2π. By selecting appropriate value of Φ, we can get larger lasing without inversion (LWI) gain and longer propagation distance in which gain exists, and hence obtain higher probe field (i.e. LWI) intensity. When Φ=π/2, the largest LWI gain and probe field intensity can be got. In addition, the atomic exit rate (γ₀) and ratio (S) of the atomic injection rates also have a considerable modulation role on the phase-dependent propagation effect. In certain value range of γ₀ (S), LWI gain and probe field intensity increase with γ₀ (S) increasing. In the open system, LWI gain and probe field intensity much larger than those in the corresponding closed system can be obtained.

Adaptive optics (AO) technique has been extensively used for large ground-based optical telescopes to overcome the effect of atmospheric turbulence. But the correction is often partial. An iterative blind deconvolution (IBD) algorithm based on maximum-likelihood (ML) method is proposed to restore the details of the object image corrected by AO. IBD algorithm and the procedure are briefly introduced and the experiment results are presented. The results show that IBD algorithm is efficient for the restoration of some useful high-frequency of the image.