类B-2型飞行器因其独特的气动布局和较强的隐身能力，成为攻防对抗和预警探测识别工作中重点关注的目标之一。通过构建类B-2型飞行器的气动外形，基于真实可压缩气体模型和辐射平衡壁面边界条件预测典型飞行工况（12 km@0.8 Ma）下的绕流场、尾喷焰和壁面温度，结合窄谱带高温气体辐射物性数据库，采用视在光线法求解辐射传输方程，获得不同观测角度、不同波段条件下目标本体和尾喷焰的红外辐射特性。结果表明：类B-2型飞行器在俯视观测角度下辐射强度最强，本体在长波波段内的辐射强度较中波波段高出近两个量级。中波波段内目标辐射强度主要来自尾喷焰，长波波段内主要来自本体。研究可为类B-2型飞行器的目标特性识别提供理论参考。

紫外光学元件损伤动力学的研究是关联物质微观结构演化与光学元件宏观性质变化的重要纽带。在光学元件后表面损伤坑形成的过程中，激光能量沉积导致材料爆炸形成高温高压物质突破表面，并伴随形成爆炸流场和喷溅射流。爆炸流场与初始起爆强度具有强关联性，对爆炸流场及喷溅行为进行研究，可以帮助分析损伤初期的材料状态变化和响应机制，是损伤动力学研究的必需环节。基于多种时间分辨成像技术，捕获了损伤发展前期的材料电离和气化响应演化行为，分析了材料损伤起爆后气化电离等过程的弛豫时间，并确定各个行为转化的关键时间节点，描述了损伤区域能量快速释放的物理过程。

在火箭发动机喷焰红外辐射预测过程中，由于弹道参数的不确定性因素存在，会影响喷焰红外辐射信号计算结果的置信度。文中以Atlas-IIA低空喷焰为研究对象，以来流速度、来流温度、来流压力和飞行攻角为不确定性输入变量，采用拉丁超立方试验设计样本，开展喷焰反应流场与红外辐射特性计算，获得各样本点对应的喷焰红外辐射响应值，利用非嵌入混沌多项式（No-intrusive Polynomial Chaos, NIPC）方法构建代理模型，采用响应面法求解NIPC多项式系数，基于统计参量研究各参量对红外辐射信号的不确定度和敏感性。结果表明来流特性引起的辐射强度不确定度与波段的选取有较高的关联度。来流速度对光谱辐射强度的灵敏程度最高，来流压力和攻角次之，来流温度的影响可忽略不计；来流速度对2.5~3.2、2.8~3.0 μm谱带内的辐射强度敏感，主Sobol指数占比均在80%左右，来流压力对4.35~4.65 μm波段辐射强度的影响占比为70%；各参数间的耦合作用对喷焰红外辐射的影响不高于4%。该研究可为火箭发动机尾喷焰红外辐射准确预估和置信度评估提供理论支撑。

Laser ablation in liquid is a scalable nanoparticle production method with applications in areas like catalysis and biomedicine. Due to laser-liquid interactions, different energy dissipation channels such as absorption by the liquid and scattering at the ablation plume and cavitation bubble lead to reduced laser energy available for nanoparticle production. Ultrashort pulse durations cause unwanted nonlinear effects in the liquid, and for ns pulses, intra-pulse energy deposition attenuation effects are to be expected. However, intermediate pulse durations ranging from hundreds of picoseconds up to one nanosecond have rarely been studied in particular in single-pulse settings. In this study, we explore the pico- to nanosecond pulse duration regimes to find the pulse duration with the highest ablation efficiency. We find that pulse durations around 1–2 ns enable the most efficient laser ablation in liquid since the laser beam shielding by the ablation plume and cavitation bubble sets in only at longer pulse durations. Furthermore, pump-probe microscopy imaging reveals that the plume dynamics in liquids start to differ from plume dynamics in air at about 2 ns after pulse impact.Laser ablation in liquid is a scalable nanoparticle production method with applications in areas like catalysis and biomedicine. Due to laser-liquid interactions, different energy dissipation channels such as absorption by the liquid and scattering at the ablation plume and cavitation bubble lead to reduced laser energy available for nanoparticle production. Ultrashort pulse durations cause unwanted nonlinear effects in the liquid, and for ns pulses, intra-pulse energy deposition attenuation effects are to be expected. However, intermediate pulse durations ranging from hundreds of picoseconds up to one nanosecond have rarely been studied in particular in single-pulse settings. In this study, we explore the pico- to nanosecond pulse duration regimes to find the pulse duration with the highest ablation efficiency. We find that pulse durations around 1–2 ns enable the most efficient laser ablation in liquid since the laser beam shielding by the ablation plume and cavitation bubble sets in only at longer pulse durations. Furthermore, pump-probe microscopy imaging reveals that the plume dynamics in liquids start to differ from plume dynamics in air at about 2 ns after pulse impact.

高超声速飞行器大攻角机动时，其离轨发动机产生的喷流与高速稀薄的大气来流产生强烈干扰，流场情况复杂，流场红外辐射也是天基红外系统探测的标志性事件。本文针对高超声速飞行器发动机喷流与稀薄来流的相互干扰情况，采用数值求解Navier-Stokes方程模拟干扰流场，采用逐线积分法得到气体红外辐射特性，结合反向蒙特卡洛方法计算得到飞行器在94公里飞行高度下，无来流、不同来流攻角、不同来流速度下的尾焰流场红外辐射特性，并针对低轨卫星的可观测性进行了评估。仿真结果表明，对于给定观测位置，在无风条件下，红外辐射在各个波段下的强度较低，最大值在10⁻⁹ W/m²量级。而在来流攻角影响下，流场红外信号强度显著上升，且来流攻角、来流速度越大，强度越大，最大值在10⁻⁶ W/m²量级。大气衰减效应对不同观测位置的可观测性影响较大。本文结果可为高超声速飞行器红外预警和反导提供参考。

近年来，近地轨道的空间碎片问题对航天应用的威胁日益严峻。通过主动移除技术手段减少在轨空间碎片的数量，从而保障空间资源的可持续开发和航天器的安全运行，已成为相关领域研究的热点。溯源了空间碎片问题的产生及沿革，分析基于不同技术途径的主动移除方案的特点。重点研究了脉冲激光主动移除空间碎片的关键技术与科学问题，总结了现阶段的技术发展情况，并对未来天基激光移除空间碎片的发展方向给出了建议。