为了提高大空间γ辐射场全局计算效率，开展了全局减方差（Global Variance Reduction，GVR）方法在大空间γ辐射场计算中的应用研究。针对计数栅元/网格体积差异造成的过度分裂问题，引入体积修正因子修改全空间权窗参数。体积修正后的基于通量的GVR方法计算的全局品质因子（FOM_G）比直接模拟提高约39倍。针对非计数区计算耗时问题，提出了非计数区修正方法，使得FOM_G因子进一步提高40%。在引入体积和非计数区修正的基础上，在大空间γ辐射场计算中与基于粒子误差、权重、径迹、数目、能量、碰撞和通量的7种GVR方法进行对比。结果表明：7种GVR方法计算的FOM_G因子比直接模拟提高2~3个量级，基于误差的标准差σ降低2~3个量级；而基于权重的GVR方法计算的FOM_G因子比直接模拟提高2 304倍，在所有GVR方法中减方差效果最好。在基于通量的GVR方法中引入光滑因子SI后，模拟计算的权窗下限随SI增加而减小，FOM_G因子随SI的增加先增加后减小。当SI=0.8时，该方法计算的FOM_G因子最大，比直接模拟提高3 246倍。

Vascular-targeted photodynamic therapy (V-PDT) is an effective treatment for port wine stains (PWS). However, repeated treatment is usually needed to achieve optimal treatment outcomes, possibly due to the limited treatment light penetration depth in the PWS lesion. The optical clearing technique can increase light penetration in depth by reducing light scattering. This study aimed to investigate the V-PDT in combination with an optical clearing agent (OCA) for the therapeutic enhancement of V-PDT in the rodent skinfold window chamber model. Vascular responses were closely monitored with laser speckle contrast imaging (LSCI), optical coherence tomography angiography, and stereo microscope before, during, and after the treatment. We further quantitatively demonstrated the effects of V-PDT in combination with OCA on the blood flow and blood vessel size of skin microvasculature. The combination of OCA and V-PDT resulted in significant vascular damage, including vasoconstriction and the reduction of blood flow. Our results indicate the promising potential of OCA for enhancing V-PDT for treating vascular-related diseases, including PWS.

In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed, an analysis method based on the fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT) is proposed and demonstrated theoretically and experimentally. The suitabilities of the rectangular window function with the narrow main lobe (high spectrum resolution) and low side lobe (high main mode energy leakage) and the Hanning window function with the wide main lobe (low spectrum resolution) and high side lobe (high energy concentration) in this kind of sensor analysis are discussed, respectively. This method can not only realize the sensing performance analysis of the various modes, but also overcome the inconsistency of the different interference wavelength (dip) sensing characteristics in the conventional analysis methods. At the same time, this method is also beneficial to solve the repetitive problem of such sensors.

杂散光抑制是保证红外遥感数据定量化反演精度和图像质量的前提。为了抑制系统杂散光，利用点源透过率（PST）与杂散光系数（VGI）的函数关系计算了VGI，并分别用VGI和杂散比（NSR）作为指标对系统外部杂散光和系统背景辐射的抑制方法进行了研究。结果表明：采用冷光学设计能有效抑制系统背景辐射，此时系统工作的三个波段NSR从4.5以上降低至0.35以下。制冷机制冷是冷光学设计和探测器工作的基础，研究了杜瓦窗口和冷屏设计对VGI、NSR和制冷机功耗的影响，进而优化了窗口和冷屏的设计参数。拟合实验数据明确了杜瓦漏热与制冷机功耗的函数关系，提出了一种低制冷功耗和高杂散光抑制的冷屏设计，此时杜瓦漏热为1.7 W，制冷机功耗为103.72 W，系统的VGI从1.95%降低至1.92%，窗口的NSR下降了60%，满足项目要求。研究结果解决了低温光学设计、制冷机功耗和杂散光抑制等一系列问题，组件通过力学试验，已成功运用于某项目用光谱成像仪中。

为了满足高功率微波系统对微波输出窗高功率容量和紧凑化的应用需求，以传统盒型窗的设计理论为基础，通过优化窗体结构和添加过渡段等手段，设计了一种C波段小型化高功率微波输出窗。通过增大窗体表面积、改变矩形波导-圆波导过渡段的连接方式可提高功率容量并缩小微波输出窗的纵向尺寸；采用“I”型的窗体结构可有效抑制三相点（真空-介质-金属）附近的次级电子倍增效应对输出窗性能的影响。在电磁仿真的基础上采用粒子模拟（Particle-in-Cell）的方法研究了微波输出窗三相点附近的次级电子倍增效应，从微观角度进一步证实了“I”型窗体结构可使三相点位置发生移动，减小三相点发射的电子在窗片表面产生次级电子倍增效应的概率，降低微波输出窗的击穿风险。设计结果表明，微波输出窗在中心频点处的主模反射系数低于0.01，传输效率高于99.9%，功率容量可达47.9 MW。

基于耦合腔磁力系统研究了多透明窗口现象以及快慢光效应。利用量子光学理论以及标准输入-输出关系，对该系统的输出特性进行了研究。结果表明，可以通过调节系统参数得到不同数目的透明窗口并得到较好的透明效果。同时，提出了一种通过测量吸收峰高度和宽度来精密测量两腔之间的相互作用强度的方法。此外，通过对系统参数进行调控，可以实现快慢光转换。该方案在精密测量和量子信息处理等领域中具有重要的指导意义。

Measurement of blood flow velocity is key to understanding physiology and pathology in vivo. While most measurements are performed at the middle of the blood vessel, little research has been done on characterizing the instantaneous blood flow velocity distribution. This is mainly due to the lack of measurement technology with high spatial and temporal resolution. Here, we tackle this problem with our recently developed dual-wavelength line-scan third-harmonic generation (THG) imaging technology. Simultaneous acquisition of dual-wavelength THG line-scanning signals enables measurement of blood flow velocities at two radially symmetric positions in both venules and arterioles in mouse brain in vivo. Our results clearly show that the instantaneous blood flow velocity is not symmetric under general conditions.

运动模糊图像点扩散函数（PSF）的精确估算是模糊图像复原的关键。为了提高PSF参数估计的准确性，消除频谱图中央亮线对模糊角度估计的干扰，提出一种运用窗函数来提高PSF参数估计精度的方法。对运动模糊图像进行二维离散傅里叶变换和对数运算，计算图像的功率频谱图，对频谱图像添加窗函数Hanning，对处理后的图像进行中值滤波平滑处理和二值变换处理，再结合形态学算法和Canny算子边缘检测对频谱图进行优化，最后通过Radon变换，得到模糊方向。根据模糊方向结果，在模糊角度方向上对运动模糊图像的频谱图进行Radon变换，分析负峰值之间的距离，得到暗条纹间距，根据暗条纹间距与模糊长度之间的关系，求出模糊长度，从而完成两个点扩散函数参数的估算。结果显示，与现有算法相比，所提算法提高了参数估计的精度，复原时产生的振铃和伪影现象减少，充分利用图像信息的同时操作简便。