Photodynamic therapy (PDT) has been increasingly used in the clinical treatment of neoplastic, inflammatory and infectious skin diseases. However, the generation of reactive oxygen species (ROS) may induce undesired side effects in normal tissue surrounding the treatment lesion, which is a big challenge for the clinical application of PDT. To date, (–)-Epigallocatechin gallate (EGCG) has been widely proposed as an antiangiogenic and antitumor agent for the protection of normal tissue from ROS-mediated oxidative damage. This study evaluates the regulation ability of EGCG for photodynamic damage of blood vessels during hematoporphyrin monomethyl ether (Hemoporfin)-mediated PDT. The quenching rate constants of EGCG for the triplet-state Hemoporfin and photosensitized ¹O₂ generation are determined to be 6.8×108 M^?1S^?1 and 1.5×108 M^?1S^?1, respectively. The vasoconstriction of blood vessels in the protected region treated with EGCG hydrogel after PDT is lower than that of the control region treated with pure hydrogel, suggesting an efficiently reduced photodamage of Hemoporfin for blood vessels treated with EGCG. This study indicates that EGCG is an efficient quencher for triplet-state Hemoporfin and ¹O₂, and EGCG could be potentially used to reduce the undesired photodamage of normal tissue in clinical PDT.

激光耦合隧道结器件是国际前沿研究热点，伴随产生的电磁场局域增强或光整流等效应在等离激元光镊、单分子成像、单光子光源等领域有着重要的应用价值。为了解隧道结中的光电相互作用和特性，首先利用反馈电沉积制备获得了固态隧道结纳米器件，然后测定了激光功率、偏置电压、偏振方向和调制频率与光电流的关系，并结合有限元法和时域有限差分方法进行理论仿真，讨论了器件中光电流的组分及相关效应。结果表明，器件局部热膨胀效应、热伏效应和热载流子效应为光电流产生的主要原因，而光整流效应因受限于激光峰值功率，其结果并不显著。这些发现可为固态隧道结器件中的光学调控以及在纳米尺度上研究激光调制电子隧穿过程提供参考。

A low-energy proton accelerator named pulsed synchronous linear accelerator (PSLA) is proposed and developed at the Institute of Fluid Physics, which is driven by unipolar-pulsed high voltages. Pulsed-accelerating electric fields and low-energy ion beams are precisely synchronized on temporal and spatial positions for continuous acceleration. The operating mode and the features of the PSLA are introduced. At present, the feasibility of a low-energy proton PSLA has been verified in principle. An average accelerating gradient up to 3 MV/m for protons is achieved.

本文采用6 kW光纤激光进行了铁基合金高速激光熔覆试验研究, 探讨了扫描速度和Ni含量对熔覆层宏观质量的影响, 采用金相显微镜表征了高速熔覆层的组织结构特征, 采用MM-U10G型磨损试验机和CS350型电化学工作站分别测定了熔覆层的耐磨性和耐蚀性。结果表明: 通过材料成分和工艺优化, 制备的高速激光熔覆层具有良好的宏观质量, 表面Ra小于12.5 μm, 熔覆层无气孔和裂纹等缺陷。不同扫描速度的激光熔覆层显微组织晶粒随着速度的提升而更加细小, 组织性能更优。扫描速度700 mm/s时的一次枝晶间距约为速度10 mm/s的1/10, 约为速度100 mm/s的1/5。随着Ni含量的增加, 熔覆层的硬度虽有所下降, 但均大于HV570, 耐蚀性均明显优于45钢, 在保证一定硬度的前提下, 熔覆层可达到与304不锈钢相当的耐蚀性。研究成果在泵阀、轴类零件和牌坊等产品的制造和再制造领域具有广泛的应用前景。

针对无人直升机系统和控制器的不确定性，基于特征值摄动的思想设计了正规化非脆弱控制器，以保证系统具有良好的鲁棒性和飞行性能。首先，建立了无人直升机的非线性姿态动态的T-S模糊模型，然后，基于特征值摄动的思想针对系统的标称部分进行了正规化设计，使得标称部分的特征值摄动受系统不确定的影响不敏感；其次，考虑系统不确定和控制器增益的加性摄动，针对不确定的部分设计了模糊非脆弱控制器，并基于Lyapunov理论分析了闭环系统的稳定性，应用LMI（Linear Matrix Inequality)方法求解了控制器参数。最后，仿真结果表明，所设计的控制器具有很好的鲁棒性。

消化道肿瘤是最常见的肿瘤疾病之一。新兴的光声成像技术可以敏锐地捕捉肿瘤周围滋养血管的信息,有助于临床进行更精准的诊断。匹配的血管增强算法可以有效突出图像中的血管网络,但光声活体内窥成像的探测角度有限,易造成明显的血管形态异常,现有方法很难实现有效的血管增强。采用自研的光声内窥系统对大鼠直肠进行活体成像,针对活体成像结果提出了一种融合结构和强度两个层面信息的三维血管增强算法,并采用该算法对结直肠血管图像进行了增强。结果表明:所提算法可以有效提升增强效果,抑制机械抖动带来的边缘毛刺,在活体状态下获取了高质量的结直肠三维血管图像,说明其在基础医学研究和临床应用中具有一定的潜在价值。