污闪是威胁电网安全可靠运行的重要原因之一, 污秽类型差异将直接影响闪络电压大小。因此, 及时掌握绝缘子污秽类型信息对预防污闪有重要作用。为此提出了一种基于SAM-ED光谱匹配的绝缘子污秽类型检测方法。采集不同污秽类型样本高光谱数据, 经黑白校正及多元散射校正(MSC)去除噪声等干扰因素;利用竞争自适应重加权采样法(CARS)对光谱数据进行特征选取, 分别在特征波段和全波段范围内通过SAM-ED光谱匹配法将测试组样本光谱与参考光谱进行匹配, 根据匹配结果对样本进行分类;实验结果表明: 相比于光谱角匹配法和最小距离法, SAM-ED光谱匹配法检测效果更好;基于全波长数据进行SAM-ED光谱匹配准确率可达95%, 基于特征波长数据进行SAM-ED光谱匹配准确率可达98.33%。

Scarring is one of the biggest areas of unmet need in the long-term success of glaucoma filtration surgery. Quantitative evaluation of the scar tissue and the post-operative structure with micron scale resolution facilitates development of anti-fibrosis techniques. However, the distinguishment of conjunctiva, sclera and the scar tissue in the surgical area still relies on pathologists’ experience. Since polarized light imaging is sensitive to anisotropic properties of the media, it is ideal for discrimination of scar in the subconjunctival and episcleral area by characterizing small differences between proportion, organization and the orientation of the fibers. In this paper, we defined the conjunctiva, sclera, and the scar tissue as three target tissues after glaucoma filtration surgery and obtained their polarization characteristics from the tissue sections by a Mueller matrix microscope. Discrimination score based on parameters derived from Mueller matrix and machine learning was calculated and tested as a diagnostic index. As a result, the discrimination score of three target tissues showed significant difference between each other (p<0.001). The visualization of the discrimination results showed significant contrast between target tissues. This study proved that Mueller matrix imaging is effective in ocular scar discrimination and paves the way for its application on other forms of ocular fibrosis as a substitute or supplementary for clinical practice.

Advances in direct laser writing to attain super-resolution are required to improve fabrication performance and develop potential applications for nanophotonics. In this study, a novel technique using single-color peripheral photoinhibition lithography was developed to improve the resolution of direct laser writing while preventing the chromatic aberration characteristics of conventional multicolor photoinhibition lithography, thus offering a robust tool for fabricating 2D and 3D nanophotonic structures. A minimal feature size of 36 nm and a resolution of 140 nm were achieved with a writing speed that was at least 10 times faster than existing photoinhibition lithography. Super-resolution and fast scanning enable the fabrication of spin-decoupled metasurfaces in the visible range within a printing duration of a few minutes. Finally, a subwavelength photonic crystal with a near-ultraviolet structural color was fabricated to demonstrate the potential of 3D printing. This technique is a flexible and reliable tool for fabricating ultracompact optical devices.

针对激光扫描和摄影测量点云非同源数据自动配准困难的问题，提出一种基于快速点特征直方图（FPFH）点云粗配准与八叉树格网迭代改进最近邻点（ICP）算法相结合的方法。在粗配准中，首先采用体素格网对点云数据进行降采样处理，然后使用FPFH进行特征匹配，最后采用采样一致性初始配准（SAC-IA）算法获取初始配准变换矩阵。在精配准中，以经典的ICP算法为基础，首先通过设置欧氏距离阈值剔除错误的对应点，然后在每个体素格网中选取精度最高的同名点对，使用奇异值分解（SVD）法计算最终配准变换矩阵。实验结果表明，所提方法可以解决激光扫描点云和摄影测量点云非同源数据的配准问题，具有一定的研究和应用价值。

全同性原理要求电子波函数必须满足交换反对称性的条件,针对其对多电子系统的瞬态吸收谱产生的影响,运用Ritz变分法求出了具有全同反对称性的氦原子波函数。在此基础上,通过求解三能级模型并与不考虑电子交换作用的旧模型对比,在理论上研究了氦原子阿秒极紫外(XUV)光瞬态吸收谱。该研究突破传统所采用的单电子跃迁模型,重点考虑电子的交换作用对XUV光瞬态吸收谱的影响。研究发现该交换作用对该瞬态吸收谱的强度和吸收峰的位置等物理量都有重要的影响,该研究结果可为运用瞬态吸收谱探测原子内电子超快关联动力学提供参考。

以18650型锂电池为研究对象, 建立双极化 Thevenin(DP-Thevenin)等效电路模型描述其动静态特征。分别以恒流脉冲放电实验和带遗忘因子的递推最小二乘法完成电池电动势及模型参数的辨识; 在 Simulink中搭建等效电路模型, 以脉冲电流作为激励进行验证, 得出模型响应电压与实际端电压契合度较好, 平均误差为 1.836%; 构建电池实验硬件电路, 编写算法程序完成了锂电池实验系统的构建。最后, 在随机测试工况下借助 Matlab分析了基于联合算法的锂电池荷电状态 (SOC)与健康状态( SOH)在预测精确度、错误初值时算法收敛性等方面的性能。实验结果表明, 算法可精确估计出电池 SOC和内阻大小, 最大误差不超过 3.5%; 且在初值相差 15%时, 算法可在319 s内收敛至真值附近, 鲁棒性较好。

针对现有的盲波束形成算法适应性较差, 多目标分析时采用级联模式存在结构复杂的问题, 采用并联模式存在稳健性较差的问题和采用时频分析时存在导向矢量估计较难的问题, 提出一种基于霍夫-迭代傅里叶变换的多目标盲波束形成算法。该算法首先通过短时傅里叶变换和霍夫变换解决导向矢量的估计问题, 然后通过设计波束图投影算子控制副瓣电平和过渡带以实现对波束的控制, 最后输出多目标盲波束。仿真实验分析表明, 该算法无需求逆, 计算量较小, 可以根据实际需要灵活设计旁瓣和零陷参数, 输出性能稳定。

锂电池及其应用近年来逐渐成为研究热点。以提高电池管理系统 (BMS)对电池荷电状态(SOC)和健康状态(SOH)的估算精确度为目标, 在建立二阶 Thevenin等效电路模型基础上提出一种能在线协同估算电池荷电状态和健康状态的改进扩展卡尔曼滤波算法。通过分阶段脉冲放电实验, 并利用最小二乘法求得模型参数。在动态应力测试工况 (DST)下借助 Matlab对比分析了改进扩展卡尔曼算法在 SOC和 SOH估计精确度、错误初值时算法收敛性、算法复杂度等方面的性能。实验表明, 利用该算法可以精确估计出各采样点处的 SOC和 SOH, 误差低于 1%;且在初值不准确情况下, 运行算法可快速收敛至真值附近, 算法估算结果的准确性与模型参数的微调无关, 鲁棒性较好。

The thermal equation of state of a natural kyanite has been investigated with a DIA-type, cubic-anvil apparatus (SAM85) combined with an energy-dispersive synchrotron X-ray radiation technique up to 8.55 GPa and 1273 K. No phase transition was observed in the studied pressuretemperature (P-T ) range. The Le Bail full profile refinement technique was used to derive the unit-cell parameters. By fixing the bulk modulus K₀ as 196 GPa and its pressure derivative K^'₀ as 4, our P-V (volume)-T data were fitted to the high temperature BircheMurnaghan equation of state. The obtained parameters for the kyanite are: V₀=294.05(9)(10^-10)³, α₀2.53(11)× 10^-5K^-1 and (?K/?T )P =-0.021(8) GPa?K^-1. These parameters have been combined with other experimentally-measured thermodynamic data for the relevant phases to calculate the P-T locus of the reaction kyanite = stishovite+ corundum. With this thermodynamically constrained phase boundary, previous high-pressure phase equilibrium experimental studies with the multi-anvil press have been evaluated.

地球内部是一个高温高压环境。 温度对于矿物的物理－化学性质有着非常重要的影响。 随着温度的升高, 矿物的分子振动、 弹性模量、 地震波波速等诸多性质有可能发生显著的变化, 从而对地球内部的相关物理－化学过程产生非常重要的影响。 高温谱学研究(如高温红外及高温拉曼)对了解矿物在高温下的物理－化学性质有着非常重要的意义。 尽管高温谱学研究中常用的加热台带有冷却装置, 能够确保加热台在很高温度下也能正常运转 (如1 500 ℃), 然而加热元件在高温下辐射出的大量热量可能使相关光聚焦物镜系统的温度急剧升高, 从而造成热损伤, 进而限制了高温谱学研究的温度范围。 本文的创新点在于为克服这个困难, 我们提供了一种简单而有效的防止高温光谱实验中显微物镜温度过高的装置, 从而扩展高温谱学研究的温度范围。 通过在物镜系统的附近添加了一套空气吹扫装置, 加速空气流动而带走多余的热量, 从而降低物镜系统的温度。 测试表明: 尽管这一装置非常简单, 但却非常有效; 当实验温度为～1 000 ℃时, 物镜下表面的温度由原来的～235 ℃下降到～68 ℃。 利用该空气吹扫装置, 我们对镁橄榄石进行了温度高达～1 300 ℃的原位拉曼光谱研究, 实验结果与其他研究报道的结果一致。 这一事实表明, 通过添加该空气吹扫装置, 高温谱学研究可以比较容易地在超过1 300 ℃的高温下进行, 所用物镜系统基本没有热损伤, 从而避免采用能承受更高温度的不同材质的物镜或者运用长焦距物镜的昂贵办法。