We demonstrate a narrow-linewidth linearly polarized 1645 nm Er:YAG laser, directly diode-pumped by a fiber-coupled continuous-wave laser diode at 1532 nm. Passive
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Three-dimensional (3D) simulations and theoretical analyses on super-short pulse generated using freeelectron lasers (FELs) at perfect synchronism are carried out with the help of our 3D OSIFEL code. The evolution of longitudinal pulse width in the Japan
针对现有的三维运动估计算法在精度、效率和稳定性等综合性能上的不足,提出了一种结合双目视觉三维重建和利用对偶四元数表达运动参数的新算法。该算法以双目视觉系统为基础,采用SIFT算法进行图像特征点的提取和匹配;根据匹配关系进行三维特征点重建,以获取三维场景中运动目标的结构参数;利用对偶四元数可同时表示刚体的旋转和平移运动的特点,实现目标对象运动参数的表达和求解。通过实验将提出的算法与现有算法(包括奇异
The detection of early gastric cancer that often develops asymptomatically is crucial for improving patient survival. The photodynamic diagnosis (PDD) of gastric cancer using 5-aminolevulinic acid/protoporphyrin IX (5-ALA/PpIX) has been reported in severa
由于受到外界环境的影响,卫星表面常常呈不规则的褶皱状,这会对其光学特性产生一定影响。故空间目标光学特性建模研究需要将表面褶皱考虑在内,但大量褶皱面元的存在会导致运算量剧增。在此将褶皱看作一种材质,提出基于宏观光学散射截面测量的双向反射分布函数(BRDF)生成方法,求得褶皱材质的BRDF数据,进一步利用误差逆传播(BP)神经网络建立了褶皱材质的BRDF模型,代替了复杂的褶皱建模过程,大大简化了计算,在保证精度的前提下解决了其实时性差的问题。同时,通过实验与仿真相结合的方式,将所设计的BRDF模型与传统BRD
Dual-grating structure thin-film silicon solar cells with different front and back grating periodicities are designed The geometrical parameters of both gratings are investigated. The reflection is greatly reduced by the front grating, whereas the absorpt