分类: 心理学 >> 心理测量 分类: 心理学 >> 心理统计 提交时间: 2020-05-25
摘要: 在心理与教育测量中,潜在加工速度反映学生运用潜在能力解决问题的效率。为在多维测验中探究潜在加工速度的多维性并实现参数估计,本研究提出多维对数正态作答时间模型。实证数据分析及模拟研究结果表明:(1)潜在加工速度具有与潜在能力相匹配的多维结构;(2)新模型可精确估计个体水平的多维潜在加工速度及与作答时间有关的题目参数;(3)冗余指定潜在加工速度具有多维性带来的负面影响低于忽略其多维性所带来的。
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: The two-color strong-field mixing in gas medium is a widely-used approach to generate bright broadband terahertz (THz) radiation. Here, we present a new and counterintuitive method to promote THz performance in two-color scheme. Beyond our knowledge that the maximum THz generation occurs with two-color foci overlapped, we found that, when the foci of two-color beams are noticeably separated along the propagation axis resulting in cascading plasmas, the THz conversion efficiency is surged by one order of magnitude and the bandwidth is stretched by more than 2 times, achieving $10^{-3}$ conversion efficiency and $>$100 THz bandwidth under the condition of 800/400 nm, $\sim$35 fs driving lasers. With the help of the pulse propagation equation and photocurrent model, the observations can be partially understood by the compromise between THz generation and absorption due to the spatial redistribution of laser energy in cascading plasmas. Present method can be extended to mid-infrared driving laser, and the new records of THz peak power and conversion efficiency are expected.