Femtosecond time-resolved fluorescence non-collinear optical parametric amplification spec- troscopy can extract the curve of spectral gain from its parametric superfluorescence. This unique spectrum correction method...Femtosecond time-resolved fluorescence non-collinear optical parametric amplification spec- troscopy can extract the curve of spectral gain from its parametric superfluorescence. This unique spectrum correction method enables fluorescence non-collinear optical parametric amplification spectroscopy acquiring the genuine transient fluorescence spectrum of the studied system. In this work we employ fluorescence non-collinear optical parametric amplification spectroscopy technique to study the solvation dynamics of DCM dye in ethanol solution, and confirm that genuine solvation correlation function and shift of peak frequency can be derived from transient fluorescence spectra after the spectral gain correction. It demonstrates that fluorescence non-collinear optical parametric amplification spectroscopy can benefit the research fields, which focuses on both fluorescence intensity dynamics and fluorescence spectral shape evolution.展开更多
Time-and frequency-resolved broadband transient grating(BB-TG) spectroscopy is used to distinguish between ground-and excite-electronic state vibrational coherence at different wavelengths. Qualitative theoretical ana...Time-and frequency-resolved broadband transient grating(BB-TG) spectroscopy is used to distinguish between ground-and excite-electronic state vibrational coherence at different wavelengths. Qualitative theoretical analysis using double-sided Feynman diagrams indicates that a superposition of ground and excited state vibrational coherence are contained in the ground state absorption(GSA) and stimulated emission(SE) overlap band, while only the excited state is contained in the excited state absorption(ESA) band. The TG experiment, in which a white light continuum(WLC) is adopted as a probe, is conducted with rhodamine101(Rh101~+) as the target molecule. Fourier analysis of TG dynamics in a positive delay time range at specific wavelengths enables us to distinguish the low-frequency vibrational modes of Rh101 in ground-and excite-electronic states.展开更多
SiC MOSFET栅极氧化物附近存在的陷阱缺陷造成其在高温高压场景下出现许多可靠性问题。提出了完整的基于瞬态电流法的陷阱表征方案,结合贝叶斯迭代反卷积算法实现对陷阱位置、时间常数和激活能的表征。基于自建陷阱测试平台在栅极和漏...SiC MOSFET栅极氧化物附近存在的陷阱缺陷造成其在高温高压场景下出现许多可靠性问题。提出了完整的基于瞬态电流法的陷阱表征方案,结合贝叶斯迭代反卷积算法实现对陷阱位置、时间常数和激活能的表征。基于自建陷阱测试平台在栅极和漏极施加不同组合的电学偏置,表征了微秒量级的两个陷阱,其时间常数分别为2×10^(-5)s和2.5×10^(-4)s,并观察到SiC MOSFET中存在同时受栅源电压和漏源电压影响的陷阱,这种现象在沟槽型器件中尤其显著,根据此特性可以分析陷阱的位置。本研究丰富了陷阱表征的信息,为陷阱的定位和表征提供了新的思路。展开更多
为了检测触电时刻剩余电流中生物体触电支路电流信号的难题,应用Hilbert-Huang变换方法,确定了生物触电时剩余电流的固有模态函数中相关系数最大的IMF分量的局部幅值达34.02 m A,且与原信号相关性系数达到0.99,同时剩余电流与触电电流...为了检测触电时刻剩余电流中生物体触电支路电流信号的难题,应用Hilbert-Huang变换方法,确定了生物触电时剩余电流的固有模态函数中相关系数最大的IMF分量的局部幅值达34.02 m A,且与原信号相关性系数达到0.99,同时剩余电流与触电电流暂态过程频谱特性具有相似变化规律。以此为基础,应用生物电流信号高频IMF分量幅值的突变特征,作为触电故障时刻确定判据,建立生物触电故障时刻判定方法,实际数据的仿真处理正确率为94.17%;筛选剩余电流分解的相关性较高的有限个数的低频固有模态IMF分量,应用逐步多元线性回归方法,提出基于剩余电流固有模态分量的生物触电支路电流幅值检测方法,仿真试验结果的平均相对误差值5.46%,具有良好的适应性和实用性,为研发基于生物体触电电流而动作的剩余电流保护装置提供参考。展开更多
文摘Femtosecond time-resolved fluorescence non-collinear optical parametric amplification spec- troscopy can extract the curve of spectral gain from its parametric superfluorescence. This unique spectrum correction method enables fluorescence non-collinear optical parametric amplification spectroscopy acquiring the genuine transient fluorescence spectrum of the studied system. In this work we employ fluorescence non-collinear optical parametric amplification spectroscopy technique to study the solvation dynamics of DCM dye in ethanol solution, and confirm that genuine solvation correlation function and shift of peak frequency can be derived from transient fluorescence spectra after the spectral gain correction. It demonstrates that fluorescence non-collinear optical parametric amplification spectroscopy can benefit the research fields, which focuses on both fluorescence intensity dynamics and fluorescence spectral shape evolution.
基金Project supported by the Science Challenge Project,China(Grant No.TZ2016001)the National Natural Science Foundation of China(Grant No.21673211)
文摘Time-and frequency-resolved broadband transient grating(BB-TG) spectroscopy is used to distinguish between ground-and excite-electronic state vibrational coherence at different wavelengths. Qualitative theoretical analysis using double-sided Feynman diagrams indicates that a superposition of ground and excited state vibrational coherence are contained in the ground state absorption(GSA) and stimulated emission(SE) overlap band, while only the excited state is contained in the excited state absorption(ESA) band. The TG experiment, in which a white light continuum(WLC) is adopted as a probe, is conducted with rhodamine101(Rh101~+) as the target molecule. Fourier analysis of TG dynamics in a positive delay time range at specific wavelengths enables us to distinguish the low-frequency vibrational modes of Rh101 in ground-and excite-electronic states.
文摘为了检测触电时刻剩余电流中生物体触电支路电流信号的难题,应用Hilbert-Huang变换方法,确定了生物触电时剩余电流的固有模态函数中相关系数最大的IMF分量的局部幅值达34.02 m A,且与原信号相关性系数达到0.99,同时剩余电流与触电电流暂态过程频谱特性具有相似变化规律。以此为基础,应用生物电流信号高频IMF分量幅值的突变特征,作为触电故障时刻确定判据,建立生物触电故障时刻判定方法,实际数据的仿真处理正确率为94.17%;筛选剩余电流分解的相关性较高的有限个数的低频固有模态IMF分量,应用逐步多元线性回归方法,提出基于剩余电流固有模态分量的生物触电支路电流幅值检测方法,仿真试验结果的平均相对误差值5.46%,具有良好的适应性和实用性,为研发基于生物体触电电流而动作的剩余电流保护装置提供参考。
