We theoretically investigate the exact solutions for generalized parity–time(PT)-reversal-symmetric Rabi models driven by external fields with monochromatic periodic, linear, and parabolic forms, respectively. The co...We theoretically investigate the exact solutions for generalized parity–time(PT)-reversal-symmetric Rabi models driven by external fields with monochromatic periodic, linear, and parabolic forms, respectively. The corresponding exact solutions are presented in terms of the confluent Heun equations without any approximation. In principle, the analytic solutions derived here are valid in the whole parameter space. Such a kind of study may offer potential coherent control schemes of the PT-symmetric two-level systems.展开更多
低温(110～130K)下,将次表层Fe结构的Pt-Fe模型催化剂(即Pt/Fe/Pt(111)结构)暴露于不同量CO气体,经不同温度退火后,采用高分辨电子能量损失谱(HREELS)研究催化剂表面CO分子的振动谱。结果表明,当CO的暴露量低于0.2 L (Langmuir)时,Pt/Fe...低温(110～130K)下,将次表层Fe结构的Pt-Fe模型催化剂(即Pt/Fe/Pt(111)结构)暴露于不同量CO气体,经不同温度退火后,采用高分辨电子能量损失谱(HREELS)研究催化剂表面CO分子的振动谱。结果表明,当CO的暴露量低于0.2 L (Langmuir)时,Pt/Fe/Pt(111)表面只存在顶位吸附;当暴露量大于0.4L,除了顶位吸附外,桥位吸附开始出现;顶位吸附分子的C-O键振动峰随着暴露量的增加不断向高波数方向偏移。退火温度影响Pt/Fe/Pt(111)表面CO的吸附形式,低于255K时,顶位吸附分子的脱附速率大于桥位吸附分子;高于255 K时,桥位吸附分子的脱附速率较大,并先于顶位吸附的CO从表面完全脱附,其完全脱附温度比Pt(111)表面低50 K。展开更多
根据PT燃油系统共轨低压信号的特点,提出一种基于VPMCD(Variable predictive model basedclass discriminate,简称VPMCD)和DS证据理论的故障诊断方法。对信号的时域和时频域指标采用VPMCD方法分别进行建模,按照预测误差最小的原则对故...根据PT燃油系统共轨低压信号的特点,提出一种基于VPMCD(Variable predictive model basedclass discriminate,简称VPMCD)和DS证据理论的故障诊断方法。对信号的时域和时频域指标采用VPMCD方法分别进行建模,按照预测误差最小的原则对故障模式进行判断。当故障的模式难以判断时,将VPM模型作为证据体,由故障训练样本中心的输出确定证据体的信任度,按预测误差的均方根计算基本概率分配,最后采用DS证据理论对各证据进行合成及决策。实践表明,VPMCD与DS证据理论的结合使用能够准确识别出PT燃油系统故障。展开更多
基金Project supported in part by the National Natural Science Foundation of China(Grant No.11874251)the Scientific Research Starting Foundation of Shaanxi Normal University,Chinathe Scientific Research Plan Funded by the Education Department of Shaanxi Province,China(Grant No.17JK0786)
文摘We theoretically investigate the exact solutions for generalized parity–time(PT)-reversal-symmetric Rabi models driven by external fields with monochromatic periodic, linear, and parabolic forms, respectively. The corresponding exact solutions are presented in terms of the confluent Heun equations without any approximation. In principle, the analytic solutions derived here are valid in the whole parameter space. Such a kind of study may offer potential coherent control schemes of the PT-symmetric two-level systems.
文摘低温(110～130K)下,将次表层Fe结构的Pt-Fe模型催化剂(即Pt/Fe/Pt(111)结构)暴露于不同量CO气体,经不同温度退火后,采用高分辨电子能量损失谱(HREELS)研究催化剂表面CO分子的振动谱。结果表明,当CO的暴露量低于0.2 L (Langmuir)时,Pt/Fe/Pt(111)表面只存在顶位吸附;当暴露量大于0.4L,除了顶位吸附外,桥位吸附开始出现;顶位吸附分子的C-O键振动峰随着暴露量的增加不断向高波数方向偏移。退火温度影响Pt/Fe/Pt(111)表面CO的吸附形式,低于255K时,顶位吸附分子的脱附速率大于桥位吸附分子;高于255 K时,桥位吸附分子的脱附速率较大,并先于顶位吸附的CO从表面完全脱附,其完全脱附温度比Pt(111)表面低50 K。
文摘根据PT燃油系统共轨低压信号的特点,提出一种基于VPMCD(Variable predictive model basedclass discriminate,简称VPMCD)和DS证据理论的故障诊断方法。对信号的时域和时频域指标采用VPMCD方法分别进行建模,按照预测误差最小的原则对故障模式进行判断。当故障的模式难以判断时,将VPM模型作为证据体,由故障训练样本中心的输出确定证据体的信任度,按预测误差的均方根计算基本概率分配,最后采用DS证据理论对各证据进行合成及决策。实践表明,VPMCD与DS证据理论的结合使用能够准确识别出PT燃油系统故障。
