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用激光蒸发方法产生了大量BxNy-负离子,发现在其形成过程中倾向于B—N成键,而团簇离子形成的气相反应方式又使其组成偏离子理想晶体配比,产生了大量的B或N悬键。结合红外振动光谱实验,还对其他一些实验现象进行了讨论。 相似文献
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The ultrafast processes of tetra-phenyl-porphyrin(TPP), tetra-t-butyl-phthalocyanine(BuPc) and nitro-tri-t-butyl-phthalocyanine (NtBuPc) have been investigated using the femtosecond time-resolved fluorescence depletion method. A sharp peak of the fluorescence depletion with delay time has been observed both for TPP and BuPc. An ultrafast two-photon absorption process has been proposed to explain the sharp peak observed. A long-lived fluorescence depletion has also been observed. It is causing by the stimulated-emission-pumping process produced by the intense probe laser pulse. 相似文献
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The (3 + 1) photon ionization spectra of SiH_4 have been measured. A basically continuous spectrum was recorded in laser wavelengths from 428 to 458 nm.Two vibrational progressions were found in the UV laser region of 347-392 nm, anda fine structure of the band at 363.5 nm was assigned.The fragment ions were detected by a time-offlight mass spectrometer. No parent ion SiH_4~+ was observed whereas SiH_2~+ and SiH_3~+ were the major products. The ratio of SiH_2~+/SiH_3~+ was approximately equal to that of single photon ionization at the same energy, but the fraction of Si~+ was increased. Some additional bands appeared in Si~+ spectrum in the range of 384-390 nm implicating that the increased Si~+ might be generated from SiH_2~+ and SiH~+ ions. 相似文献
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研究了在强激光脉冲中各种不同取向的N2分子发生场致电离的电离几率和表观电离效率.用量子化学方法计算了N2+分子离子在各种不同取向上的势能曲线,然后用传递矩阵方法得到了N2分子在不同方向上的电离几率,经过角度平均之后得到了各种取向的所有N2分子的总电离几率,并对计算结果进行了激光时间和空间修正.用800nm和70fs的激光脉冲对N2分子进行了在强激光场中的电离实验,得到了N2分子电离后产生的电子的角度分布图和电离几率随激光功率密度变化的关系曲线.实验结果和理论计算结果符合得很好. 相似文献
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对乙酰基的基态(X12A′)和激发态进行了理论和实验研究。通过采用MRSDCI和MP2方法计算,获得了CH3CO自由基的四个电子激发态(A12A″,B22A′,C32A′,D22A″),其垂直激发能分别为250.8kJ·mol-1,472.3kJ·mol-1,645.8kJ·mol-1和674.7kJ·mol-1。运用时间分辨付里叶红外光谱仪(TR-FTIR)分别研究了CH3CO自由基的热解和光解反应,观察到初生产物CO(V)的红外发射光谱.势垒仅为75.2kJ·mol-1的基态CH3CO极易热解.532um的激光只能将CH3CO激发到束缚态A12A″,故未观察到CO信号;而248nm或266nm的激光可使CH3CO发生B22A′←X12A′跃迁,生成高振动激发的CO(V8)产物. 相似文献